///////////////////////A RIVER RUNS THROUGH IT
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Becoming a Freethinker and a Scientist
By Albert Einstein
Taken from:
Albert Einstein's Autobiographical NotesOpen Court Publishing Company,LaSalle and Chicago, Illinois, 1979. pp 3-5.
When I was a fairly precocious young man I became thoroughly impressed with the futility of the hopes and strivings that chase most men restlessly through life. Moreover, I soon discovered the cruelty of that chase, which in those years was much more carefully covered up by hypocrisy and glittering words than is the case today. By the mere existence of his stomach everyone was condemned to participate in that chase. The stomach might well be satisfied by such participation, but not man insofar as he is a thinking and feeling being.
As the first way out there was religion, which is implanted into every child by way of the traditional education-machine. Thus I came - though the child of entirely irreligious (Jewish) parents - to a deep religiousness, which, however, reached an abrupt end at the age of twelve. Through the reading of popular scientific books I soon reached the conviction that much in the stories of the Bible could not be true. The consequence was a positively fanatic orgy of freethinking coupled with the impression that youth is intentionally being deceived by the state through lies; it was a crushing impression. Mistrust of every kind of authority grew out of this experience, a skeptical attitude toward the convictions that were alive in any specific social environment-an attitude that has never again left me, even though, later on, it has been tempered by a better insight into the causal connections.
It is quite clear to me that the religious paradise of youth, which was thus lost, was a first attempt to free myself from the chains of the "merely personal," from an existence dominated by wishes, hopes, and primitive feelings. Out yonder there was this huge world, which exists independently of us human beings and which stands before us like a great, eternal riddle, at least partially accessible to our inspection and thinking. The contemplation of this world beckoned as a liberation, and I soon noticed that many a man whom I had learned to esteem and to admire had found inner freedom and security in its pursuit. The mental grasp of this extra-personal world within the frame of our capabilities presented itself to my mind, half consciously, half unconsciously, as a supreme goal. Similarly motivated men of the present and of the past, as well as the insights they had achieved, were the friends who could not be lost. The road to this paradise was not as comfortable and alluring as the road to the religious paradise; but it has shown itself reliable, and I have never regretted having chosen it.
/////////////////////Five Bad Evolutionary DesignsCharles Sullivan
Have you ever seen those nature documentaries where the narrator describes how perfectly designed, say, the cheetah, the polar bear, or the chameleon is for its environment? Of course, calling an animal perfectly designed is just shorthand for saying that the slow processes of evolution have led to that animal's well-adapted features. Yet evolution hasn't always generated the best designs, or at least not the best from an engineering perspective. In fact, some features seem downright poorly designed. This should come as no surprise when we understand a little about how evolution works.
When new features evolve in a species, they tend to build on already existing features. They aren't built from scratch. It's just too costly for evolution to go back to the drawing board and start over. This explains why lungs evolved from the swim bladders of ancient fish. This also explains why dolphins don't move their tails from side to side like fish do. The up and down movement of dolphin tails was built upon the galloping motion of their land-dwelling four-legged ancestors.
From an evolutionary standpoint new features don't need to have the best possible design either. They just need to be good enough to allow the organism to live long enough to reproduce. The evolution of the human body is no exception. We have body parts whose design is wanting, but they've been good enough to keep our species from going the way of the dinosaurs. Consider the following suboptimal designs in the human body.
Design One: The Pharynx
The human pharynx is the part of the throat that begins behind the nose and leads down to the voice box. It does double duty as a tube for breathing and for swallowing. But when you're swallowing you can't breathe, and when you're breathing you can't swallow. That's why humans run a serious risk of choking if the pharynx doesn't close at the right time when eating.
Curiously, human infants under six months and chimpanzees don't have this problem. But infants and chimps can't talk, and without our uniquely situated pharynx we wouldn't be able to talk either. The evolutionary advantage of talking must have outweighed the risks of choking in our early human ancestors. All in all, it's not a bad tradeoff, but engineers could certainly come up with a safer design especially if they didn't have to build on preexisting features.
Design Two: The Birth Canal
The Bible says that God punished Eve and her female descendants with painful childbirth because she partook of the forbidden fruit. Presumably, childbirth would be a snap if not for that damned curse. And not only has pain long accompanied childbirth, but so has death. The rate of mothers dying during childbirth in the United States in 1900 was about 65% higher than it is today.
You could blame God, or Eve, or the serpent. Or you could point the finger at bipedalism--walking upright on two legs. This evolutionary innovation forced a smaller pelvis on us. But bipedalism isn't the whole story. Humans have evolved big brains, and we needed a big container to hold those brains. This is why human infants are born more premature and helpless than other mammals. Babies need to get through the birth canal before their heads get too big.
Design Three: The Jaw
The human jaw has too many teeth for its size. Many people have no room for wisdom teeth (third molars) if they get them, and a lot of people's teeth have to fight one another for limited territory, leading to crooked teeth and orthodontists. Impacted wisdom teeth can result in serious infections, and before modern dentistry these late eruptors could be deadly. If you couldn't eat, you died.
There's no consensus on why human jaws got smaller, but the fossilized jawbones of our Homo erectus ancestors show that, compared to us, they had massive jaws with huge molars. Some scientists suggest that our small jaw may have evolved in response to eating smashed and cooked food, so that over time there was little advantage to having a bigger jaw. Other scientists implicate the deactivation of a gene responsible for large jaw muscles, which may have allowed for our skulls to take on a new shape providing more room for those big brains of ours. Either way, we're stuck with small toothy mouths.
Design Four: The Appendix
This is a case of a vestigial organ if ever there was one. The human appendix has no known function, except perhaps to put money in surgeons' pockets. About the size of a finger, this organ is located at the beginning of the large intestine. Undigestible food that enters the appendix is normally forced out by muscular contractions. But when it isn't, the result is a potentially deadly infection.
The appendix is related to a digestive organ found in many other vertebrates. This is the cecum (pronounced SEE-cum), and it's largest in herbivores, where it helps to digest plant matter. Since evolution isn't keen on cleaning up after itself, we're left with a useless and potentially life-threatening organ. In fact, NASA is so concerned about appendixes bursting in outer space that it's considering requiring appendectomies prior to future long-term missions.
Design Five: The Spine
The spines of four-legged mammals work well horizontally. But when the spine stands up vertically, as in humans, it creates a lot of pressure on the vertebral discs. These discs can become compressed and slip, causing herniated discs and all manner of back pain and expensive therapy.
Standing on two legs must have benefited our early hominid ancestors who first adapted the upright position. A brand new spine designed for walking upright would have been an improvement, but instead evolution had to work with what it already had. There's no consensus on what advantages walking upright initially provided, but a widely-held view is that it freed up the hands for carrying food and manipulating objects. That's not a bad tradeoff, considering that it now allows us to rub our aching backs.
Building Upward
While evolution has created some wonderful adaptations that really do seem like optimal designs, it hasn't always done so. This is because novel features aren't designed from the ground up, but built up slowly on already existing features. Where an engineer would start from scratch, natural selection builds on whatever foundations it already has. As Richard Dawkins once put it: "Natural selection is like a robot that can only climb uphill, even if this leaves it stuck on top of a measly hillock. There is no mechanism for going downhill, for crossing the valley to the lower slopes of the high mountain on the other side."
///////////////////////The Ann Arbor News in Michigan reported 9 Nov 07:Scholars debate assisted suicideU-M symposium brings out stories, argumentsBY DAVE GERSHMAN, The Ann Arbor NewsErwin Chemerinsky recalled how his father, hospitalized while dying in excruciating pain from lung cancer, pleaded unsuccessfully with his doctors to help him end his life."I will never understand the interest of the state of Indiana in keeping him alive,'' said Chemerinsky, a professor from Duke Law School.Legal scholars and people on both sides brought the debate over physician-assisted suicide to the University of Michigan Law School on Thursday at a symposium.Chemerinsky's father died about 15 years ago. Since then, physicians have made great strides in treating the pain and suffering of terminally ill patients, said panelist Herbert Hendin, president and medical director of Suicide Prevention International."His father was really abandoned by an insensitive and uninformed physician,'' Hendin said. "That certainly contributed to his (father's) distress.''Ten years ago, the U.S. Supreme Court ruled in separate cases from Washington and New York to uphold state bans on physician-assisted suicide. The judges found no right in the Constitution to physician-assisted suicide.Chemerinsky argued the court made the wrong ruling and could have extended the privacy doctrine to cover the right to physician-assisted suicide. A series of rulings by the court has held that the Constitution protects fundamental rights of privacy not specifically mentioned in the document - such as reproductive freedom and abortion.These terminally ill patients are not suicidal, he said. They want to live, but they know they are going to die and don't want to die in a horrible manner, Chemerinsky said. He questioned why a state would want to keep such a patient "alive against his will.''Yale Kamisar, an emeritus U-M law professor, acknowledged that proponents of assisted suicide can tell compelling stories, but said he worried any right to assisted suicide could be extended beyond just people suffering in pain with a short time to live. He said proponents of assisted suicide would push the boundary."I'm convinced the day after they establish that right (to assisted suicide) they're back in court saying, 'This guy's got 20 years to live. He's paralyzed from the neck down. He's got a greater right to die,''' he said.Kamisar said he's concerned patients would be defending their rights to live. "If you're complaining because you're suffering, people will say, 'What the hell, you got an option to kill yourself and have a doctor do it for you,''' he said.In its rulings in 1997, the Supreme Court left the door open for states to tackle the issue. In 1998, Oregon implemented its voter-approved Death with Dignity Act, allowing physicians to prescribe drugs to some terminally ill patients allowing them to end their lives. About 30 patients end their lives in that manner each year.Kathryn Tucker, director of legal affairs for Compassion and Choices, said those people generally had health insurance and many used hospice care. But the law allows them to plan their death at home, peacefully. Without the law, those patients would have found less regulated and secure ways of ending their lives. "We are in the back alley,'' she said.Still, Hendin questioned the administration of the law, saying physicians have prescribed medications without a psychiatric evaluation of patients who may have experienced thoughts of suicide before they fell ill.
/////////////////////The ERGO news list exists primarily to provide international news and views on the issue of the right to choose to die.In this posting we allow a person (known to us) to let off steam about dealing with her degenerative illness. - List manager.All of this "stuff" regarding MS hits me - big time hits me.Why? I have MS.I am currently 49 years old. I no longer have any one for anything. And, yes, this does include commit suicide or death with dignity (depending upon one's point of view concerning this personal act of release).I do not remember a lot (maybe I've always been stupid but maybe it's just the MS - I don't know nor do I any longer have any one to ask) but I do know/remember that when I was in my 20s a neighbor lady had a stroke. I thought people died from things like strokes and heart attacks. I was surprised that (I will call her Leah for this story) lived. yes, she was partially/mostly paralyzed until she died, which was in 2006, and which means that survived for around 20-30 years in this condition - without the ability to talk, without the ability to walk like a "normal" person - without a bunch of "things" such a "normal" person would do. From the very beginning of "Leah's" journey into this awfulness, I knew that I did not want to exist that way.it may be arrognant but I believe that I deserve to have some respect - including respect for personal dignity as it involves personal and/or daily "things" such as bathroom (stop shitting/peeing my pants all the time), dressing (doing it myself), hair (washing it myself).And, well, as is the way of the "universe", I was first given a "probable" that I had MS, which moved into a "yep, you have it" when I was first in the hospital in 1994 (diagnosis" intermit-relapsing ms), followed by different "attacks" & by the most recent hospitalization (feb-mar 2003) (diagnosis: progressive MS).I was AND AM counting on the ability to achieve a certain amount of dignity to my existence, including My Death. I no longer have any one for anything - including how Mr Humphry believes that 'people should not die alone' but, well, I will have to cause no will/can help me because, like this "pickup" person, they are all "into" the "gotta be alive -= no matter HOW you are alive - just breathe & take up space" kind of thing.Recently in one of these right-to-die lists there was a story about a lady in Australia who achieved her peace with Nembutal. All I could think & believe is "Good for her!" AND "I sure wish I could get some of those pills!".A person in the vol 13 #192 issue states "life is complicated" and, well, I'll agree to/with that. but, well, to/for me, life is also individual - AND should be based on personal choices. no, I've no personal choice to start a fire and kill myself plus a bunch of different people but, well, I would love to be able to know for certain that I can release myself from these personal agonies without any hindrance from any holy roller or any holier than thou person because, well, IT IS MY CHOCIE, MY OPTION AND, well, since not even those "people" at the MS Society can/will understand, it is up to ME - NOT them.Plus, well, euthanasia and death are very personal and should not, in my opinion, be judged by any doctors or lawyers OR any other person BECAUSE it is so very personal.Yes, I am extremely biased because I have had numerous "people" say things like how I am being "irrational" or that "no, no, you don't want to do that" but, yeah, I do - I just don't know when because in all honesty, I don't know WHEN my MS is going to be bad enough for me to "not take it any more". I've definitely tried to figure it out.And, well, when I'm dead and in the coroner's office and it is "found" that I've a "Mental illness," I DON'T CARE - I JUST WANT TO BE ABLE TO RELEASE MYSELF FROM ALL OF THESE PAINS & AGONIES AND FROM ALL OF THIS .... FROM ALL OF THIS - - I JUST WANT THE OPTION TO DO THIS MYSELF.I know that in a recent right-to-die list there was something about an "opinion" about how even in/where there are laws available, people still opt to have death with dignity without involving whomever with those laws etc and, yes, I wholeheartedly agree because, well, a person would have to go thru all kinds of crap and legal tape and, well, who the heck needs that when you just get tired of (in my case) not being able to do anything which you used to be able to do (such as write, or paint or walk). I'm 49 years old - why the hell do I have to continue with this of "stuff" for another 5=10 y ears just to "be alive"??!?!??!?!?With all of this financial difficulties involved in a chronic illness & disability as well as no longer having any one for anything (nope - not even a definite person to be the executor/executrix of/in My Last Will & Testament!), I have more than once since My Mom passed away (nov 2005) told myself something like "if had ..... now, I'd do it!" - - yes, like that L.A. comedian who "recently" shot himself, I'd have an autopsy done and the coroner would say something like "she was mentally ill" but, in truth, how the heck does this doctor (or any one else for that matter!) know or understand what I do, what I go thru ??!?!!?The MS society used to have a thing about how MS is/was "dee-bill-ah-tate-ting" and I always brushed it aside until one day I realized that I am no longer able to do "stuff" that I enjoy - - I have ALWAYS valued being able to learn - including being able to not only read but also to take college courses (one course at a time of course!). I remember being able to write Journals and Diaries when I was young & younger (or should that be "growing up"?) I used to be able to read - not just text books but also for enjoyment (yep - even the "old" nancy drew mysteries - or the "old" jacqueline suzanne). I cannot do ANY of that stuff any more.I can Jouranl if/when the computer is working AND when/if I can type. but no on ALL of the reading - I've tried but even with ADA stuff, I can't "do" college any more - I had to quit back in 2003-2004.And, well, for someone who used to pride herself on the ability to talk or to write, which is ALL gone now, what the hell do I have ?My MS has taken away a LOT of "things" that I used to take for granted, that I always enjoyed. why the heck is having the ability to release myself from these agonies so darn awful? for me, I do NOT want some "darn" person or a holier-than-thou group saying "oh, she's still alive, she shouldn't die just cause of her MS" - I used to be able to write but now I can hardly (as well as with lots of pain) hold a pen (and, yes, even a pen with one of those "gripper" things that is supposed to make it "easy" for someone with a disability or arthritis write - or something similar to the kind of gadget that "the government" says should be used cause, hey, it's gonna make it "easier" for ya!Once I spoke to someone who said something like "oh, for us ...." (meaning the "old" Hemlock Society) because there was/is now a specific "route" to take and, yes, I already have the helium tank and the tubing because when it is "time," I won't have any one to go get anything for me nor do I have any one around me to or can believe in any thing that I can/do believe in.Do I want to use it? no. why? well, I am not very important but it may backfire and that coroner crap I was referring to could be used against the maker of the product etc and, therefore, I may still be stuck with what Mr Humphry.and, well, perhaps this lengthy "note" will be more of bother than it's worth and for that , I truly am sorry.Why? well, I am not out to save the world - I used to want to try to do that but nowadays all I want is for a certain amount of respect - a certain amount of how I feel to be recognized as being ok to feel whatever it is , ok to believe whatever I believe - I am just so friggin sick & tired of all of these darn "groups" trying to run everyone's everything - and, well, since I don't think ergo is involved in pushing ANY one to do ANY thing, w hich I not only appreciate, I am grateful too cause I believe in their purpose.By the way, about that woman who said something to me about "oh, no, we have ... now" - I am not changing my opinion, if a person wants/needs to kill himself/herself, then so be it - I won't stop anyone - in my opinion, having the courage to kill oneself is an extremely important & personal ability - I won't stop anybody - I have for MANY years believed that suicide is a courageous act and is something that should NOT be against the law.And, well, with my MS, my beliefs in/about/on this issue have only strengthened cause I want NO ONE to stop me - if I ever get the courage to try to die (cause, well, in truth, it's NOT that I WANT to die - I would just like all of these pains and aggravations and frustrations and basic agonies and embarrassments to STOP - I absolutey positively detest those people who say things like 'just deal with it" cause, well, I have and AM and WHEN am I going to get tired enough of 'dealing with it' ? I don't know BUT when I do, I want NO ONE to stop me and, just like what Mr Humphry wrote, I do NOT want to be labelled as 'the crazy person' (or whatever Mr Humphry wrote - I don't remember his exact words, for which I'm sorry cause he is a heck of a lot more eloquent then me!)ok - I'll shut up now. thanks again. bye. Elizabeth (full name and email address withheld)11/10/2007
//////////////////////////The Associated Press reported: Japan's suicide rate remains high: 50 percent are health problemsBy CARL FREIRE, Associated Press Writer, Nov 9,TOKYO - Japan's employers should provide mental health services to workers suffering from depression and other illnesses, the government said Friday after reporting that more than 30,000 people killed themselves last year.In its first annual report on suicide and suicide prevention measures, the Cabinet Office said 32,155 people killed themselves in 2006, the 9th straight year the figure has exceeded 30,000.The total number of suicides represents a drop of 397 from the previous year, the government said. Still, Japan's suicide rate ranks 9th highest in the world, the government added, citing World Health Organization data. Lithuania had the highest rate, followed by Belarus and Russia, while the U.S. ranked 43.Health problems were believed to factor in almost 50 percent of the Japan's suicides in 2006, followed by money problems and household difficulties, the report said. Forty-eight percent of those who killed themselves were unemployed, it said.Suicides first passed the 30,000 mark in 1998 during an economic slump that left many bankrupt, jobless and desperate."This is a problem that needs to be dealt with comprehensively by society," government spokesman Nobutaka Machimura said at a news conference.The central government and local authorities should work together to implement a law approved in June that calls on employers to offer mental health services to employees, Machimura said.Other measures implemented by the government in June aim to tackle unemployment and filter Web sites that promote suicide. The government's goal is to cut the suicide rate by 20 percent in 10 years.
//////////////////////Anger is the only thing to put off till tomorrow.-- Slovakian Proverb Beware the fury of a patient man.-- John Dryden
//////////////////Caring for Your Introvert
October 8th, 2007
“Do you know someone who needs hours alone every day? Who loves quiet conversations about feelings or ideas, and can give a dynamite presentation to a big audience, but seems awkward in groups and maladroit at small talk? Who has to be dragged to parties and then needs the rest of the day to recuperate? Who growls or scowls or grunts or winces when accosted with pleasantries by people who are just trying to be nice?”
Thus begins the introvert’s manifesto, a piece by Jonathan Rauch in The Atlantic titled “Caring for Your Introvert.” Published in March 2003, the short essay has triggered an unexpectedly enthusiastic response. Four and a half years later, it still draws more traffic than any other page in the archives of the magazine. Rauch explains that introverts are not shy or anti-social, but are exhausted by other people. The piece perfectly describes me, but it doesn’t give many specific pointers for how to deal with an introvert. Here are some things that have been on my mind that I think other introverts will agree with.
DOs and DON’Ts
DON’T talk to me before I’ve had my coffee. Caffeine is an introvert’s best friend. I have just as much energy as the next guy, but talking requires a ton.
DO say hello. Just don’t say anything else. As much as I may love you, I wasn’t planning on seeing you on the street. If I had something to say to you besides hello, I would’ve scheduled a lunch or something.
DON’T talk to me if I don’t know you. Trust me, if you like awkward, empty conversations with strangers, we have nothing in common.
DO call me. I have some of my best conversations on the phone. I can spend hours on the phone talking about something I wouldn’t have spent one minute on in person. Phone conversations are premeditated, one on one, and in a controlled environment. And they’re easy to end.
DON’T make conversation in a line of any sort. Talking in lines should be illegal. There’s no clearer example of a situation where I set out to do something that did not include having a conversation. I can’t tell you how many times I’ve had to change my plans for lunch after seeing someone I know in line. I wish it were socially acceptable to wear a huge cardboard box while waiting in line. If you see me, pretend I am.
DO make conversation over a meal. Meals are another high point for introverts. Personally, I think it’s because both parties are seated. Talking is an activity for me, not something that goes on in the background. Eating tends to be automatic enough that I can give the conversation my full attention.
DON’T tell me I don’t go out enough. You don’t stay in enough. My room is my sanctuary. I’d love to spend time with you here. I have no interest in moving to a location with people I don’t know, where I’ll have to stand up, where I’ll have to yell to be heard, where no one has any interest in talking about anything anyone really cares about, and where it’s probably too warm.
DO talk to me about yourself. Whereas it completely drains me to make small talk, big talk is energizing and fun. It doesn’t have to be philosophical or important, just interesting and personal. I could write a whole guide on this one tip. Here’s a short summary: don’t talk to me about the weather, friends in common, the news, our professors, or our homework assignments. Do tell me stories about yourself, tell me what you did today, tell me what annoys you, tell me what you’ve been thinking about. Introverts are great listeners if what we’re listening to has substance. If I’m talking to you, I want to know you and I want you to know me.
DON’T call me “serious.” For some reason, it’s taboo to say anything thoughtful in a group setting. I can’t tell you how many times someone has responded to me with something like “Wow Danny, you’ve really thought that through,” and then chuckled, as if I were some sort of novelty. Of course I’ve thought it through, or I wouldn’t have said it.
DO embrace silence. If there’s nothing worth talking about, everyone’s time is better spent thinking. Most silences aren’t awkward, unless you’re just an awkward person.
DON’T think that I like being alone. I need to be alone after being in a group for a while, to recharge. But I love being around people most of the time, even if we’re not engaging in anything. There’s a great line from Waiting for Godot: “Don’t talk to me. Don’t speak to me. Stay with me.”
After Rauch’s essay was published, there was a huge response (follow up interview and email compilation). One email talked about an introvert anthem: “Every Word You Say,” by Jesse Winchester. The introverted emailer wrote that she danced with her extroverted husband at their wedding to Jerry Garcia’s cover of the song. The opening lyrics are great: “I’m no good company, I guess that’s true/I like my silence, like I love you/But if you feel like talking, talk away/I’m gonna hang on every word you say.” It turned out to be pretty hard to find, but I managed to turn up both versions. Here they are, in a Canals exclusive.
digg_url = \\\'http://digg.com/health/Caring_for_Your_Introvert_part_2\\\';
Jesse Winchester - Every Word You Say
Jerry Garcia - Every Word You Say
-Danny
29 comments ↓
#1 Anne on 10.09.07 at 11:57 pm
I loved this article. I am an extrovert married to an introvert who I love a great deal but who also can drive me a little crazy. My understanding and respect for my husband increased significantly when our son was diagnosed with autism. Not that introverts are autistic. (I don’t want to get anyone angry at me!) However, like our son, when my husband is tired or overworked, he CANNOT deal with a lot of people. He really isn’t being rude. Coming from a huge family, that was hard for me to understand.
Anyway, that’s for the link. I printed it for my husband and he really enjoyed it.
#2 Arianne on 10.13.07 at 12:36 am
Well I’m an introvert married to an extrovert and sometimes he drives me crazy too. I wish that sometimes he wouldn’t talk so much. While I’m ducking for cover trying to avoid someone I may recognize at the mall, he’s making his way towards them! The ‘just say hello’ rule is utter perfection.
#3 David Hill on 10.19.07 at 3:13 am
What a sad read.
#4 Barbara on 10.20.07 at 1:23 am
I’m an introvert and related to alot of this, but I don’t mind talking to strangers and I tolerate conversations in the morning.
I don’t understand why David thinks this is a sad read. I like being an introvert, the only problem I have with it is insensitive extroverts (not to say all extroverts are insensitive). If the world were full of only extroverts it would be very one dimensional.
#5 Kate A on 10.20.07 at 5:21 am
Sad, why sad? This is my life and think its great. Maybe my life doesn’t have as much fun using an extroverts definition, but using an introverts definition it is a great life. To each her own.
#6 Tom G on 10.20.07 at 12:46 pm
The sadness comes from a lack of understanding. We each have to feel comfortable in our own skins. Some people do not understand that others have different needs, and consider it sad when others don’t embrace the same joys. I love the outdoors, is it sad that someone else prefers to be a homebody?
#7 Kredd on 10.20.07 at 9:40 pm
If only my husband could understand that my need to be alone doesn’t mean that I don’t love him! I just need time alone to recharge, restore, recoup and have quiet. He takes it personally. I am emailing him a link.
#8 Stutz on 10.21.07 at 11:00 am
This is good stuff. One thing that I and other introverts I know would differ with you on is the phone — I HATE talking on the phone, because the conversation is forced, and all pauses are awkward. At least in person you can look around, pretending to be interested in your surroundings when you need a break from talking. And you can use your face and body language when needed.
I think the most important thing to convey is that we like talking when it’s about big ideas. As Eleanor Roosevelt said, “Great minds discuss ideas; average minds discuss events; small minds discuss people.”
One rule I would add: DON’T stare at me throughout a conversation; direct eye contact is powerful (like looking into a bright light) and should be limited to when you’re saying something important or conveying information. If we’re just chatting, it feels like I’m an animal in a zoo, here to amuse you with my facial expressions. It feels both condescending and uncomfortable.
#9 Dylan Fox on 10.21.07 at 4:36 pm
It felt great reading this. All my life, people have been telling me that I’ve been doing it wrong (’get a life’ has always been a popular quote). It’s good to know that I wasn’t doing it wrong after all, and the people telling me I was were just extroverts who hadn’t taken the time to understand we view life differently to them
#10 Alex on 10.21.07 at 6:54 pm
I’m not proud of being an introvert but it seems okay considering the alternative. I think the problem is less with these people and more with what our society values. Why can’t someone say something political or even philosophical in a group without getting a “Whoa heavy,” response. Why does everything have to be fluff and pop culture in order to be deemed interesting and acceptable conversation?
That really bothers me that someone called it a “sad read.” For once I was sort of feeling like there were other people I could related to but before I even got to the end of the page I felt alienated all over again.
#11 Chris on 10.21.07 at 10:00 pm
I agree. You hit a few things spot on.
#12 KaylyRed on 10.22.07 at 6:08 am
I enjoyed your article. I’m definitely an introvert in that I find the company of other people draining and don’t really enjoy social situations. I absolutely need alone time, and I can be unbearable when I don’t get it.
Still, I think I’ve learned some coping skills, and I think any introvert can. There’s no need for us introverts to try and change (in fact, I don’t believe we can), but there are ways to make dealing with an introverted world just a little easier. Maybe I’ll blog about them some day.
#13 heidi van veghel on 10.22.07 at 3:17 pm
well said. this is some of the most validating words ive ever read. i get frustrated as well when i try to talk with people and my attempt at deep conversation is usually overshadowed by, for example, gossip. i get so sick of poeple pratically lecturing me on going out. i need and love the time alone and dont like explaining why. the biggest drawback is what it can do to a relationship. i think it is really important to be very honest with close friends about this. i know im often misjudged and people misinterpret me as stuck up. thank you sop much for sharing this. brillant.
#14 morbo on 10.22.07 at 10:20 pm
puny earthlings! this is an interesting read! morbo is actually an introvert with culture shock…morbo doubts if extroverts or normal people will visit this page/ be interested in it/ try to follow it although he sees a few comments from them. When Morbo’s people invade this puny planet they shall be the first meal to our death rays! muhaha…sorry if this is lame
#15 thesimulacra on 10.23.07 at 1:13 pm
I have to say everything except 1-4 is dead on. I have less contempt for empty conversations with strangers than with friends or coworkers I’ve known for awhile, so as long as it’s one-on-one polite conversation (with strangers) I’m fine. At parties it’s different, and I’m only able to tolerate them if I find one or two people to zero in on and have a meaningful conversation with them, away from the group. I don’t need coffee in the morning at all, and I hate talking on the phone for the same reasons as were elucidated by someone else above. Honestly it took me a long time to come to grips with my introvertedness, because I had to understand that it’s not the same thing as being shy. Shy people are reclusive from all social situations because they’re afraid of what people might say or think, introverts don’t really care and just find ourselves exhausted by people.
Another clarification for non-introverts - we don’t typically like parties, but that doesn’t mean we only want to stay inside. We like going out and doing things that enable small, personal conversations (small dinners, movies, etc) and though I can’t speak for everyone, I know that I LOVE the outdoors.
#16 Julie on 10.24.07 at 8:00 am
OMG I thought my ex was just weird but turns out plenty of people are like him! Not that introverts are weird but I just thought he was one of a kind. He always needed to be alone in his room, which was a bit of a pain when I had gone round his to spend time with him, but i always need to be with people, with particular emphasis on the need. I’m not loud or annoying like you would imagine an extrovert to be but I just go crazy if i’m left on my own and I absolutely hate it! Needless to say my ex and I were complete opposites and we drove each other mad so we eventually split up! It’s nice to know he wasn’t just ‘weird’!
#17 Kelly on 10.26.07 at 7:21 am
I just “stumble!”ed on this article and was Wow’d. I even followed all links and printed 17 pages out so i can hand it to my girlfriend. I love her to death but there are times she just drives me nuts with her need to go out. There isn’t a single day that she doesn’t head downtown for coffee or to her sisters for a visit. She often thinks i am being anti-social and ask me “are you ok?” & “is everything alright?” or “whats wrong?” this averages 10 times a day. I on the other hand i love to sit in my apartment by myself and can go days without talking to people. Hopefully reading the things i printed out will help my girlfriend understand i’m not crazy, just introvert. Thanks for keeping a story from 2003 current and available for other to find.
#18 Ben Conte on 10.29.07 at 5:40 am
Thank you so much just for publishing this page. It makes me feel less alienated and alone by how I interact and relate to people. Almost every single one of your points I could relate to perfectly…especially the substance in conversation, dislike of pointless ’small talk’, the seriousness point, and the anecdote with the Godot reference. I am an eighteen year old college freshman and am going through what I like to call existential angst in regards to my role in society. These small comments helped even if temporarily. Thanks.
#19 Ben Conte on 10.29.07 at 5:48 am
lmao. btw just like kelly above me i ’stumble’d on this page as well. thank god for firefox. ’stumble upon’ is my new best friend haha
#20 grownupsarebetter on 10.30.07 at 2:57 am
Can I call you? We can talk about how I’ve discovered the ‘extroverted’ rules and now use them to advantage. My ‘experimental pilot project’ trying out my theory had unexpected consequences - I became incredibly popular almost instantly (crazy), was flooded with job offers (more crazy) and offers of stellar personal references from people I barely knew(beyond all crazy) and within a month had landed a much better paying and more responsible position than I could have possibly imageined with my experience. (Ultimately CRAZY! In a good way..) Turns out that extroverts aren’t like us at all! They are much more simple and therefore…um…easier to please. I’m really tired though as I needed to put in a sustained ‘extroverted’ effort. When the ‘trial’ period for the job is over I look forward to letting out my breather and letting go of that perma -your-my-bestest-friend-ever smile!
#21 stazquatch on 10.30.07 at 11:36 pm
Interesting article.I don’t like the terms introvert/extrovert. Life is not black and white like that. Merely defining yourself as one thing is setting an unconscious mental limit on your ability to grow as a person over time. I personally share many traits of both introvert and extrovert. Sometimes things are best left undefined.And to ‘grownupsarebetter’, you come across as somewhat condescending.
#22 jeroboam bramblejam on 10.31.07 at 12:38 am
My impression is that the ‘introverted’ are simply more sensitive to the noisy static of the mundane, familiar and ordinary, and so they resist the company of those who embody such. I was glad to discover that the clinically introverted can still be outgoing among strangers; I am so because of the likelihood - the inevitability - of meeting the interesting and stimulating among them. I still enjoy the company of nice folk regardless of their depth because I regard kindness as an essential, pleasing and even interesting human trait. But life and time are too precious to be distracted by the quotidian. So excuse me while I resume ‘Stumbling’.Warm wishes
#23 jw on 11.02.07 at 5:15 am
Just curious about the author… since the tagline for the website is ‘from birth to deaf’… deaf referring to listening to loud music too long, or deaf meaning communicates through sign language? it got me thinking whether a person’s tendency toward extroversion/introversion could be related to their communication method and which social circles they’re communicating in at the time. just a thought.
#24 Dreamrift: Welcome on 11.03.07 at 5:40 am
[…] This sounds a lot like me (not shockingly - I have a Meyers-Briggs type of ISTJ, and, in fact, scored 0 in the “E” (extravert) category last time I took that particular test). […]
#25 Martha Hood on 11.04.07 at 3:24 am
I am an introvert who is able to get “out there” as needed. I love being alone and like someone mentioned came to believe that I was “doing it wrong” because my goals and interests aren’t of the mainstream. It has taken me years to accept myself as I am…and not hurt because I am not like everyone else!!
#26 Doug Robertson on 11.04.07 at 10:05 pm
Hey, this is perfect … describes me exactly, and puts into words what I would not be able to explain nearly as effectively. Bravo.
#27 rw on 11.06.07 at 4:35 pm
i am an introvert, and through my experiences, i have to say that i wish i had a consistent person whom i could simply get coffee with in the evenings and have a discourse about politics, art, music, etc. being 21 and in college places a large amount of pressure on the party and social life in our day and age, and i simply reminisce over the days when i walked home in the evenings, listened to jazz, got home, made a pot of coffee and enjoyed the scenery of the world outside.
consistently however, the social pressures of friends and family wondering this and that about my days, wanting extensive detailed accounts of my days have grown increasingly persistent, and occasionally drive me crazy. i definitely dont have the energy for that. i always get the “you work to hard” line. i dont think so, i think i just get my rise out of thinking, along with the occasional opportunity to apply it here and there. anyone agree or in a similar boat?
#28 Amy on 11.09.07 at 12:42 am
I disagree with Sazquatch about the introversion/extraversion terms. I think they are valuable and useful in helping us understand ourselves and others. The actual tests for these traits place us on a scale from 10 to 100; I come out as just slightly introverted. In life I am a definite introvert but not at all an extreme one, so I agree with the test results.I don’t like parties or bars because it’s virtually impossible to hold what I would consider an interesting conversation in those places. And I also get those goofy remarks like “wow, that’s really deep.” Why would I waste my breath if I didn’t have something to say? I also don’t like to talk in the morning, especially before I’ve had any caffeine.However, I differ when it comes to talking with strangers in line and at bus stops. I really enjoy meeting new people and want to know what other people’s lives are like. These are not superficial conversations: I hear about people’s relatives in the hospital, people’s financial problems, violence etc… I have been puzzled when my friendliness is met with silence, but I guess some people are really uncomfortable talking with strangers…
#29 Jon on 11.10.07 at 3:08 am
I am also an introvert, and I relate to nearly everything above. I can formulate great presentations, but I HATE presenting or getting up in front of people. The part about avoiding someone you know when out in public is exactly how I feel. Although I enjoy and embrace being an introvert, I also strive to step outside my comfort zone everyday, and learn to be more comfortable around people.
////////////////////////Zen to Done: The SIMPLE Productivity System
Posted: 08 Nov 2007 03:15 PM CST
Deep in my heart I want to be organized. Somehow, though, what’s on the inside never manifests itself on the outside. My office is filled with stacks of personal finance books, money magazines, and scribbled notes. My e-mail box is packed with questions from GRS readers, guest posts, and correspondence from friends — sometimes I have time to read this stuff and reply to it, but mostly I don’t.
For years, I’ve been searching for the Holy Grail of productivity systems. I haven’t found it yet. I did my best to implement David Allen’s popular Getting Things Done, but the system breaks too easily when not maintained every single day. I need something simpler.
Leo Babauta from Zen Habits may have the answer. He just released Zen to Done: The Ultimate Simple Productivity System, a $9.50 e-book designed “for those who want to get their lives organized and actually execute the things on their to-do list”. Zen to Done focuses on simplicity, on actually doing things instead of planning to do them. Leo writes:
If you̢۪ve been having trouble with Getting Things Done, as great as it is, Zen to Done might be just for you. It focuses on the habit changes necessary for Getting Things Done, in a more practical way, and it focuses on doing, on simplifying, and on adding a simple structure.
I was ready to dismiss Zen to Done as “yet another system J.D. won’t be able to follow”. But after starting to read the book, I couldn’t stop. I realized that maybe — maybe — this was something that could work for me. Though Zen to Done features a detailed description of Leo’s 10-step system (as well as some handy forms), I’m most attracted to what Leo calls “minimalist ZTD” — a bare-bones productivity plan designed to capture ideas and to actually do things. At its core, Zen to Done asks readers to do just these things:
Carry a notebook or an index card. When you think of something that needs to be done, write it down. These are your new to-do items.
At the end of the day, add the new items to a master list. My master to-do list will be a text file on my computer. I already have one that contains dozens of tasks I want to accomplish.
Each morning, designate up to three items from the list as Most Important Tasks. These are the things you will get done today. These take priority over everything else. Try to get them done as early as possible.
Make quick decisions. Don’t procrastinate. Don’t let things accumulate.
That’s it. This system is brilliant in its simplicity. I have high hopes that this is a productivity plan I can actually stick to! If you, too, have tried other systems and failed, consider Zen to Done.
////////////////////Congenital Malaria in the United States Lesko, C.R., et al. - Health care professionals should have heightened vigilance for malaria in pregnant women who have emigrated from or traveled to malaria-endemic areas within the past year, as well as in their offspring. Such women with episodes of fever during pregnancy should have a blood film to test for malaria performed promptly and should be treated appropriately. Treatment of a mother does not negate the need for heightened vigilance in her newborn. Health care professionals should be aware that congenital P vivax malaria does not need to be treated with primaquine [more...]
Archives of Pediatrics and Adolescent Medicine, 11/08/07
///////////////////////////Lenz microphthalmic syndrome in an Indian patient Arvind, G., et al. - A case of Lenz microphthalmia syndrome in a seven-month-old male child having features of unilateral anophthalmia, microcephaly, external ear and finger abnormalities, hydrocele and hypospadias is being reported. The unilateral involvement and anophthalmia is rare in Lenz syndrome. The manifestation of hydrocele in association with this syndrome has not been seen in earlier cases [more...]
Indian Journal of Ophthalmology, 11/08/07 Free Full Text
/////////////////////Review of cases presenting with microcephaly and bilateral congenital cataract in a paediatric cataract clinic Goyal, R., et al. - The presence of microcephaly in children presenting with bilateral cataracts in infancy is strongly suggestive of a syndromic cause. Early-onset Cockayne syndrome was the commonest underlying diagnosis in our series, but clinicians should be aware of other possibilities, and we discuss the differential diagnosis [more...]
Eye, 11/07/07
//////////////////////////Tuesday, November 06, 2007
New planet 'may be home to aliens'
Excited astronomers have discovered a new planet that could be home to alien life, they revealed tonight. The world is orbiting a nearby star like the Sun in its so-called "habitable zone" - just the right distance for liquid water to exist.It is the fifth planet to be identified in orbit around the star 55 Cancri, a star very similar in type and age to our own Sun, making it a virtual twin of our own solar system.The star, which is dimly visible to the naked eye in the constellation of Cancer, now holds the record for the number of worlds in orbit, after our own Sun. It lies just 41 light-years away - right on our cosmic doorstep.
/////////////////////Interleukin-6 gene variants and the risk of sepsis development in children Michalek, J., et al. - A proinflamatory cytokine interleukin-6 (IL-6) plays an important role in the development, pathogenesis and outcome of SIRS, sepsis and septic shock. We have evaluated the role of the IL-6 gene polymorphisms in pediatric patients. A total of 421 consecutive pediatric patients admitted to the pediatric intensive care unit with fever, systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock, or multiple organ distress syndrome (MODS) were studied together with 644 healthy controls. DNA was isolated and two IL-6 gene polymorphisms (G-174>C and G-572>C) were analyzed [more...]
Human Immunology, 11/06/07
////////////////////////////Cosmic Ray Mystery Source: Supermassive Black Holes?The most energetic particles in the universe – ultrahigh-energy cosmic rays – likely come from supermassive black holes in the hearts of nearby active galaxies, says a study by scientists from nearly 90 research institutions worldwide, including the University of Utah. (Embargo expired on 08-Nov-2007 at 14:00 ET)Science, 9-Nov-2007—University of Utah
////////////////////////
Charles Schultz Philosophy
The following is the philosophy of Charles Schultz, the creator of the "Peanuts" comic strip. You don't have to actually answer the questions. Just read the e-mail straight through, and you'll get the point. 1. Name the five wealthiest people in the world. 2. Name the last five Heisman trophy winners. 3. Name the last five winners of the Miss America. 4. Name ten people who have won the Nobel or Pulitzer Prize. 5. Name the last half dozen Academy Award winner for best actor and actress. 6. Name the last decade's worth of World Series winners. How did you do?The point is, none of us remember the headliners of yesterday. These are no second-rate achievers. They are the best in their fields. But the applause dies. Awards tarnish. Achievements are forgotten. Accolades and certificates are buried with their owners .
Here's another quiz. See how you do on this one: 1. List a few teachers who aided your journey through school.2. Name three friends who have helped you through a difficult time. 3. Name five people who have taught you something worthwhile. 4. Think of a few people who have made you feel appreciated and special. 5. Think of five people you enjoy spending time with Easier?The lesson: The people who make a difference in your life are not the ones with the most credentials, the most money, or the most awards. They are the ones that care . Pass this on to those people who have made a difference in your life.?? "Don't worry about the world coming to an end today. It's already tomorrow in Australia." (Charles Schultz)
///////////////////67 ways to outlive 106 billion people
Unless there is some remarkable advance in medical technology between now and the year 2092, I will not live to see 2093. The oldest known human, Jeanne Calment, died at the age of 122 in 1997. So unless I outlive the longest-lived human, I am doomed. Keep in mind, for me to outlive her would mean that my lifespan would exceed that of the preceding 106+ billion people who have lived on the planet. I don’t like those odds. However, I plan to do my best to beat them.
That’s why, like Khrushchev, I will bury you. I won’t be happy, of course, I’ll feel terrible. But it wasn’t anything I did. In fact, it was a lot of things I didn’t do that made the difference between us. Some of them I had already started to do in 2007. Some of them were things I picked up doing later in my life. Sure, I should have done them sooner, but at least I started doing them eventually. Some of these were things I never did in the first place, which helped me even more. I actually hoped that you would start doing them too. So why will I bury you? Simple… because I:
always, always, always wear a seatbelt.
don’t eat meat except on rare occasions.
always stay positive.
am the master of my thoughts. I control them; they never control me.never skip breakfast.
eat organic foods when available, natural when they aren’t and never touch any sort of artificially created foodstuffs.
never add salt to my food.
make at least 50% of my diet raw vegetables and fruits.
steer clear of drugs.
don’t smoke.
don’t keep a gun in the house.
run at least 3 times a week at a reasonable pace.
do moderate weight training.
have a positive outlook on life.
do not work in a job that I hate. In fact, I love my job.
am no longer afraid of money and give it no power over me.
made a decision to be free of money, have that goal written down and carry it with me everywhere.
treasure my time with my family.
take care of my health by making regular visits to the doctor.
floss.
drink alcohol in moderation.
never drink and drive.
understand that the root of all suffering was craving.
no longer subscribe to militant atheism but instead allowed myself to believe in a gentler agnosticism, and most importantly not to obsess on a battle that’s really not relevant to my life.
play with my kids.
love my wife without reserve.
maintained strong relationships with my extended family.
give back to my community.
never dwell on the past.
never dream too much of the future.
stay fully engaged in the present.
am grateful
do not watch TV.
no longer have violent entertainment in my life.
never read the news.
eliminate toxic materials from my household.
never stop learning new things.
meditate daily.
smile and laugh.
spend time outdoors.
surround myself with positive people.
enjoy reading.
dress for comfort.
keep a clear and simple todo list.
live up to my promises.
forget slights against me.
remember dates that are important to others.
take my vitamins.
get plenty of sun.
breathe deeply at least once per day.
quit drinking caffeine.
never drink soda.
celebrate holidays with enthusiasm.
wake up early.
sleep just enough to feel rested.
relax.
never overeat, but also never skip meals.
steer clear of gossip.
give to charity.
do good deeds.
am kind to the elderly.
never compromise on my morals.
live an ethical life in terms of how I treat my environment and other living things.
focus on the distance.
travel.
don’t waste time on regret.
remember that after 2093, I will only exist in memories. The memory of my children will be my immortality.
never forget that this is not a trial life, or a starter life, or a dress rehearsal.
-->
Comments (13)
13 Responses to “67 ways to outlive 106 billion people”
on 06 Nov 2007 at 12:42 pm 1. SavingDiva said …
That is quite a list! Your diet is extremely impressive! 50% raw fruit and vegetables! WOW! I was content when mine is about 1/3!
on 06 Nov 2007 at 12:48 pm 2. kevin said …
How does not keeping a gun in the house make you live longer?
Actually, having a gun may save and extend your life one day (e.g. self-defense)
on 06 Nov 2007 at 1:45 pm 3. Xias said …
Nice list! I’ve made an overhaul to my nutrition as well since I graduated college. I’ve always had a great work ethic when it comes to exercise (6x a week) but pizza and beer every weekend was no way to achieve longetivity
on 06 Nov 2007 at 1:50 pm 4. Matt Wolfe said …
This is a great list. I’ve made great strides to improve my eating and exercise and I’ve been trying to eliminate stress as much as possible. You have some great suggestions.
on 06 Nov 2007 at 1:59 pm 5. guinness416 said …
Another option is that when you get to your 2 million you could liquidate it all and go volunteer for Aubrey de Gray.
Naw, really good list. I’ve printed it out and will read and think about it properly this evening. I would also add “don’t drive” (less stress, no snow driving, less chance of boy racers killing you) but I’m a zealot like that. Don’t follow the Irish rugby or football teams is probably another bullet point, I swear they’ve taken 5 years off my life in the past 90 days.
on 06 Nov 2007 at 2:52 pm 6. Danny Tsang said …
Whoa, great list! I’m going down the list saying “I do this, need to work on that, can’t do that” haha. Awesome.
on 06 Nov 2007 at 10:33 pm 7. bripblap said …
Thanks everyone for the encouragement - saying it’s a good list is very helpful to keep me motivated too. I will point out that Saving Diva’s comment makes me reiterate that I’m not 100% of the way there on all of these! These are all things I plan on, but a bunch of them - quit drinking caffeine jumps to mind - are GOALS. Still not there yet. Down to one cup of coffee per day, no soda, just a little green tea and a lot of herbal tea, but not 100% there yet. The raw veggies thing is close, but if you audited my food it might be closer to 30-40%, although a lot of the cooked food is just cooked veggies.
@Kevin: I know the Center for Injury Control, for example says that if a gun is kept in the home, a woman or child are more likely to be harmed by that gun than an intruder. States with higher rates of gun ownership have higher rates of homicide. In a very general sense, I believe having a gun in the home - especially with small children, like I have - is not a step towards a long life. I grew up with guns all around me, and it was obvious to me that the chances they would be used in self-defense were much smaller than the chance they’d be used against us in some way.
But in all fairness that’s a matter for HUGE debate, and I’m actually not a particularly vocal anti-gun person. Just going with the stats…
on 09 Nov 2007 at 4:55 am 8. DaveC said …
In one point you say point take drugs, in another point you say drink alcohol in moderation - that a bit hypocritical !!
on 09 Nov 2007 at 7:20 am 9. bripblap said …
@DaveC: Maybe you’re interpreting something differently, but I don’t think I advocate taking drugs anywhere in that list - the only mention of drugs is “steer clear of drugs,” which means stay away from drugs.
on 09 Nov 2007 at 9:36 pm 10. hi said …
is this a joke? does it worth living if you don’t watch TV?
on 10 Nov 2007 at 1:45 pm 11. joe said …
each of those things SLIGHTLY modifies the chance of longevity.
Seriously, of the oldest living people, most did not ascribe to your version of reality. The truth of the matter is that a majority factor in our time of death is pure randomness. In other words, some unhealthy, ornery, combative person could live to 95, while i could die today at 23 from a myriad of events beyond my control.
It’s a good list for building a positive frame of mind, and will probably allow for a greater enjoyment of the time you have - but don’t expect it to make you survive until 2093.
On the other hand, by 2093 some unthought of scientific breakthrough could very well extend human life well beyond the century mark… so you might make it anyways.
on 10 Nov 2007 at 5:13 pm 12. Hank said …
The claim that women and children are more likely to be harmed by having a gun in the home is pretty much false if you use proper precautions (trigger guards, etc.). Kellerman claims that having a gun in the home increases the chances of a homicide in the home by 2.7 times! But, that’s only if you are a criminal who uses drugs and has a history of violence, which doesn’t sound like you. And if you teach your family about guns rather than hiding it and forbidding it from your kids, they will learn to respect it, and will lose their curiosity.
From http://www.guncite.com/gun-control-kellermann-3times.html:“As mentioned, a reasonable estimate of gun victims killed by a gun from the victim’s home is 34%. However, this number drops to 12.6% when households having a prior arrestee are excluded, and drops further to 7% when households with prior arrests, illicit drug use, or a history of violence are excluded. (That’s 3.5% of all matched cases. Likewise, the previously mentioned 4½ percent figure of all homicides involving a victim killed by a gun in the home falls to 2.1%.)”
What would you do if a burgler came into your house? Hide? Attack him with a sword? I don’t like the idea of hiding.
on 10 Nov 2007 at 6:42 pm 13. Shelly said …
If you don’t have a relationship with Christ AND believe he died for you because he loves you, on that list, you might as well hang it up. You are only a man and NO MATTER what you try to do, (eating healthy, exercise, etc.) is not going to make you happy and live a life even worth living. What great is it to a man to live a happy life and not a happy afterlife?… You were put on this earth for one reason and one reason only….I will pray that your eyes and heart will be open to the truth. I would rather believe in Jesus and have a chance of going to heaven, versuses not believing in him and then finding out when he does return that I was wrong….its your choice. I am not here to preach to you, just care about you and want to see you in the afterlife.
///////////////////////////Life Extension Update Exclusive
Higher vitamin D levels linked to reduced telomere shortening
The November, 2007 issue of the American Journal of Clinical Nutrition published an article describing the discovery of British and American researchers of an association between longer telomeres and increased levels of vitamin D. Telomeres are caps on the ends of chromosomes which have been found to shorten with age, as well as with increased oxidative stress and inflammation. The finding suggests that vitamin D may play a role in slowing the onset of age-related diseases.
Dr J. Brent Richards at King's College, London School of Medicine and colleagues studied 2,160 female twins aged 19 to 79 for the current research. Blood samples were analyzed for serum vitamin D levels, C-reactive protein (CRP, a marker of inflammation) and additional factors, and telomere length was measured in the DNA of peripheral white blood cells (leukocytes).
As expected, older participants had shorter telomeres; however, leukocyte telomere length (LTL) was greater among subjects whose levels of vitamin D were high compared to those with low concentrations, a finding which persisted after adjustment for age and other factors. Participants in the top one-third of serum vitamin D levels had telomeres that averaged 107 base pairs longer than those in the lowest third, equivalent to a five year difference in chronologic aging.
Telomere length was also greater in those with lower C-reactive protein levels than in subjects with higher concentrations. When participants who had the highest CRP and lowest vitamin D concentrations were compared with those who had the lowest CRP and highest vitamin D levels, the difference in telomere length was equivalent to 7.6 years of aging.
In a subset analysis of vitamin D supplement users, those who supplemented were also found to have longer telomeres than those who did not supplement with the vitamin.
In their discussion concerning mechanisms of action, the authors note that inflammation and oxidative stress are key determinants in the biology of aging, and that vitamin D decreases mediators of systemic inflammation such as interleukin-2 and tumor necrosis factor-alpha. While habits that increase oxidative stress and inflammation may be difficult to change, they observe that “vitamin D concentrations are easily modifiable through nutritional supplementation or sunshine exposure.”
“Although both LTL and serum vitamin D concentrations decrease with age and are thus possible markers of aging in general, we have shown that the positive association between LTL and vitamin D concentrations is independent of age and many other covariates,” the authors conclude. “Longitudinal studies or randomized controlled trials of supplementation exploring the effect of vitamin D on LTL will be necessary to unequivocally establish the relation between vitamin D and leukocyte telomere dynamics; but for the moment, our data suggest another potential benefit of vitamin D—on the aging process and age-related disease.”
Health Concern
Inflammation
While some doctors are finally catching on to the fact that elevated C-reactive protein increases heart attack and stroke risk, they still know little about its other dangers. Even fewer practicing physicians understand that pro-inflammatory cytokines are an underlying cause of systemic inflammation that is indicated by excess C-reactive protein in the blood.
It is well established the elevated C-reactive protein, IL-6 and other inflammatory cytokines indicate significantly greater risks of contracting or dying from specific diseases (heart attack, stroke, Alzheimer's disease, etc.).
A group of doctors wanted to ascertain if C-reactive protein and IL-6 could also predict the risks of all-cause mortality. In a study published in the American Journal of Medicine, a sample of 1,293 healthy elderly people were was followed for a period of 4.6 years (Harris et al. 1999). Higher IL-6 levels were associated with a twofold greater risk of death. Higher C-reactive protein was also associated with a greater risk of death, but to a lesser extent than elevated IL-6. Subjects with both high C-reactive protein and IL-6 were 2.6 times more likely to die during follow up than those with low levels of both of these measurements of inflammation.
//////////////////DARK SIDE OF HIPPOS
//////////////////////FINDINGS
Go ahead, rationalize. Monkeys do it, too.
By John Tierney
Published: November 6, 2007
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For half a century, social psychologists have been trying to figure out the human gift for rationalizing irrational behavior. Why did we evolve with brains that salute our shrewdness for buying the neon yellow car with bad gas mileage? The brain keeps sending one message — Yesss! Genius! — while our friends and family are saying, "Well... "
This self-delusion, the result of what's called cognitive dissonance, has been demonstrated over and over by researchers who have come up with increasingly elaborate explanations for it. Psychologists have suggested we hone our skills of rationalization in order to impress others, reaffirm our "moral integrity" and protect our "self-concept" and feeling of "global self-worth."
If so, capuchin monkeys are a lot more complicated than we thought. Or, we're less complicated. In a paper in Psychological Science, researchers at Yale report finding the first evidence of cognitive dissonance in monkeys and in a group in some ways even less sophisticated, 4-year-old humans.
The Yale experiment was a variation of the classic one that first demonstrated cognitive dissonance, a term coined by the social psychologist Leon Festinger. In 1956 one of his students, Jack Brehm, carted some of his own wedding gifts into the lab (it was a low-budget experiment) and asked people to rate the desirability of things like an electric sandwich press, a desk lamp, a stopwatch and a transistor radio.
Then they were given a choice between two items they considered equally attractive, and told they could take one home. (At the end of the experiment Brehm had to confess he couldn't really afford to give them anything, causing one woman to break down in tears.) After making a choice (but before having it snatched away), they were asked to rate all the items again.
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Suddenly they had a new perspective. If they had chosen the electric sandwich press over the toaster, they raised its rating and downgraded the toaster. They convinced themselves they had made by far the right choice.
So, apparently, did the children and capuchin monkeys studied at Yale by Louisa C. Egan, Laurie R. Santos and Paul Bloom. The psychologists offered the children stickers and the monkeys M&M's.
Once a monkey was observed to show an equal preference for three colors of M&M's — say, red, blue and green — he was given a choice between two of them. If he chose red over blue, his preference changed and he downgraded blue. When he was subsequently given a choice between blue and green, it was no longer an even contest — he was now much more likely to reject the blue.
The monkey seemed to be coping the same way humans do. When you reject the toaster, you could spend a lot of time second-guessing yourself, and that phenomenon, much less common, is called buyer's remorse. (For more on that, go to www.tierneylab.com).
But in general, people deal with cognitive dissonance — the clashing of conflicting thoughts — by eliminating one of the thoughts. The notion that the toaster is desirable conflicts with the knowledge that you just passed it up, so you banish the notion. The cognitive dissonance is gone; you are smug.
Of course, when you see others engaging in this sort of rationalization, it can look silly or pathological, as if they have a desperate need to justify themselves or are cynically telling lies they couldn't possibly believe themselves. But you don't expect to see such high-level mental contortions in 4-year-olds or monkeys.
As the Yale researchers write, these results indicate either that monkeys and children have "richer motivational complexity" than we realize, or our ways of dealing with cognitive dissonance are "mechanistically simpler than previously thought." Another psychologist, Matthew Lieberman of the University of California, Los Angeles, suggests it's the latter.
"If little children and primates show pretty much the same pattern you see in adults, it calls into question just how deliberate these rationalization processes are," he says. "We tend to think people have an explicit agenda to rewrite history to make themselves look right, but that's an outsider's perspective. This experiment shows that there isn't always much conscious thought going on."
The new results jibe with those of a dissonance experiment that Dr. Lieberman and colleagues did with amnesiacs, people with impaired short-term memories, who were asked to rank an assortment of paintings. Then they chose among selected ones and ranked the whole group again. By the second time they ranked the paintings, they couldn't consciously recall their earlier rankings or their choices, so they presumably didn't have a psychic need to rewrite history.
//////////////////////////
Universe 'child of previous one'
By Sarah Cruddas
A "dark matter" parallel universe may exist (Image: Nasa/Esa)A joint UK-US team has put forward an alternative theory of cosmic evolution.
It proposes that the Universe undergoes cycles of "Big Bangs" and "Big Crunches", meaning our Universe is merely a "child of the previous one".
It challenges the conventional view of the cosmos, which observations show to be 12-14 billion years old.
The new ideas, reported in the journal Science, may explain why the expansion of the Universe is accelerating, the researchers say.
"At present the conventional view is that all of space, time, matter and energy began at a single point, which then expanded and cooled, leaving the Universe as it is today," said Professor Paul Steinhardt of Princeton University, New Jersey.
"However, this new theory suggests that there's a continuous cycle of universes, with each a repeat of the last, but not an exact replica.
"It can be thought of as a child of the previous universe."
Cosmological constant
The new idea builds on previous work by the same team, and is set to challenge the current model.
Einstein: "The greatest blunder of my career."Back in the 1920s, when Einstein was developing his general theory of relativity, he introduced a constant, known as the cosmological constant, to explain his idea of a static Universe.
Einstein's equations predicted a Universe collapsing under its own gravitational force, whereas observation showed it clearly was not contracting.
The cosmological constant represented an inherent pressure or force associated with free space, which would be resisting the gravity-drive contraction.
The concept was later abandoned when observations showed the Universe to be expanding - causing Einstein to label the cosmological constant as "the greatest blunder of my career".
In 1998, a form of the constant was re-habilitated when it was found that the Universe's expansion was actually speeding up.
Unanswered questions
Although the re-introduction of the constant enabled calculations to match theory, it also raised the question that there was something in physics that was "missing".
Things that are happening now will help to create another universe in the future
Prof Neil TurokProfessor Neil Turok, of Cambridge University, told the BBC News website: "When the value of the cosmological constant was calculated, it was found to be much smaller than expected.
"The explanation as to why this constant is so small has become one of the biggest problems in physics.
"At present, the only explanation for this is that things just have to be that way." This theory leaves many questions unanswered, but now Professors Steinhardt and Turok have developed a new theory to explain why the cosmological constant is so small.
They suggest that time actually began before the Big Bang, meaning there was a pre-existing universe.
This would also mean that the current Universe is much older than presently accepted.
Dark matter
"At present there may be an alternative 'dark matter' universe that exists at the same time as ours, but we could never reach it," explained Professor Turok.
"The best way to think of this is to think of a pane of double glazing with a fly on it. The fly is unable to cross over from one side to another, just like we are unable to get from one universe to another.
"These two universes are drawn together by the force of gravity and will eventually collide.
"This means that things that are happening now will help to create another universe in the future."
//////////////////////
One Big Bang, or were there many?
· New theory tries to solve problem Einstein raised· Universe may be much older, say cosmologists
James Randerson, science correspondent
The Guardian
Friday May 5 2006
The universe is at least 986 billion years older than physicists thought and is probably much older still, according to a radical new theory.
The revolutionary study suggests that time did not begin with the big bang 14 billion years ago. This mammoth explosion which created all the matter we see around us, was just the most recent of many.
The standard big bang theory says the universe began with a massive explosion, but the new theory suggests it is a cyclic event that consists of repeating big bangs.
"People have inferred that time began then, but there really wasn't any reason for that inference," said Neil Turok, a theoretical physicist at the University of Cambridge, "What we are proposing is very radical. It's saying there was time before the big bang."
Under his theory, published today in the journal Science with Paul Steinhardt at Princeton University in New Jersey, the universe must be at least a trillion years old with many big bangs happening before our own. With each bang, the theory predicts that matter keeps on expanding and dissipating into infinite space before another horrendous blast of radiation and matter replenishes it. "I think it is much more likely to be far older than a trillion years though," said Prof Turok. "There doesn't have to be a beginning of time. According to our theory, the universe may be infinitely old and infinitely large."
Today most cosmologists believe the universe will carry on expanding until all the stars burn out, leaving nothing but their cold dead remains. But there is an inherent problem with this picture. The Cosmological Constant - a mysterious force first postulated by Albert Einstein that appears to be driving the galaxies apart - is much too small to fit the theory. Einstein later renounced it as his "biggest blunder".
The Cosmological Constant is a mathematical representation of the energy of empty space, also known as "dark energy", which exerts a kind of anti-gravity force pushing galaxies apart at an accelerating rate.
It happens to be a googol (1 followed by 100 zeroes) times smaller than would be expected if the universe was created in a single Big Bang. But its value could be explained if the universe was much, much older than most experts believe.
Mechanisms exist that would allow the Constant to decrease incrementally through time. But these processes would take so long that, according to the standard theory, all matter in the universe would totally dissipate in the meantime.
Turok and Steinhardt's theory is an alternative to another explanation called the "anthropic principle", which argues that the constant can have a range of values in different parts of the universe but that we happen to live in a region conducive to life.
"The anthropic explanations are very controversial and many people do not like them," said Alexander Vilenkin a professor of theoretical physics at Tufts University in Massachusetts. Rather than making precise predictions for features of the universe the anthropic principle gives a vague range of values so it is difficult for physicists to test, he added.
"It's absolutely terrible, it really is giving up," said Prof Turok, "It's saying that we are never going to understand the state of the universe. It just has to be that way for us to exist." His explanation by contrast is built up from first principles.
But if he's right, how long have we got until the next big bang? "We can't predict when it will happen with any precision - all we can say is it won't be within the next 10 billion years." Good job, because if we were around we would instantly disintegrate into massless particles of light.
////////////////////
Recycled Universe: Theory Could Solve Cosmic Mystery By Ker ThanStaff Writerposted: 08 May 200612:28 am ET
One of the biggest mysteries in cosmology could be explained by a controversial theory in which the universe explodes into existence not just once, but repeatedly in endless cycles of death and rebirth.
Called the cyclic universe theory, it could potentially explain why a mysterious repulsive form of energy known as the "cosmological constant" and which is accelerating the expansion of the universe is several orders of magnitude smaller than predicted by the standard Big Bang model.
In a new study detailed in the May 5 issue of the journal Science, Paul Steinhardt of Princeton University and Neil Turok of Cambridge University propose that the constant was once much larger, but that its value decayed with each incarnation of the universe.
Puzzling great minds
The cosmological constant, also known as "lambda", is thought to be a form of energy that gravitationally repels itself and causes the expansion of the universe to speed up.
Einstein initially proposed it as a counterforce to the gravitational attraction of matter to explain why the universe appeared static, neither growing nor shrinking. He later discarded the idea, however, when observations by astronomer Edwin Hubble revealed the universe was in fact expanding.
Lambda was revived in the late 1990s when astronomers discovered that the universe was not only expanding, but that it was doing so at an accelerated pace.
Scientists are still not sure what lambda is. According to one popular idea, it is the energy of space itself. According to quantum physics, the seemingly empty vacuum of space actually contains phantom particles that continually blink in and out of existence like flecks of sea foam. These particles are fleeting, but their energies combine to give every cubic centimeter of space a certain amount of energy. According to general relativity, this "vacuum energy" produces an anti-gravitational force that pushes space-and the matter in it-apart.
But there is a problem: the lambda that scientists have detected is more than a googol (1 followed by 100 zeros)times smaller than what theory predicts. To explain such a large discrepancy, physicists have been forced to come up with ever wilder theories.
Explaining lambda
One idea is that the lambda is not really small, but only seems so because it is being cancelled out by another unknown force with near perfect precision. To date, though, no mechanism has been found that can cause this cancellation.
An alternative solution is that of "anthropic selection," a controversial idea that attempts to explain why so many constants in nature appear to be precisely the right value to produce life. If lambda were too large, for example, the universe would have instantly blown up shortly after the Big Bang.
According to the so-called Anthropic Principle, certain features of the universe are selected by the requirement that observers-in our case, humans-can detect them. In other words, only in a universe where lambda is small can intelligent beings exist who can wonder why it is small.
There are different ideas about how anthropic selection works. One possibility is that there are many parallel universes coexisting together; each would have constants of different values and in our universe, those constants can sustain life.
A similar idea is that there is only one infinite universe, but lambda varies from region to region. We just happen to live in a rare bubble where the constant is just right for galaxies and stars-and us-to form.
Anthropic selection makes many scientists uneasy because it suggests that the laws of physics might work differently in remote parts of the universe. In its strongest form, anthropic selection could also be viewed as support for creationism, since it suggests that the universe is somehow fine-tuned specifically for intelligent life.
"The anthropic idea suggests that, in order to explain the universe that we do see, we must make very strong assumptions about other universes we can never see," Steinhardt told SPACE.com. "Also, it assumes our universe is atypical. These assumptions are not normal in science and it's not clear that we must head in such a radical direction."
Cyclic universe
The idea of a cyclic universe, first proposed in 2002 by Steinhardt and Turok, is an alternative to anthropic selection.
"The [value of lambda] is one of the prime mysteries of physics," Steinhardt said. "It's really been so puzzling that it's driven the physics community to this anthropic approach. So it's important to know if a non-anthropic solution might exist."
The researchers' latest tweak to their model is to have the value of lambda decay over time with each passing cycle of the universe and even within a single cycle.
Scientists experimented with a varying lambda before within the context of the standard Big Bang model, but it didn't work because the time required for it to reach its current low value was far longer than the known age of the universe.
Combining a decaying lambda with a cyclic universe potentially solves this problem.
'Ingenious'
Although he expressed other concerns about the cyclic universe theory, Alexander Vilenkin, a cosmologist at Tufts University in Massachusetts who was not involved in the study, said Steinhardt and Turok's solution to the cosmological constant problem was "ingenious."
In a cyclic universe, new matter and energy are created about every trillion years when two sheet-like "branes" collide along an extra dimension of space. Branes are predicted by string theory.
Because there can be endless cycles, the universe would be far older than the 14.7 billion years that scientists currently estimate. This would allow ample time for lambda to shrink to what astronomers see now.
Steinhardt and Turok think lambda decreased in such a way that the rate of decay slowed with time. This means that observers measuring lambda are much more likely to get a small value than a large one.
Because a high lamda prevents the universe as we know it from forming, early cycles of the universe would have been void of galaxies, stars and life; only in later cycles, when lamda had decreased to a much smaller value, could matter coalesce to create the world we inhabit today.
The pair estimates that each cycle lasted about a trillion years. During this time, the universe runs its natural course, but all the while matter and energy fans out through space until they are extremely dilute.
"They are so dilute, in fact, that we would likely see not even a single particle of that early matter and radiation within our horizon-that is, the patch of space we can see," Steinhardt said.
Once the universe is emptied out, a weak attractive force brings our universe's two branes together in a cosmic collision. Each collision is essentially a new Big Bang that infuses the aging universe with new matter and energy.
Steinhardt says their crazy theory can be tested: the inflationary Big Bang theory predicts that gravitational waves produced at the end of inflation leave an imprint on the cosmic microwave background, a diffuse form of electromagnetic radiation that fills the universe.
If future experiments show the polarization pattern produced by such waves, it would disprove the cyclic universe theory, ruling it out as a possible solution to the cosmological constant problem.
/////////////////Could cyclic universe explain mystery?
Theorists suggest Big Bangs and Crunches lead to cosmic balance
Princeton University
This graphic illustrates how the repeated collision and retreat of two branes in extradimensional space might give rise to a cyclic universe.
INTERACTIVE
Beyond the Big BangLearn more about the theory of cosmic inflation
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One of the biggest mysteries in cosmology could be explained by a controversial theory in which the universe explodes into existence not just once, but repeatedly in endless cycles of death and rebirth.
Called the cyclic universe theory, it could potentially explain why a mysterious repulsive form of energy known as the "cosmological constant," which is accelerating the expansion of the universe, is several orders of magnitude smaller than predicted by the standard Big Bang model.
In the May 5 issue of the journal Science, Paul Steinhardt of Princeton University and Neil Turok of Cambridge University propose that the constant was once much larger, but that its value decayed with each incarnation of the universe.
Story continues below ↓
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The cosmological constant, also known as "lambda," is thought to be a form of energy that gravitationally repels itself and causes the expansion of the universe to speed up.
Albert Einstein initially proposed it as a counterforce to the gravitational attraction of matter to explain why the universe appeared static, neither growing nor shrinking. He later discarded the idea, however, when observations by astronomer Edwin Hubble revealed the universe was in fact expanding.
Lambda was revived in the late 1990s when astronomers discovered that the universe was not only expanding, but that it was doing so at an accelerated pace.
Scientists are still not sure what lambda is. According to one popular idea, it is the energy of space itself. According to quantum physics, the seemingly empty vacuum of space actually contains phantom particles that continually blink in and out of existence like flecks of sea foam. These particles are fleeting, but their energies combine to give every cubic centimeter of space a certain amount of energy. According to general relativity, this "vacuum energy" produces an antigravitational force that pushes space — and the matter in it — apart.
But there is a problem: The lambda that scientists have detected is more than a googol (1 followed by 100 zeros) times smaller than what theory predicts. To explain such a large discrepancy, physicists have been forced to come up with ever wilder theories.
Explaining lambdaOne idea is that the lambda is not really small, but only seems so because it is being cancelled out by another unknown force with near perfect precision. To date, though, no mechanism has been found that can cause this cancellation.
An alternative solution is that of "anthropic selection," a controversial idea that attempts to explain why so many constants in nature appear to be precisely the right value to produce life. If lambda were too large, for example, the universe would have instantly blown up shortly after the Big Bang.
According to the so-called Anthropic Principle, certain features of the universe are selected by the requirement that observers — in our case, humans — can detect them. In other words, only in a universe where lambda is small can intelligent beings exist who can wonder why it is small.
There are different ideas about how anthropic selection works. One possibility is that there are many parallel universes coexisting together; each would have constants of different values and in our universe, those constants can sustain life.
A similar idea is that there is only one infinite universe, but lambda varies from region to region. We just happen to live in a rare bubble where the constant is just right for galaxies and stars — and us — to form.
Anthropic selection makes many scientists uneasy because it suggests that the laws of physics might work differently in remote parts of the universe. In its strongest form, anthropic selection could also be viewed as support for creationism, since it suggests that the universe is fine-tuned specifically for intelligent life.
"The anthropic idea suggests that, in order to explain the universe that we do see, we must make very strong assumptions about other universes we can never see," Steinhardt told Space.com. "Also, it assumes our universe is atypical. These assumptions are not normal in science, and it's not clear that we must head in such a radical direction."
Cyclic universeThe idea of a cyclic universe, first proposed in 2002 by Steinhardt and Turok, is an alternative to anthropic selection.
"The [value of lambda] is one of the prime mysteries of physics," Steinhardt said. "It's really been so puzzling that it's driven the physics community to this anthropic approach. So it's important to know if a non-anthropic solution might exist."
The researchers' latest tweak to their model is to have the value of lambda decay over time with each passing cycle of the universe and even within a single cycle.
Scientists experimented with a varying lambda before within the context of the standard Big Bang model, but it didn't work because the time required for it to reach its current low value was far longer than the known age of the universe.
Combining a decaying lambda with a cyclic universe potentially solves this problem.
'Ingenious'Although he expressed other concerns about the cyclic universe theory, Alexander Vilenkin, a cosmologist at Tufts University in Massachusetts who was not involved in the study, said Steinhardt and Turok's solution to the cosmological constant problem was "ingenious."
In a cyclic universe, new matter and energy are created about every trillion years when two sheetlike "branes" collide along an extra dimension of space. Branes are predicted by string theory.
Because there can be endless cycles, the universe would be far older than the 14.7 billion years that scientists currently estimate. This would allow ample time for lambda to shrink to what astronomers see now.
Steinhardt and Turok think lambda decreased in such a way that the rate of decay slowed with time. This means that observers measuring lambda are much more likely to get a small value than a large one.
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CYCLIC UNIVERSE OR BUBBLE UNIVERSE?
The cyclic-universe concept is a minority opinion: More cosmologists suggest that there is a large landscape of possible configurations for the universe, and that billions upon billions of closed "bubble universes" may exist in higher dimensions. Some of those bubbles may blink out immediately, while others last long enough to spawn stars, planets and life. In the journal Science, Tufts University's Alexander Vilenkin sides with the bubble-universe concept. The explanation may not be totally satisfying, but it appears to be "more compelling," he writes.• Questioning the Big Bang• Princeton: The cyclic universe• Stanford: Inflationary multiverse (PDF)
Alan Boyle / MSNBC.comBecause a high lambda prevents the universe as we know it from forming, early cycles of the universe would have been void of galaxies, stars and life; only in later cycles, when lambda had decreased to a much smaller value, could matter coalesce to create the world we inhabit today.
The pair estimates that each cycle lasted about a trillion years. During this time, the universe runs its natural course, but all the while matter and energy fans out through space until they are extremely dilute.
"They are so dilute, in fact, that we would likely see not even a single particle of that early matter and radiation within our horizon — that is, the patch of space we can see," Steinhardt said.
Once the universe is emptied out, a weak attractive force brings our universe's two branes together in a cosmic collision. Each collision is essentially a new Big Bang that infuses the aging universe with new matter and energy.
Steinhardt says their crazy theory can be tested: the inflationary Big Bang theory predicts that gravitational waves produced at the end of inflation leave an imprint on the cosmic microwave background, a diffuse form of electromagnetic radiation that fills the universe.
If future experiments show the polarization pattern produced by such waves, it would disprove the cyclic universe theory, ruling it out as a possible solution for the cosmological constant puzzle.
/////////////////////////Karen Stern’s Final ExitOctober 29, 2007, Kingman, ArizonaBy Richard N. Côté / dickcote@earthlink.netKaren Stern, a vivacious 53-year-old, guitar-playing singer and writer of loopy, infectiously funny songs, died on the morning of October 29, 2007, in a motel in Kingman, Arizona.She had informed the front desk clerk about 7:00 a.m. that she would be checking out that day. When she had not done so by 11:00 a.m., a motel staff member went to her room. Karen was found in her bed, neatly dressed, with an empty tank of helium gas nearby. She had committed suicide in a gentle, painless way by breathing pure helium, which rendered her unconscious within a minute or two and dead within five or ten minutes. The hotel immediately called 911, but the paramedics could do nothing to help her.A native of the Northeast, she had chosen Kingman, Arizona, as one of her temporary sanctuaries in the last several years. Its dry climate offered some relief from the severe effects of the two baffling and exhausting afflictions from which she had suffered for many years: Morgellons Syndrome and Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS).According to the CFIDS Association (www.cfids.org), “Chronic fatigue and immune dysfunction syndrome, also known as chronic fatigue syndrome (CFS), myalgic encephalomyelitis (ME) and by other names, is a complex and debilitating chronic illness that affects the brain and multiple body systems.”Morgellons Syndrome is equally baffling to science. The Morgellons Research Foundation (www.morgellons.org) found that although some patients did find physicians willing to help them, “many patients reported feeling abandoned by physicians unwilling to investigate their illness. These patients tried valiantly to find a modicum of relief in the face of an otherwise ineffective medical system.” Karen, who spent years intensively researching her ailments, was one of those patients.Numerous doctors could not alleviate the increasingly tortured existence she had lived for the past several years. As her conditions worsened, and life became progressively more unbearable, Karen consulted numerous experts on the subject of suicide, and had received extensive advice on how to find the strength to live, as well as how to put an end to her pain peacefully, should she choose to do so. She spent an enormous amount of time conducting research on how to achieve a rapid, painless death. Ultimately, she chose the helium method because it was recommended in the world’s best-selling suicide how-to book, Final Exit, by Derek Humphry, and because the supplies could all be obtained locally, legally, and without having to involve anyone else.Known to her friends as a funny, gregarious, kindhearted, and genuinely talented artist, she released her first CD, “Virgin Mirth,” ( www.virginmirth.com) in 2003. Just prior to her death, the tall, slender, dark-haired woman composed two new songs drawn from the reality of her final years. The first, “Checking Out is Hard To Do” (subtitled, with her characteristic humor, “Derek Humphry’s Fight Song”) expresses the enormous difficulty she had finding someone to be at her side as she died. It contains the lines,“Remember when we put Rex down?I'd be lucky if I was a hound.”This reflects the reality that animals in excruciating, unending pain can expect to be “put to sleep” (euthanized) quickly and painlessly, whereas humans must often suffer unabating torment for years, barred by doctors, hospitals, and lawyers from choosing a death with dignity at the time and place of their own choosing.Her second recent work, “The Morgellons Song,” describes the torment of victims of that malady. She wrote, “You may know this beautiful song, 'Crying Over You'.... [by Roy Orbison] which was performed by Carrie Underwood couple years ago on American Idol....well this lyric just had to be written...i couldn't resist...this is very hard to sing, but if you work on it, it might be a lot of fun, and you'll create good juju against those [Morgellons’] bugs. They may have infinite adaptability, but can they write a song?”Karen Stern is survived by her family, a wide circle of friends, an enormous group of fellow Morgellons’ and CFIDS co-sufferers, and the author, who, via telephone conversations, had the pleasure of hearing her play the guitar and sing; the honor of learning about her greatest joys and worst fears; and appreciation for her enormous emotional strength over a period of seven months.R.N.C.
////////////////A Cosmic Coincidence Resurrects the Cyclical Universe
Over the past five years or so, scientists have finally converged on a model of the universe that explains (or at least permits) all of its characteristics. The new cosmological model has one very surprising feature, however, which is supported by several robust and unrelated observations. In addition to matter and radiation, it seems that the vacuum of space is filled with a mysterious ‘dark energy’ that pushes the universe apart. While the dark energy helps us explain a great many things, it also resurrects an old problem once thought buried—the idea that our universe is the product of a highly unlikely cosmic coincidence.
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During the decades following common acceptance of the Big Bang model, physicists and astronomers tried very hard to measure the composition of the universe. According to theory, the average density of the universe would determine its ultimate fate. A universe with too little matter would expand forever, and its average density would eventually drop to zero. A universe with too much matter, on the other hand, would one day collapse under its own gravity (the ‘Big Crunch’). Only one special value, the critical density, could prevent both a Big Crunch and the unchecked expansion of the universe.
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Those with philosophical objections to a dying universe had only three alternatives. One idea was that we actually lived in a steady state universe. In this model, the universe expands at a constant rate but produces an occasional atom out of the void to maintain its average density. A steady state universe is infinite, and need not have had a Big Bang at all. Another way out was to have a cyclical universe, whose every Big Crunch is followed by another Big Bang. The cyclical universe model didn’t improve our own long-term prospects, but it at least preserved the universe itself from extinction. Unfortunately, neither of these models survived under the pressure of improving astronomical observations. By the 1970s, a critical density Big Bang model was the only viable solution for a stable universe. Unfortunately, even the most generous accounting of matter in the universe added up to only about half of the required density. Cosmologists were stuck with an unstable universe, doomed to end in cold and darkness. A universe that expands forever is not so bad, if the data require it; the future history of the universe might be disappointing to aesthetes, but a scientist will just shrug and accept the result. The Big Bang model, however, still had a big problem: our low-density universe could only arise from a highly unlikely coincidence of initial conditions. An expanding universe is fine in principle, but it mustn’t expand too quickly! For galaxies, stars, and planets to form, the average density of matter has to stay relatively high for at least a few billion years. To satisfy even this one vague constraint, it turns out that the initial density of the universe would have had to be very close to the critical value1. How close? The answer is a bit hard to swallow even to a disinterested physicist! A difference of one part in a million billion (1015) would allow galaxies to form before the expansion of the universe pulls everything too far apart for new structures to form. This is known as a fine-tuning problem: to explain the observed properties of the universe under the Big Bang model, physicists had to assume a very specific value for its initial density. If the universe were actually at the critical density, which has a clear physical significance, the fine-tuning problem wouldn’t be so bad. A universe starting at the critical density remains at the critical density forever, which sounds like a clue to some deeper physical law. One might claim that an unknown physical process makes this the only possible value. But in knowing that the initial density was some other number, physicists had to admit that any initial density was possible. Although we live in a universe capable of supporting life, the probability that such a universe came into existence randomly seemed to be infinitesimal. The fine-tuning problem was eventually solved by borrowing ideas from quantum field theory, a branch of physics dealing with fundamental particles and their interactions. During the Eighties and Nineties, most physicists were content with the Big Bang model and believed that a quantum mechanical process called inflation pushed the density of the early universe very close to its critical value in a brief period of runaway expansion. During inflation, the universe was dominated by a field of energy not unlike the dark energy being discussed today. In this scenario, the initial density of the universe was no longer relevant—inflation would drive any initial value towards the critical value in the blink of an eye. At the turn of the millennium, however, this tidy theory began to fail. Large-scale surveys discovered distant supernovae by the dozen, allowing astronomers to determine how fast the universe was expanding billions of years ago. The cosmology du jour predicted that the universe was slowing down, but these and subsequent observations have shown that the expansion is actually speeding up! To explain this result, Einstein’s cosmological constant had to be brought back into the picture. This parameter corresponds to the energy density of a vacuum (the ‘dark energy’), and just like the matter density the cosmological ‘constant’ evolves along with the universe.
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Meaning of Life Explained A Plausible Theory for Our Universe Science Based and LogicalWhyyouexist.blogspot.comThe fine-tuning problem has therefore returned, in a different form. The initial density of vacuum energy had to be very close to zero at the Big Bang, or else an accelerating expansion would have driven apart all the matter before stars could form. Inflation can’t solve the problem this time; technically speaking, the cosmological constant is itself one cause of inflation. Once again, cosmologists find themselves debating the initial conditions of the universe. One common explanation, which has been used for decades to solve fine-tuning problems, is called the anthropic principle. In essence, this is the statement that we must live in a universe that can support life because we are here to observe it. This statement isn’t very satisfying, however, since it doesn’t offer any new insight into the nature of the universe. In modern times, physicists such as Alexander Vilenkin (Tufts University) have begun to suggest that our universe is only one of many. They envision an eternally expanding field of fundamental energy, effervescent with an infinity of universes. Each one has a Big Bang of its own, popping into existence wherever quantum fluctuations cool the fundamental field sufficiently. If there are an infinite number of universes, then it is certainly much less surprising that some would be habitable. Our particular combination of cosmological parameters, however, remains a highly improbable event in its own right. Advances in string theory and our understanding of higher dimensional spaces have made possible an even more astonishing solution to the coincidence problem. Quantum mechanical models have been proposed that allow the cosmological constant to decay from any initial value to almost zero. Such models, however, have two problems: first, the process typically requires trillions of years; and second, while the cosmological constant is large the density of matter in the universe drops to zero very quickly. But what if the universe is much older than it appears? Professors Paul Steinhardt (Princeton University) and Neil Turok (Cambridge University) have come up with a novel solution that gives the cosmological constant time to decay to its required value. Resurrecting a ghost of the cyclical universe, they propose that our universe is one of two embedded in the eleven-dimensional space of string theory. The two universes are linked with a spring-like attraction, and so pass through each other (moving along one of the higher dimensions) periodically. Every time they interact, enormous energies are released and both universes fill with hot plasma—a new Big Bang. There is no Big Crunch, as both universes are constantly expanding. A trillion years or so after one Big Bang, when the universe is practically empty, another Big Bang occurs and the stars and galaxies can form once more. The underlying cosmological constant, however, is unaffected by this process and has all the time it needs to decay to a small value. Eventually stars and galaxies will have time to form, and the same will be true of every subsequent cycle. In this modern version of the old cyclical model, the coincidence is resolved because only a few cycles are required for the cosmological constant to decay. The number of star-producing cycles following the decay, however, is practically infinite. Either way, it is clear that our perspective has changed. A single universe is no longer satisfying, given the most unlikely nature of our own. To explain our existence, it seems we must imagine others.
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////////////Asked Questions in Cosmology
Tutorial : Part 1 Part 2 Part 3 Part 4 Age Distances Bibliography Relativity
What is the currently most accepted model for the Universe?
What is the evidence for the Big Bang?
What happened during the Big Bang?
What is this "anti-gravity"? [The cosmological constant]
Why do we think that the expansion of the Universe is accelerating?
What is quintessence?
How old is the Universe?
If the Universe is only 14 billion years old, why isn't the most distant object we can see 7 billion light years away?
If the Universe is only 14 billion years old, how can we see objects that are now 47 billion light years away?
Is the Universe really infinite or just really big?
How can the Universe be infinite if it was all concentrated into a point at the Big Bang?
How can the oldest stars in the Universe be older than the Universe?
Can objects move away from us faster than the speed of light?
What is the redshift?
Are quasars really at the large distances indicated by their redshifts?
What about objects with discordant redshifts, like Stephan's Quintet?
Has the time dilation of distant source light curves predicted by the Big Bang been observed?
Are galaxies really moving away from us or is space just expanding?
Why doesn't the Solar System expand if the whole Universe is expanding?
Is the Universe expanding or is it just that our definitions of length and time are changing?
Why haven't the CMBR photons outrun the galaxies in the Big Bang?
Where was the center of the Big Bang?
What is meant by a flat Universe?
Is the Big Bang a Black Hole?
What is the Universe expanding into?
What came before the Big Bang?
Doug Scott's Cosmic Microwave Background Radiation (CMBR) FAQ
Can the CMBR be redshifted starlight?
Why is the sky dark at night?
Will the Universe expand forever or recollapse?
Does entropy prevent a Big Crunch?
What about the oscillating Universe?
What is the dark matter?
What about MOND?
What is the value of the Hubble constant?
What can a layperson do in cosmology?
When will the next WMAP data release occur?
Ask your own question!
What is the currently most accepted model for the Universe?
The current best fit model is a flat ΛCDM Big Bang model where the expansion of the Universe is accelerating, and the age of the Universe is 13.7 billion years.
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What is the evidence for the Big Bang?
The evidence for the Big Bang comes from many pieces of observational data that are consistent with the Big Bang. None of these prove the Big Bang, since scientific theories are not proven. Many of these facts are consistent with the Big Bang and some other cosmological models, but taken together these observations show that the Big Bang is the best current model for the Universe. These observations include:
The darkness of the night sky - Olbers' paradox.
The Hubble Law - the linear distance vs redshift law. The data are now very good.
Homogeneity - fair data showing that our location in the Universe is not special.
Isotropy - very strong data showing that the sky looks the same in all directions to 1 part in 100,000.
Time dilation in supernova light curves. The observations listed above are consistent with the Big Bang or with the Steady State model, but many observations support the Big Bang over the Steady State:
Radio source and quasar counts vs. flux. These show that the Universe has evolved.
Existence of the blackbody CMB. This shows that the Universe has evolved from a dense, isothermal state.
Variation of TCMB with redshift. This is a direct observation of the evolution of the Universe.
Deuterium, 3He, 4He, and 7Li abundances. These light isotopes are all well fit by predicted reactions occurring in the First Three Minutes. Finally, the angular power spectrum of the CMB anisotropy that does exist at the several parts per million level is consistent with a dark matter dominated Big Bang model that went through the inflationary scenario.
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Why do we think that the expansion of the Universe is accelerating?
The evidence for an accelerating expansion comes from observations of the brightness of distant supernovae. We observe the redshift of a supernova which tells us by what the factor the Universe has expanded since the supernova exploded. This factor is (1+z), where z is the redshift. But in order to determine the expected brightness of the supernova, we need to know its distance now. If the expansion of the Universe is accelerating due to a cosmological constant, then the expansion was slower in the past, and thus the time required to expand by a given factor is longer, and the distance NOW is larger. But if the expansion is decelerating, it was faster in the past and the distance NOW is smaller. Thus for an accelerating expansion the supernovae at high redshifts will appear to be fainter than they would for a decelerating expansion because their current distances are larger. Note that these distances are all proportional to the age of the Universe [or 1/Ho], but this dependence cancels out when the brightness of a nearby supernova at z close to 0.1 is compared to a distant supernova with z close to 1.
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What is quintessence?
Quintessence, or the fifth essence, is a fifth element beyond the standard earth, air, fire and water of ancient chemistry. Steinhardt and colleagues have adopted quintessence as the name for a particular model for the vacuum energy which causes the accelerating expansion of the Universe. A search of astro-ph on the LANL preprint server arXiv for "quintessence" in the abstract hits over 600 articles of which the oldest dates from 1998.
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If the Universe is only 14 billion years old, why isn't the most distant object we can see 7 billion light years away?
This question makes some hidden assumptions about space and time which are not consistent with all definitions of distance and time. One assumes that all the galaxies left from a single point at the Big Bang, and the most distant one traveled away from us for half the age of the Universe at almost the speed of light, and then emitted light which came back to us at the speed of light. By assuming constant velocities, we must ignore gravity, so this would only happen in a nearly empty Universe. In the empty Universe, one of the many possible definitions of distance does agree with the assumptions in this question: the angular size distance, and it does reach a maximum value of the speed of light times one half the age of the Universe. See Part 2 of the cosmology tutorial for a discussion of the other kinds of distances which go to infinity in the empty Universe model since this gives an unbounded Universe.
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If the Universe is only 14 billion years old, how can we see objects that are now 47 billion light years away?
When talking about the distance of a moving object, we mean the spatial separation NOW, with the positions of both objects specified at the current time. In an expanding Universe this distance NOW is larger than the speed of light times the light travel time due to the increase of separations between objects as the Universe expands. This is not due to any change in the units of space and time, but just caused by things being farther apart now than they used to be.
What is the distance NOW to the most distant thing we can see? Let's take the age of the Universe to be 14 billion years. In that time light travels 14 billion light years, and some people stop here. But the distance has grown since the light traveled. The average time when the light was traveling was 7 billion years ago. For the critical density case, the scale factor for the Universe goes like the 2/3 power of the time since the Big Bang, so the Universe has grown by a factor of 22/3 = 1.59 since the midpoint of the light's trip. But the size of the Universe changes continuously, so we should divide the light's trip into short intervals. First take two intervals: 7 billion years at an average time 10.5 billion years after the Big Bang, which gives 7 billion light years that have grown by a factor of 1/(0.75)2/3 = 1.21, plus another 7 billion light years at an average time 3.5 billion years after the Big Bang, which has grown by a factor of 42/3 = 2.52. Thus with 1 interval we got 1.59*14 = 22.3 billion light years, while with two intervals we get 7*(1.21+2.52) = 26.1 billion light years. With 8192 intervals we get 41 billion light years. In the limit of very many time intervals we get 42 billion light years. With calculus this whole paragraph reduces to this.
Another way of seeing this is to consider a photon and a galaxy 42 billion light years away from us now, 14 billion years after the Big Bang. The distance of this photon satisfies D = 3ct. If we wait for 0.1 billion years, the Universe will grow by a factor of (14.1/14)2/3 = 1.0048, so the galaxy will be 1.0048*42 = 42.2 billion light years away. But the light will have traveled 0.1 billion light years further than the galaxy because it moves at the speed of light relative to the matter in its vicinity and will thus be at D = 42.3 billion light years, so D = 3ct is still satisfied.
If the Universe does not have the critical density then the distance is different, and for the low densities that are more likely the distance NOW to the most distant object we can see is bigger than 3 times the speed of light times the age of the Universe. The current best fit model which has an accelerating expansion gives a maximum distance we can see of 47 billion light years.
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Is the Universe really infinite or just really big?
We have observations that say that the radius of curvature of the Universe is bigger than 70 billion light years. But the observations allow for either a positive or negative curvature, and this range includes the flat Universe with infinite radius of curvature. The negatively curved space is also infinite in volume even though it is curved. So we know empirically that the volume of the Universe is more than 20 times bigger than volume of the observable Universe. Since we can only look at small piece of an object that has a large radius of curvature, it looks flat. The simplest mathematical model for computing the observed properties of the Universe is then flat Euclidean space. This model is infinite, but what we know about the Universe is that it is really big.
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How can the oldest stars in the Universe be older than the Universe?
Of course the Universe has to be older than the oldest stars in it. So this question basically asks: which estimate is wrong -
The age of the Universe
The age of the oldest stars
Both The age of the Universe is determined from its expansion rate: the Hubble constant, which is the ratio of the radial velocity of a distant galaxy to its distance. The radial velocity is easy to measure, but the distances are not. Thus there is currently a 11% uncertainty in the value of the Hubble constant measured directly by the Hubble Space Telescope. John Huchra gives a good discussion of the historical uncertainties in the Hubble constant since even before Hubble's work. There is now a more precise but more indirect determination from WMAP observations of the CMB anisotropy.
The estimated age of the Universe has been increased by the observations of an accelerated expansion of the Universe. The current best value is 13.7 +/- 0.2 billion years from WMAP.
Determining the age of the oldest stars requires a knowledge of their luminosity, which depends on their distance. This leads to a 15% uncertainty in the ages of the oldest stars due to the difficulty in determining distances.
Thus the discrepancy between the age of the oldest things in the Universe and the age inferred from the expansion rate was always within the margin of error. In fact, in 1997 improved distances from the HIPPARCOS satellite suggested that the oldest stars were younger, and the WMAP results in 2003 suggest that the Universe is older, so the discrepancy has disappeared.
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Can objects move away from us faster than the speed of light?
Again, this is a question that depends on which of the many distance definitions one uses. However, if we assume that the distance of an object at time t is the distance from our position at time t to the object's position at time t measured by a set of observers moving with the expansion of the Universe, and all making their observations when they see the Universe as having age t, then the velocity (change in D per change in t) can definitely be larger than the speed of light. This is not a contradiction of special relativity because this distance is not the same as the spatial distance used in SR, and the age of the Universe is not the same as the time used in SR. In the special case of the empty Universe, where one can show the model in both special relativistic and cosmological coordinates, the velocity defined by change in cosmological distance per unit cosmic time is given by v = c ln(1+z), where z is the redshift, which clearly goes to infinity as the redshift goes to infinity, and is larger than c for z > 1.718. For the critical density Universe, this velocity is given by v = 2c[1-(1+z)-0.5] which is larger than c for z > 3 . For the concordance model based on CMB data and the acceleration of the expansion measured using supernovae, a flat Universe with OmegaM = 0.27, the velocity is greater than c for z > 1.407.
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What is the redshift?
The redshift of an object is the amount by which the spectral lines in the source are shifted to the red. That is, the wavelengths get longer. To be precise, the redshift is given by z = [λobs-λem]/λem
where λem is the emitted wavelength of a line, which is known from laboratory measurements, and λobs is the observed wavelength of the line. In an expanding Universe, distant objects are redshifted, with z = Ho D/c for small distances. This law was discovered by Hubble and Ho is known as the Hubble constant.
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Are quasars really at the large distances indicated by their redshifts?
The short answer is
Yes!
Stockton (1978, ApJ, 223, 747) observed faint galaxies near in the sky to bright quasars at moderate redshifts. He chose quasars with moderate redshifts so he would still be able to see galaxies at the redshift of the quasar. He found that a good fraction of the redshifts of the faint galaxies agreed with the redshifts of the quasars. In other words, quasars are associated with galaxies that have the same redshift as the quasar and have just the brightness expected if the quasars are at their cosmological distances. Thus at least some quasars are at the distance indicated by their redshifts, and this includes some of the most luminous quasars: for example 3C273. Thus the simple answer selected by Occam's razor is that all quasars are at the distances indicated by their redshifts.
A further argument in favor of cosmological redshifts for quasars is the essentially perfect rank ordering implied by the fact that quasar absorption line system always have redshifts less than or equal to the quasar emission line redshift. In gravitational lens systems, the redshift of the lens is always less than the redshift of the lensed object. Thus intervening systems like lensing galaxies or absorbing clouds, which obviously have smaller distances than the quasars, also have smaller redshifts.
The statistical arguments advanced by Arp and others in favor of anomalous quasar redshifts are often incorrect.
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What about objects with discordant redshifts, like Stephan's Quintet?
One famous example of objects with different redshifts appearing in the same part of the sky is Stephan's Quintet. But the low redshift galaxy (in the lower left) is obviously more resolved into stars and looks "bumpier". By the surface brightness fluctuation method of distance determination, this bumpiness means that the low redshift galaxy is indeed much closer to us than the other four members of the quintet.
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Has the time dilation of distant source light curves predicted by the Big Bang been observed?
This time dilation is a consequence of the standard interpretation of the redshift: a supernova that takes 20 days to decay will appear to take 40 days to decay when observed at redshift z=1. The time dilation has been observed, with 5 different published measurements of this effect in supernova light curves. These papers are:
Leibundgut etal, 1996, ApJL, 466, L21-L24
Goldhaber etal, in Thermonuclear Supernovae (NATO ASI), eds. R. Canal, P. Ruiz-LaPuente, and J. Isern.
Riess etal, 1997, AJ, 114, 722.
Perlmutter etal, 1998, Nature, 391, 51.
Goldhaber etal, ApJ in press. These observations contradict tired light models of the redshift.
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Are galaxies really moving away from us or is space just expanding?
This depends on how you measure things, or your choice of coordinates. In one view, the spatial positions of galaxies are changing, and this causes the redshift. In another view, the galaxies are at fixed coordinates, but the distance between fixed points increases with time, and this causes the redshift. General relativity explains how to transform from one view to the other, and the observable effects like the redshift are the same in both views. Part 3 of the tutorial shows space-time diagrams for the Universe drawn in both ways.
In the absence of the cosmological constant, an object released at rest with respect to us does not then fly away from us to join the Hubble flow. Instead, it falls toward us, and then joins the Hubble flow on the other side of the sky, as discussed by Davis, Lineweaver & Webb (2003, AJP, 71, 358). In what are arguably the most reasonable coordinates, the cosmic time t and the distance D(t) measured entirely at the cosmic time t, the acceleration is given by g = -GM(r
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Why doesn't the Solar System expand if the whole Universe is expanding?
This question is best answered in the coordinate system where the galaxies change their positions. The galaxies are receding from us because they started out receding from us, and the force of gravity just causes an acceleration that causes them to slow down, or speed up in the case of an accelerating expansion. Planets are going around the Sun in fixed size orbits because they are bound to the Sun. Everything is just moving under the influence of Newton's laws (with very slight modifications due to relativity). [Illustration] For the technically minded, Cooperstock et al. computes that the influence of the cosmological expansion on the Earth's orbit around the Sun amounts to a growth by only one part in a septillion over the age of the Solar System. This effect is caused by the cosmological background density within the Solar System going down as the Universe expands, which may or may not happen depending on the nature of the dark matter. The mass loss of the Sun due to its luminosity and the Solar wind leads to a much larger [but still tiny] growth of the Earth's orbit which has nothing to do with the expansion of the Universe. Even on the much larger (million light year) scale of clusters of galaxies, the effect of the expansion of the Universe is 10 million times smaller than the gravitational binding of the cluster.
Also see the Relativity FAQ answer to this question.
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Is the Universe expanding or is it just that our definitions of length and time are changing?
The definitions of length and time are not changing in the standard model. The second is still 9192631770 cycles of a Cesium atomic clock and the meter is still the distance light travels in 9192631770/299792458 cycles of a Cesium atomic clock.
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What is meant by a flat Universe?
The Universe appears to be homogeneous and isotropic, and there are only three possible geometries that are homogeneous and isotropic as shown in Part 3. A flat space has Euclidean geometry, where the sum of the angles in a triangle is 180o. A curved space has non-Euclidean geometry. In a positively curved, or hyperspherical space, the sum of the angles in a triangle is bigger than 180o, and this angle excess gives the area of the triangle divided by the square of the radius of the surface. In a negatively curved or hyperbolic space, the sum of the angles in a triangle is less than 180o. When Gauss invented this non-Euclidean geometry he actually tried measuring a large triangle, but he got an angle sum of 180o because the radius of the Universe is very large (if not infinite) so the angle excess or deficit has to be tiny for any triangle we can measure. If the radius is infinite, then the Universe is flat.
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Bolyai developed this geometry and published it, whereupon Gauss wrote to Bolyai's father: "To praise it would amount to praising myself. For the entire content of the work ... coincides almost exactly with my own meditations which have occupied my mind for the past thirty or thirty-five years." And Lobachevsky had published very similar work in the obscure Kazan Messenger.
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Is the Big Bang a Black Hole?
The Big Bang is really nothing like a black hole. The Big Bang is a singularity extending through all space at a single instant, while a black hole is a singularity extending through all time at a single point. For more, see the sci.physics FAQ.
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What is the Universe expanding into?
This question is based on the ever popular misconception that the Universe is some curved object embedded in a higher dimensional space, and that the Universe is expanding into this space. This misconception is probably fostered by the balloon analogy which shows a 2-D spherical model of the Universe expanding in a 3-D space. While it is possible to think of the Universe this way, it is not necessary, and there is nothing whatsoever that we have measured or can measure that will show us anything about the larger space. Everything that we measure is within the Universe, and we see no edge or boundary or center of expansion. Thus the Universe is not expanding into anything that we can see, and this is not a profitable thing to think about. Just as Dali's Corpus Hypercubicus is just a 2-D picture of a 3-D object that represents the surface of a 4-D cube, remember that the balloon analogy is just a 2-D picture of a 3-D situation that is supposed to help you think about a curved 3-D space, but it does not mean that there is really a 4-D space that the Universe is expanding into. Or you can ask
Dr. Science
:)
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What came before the Big Bang?
The standard Big Bang model is singular at the time of the Big Bang, t = 0. This means that one cannot even define time, since spacetime is singular. In some models like the chaotic or perpetual inflation favored by Linde, the Big Bang is just one of many inflating bubbles in a spacetime foam. But there is no possibility of getting information from outside our own one bubble. Thus I conclude that: "Whereof one cannot speak, thereof one must be silent."
From Bruce Margon and Craig Hogan at the Univ. of Washington
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Why is the sky dark at night?If the Universe were infinitely old, and infinite in extent, and stars could shine forever, then every direction you looked would eventually end on the surface of a star, and the whole sky would be as bright as the surface of the Sun. This is known as Olbers' Paradox after Heinrich Wilhelm Olbers [1757-1840] who wrote about it in 1823-1826 but it was also discussed earlier. Absorption by interstellar dust does not circumvent this paradox, since dust reradiates whatever radiation it absorbs within a few minutes, which is much less than the age of the Universe. However, the Universe is not infinitely old, and the expansion of the Universe reduces the accumulated energy radiated by distant stars. Either one of these effects acting alone would solve Olbers' Paradox, but they both act at once.
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Will the Universe expand forever or recollapse?This depends on the ratio of the density of the Universe to the critical density. If the density is higher than the critical density the Universe will recollapse in a Big Crunch. But current data suggest that the density is less than or equal to the critical density so the Universe will expand forever. See Part 3 of the tutorial for more information.
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Does entropy prevent a Big Crunch?
The issue of entropy in the Universe is subtle and not entirely settled. Theorists are still trying to work out what happens to the entropy of matter that falls into a black hole, a problem which involves both quantum mechanics and strong gravity. When a successful theory of quantum gravity is worked out, it should explain why the Universe came out of the Big Bang singularity with a very large entropy, and what happens to the entropy of the Universe if it recollapses.
Entropy is related to the number of ways a system can be in a given state or condition. Thus a shuffled deck of cards has a higher entropy than a new deck with all the suits in order. Adding energy to a system usually opens up more states, and increases the entropy. The temperature of a system is defined such that kT is the amount of energy needed to increase the number of available states by a factor of e = 2.71828... where k is Boltzmann's constant. Transferring heat from a hot piece of a system to a cold piece increases the number of ways to arrange the cold part by a larger factor than the decrease in the number of ways to arrange the hot piece. Thus the normal flow of heat from hot to cold causes an increase in the number of ways the whole system can be arranged which is then an increase in the total entropy of the whole system.
Entropy need not always increase in open systems. Energy could be used to make entropy decrease for a particular system. Your refrigerator does this by removing heat from the interior, if you consider the interior of your refrigerator to be a separate system. Of course, if you consider both the internal and external portions of the refrigerator then there is a net increase of entropy due to the inefficiency of the refrigerator.
Since entropy is a statistical concept, short term fluctuations in small systems can allow entropy to decrease.
Entropy remains constant in a system with a uniform temperature that has no heat added or subtracted from it. This is thought to be more or less the case for the Universe or for any representative piece of the Universe that expands or contracts in the same way the Universe does. The vast majority of the entropy of the Universe is in the cosmic microwave background radiation because the vast majority of particles in the Universe are the photons of the CMB. As the Universe expands, the temperature of the radiation drops to maintain constant entropy. If the Universe were to collapse at some point, the radiation would heat back up to maintain constant entropy. When the Universe expanded the radiation started out in thermal equilibrium with the matter and then de-coupled. In the collapse the radiation and the matter would once again come into thermal equilibrium. Whatever happened with the dynamics of the matter in the interim would be reflected in the final thermal equilibrium with the radiation. The final entropy of the Universe as it approaches the Big Crunch singularity would be larger than the initial entropy of the Universe because of the heat added by nuclear fusion in stars, so a recollapse does not involve a decrease in entropy.
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What about the oscillating Universe?If the Universe recollapses, then there is another singularity at the time of the Big Crunch. A singularity means that the laws of physics break down, so we have no way to predict whether the Big Crunch will connect to another cycle of expansion. Even if the density were high enough to cause a recollapse, there would be no guarantee that the Universe would oscillate. But the current evidence is strongly against any recollapse, which would rule out the oscillating Universe. See PBS or Ask an Astronomer about this.
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What is the dark matter?
When astronomers add up the masses and luminosities of the stars near the Sun, they find that there are about 3 solar masses for every 1 solar luminosity. When they measure the total mass of clusters of galaxies and compare that to the total luminosity of the clusters, they find about 300 solar masses for every solar luminosity. Evidently most of the mass in the Universe is dark. If the Universe has the critical density then there are about 1000 solar masses for every solar luminosity, so an even greater fraction of the Universe is dark matter. But the theory of Big Bang nucleosynthesis says that the density of ordinary matter (anything made from atoms) can be at most 10% of the critical density, so the majority of the Universe does not emit light, does not scatter light, does not absorb light, and is not even made out of atoms. It can only be "seen" by its gravitational effects. This "non-baryonic" dark matter can be neutrinos, if they have small masses instead of being massless, or it can be WIMPs (Weakly Interacting Massive Particles), or it could be primordial black holes. My nominee for the "least likely to be caught" award goes to hypothetical stable Planck mass remnants of primordial black holes that have evaporated due to Hawking radiation. The Hawking radiation from the not-yet evaporated primordial black holes may be detectable by future gamma ray telescopes, but the 20 microgram remnants would be very hard to detect.
Also see the Relativity FAQ answer to this question, the Cryogenic Dark Matter Search (CDMS) home page, and Martin White on dark matter.Dr. Science
on dark matter :).
-->
See CDM
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What about MOND?MOND, for Modification of Newtonian Dynamics, is an alternative theory that tries to explain away the need for dark matter. While some people are still trying to get it to work in cosmological models, it is not widely accepted.
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What is the value of the Hubble constant?
This is the question that professional astronomers ask the most frequently. For many decades the Sandage [Ho = 50] and de Vaucouleurs [Ho = 100] camps battled in a long lasting distance scale controversy. Many outsiders thought that the geometric mean of these values, Ho = 71 km/sec/Mpc, was a good compromise. The Sunyaev-Zeldovich effect has been used to determine Ho = 77 +/- 10 km/sec/Mpc. The Hubble Space Telescope Key Project team came up with the answer Ho = 72 +/- 8 km/sec/Mpc, the Cepheids in the nuclear maser ring galaxy NGC 4258 gave 74 +/- 6 km/sec/Mpc, and the double-lined eclipsing binary in M33 gave 61 +/- 4 km/sec/Mpc. These average to 71 +/- 5 km/sec/Mpc. Finally WMAP came up with:
Ho = 71 +/- 3.5 km/sec/Mpcbased on a flat Lambda-CDM model fit to the CMB angular power spectrum but I would rather see
because it would be consistent with a simple Universe with dark matter but no dark energy. But the supernova evidence for an accelerating Universe makes this rather unlikely, even if the Hubble constant data were wrong.
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What can a layperson do in cosmology?
Stay in school! There is a lot to learn about the Universe.
Keep taking math and science courses!The book of nature lies continuously open before our eyes (I speak of the Universe) but it can't be understood without first learning to understand the language and characters in which it is written. It is written in mathematical language, and its characters are geometrical figures. - Galileo GalileiThat was true 400 years ago and it is much more true today!
If you are out of school, check out the bibliography.
Tell your Congressman and Senators to support astrophysics research at NASA, NSF, and DOE.
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When is the next WMAP data release?
The data release at 1700 UTC on 16 Mar 2006 included the first 3 years of data. The hourglass has been turned over. There will be further releases but the schedule is not yet known.
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Ned Wright's Home Page
Tutorial : Part 1 Part 2 Part 3 Part 4 Age Distances Bibliography Relativity
© 1996-2007 Edward L. Wright. Last modified 10 Feb 2007
////////////////////// cyclical universe with multiple Big Bangs could explain one of the greatest mysteries in cosmology today.
by Maggie Wittlin • Posted May 10, 2006 12:35 AM
Cosmologists know there is something seriously wrong with the standard Big Bang cosmological model. The magnitude of the cosmological constant—a mathematical representation of the energy of empty space—predicted by this theory differs from the measured value by a factor of 10120.
Last week, a paper published online by the journal Science contained a resolution to this disturbing discrepancy. Its authors contend that a very old cyclic universe, one with several "Big Bangs" in its past, each marking the beginning of a new universe, could explain the observed value of the cosmological constant.
"You can have a cosmological constant which is very, very slowly decreasing, over many, many cycles," said the study's lead author, Princeton physics professor Paul Steinhardt. "So you have many, many cycles when it was large. But then if you wait long enough, it gets smaller and smaller and smaller."
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The disparity between theory and reality lies in calculating vacuum energy—the energy of empty space—which comes from quantum fluctuations that bring pairs of fundamental particles into and out of existence.
"If you're trying to add up the total energy of the universe, you'd be adding up all these contributions," Steinhardt said. "The problem is, when you look at any one of the contributions, they're exponentially huge compared to the actual observed value of the cosmological constant."
In the past, physicists sought a natural symmetry to show that vacuum energy was negligible, Steinhardt said. But they abandoned this search a decade ago when they found that the universe is accelerating in its expansion, giving it a positive vacuum energy.
In the new paper, Steinhardt and his colleague, Cambridge professor Neil Turok, propose that if the universe is very old—far older than the widely believed age of 14 billion years—and Big Bangs occur cyclically, the cosmological constant may have once been large, then gradually decreased over many cycles. They propose that the rate of change of the constant decreases as it gets smaller; so, for most of the time, the universe has a small cosmological constant, as ours does now.
A primary advantage of the model, said Steinhardt, is that the conditions we observe are typical, whereas standard models predict only a tiny fraction of a universe will be conducive to life. Proponents of these theories often justify our extraordinarily unlikely conditions with the anthropic principle, which argues that we could only exist in these rare conditions. Therefore, it's unsurprising that, since we do exist, we observe these rare conditions.
UCLA astronomy professor Ned Wright said that even though there is currently no way to verify the model, the authors have a strong hypothesis.
"This paper by Steinhardt and Turok combines two speculative ideas, and the combination is more interesting than the individual pieces," Wright said via e-mail, referring to the notions of a cyclic universe and the small, positive cosmological constant over time.
He added that future evidence of an inflationary period—an early epoch of rapid expansion absent here, but integral to the standard Big Bang model—could overturn the new theory.
Steinhardt concedes that the model may eventually be falsified, but he said it gives scientists a new way of approaching cosmological questions.
"It's premature," he said. "But it sort of opens my mind up to this new way of solving certain problems by using the idea that the universe is much older, and so things may not be what you might typically expect—they may have been evolving over time in some regular, predictable way."
////////////////////The Endless Universe: A Brief Introduction to the Cyclic Universe
Paul J. Steinhardt Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544, USA
Over the last century, cosmologists have converged on a highly successful theory of the evolution of the Universe - the big bang/inflationary picture.[1] According to this picture, space and time sprung into being 15 billion years ago in a `big bang.' When the Universe emerged, it was filled with particles and radiation of nearly infinite temperature and density. Instants later, the Universe underwent a period of extraordinarily rapid, superluminal expansion (`inflation') which made the Universe homogeneous and flat and which created fluctuations that seeded the formation of galaxies and large-scale structure.
In the last decades, cosmological observations have supported the predictions of the big bang and inflationary theory in exquisite detail.[1,5] They have also provided one major surprise. It appears that, billions of years after the big bang, following the formation of galaxies, the Universe was overtaken by some form of dark energy that is causing the expansion rate to accelerate. Although dark energy was unanticipated and has no particular role in the big bang/inflationary picture, the general view has been that it can simply be added by fiat to the initial make-up of the Universe. There is no compelling reason for a new theoretical approach. Quite the contrary, many cosmologists regard the basic cosmic story as being settled.
In this context, a new paradigm has been recently proposed by Paul Steinhardt (Princeton) and Neil Turok (Cambridge) - the cyclic universe - that turns the conventional picture topsy-turvy. (Perhaps the model should be called an old paradigm since it reinvigorates ancient cosmic mythologies and philosophies, albeit using the tools of 21st century physics.) In this picture, space and time exist forever. The big bang is not the beginning of time. Rather, it is a bridge to a pre-existing contracting era. The Universe undergoes an endless sequence of cycles in which it contracts in a big crunch and re-emerges in an expanding big bang, with trillions of years of evolution in between. The temperature and density of the universe do not become infinite at any point in the cycle; indeed, they never exceed a finite bound (about a trillion trillion degrees). No inflation has taken place since the big bang. The current homogeneity and flatness were created by events that occurred before the most recent big bang. The seeds for galaxy formation were created by instabilities arising as the Universe was collapsing towards a big crunch, prior to our big bang.
The prospects for an alternative cosmology that is so different from the well-established convention would seem extremely dim. Yet, the cyclic model recoups all of the successful predictions of the big bang/inflationary theory and has sufficient additional predictive power to address many questions which the big bang/inflationary model does not address at all: What occurred at the initial singularity? What is the ultimate fate of the Universe? What is the role of dark energy and the recently observed cosmic acceleration? Does time, and the arrow of time, exist before the big bang? or after the big crunch?
In the new paradigm, each cycle proceeds through a period of radiation and matter domination consistent with standard cosmology, producing the observed primordial abundance of elements, the cosmic microwave background, the expansion of galaxies, etc. For the next trillion years or more, the Universe undergoes a period of slow cosmic acceleration (as detected in recent observations[1]) which ultimately empties the Universe of all of the entropy and black holes produced in the preceding cycle and triggers the events that lead to contraction and a big crunch. Note that dark energy is not simply added on - it plays an essential role. The transition from big crunch to big bang automatically replenishes the Universe by creating new matter and radiation. Gravity and the transition from big crunch to big bang keep the cycles going forever. In fact, as will be discussed, the cyclic behavior is a strong attractor. That is, even if the Universe were disrupted from its periodic behavior, it would rapidly reconverge to the cyclic solution.
The linchpin to the new paradigm is the transition from big crunch to big bang. The transition was thought to be an impossible passage in which the laws of physics blow up. However, recent developments in superstring theory suggest that the cosmic singularity is otherwise, as the two authors have argued in a recent paper with Justin Khoury (Princeton), Burt Ovrut (Penn) and Nathan Seiberg (IAS). Superstring theory relies on the idea that the Universe contains nine or ten spatial dimensions, depending on the formulation, all but three of which are curled up in a compact manifold of microscopic size. In this framework, the big bang and big crunch may be an illusion. Expressed in the usual variables of general relativity, it may appear that our usual space and time are disappearing. However, viewed with the proper variables, our usual space dimensions actually remain infinite and time runs continuously. The transition from big crunch to big bang is due, instead, to the collapse, bounce and re-expansion of one of the extra dimensions. For example, in a variant known as M theory, the Universe consists of two branes (surfaces) bounding an extra dimension, and the singularity corresponds to a collision and bounce of the two branes. The temperature and density of ordinary radiation and matter remain finite at the bounce, and particles move continuously in a natural and intuitive way. By dispelling the myth that the big bang is a beginning of space and time, superstring theory opens up new possibilities for the cosmological history of the Universe. Six months ago, the ``ekpyrotic model"[4] was proposed by Khoury, Ovrut, Steinhardt and Turok as one new possibility based on the idea of making a universe from a single collapse of the extra dimension. The cyclic model builds on lessons learned from the ekpyrotic example to produce a picture with remarkable predictive and explanatory power.
///////////////////////Burden of Acute Sore Throat and Group A Streptococcal Pharyngitis in School-aged Children and Their Families in Australia Danchin, M.H., et al. - Group A streptococcal pharyngitis is still common, and the peak incidence occurs in school-aged children. However, the incidence in adults is higher than expected, and the number of secondary cases in families may be an important factor when considering the potential benefits of treatment [more...]
Pediatrics, 11/08/07
/////////////////////Sudden infant death syndrome Moon, R.Y., et al. - Despite declines in prevalence during the past two decades, sudden infant death syndrome (SIDS) continues to be the leading cause of death for infants aged between 1 month and 1 year in developed countries. Behavioural risk factors identified in epidemiological studies include prone and side positions for infant sleep, smoke exposure, soft bedding and sleep surfaces, and overheating. Evidence also suggests that pacifier use at sleep time and room sharing without bed sharing are associated with decreased risk of SIDS [more...]
The Lancet, 11/05/07
///////////////////Quantum CosmologyThe physical laws that govern the universe prescribe how an initial state evolves with time. In classical physics, if the initial state of a system is specified exactly then the subsequent motion will be completely predictable. In quantum physics, specifying the initial state of a system allows one to calculate the probability that it will be found in any other state at a later time. Cosmology attempts to describe the behaviour of the entire universe using these physical laws. In applying these laws to the universe one immediately encounters a problem. What is the initial state that the laws should be applied to? In practice, cosmologists tend to work backwards by using the observed properties of the universe now to understand what it was like at earlier times. This approach has proved very successful. However it has led cosmologists back to the question of the initial conditions.
Inflation (a period of accelerating expansion in the very early universe) is now accepted as the standard explanation of several cosmological problems. In order for inflation to have occurred, the universe must have been formed containing some matter in a highly excited state. Inflationary theory does not address the question of why this matter was in such an excited state. Answering this demands a theory of the pre-inflationary initial conditions. There are two serious candidates for such a theory. The first, proposed by Andrei Linde of Stanford University, is called chaotic inflation. According to chaotic inflation, the universe starts off in a completely random state. In some regions matter will be more energetic than in others and inflation could ensue, producing the observable universe.
The second contender for a theory of initial conditions is quantum cosmology, the application of quantum theory to the entire universe. At first this sounds absurd because typically large systems (such as the universe) obey classical, not quantum, laws. Einstein's theory of general relativity is a classical theory that accurately describes the evolution of the universe from the first fraction of a second of its existence to now. However it is known that general relativity is inconsistent with the principles of quantum theory and is therefore not an appropriate description of physical processes that occur at very small length scales or over very short times. To describe such processes one requires a theory of quantum gravity.
In non-gravitational physics the approach to quantum theory that has proved most successful involves mathematical objects known as path integrals. Path integrals were introduced by the Nobel prizewinner Richard Feynman, of CalTech. In the path integral approach, the probability that a system in an initial state A will evolve to a final state B is given by adding up a contribution from every possible history of the system that starts in A and ends in B. For this reason a path integral is often referred to as a `sum over histories'. For large systems, contributions from similar histories cancel each other in the sum and only one history is important. This history is the history that classical physics would predict.
For mathematical reasons, path integrals are formulated in a background with four spatial dimensions rather than three spatial dimensions and one time dimension. There is a procedure known as `analytic continuation' which can be used to convert results expressed in terms of four spatial dimensions into results expressed in terms of three spatial dimensions and one time dimension. This effectively converts one of the spatial dimensions into the time dimension. This spatial dimension is sometimes referred to as `imaginary' time because it involves the use of so-called imaginary numbers, which are well defined mathematical objects used every day by electrical engineers.
The success of path integrals in describing non-gravitational physics naturally led to attempts to describe gravity using path integrals. Gravity is rather different from the other physical forces, whose classical description involves fields (e.g. electric or magnetic fields) propagating in spacetime. The classical description of gravity is given by general relativity, which says that the gravitational force is related to the curvature of spacetime itself i.e. to its geometry. Unlike for non-gravitational physics, spacetime is not just the arena in which physical processes take place but it is a dynamical field. Therefore a sum over histories of the gravitational field in quantum gravity is really a sum over possible geometries for spacetime.
The gravitational field at a fixed time can be described by the geometry of the three spatial dimensions at that time. The history of the gravitational field is described by the four dimensional spacetime that these three spatial dimensions sweep out in time. Therefore the path integral is a sum over all four dimensional spacetime geometries that interpolate between the initial and final three dimensional geometries. In other words it is a sum over all four dimensional spacetimes with two three dimensional boundaries which match the initial and final conditions. Once again, mathematical subtleties require that the path integral be formulated in four spatial dimensions rather than three spatial dimensions and one time dimension.
The path integral formulation of quantum gravity has many mathematical problems. It is also not clear how it relates to more modern attempts at constructing a theory of quantum gravity such as string/M-theory. However it can be used to correctly calculate quantities that can be calculated independently in other ways e.g. black hole temperatures and entropies.
We can now return to cosmology. At any moment, the universe is described by the geometry of the three spatial dimensions as well as by any matter fields that may be present. Given this data one can, in principle, use the path integral to calculate the probability of evolving to any other prescribed state at a later time. However this still requires a knowledge of the initial state, it does not explain it.
Quantum cosmology is a possible solution to this problem. In 1983, Stephen Hawking and James Hartle developed a theory of quantum cosmology which has become known as the `No Boundary Proposal'. Recall that the path integral involves a sum over four dimensional geometries that have boundaries matching onto the initial and final three geometries. The Hartle-Hawking proposal is to simply do away with the initial three geometry i.e. to only include four dimensional geometries that match onto the final three geometry. The path integral is interpreted as giving the probability of a universe with certain properties (i.e. those of the boundary three geometry) being created from nothing.
In practice, calculating probabilities in quantum cosmology using the full path integral is formidably difficult and an approximation has to be used. This is known as the semiclassical approximation because its validity lies somewhere between that of classical and quantum physics. In the semiclassical approximation one argues that most of the four dimensional geometries occuring in the path integral will give very small contributions to the path integral and hence these can be neglected. The path integral can be calculated by just considering a few geometries that give a particularly large contribution. These are known as instantons. Instantons don't exist for all choices of boundary three geometry; however those three geometries that do admit the existence of instantons are more probable than those that don't. Therefore attention is usually restricted to three geometries close to these.
Remember that the path integral is a sum over geometries with four spatial dimensions. Therefore an instanton has four spatial dimensions and a boundary that matches the three geometry whose probability we wish to compute. Typical instantons resemble (four dimensional) surfaces of spheres with the three geometry slicing the sphere in half. They can be used to calculate the quantum process of universe creation, which cannot be described using classical general relativity. They only usually exist for small three geometries, corresponding to the creation of a small universe. Note that the concept of time does not arise in this process. Universe creation is not something that takes place inside some bigger spacetime arena - the instanton describes the spontaneous appearance of a universe from literally nothing. Once the universe exists, quantum cosmology can be approximated by general relativity so time appears.
People have found different types of instantons that can provide the initial conditions for realistic universes. The first attempt to find an instanton that describes the creation of a universe within the context of the `no boundary' proposal was made by Stephen Hawking and Ian Moss. The Hawking-Moss instanton describes the creation of an eternally inflating universe with `closed' spatial three-geometries.
It is presently an unsolved question whether our universe contains closed, flat or open spatial three-geometries. In a flat universe, the large-scale spatial geometry looks like the ordinary three-dimensional space we experience around us. In contrast to this, the spatial sections of a realistic closed universe would look like three-dimensional (surfaces of) spheres with a very large but finite radius. An open geometry would look like an infinite hyperboloid. Only a closed universe would therefore be finite. There is, however, nowadays strong evidence from cosmological observations in favour of an infinite open universe. It is therefore an important question whether there exist instantons that describe the creation of open universes.
The idea behind the Coleman-De Luccia instanton, discovered in 1987, is that the matter in the early universe is initially in a state known as a false vacuum. A false vacuum is a classically stable excited state which is quantum mechanically unstable. In the quantum theory, matter which is in a false vacuum may `tunnel' to its true vacuum state. The quantum tunnelling of the matter in the early universe was described by Coleman and De Luccia. They showed that false vacuum decay proceeds via the nucleation of bubbles in the false vacuum. Inside each bubble the matter has tunnelled. Surprisingly, the interior of such a bubble is an infinite open universe in which inflation may occur. The cosmological instanton describing the creation of an open universe via this bubble nucleation is known as a Coleman-De Luccia instanton.
The Coleman-De Luccia Instanton
Remember that this scenario requires the existence of a false vacuum for the matter in the early universe. Moreover, the condition for inflation to occur once the universe has been created strongly constrains the way the matter decays to its true vacuum. Therefore the creation of open inflating universes appears to be rather contrived in the absence of any explanation of these specific pre-inflationary initial conditions.
Recently, Stephen Hawking and Neil Turok have proposed a bold solution to this problem. They constructed a class of instantons that give rise to open universes in a similar way to the instantons of Coleman and De Luccia. However, they did not require the existence of a false vacuum or other very specific properties of the excited matter state. The price they pay for this is that their instantons have singularities: places where the curvature becomes infinite. Since singularities are usually regarded as places where the theory breaks down and must be replaced by a more fundamental theory, this is a quite controversial feature of their work.
The Hawking-Turok Instanton
The question of course arises which of these instantons describes correctly the creation of our own universe. The way one might hope to distinguish between different theories of quantum cosmology is by considering quantum fluctuations about these instantons. The Heisenberg uncertainty principle in quantum mechanics implies that vacuum fluctuations are present in every quantum theory. In the full quantum picture therefore, an instanton provides us just with a background geometry in the path integral with respect to which quantum fluctuations need to be considered.
During inflation, these quantum mechanical vacuum fluctuations are amplified and due to the accelerating expansion of the universe they are stretched to macroscopic length scales. Later on, when the universe has cooled, they seed the growth of large scale structures (e.g. galaxies) like those we see today. One sees the imprint of these primordial fluctuations as small temperature perturbations in the cosmic microwave background radiation.
Since different types of instantons predict slightly different fluctuation spectra, the temperature perturbations in the cosmic microwave background radiation will depend on the instanton from which the universe was created. In the next decade the satellites MAP and PLANCK will be launched to measure the temperature of the microwave background radiation in different directions on the sky to a very high accuracy. The observations will not only provide us with a very important test of inflation itself but may also be the first possibility to observationally distinguish between different theories for quantum cosmology.
The observations made by MAP and PLANCK will therefore turn the `no boundary' proposal and instanton cosmology into real testable science!
//////////////////A Cosmic Coincidence Resurrects the Cyclical Universe
From: http://www.physorg.com/news68731082.html
Jun 05, 2006
Over the past five years or so, scientists have finally converged on a model of the universe that explains (or at least permits) all of its characteristics. The new cosmological model has one very surprising feature, however, which is supported by several robust and unrelated observations. In addition to matter and radiation, it seems that the vacuum of space is filled with a mysterious ‘dark energy’ that pushes the universe apart. While the dark energy helps us explain a great many things, it also resurrects an old problem once thought buried—the idea that our universe is the product of a highly unlikely cosmic coincidence.
During the decades following common acceptance of the Big Bang model, physicists and astronomers tried very hard to measure the composition of the universe. According to theory, the average density of the universe would determine its ultimate fate. A universe with too little matter would expand forever, and its average density would eventually drop to zero. A universe with too much matter, on the other hand, would one day collapse under its own gravity (the ‘Big Crunch’). Only one special value, the critical density, could prevent both a Big Crunch and the unchecked expansion of the universe. Those with philosophical objections to a dying universe had only three alternatives. One idea was that we actually lived in a steady state universe. In this model, the universe expands at a constant rate but produces an occasional atom out of the void to maintain its average density. A steady state universe is infinite, and need not have had a Big Bang at all. Another way out was to have a cyclical universe, whose every Big Crunch is followed by another Big Bang. The cyclical universe model didn’t improve our own long-term prospects, but it at least preserved the universe itself from extinction. Unfortunately, neither of these models survived under the pressure of improving astronomical observations. By the 1970s, a critical density Big Bang model was the only viable solution for a stable universe. Unfortunately, even the most generous accounting of matter in the universe added up to only about half of the required density. Cosmologists were stuck with an unstable universe, doomed to end in cold and darkness. A universe that expands forever is not so bad, if the data require it; the future history of the universe might be disappointing to aesthetes, but a scientist will just shrug and accept the result. The Big Bang model, however, still had a big problem: our low-density universe could only arise from a highly unlikely coincidence of initial conditions. An expanding universe is fine in principle, but it mustn’t expand too quickly! For galaxies, stars, and planets to form, the average density of matter has to stay relatively high for at least a few billion years. To satisfy even this one vague constraint, it turns out that the initial density of the universe would have had to be very close to the critical value1. How close? The answer is a bit hard to swallow even to a disinterested physicist! A difference of one part in a million billion (1015) would allow galaxies to form before the expansion of the universe pulls everything too far apart for new structures to form. This is known as a fine-tuning problem: to explain the observed properties of the universe under the Big Bang model, physicists had to assume a very specific value for its initial density. If the universe were actually at the critical density, which has a clear physical significance, the fine-tuning problem wouldn’t be so bad. A universe starting at the critical density remains at the critical density forever, which sounds like a clue to some deeper physical law. One might claim that an unknown physical process makes this the only possible value. But in knowing that the initial density was some other number, physicists had to admit that any initial density was possible. Although we live in a universe capable of supporting life, the probability that such a universe came into existence randomly seemed to be infinitesimal. The fine-tuning problem was eventually solved by borrowing ideas from quantum field theory, a branch of physics dealing with fundamental particles and their interactions. During the Eighties and Nineties, most physicists were content with the Big Bang model and believed that a quantum mechanical process called inflation pushed the density of the early universe very close to its critical value in a brief period of runaway expansion. During inflation, the universe was dominated by a field of energy not unlike the dark energy being discussed today. In this scenario, the initial density of the universe was no longer relevant—inflation would drive any initial value towards the critical value in the blink of an eye. At the turn of the millennium, however, this tidy theory began to fail. Large-scale surveys discovered distant supernovae by the dozen, allowing astronomers to determine how fast the universe was expanding billions of years ago. The cosmology du jour predicted that the universe was slowing down, but these and subsequent observations have shown that the expansion is actually speeding up! To explain this result, Einstein’s cosmological constant had to be brought back into the picture. This parameter corresponds to the energy density of a vacuum (the ‘dark energy’), and just like the matter density the cosmological ‘constant’ evolves along with the universe.
The fine-tuning problem has therefore returned, in a different form. The initial density of vacuum energy had to be very close to zero at the Big Bang, or else an accelerating expansion would have driven apart all the matter before stars could form. Inflation can’t solve the problem this time; technically speaking, the cosmological constant is itself one cause of inflation. Once again, cosmologists find themselves debating the initial conditions of the universe. One common explanation, which has been used for decades to solve fine-tuning problems, is called the anthropic principle. In essence, this is the statement that we must live in a universe that can support life because we are here to observe it. This statement isn’t very satisfying, however, since it doesn’t offer any new insight into the nature of the universe. In modern times, physicists such as Alexander Vilenkin (Tufts University) have begun to suggest that our universe is only one of many. They envision an eternally expanding field of fundamental energy, effervescent with an infinity of universes. Each one has a Big Bang of its own, popping into existence wherever quantum fluctuations cool the fundamental field sufficiently. If there are an infinite number of universes, then it is certainly much less surprising that some would be habitable. Our particular combination of cosmological parameters, however, remains a highly improbable event in its own right. Advances in string theory and our understanding of higher dimensional spaces have made possible an even more astonishing solution to the coincidence problem. Quantum mechanical models have been proposed that allow the cosmological constant to decay from any initial value to almost zero. Such models, however, have two problems: first, the process typically requires trillions of years; and second, while the cosmological constant is large the density of matter in the universe drops to zero very quickly. But what if the universe is much older than it appears? Professors Paul Steinhardt (Princeton University) and Neil Turok (Cambridge University) have come up with a novel solution that gives the cosmological constant time to decay to its required value. Resurrecting a ghost of the cyclical universe, they propose that our universe is one of two embedded in the eleven-dimensional space of string theory. The two universes are linked with a spring-like attraction, and so pass through each other (moving along one of the higher dimensions) periodically. Every time they interact, enormous energies are released and both universes fill with hot plasma—a new Big Bang. There is no Big Crunch, as both universes are constantly expanding. A trillion years or so after one Big Bang, when the universe is practically empty, another Big Bang occurs and the stars and galaxies can form once more. The underlying cosmological constant, however, is unaffected by this process and has all the time it needs to decay to a small value. Eventually stars and galaxies will have time to form, and the same will be true of every subsequent cycle. In this modern version of the old cyclical model, the coincidence is resolved because only a few cycles are required for the cosmological constant to decay. The number of star-producing cycles following the decay, however, is practically infinite. Either way, it is clear that our perspective has changed. A single universe is no longer satisfying, given the most unlikely nature of our own. To explain our existence, it seems we must imagine others.
///////////////////As pure (and as toxic) as a clear mountain stream
This columnist is saddened by warnings of a health hazard on the hillsides
Melanie Reid
Here’s an interesting dilemma. Out for a weekend walk with your family, you start to climb a beautiful, remote hill. As the weather is unexpectedly warm, you soon finish the water you brought with you. While you pause half way up, enjoying the view, your eight-year-old tells you she is parched and wants to drink from the cold, clear mountain stream that burbles at your feet.
Do you (a) smile beatifically and let her do it; telling her she will never have tasted such pure water; or (b) tell her on no account to touch it as it might well be contaminated with E.coli 0157 that could, within hours, strip the lining of her intestines to something resembling strawberry jam, and then move into her kidneys, first destroying their function and then shutting down her life, despite the best technology the NHS could offer her.
The majority of Times readers, I warrant, would plump for option (a). Quite a lot, too, I am sure will be irritated even to be asked such a question. Of course it is safe to drink fast-moving mountain water! What sort of neurotic, twisted, risk-averse world is this when we question the inalienable human right to quench one’s thirst in wild places! Why, you’ve been drinking out of mountain streams since you were a child and it’s never done you any harm.
Up until last week, I belonged in this category. Militantly so, in fact. Like millions who grew up with a muddy-kneed ethos, running wild in the countryside, camping, drinking out of streams and helping on farms, my spiritual mainstay was the certainty that a little bit of dirt was good for you.
But I’ve been got at by the scientists. Pinned down long enough by the guardians of public safety to learn, reluctantly, that those of us who scoff at dangers should at the very least open our minds to the current evidence.
Because these are the facts. Thirty or 40 years ago, when a lot of us were growing up, E.coli 0157 simply did not exist. It just wasn’t there. Mouthful of dirt in the farmyard? Quite safe.
Now E.coli occurs everywhere, randomly, in the countryside. The microbe has evolved successfully; it’s learnt how to colonise cattle and sheep and produce a toxin that is potentially deadly to humans. From being initially food borne – the “hamburger bug” of the 1980s – it is now carried in water courses and in dung on the land. Researchers have discovered the microbe on one in five of all farms, right across the UK, and have established that 8 per cent of cattle carry it, with 2 per cent being “super-shedders”, capable of excreting thousands of millions of microbes.
Researchers from the Scottish Agricultural College - and they’re vets, so I’m inclined to trust them - es timate that the real figure for the number of people made sick by the bug is five to ten times higher than is recorded, for in many cases E.coli 0157 infection does not require admission to hospital. Yet in the young and old, it can result in death.
There is now a move to raise public awareness about the increasing incidence of the bug in the natural environment. And this is where it gets controversial; for it is all about balance of risk. And scientists have to convince us that this is not just another manifestation of the nanny state, possessed of a burning desire to overregulate.
What they’re trying to formulate at the moment is what controls to put on animals, and how to inform walkers, campers, farmers; and people who live in rural communities with private water supplies. It looks like being a predictable litany: get your private water supply checked; wash your hands after handling animals; carry hand wipes; use bottled water; don’t drink from streams; don’t picnic or camp where animals are grazing; don’t get too muddy.
One scientist even used the analogy of traffic to convince those who resist the advice. In the 1920s you could walk across the road without looking right or left. Would you do that today?
The argument – that improvements in hygiene, not medicine, made the world safer – is a persuasive one, but it’s also terribly sad. There’s something desperately mournful about being told that the countryside, the wellspring of us all, is now a threat. It feels like the severing of some important connection, because in a funny way, the countryside has come to represent the lost land of the free: the last place where you can find an illusion of escape.
There’s an irony, too, in that the rush to the great outdoors has never been greater. It is the main thrust of domestic tourism these days; and an essential plank in our war on obesity and inactivity. The Camping and Caravanning Club says that camping is 7.2 per cent up this autumn; that the average age of campers is falling; and families seeking “green” holidays are spending £32 million in British rural economies.
What these people want from the countryside are the intangibles – freedom, space, release from regulation. They don’t want to be told, don’t drink the water, don’t picnic in the fields, don’t pet the animals, wash your hands – in essence, hurry back to the city where it’s safe.
And so we must make our own judgments about the risk posed by E.coli 0157. The risk-adverse will keep Boots in business with babywipes and bottled water, and stay in city parks. The mountaineers will curse and keep drinking (on the entirely logical grounds that the chance of falling off a cliff is much higher than the chance of E.coli).
And the in-betweenies, such as me, shackled by nostalgia, will fret and grumble. Generally, I am allergic to the safety codes pumped out by civil servants, largely because the givers of safety advice must err on the side of caution to protect themselves, ergo there’s no such thing as objective official advice.
But I wouldn’t let a child drink hill water any more.
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Bear Grylls has the right idea: If you can follow the stream up to where it comes out of the ground, it should be alright.
Tony, Champaign, Illinois
It has never been wise to drink from streams or other natural water sources. I recall that on a school trip about 20 years ago, part of the group that I was with were considering whether to risk drinking from a stream in the Welsh hills. They didn't and later they were glad that they hadn't because a dead sheep was found in the stream further up the hill!
Charles, Bath, UK
Having read "Scouting for Boys" about 30 years ago (the book having been written almost a century ago), I remember clearly that Lord Baden Powell was quite CLEAR about the fact that water found "in the hills" (or indeed anywhere in the wilderness) was NOT supposed to be consumed by humans before being treated (i.e. boiled). This was also the advice given by our scout leaders and I have been aware of this ever since (although I did not strictly keep to it).Even without the risk of E-coli 0157 the prospect of drinking water which might be "contaminated" with excrements of all sort of wild and domestic animals is not highly appealing. This article rather shows how detached from "real" outdoor life many people today have become, expecting "tap water" -quality and domestic sanitation levels from "the great outdoors.
//////////////////////When Branes Collide
Stringing together a new theory for the origin of the universe
Ron Cowen
For an eternity, our universe lay dormant—a frozen, featureless netherworld. Then, about 15 billion years ago, the cosmos got an abrupt wake-up call.
In the ekpyrotic model, our universe is represented as a three-dimensional membrane embedded in a five-dimensional surface. That "brane" (blue at left) is known as a boundary brane because it lies at one boundary of the fifth dimension. Another boundary brane lies some distance away, on the other side of the fifth dimension.Steinhardt et al.
A parallel universe moving along a hidden dimension smacked into ours. The collision heated our universe, creating a sea of quarks, electrons, protons, photons, and other subatomic particles. It also imparted microscopic ripples, like ocean waves crashing on a shore.
These ripples generated tiny fluctuations in temperature and density, the seeds from which all cosmic architecture—from stars to gargantuan clusters of galaxies to galactic super clusters—ultimately arose.
This model for the evolution of the cosmos, first presented at a cosmology meeting at the Space Telescope Science Institute in Baltimore last April, has been widely discussed and debated ever since. Although the hypothesis sounds like science fiction, some scientists say it's the first serious challenge to the reigning model of the birth of the universe.
In one version of the model, a brane (violet) peels off the distant boundary brane and collides with the brane destined to become our universe.Steinhardt et al.
According to the standard theory, the universe was born some 15 billion years ago in a hot, expanding fireball, an event scientists call the Big Bang. The universe then underwent a brief spurt of faster-than-light expansion, called inflation, before settling down to the much slower, steady expansion observed today.
"After many years in which we had a single model—[the Big Bang combined with] inflation—for the universe's beginning, we now have an alternative," comments theorist Mario Livio of the Space Telescope Science Institute, one of the organizers of the April meeting on this topic.
"The reason that this is important is that in spite of its attractive features, inflation theory has not been tested observationally in any detail," he notes. Livio adds that the new model "provides us with a potential true test that can distinguish between it and inflation."
"I don't think it's by any means yet a real rival to inflation, but I think it is a model well worth pursuing," says Alan H. Guth of the Massachusetts Institute of Technology, one of the developers of the inflation model.
No bang
Despite its name, nothing goes bang in the Big Bang theory. The cataclysm it proposes wasn't anything like a bomb exploding into preexisting space, since all space was contained inside the infant universe. Rather, the Big Bang refers to the event when the immense energy in the infant universe drove it to expand.
The energy imparted from this Big Crunch ignites the Big Bang (red)...Steinhardt et al.
In the new hypothesis, however, "our universe begins in a static, featureless state" that persisted for eons, notes Paul J. Steinhardt of Princeton University. That dormant period may have lasted a hundred trillion trillion years. Then, there really was a bang—a giant collision that heated the cosmos to a high temperature. This collision sparked the steady expansion of the universe, and over time, gravity molded gas clouds into stars and galaxies—equivalent to what happens in the widely accepted Big Bang scenario.
To generate that all-important collision, the new model presupposes hidden dimensions and myriad universes floating through space like parallel plates. By chance, one of those plates whacked into the one destined to become our universe.
...and sets the stage for the formation of the galaxies seen in the universe today.Steinhardt et al.
"It's a very radical idea we have," admits Burt A. Ovrut of the University of Pennsylvania in Philadelphia. "The old idea was that the universe started out at some time zero and ballooned outwards in a burst of inflation. We're now proposing that `time zero' was just a marker, that the universe really existed long before that."
Steinhardt, Ovrut, and their colleagues Justin Khoury of Princeton and Neil Turok of the DAMTP in Cambridge, England, call their model the ekpyrotic universe, from the Greek word for conflagration.
"We might have used the term `Big Bang', but that name was taken," jokes Ovrut.
Fix needed?
If a theory ain't broken, why fix it? Even in its most primitive form, which does not include inflation, the Big Bang theory correctly predicts the cosmic abundance of helium and deuterium and the temperature of the radiation left over from the birth of the universe.
The classical Big Bang picture was first proposed in the late 1920s. Two decades ago, researchers realized that the scenario needed to be modified.
In its original form, the model would lead to a universe vastly different from the one we live in. For instance, the theory doesn't provide a way for stars, galaxies, and larger structures to arise, notes Steinhardt. Moreover, the Big Bang model would tend to produce a cosmos whose composition and density would vary widely from place to place and whose overall geometry would be warped or curved.
That's in stark contrast to numerous observations, which reveal a universe that is the same, on the large scale, in all directions and has just the right amount of matter and energy to keep it perfectly flat.
In 1980, Guth amended the Big Bang theory to account for these discrepancies. Refined by several researchers over the past 2 decades, Guth's model posits that the infant cosmos underwent a brief but enormous episode of inflation, ballooning at a rate faster than the speed of light. In just 10–32 seconds, the universe expanded its girth by a factor of about 100 trillion trillion, more than it has in the billions of years that have elapsed since.
The inflation model accomplishes several feats (SN: 12/19&26/98, p. 392: http://www.sciencenews.org/sn_arc98/12_19_98/bob1.htm). It explains why widely separated parts of the universe—regions so far apart that all communication between them is impossible—can nonetheless look as similar as the closest of neighbors. Inflation theory suggests that when the universe began, these regions were indeed neighbors and then rapidly spread far apart.
Inflation also makes the universe flat. Any curvature to space-time would have been stretched out by this era of faster-than-light expansion.
Furthermore, the ballooning would have provided a way for chance subatomic fluctuations in the early universe to inflate to macroscopic proportions. Over time, gravity could then have molded these variations into the spidery network of galaxies and voids seen in the universe today.
The Big Bang model combined with inflation matches several important observations, including the detailed structure of the radiation called the cosmic microwave background, which is left over from the universe's birth. Data gathered by several balloon-borne and ground-based telescopes fit the predictions of the inflation model (SN: 4/28/01, p. 261: Available to subscribers at http://www.sciencenews.org/20010428/fob3.asp).
Yet some cosmologists view inflation as a mysterious, ad hoc device. For instance, notes Steinhardt, no one knows what type of force triggered the onset of inflation or what ended it. "We've been searching for several years to find either a more natural way of incorporating inflation or an alternative model based on new physics," he says.
String theory
Inflation, Steinhardt says, is based on quantum field theory, which views every elementary particle as a pointlike object. In the past decade, however, physicists have begun thinking about elementary particles in a new way, based on a model called string theory.
According to this view, electrons, quarks, and all the other elementary particles in the universe behave as point particles when observed at a distance, but each is actually composed of tiny loops or strings of energy. The different vibrations of a string, like the different notes that can be plucked on a violin, correspond to different particles.
"It's a beautiful idea because it says that all of the particles we see actually arise from a single object—string," says Ovrut.
Each string vibrates in a space-time that has 11 dimensions—7 dimensions beyond the usual 3 of space and 1 of time (SN: 2/19/00, p. 122: http://www.sciencenews.org/20000219/bob1.asp). The newest twist on string theory, dubbed M theory, allows for more-complex objects: surfaces rather than just strings. These surfaces are known as membranes, or just branes.
Many physicists are studying branes in the hope of linking gravity and the other fundamental forces of nature to the elementary particles that communicate these forces. According to Steinhardt and his colleagues, certain types of branes may turn out to have profound consequences for cosmology.
Instead of working with the 11 dimensions implied by M theory, the researchers have focused on branes that exist in 5 dimensions. In this model, the other 6 dimensions are tightly curled up and can be ignored. Certain branes that exist in this abstract five-dimensional space can be represented by infinitely long, parallel planes and seem to have a close correspondence to our universe.
In this construct, our cosmos could have plenty of company. Other would-be universes—also represented by branes—may be floating through the fifth dimension. These branes would remain invisible because particles and light can't travel through the fifth dimension. However, gravity can couple matter across that dimension, and collisions between branes are possible.
In the ekpyrotic scenario, the fifth dimension is finite in size and bounded on either side by a three-dimensional brane. One of these boundary branes was the surface that was to become our own cosmos, and the other represents another universe. In the version of the theory first described last April, a third brane peels off the opposing boundary brane and bangs into ours. In the collision, it melds with our brane, igniting the Big Bang.
"There is a certain sense in which this is like two pieces of putty slamming into each other and heating up," says Ovrut.
Critics of the scenario, as well as Steinhardt's team, have noted that the universe created by the impact contracts rather than expands. If so, it wouldn't have generated a cosmos like ours.
In a modified version of the ekpyrotic theory, posted Aug. 26 on the Internet (http://xxx.lanl.gov/abs/hep-th/0108187), Steinhardt, Nathan Seiberg of the Institute of Advanced Study in Princeton, N.J., and their collaborators say such concerns are now unwarranted. According to their calculations, the new model can produce a collision without having to rely on one invisible brane peeling off from another.
Instead, one of the boundary branes moves slowly but steadily toward the other, attracted by an exchange of lower-dimension branes between the two. As the boundary brane moves, it shrinks the fifth dimension. When the two boundary branes touch, the fifth dimension collapses completely, an event the researchers call the Big Crunch.
As in the earlier version of the theory, the collision triggers the Big Bang. However after the impact, the two boundary branes bounce off each other and move apart, recreating the fifth dimension. This rebound starts the expansion of our universe.
In either version of the theory, the laws that govern elementary particle physics require that the boundary branes be flat as a pancake before they collide and that they stay that way afterwards. Consequently, the universe generated by the collision is flat. An episode of inflation isn't needed to stretch out any curvature since none ever existed.
Because the impact is so uniform—exactly the same force is applied up and down the flat boundary between the two branes— widely separated parts of the universe get the same kick and thus evolve in exactly the same way after the collision. This accounts for the uniformity of distant reaches of the cosmos without having to invoke an episode of inflation.
Due to quantum effects, which make the boundary between the branes slightly uneven, some parts of our brane would be struck ever so slightly earlier or later than other parts. This would create tiny temperature differences within the struck brane that, like those in the standard Big Bang model, become the seeds for galaxy formation. The collision also causes the brane to stretch or expand, accounting for the expansion of the universe observed today.
The researchers "make a graceful transition from the Big Crunch to the Big Bang," says David N. Spergel of Princeton University. "This is arguably a `new ekpyrotic universe' that appears to be more elegant than the old model."
Which theory?
According to Steinhardt, the ekpyrotic theory does everything that Big Bang plus inflation accomplishes. "It's just that we happened to discover one theory first—20 years ago," he says.
"What [the ekpyrotic theory] has going for it is a much closer relationship to string theory than any formulation we currently have of inflation," says Guth. "String theory is simply the only hope we currently have for a quantum theory of gravity, and obviously gravity has to be quantized to be consistent with the rest of what we know about physics."
Nonetheless, "I'm still somewhat skeptical about the whole thing," Guth adds. "They need to make very strong assumptions about the initial conditions—they're really starting out with a universe that's already infinite and uniform."
Another developer of the inflation model, Andrei Linde of Stanford University, takes a much dimmer view of the new work and has posted several papers on the Internet lambasting the ekpyrotic model. He says that to produce galaxies, Steinhardt and his colleagues have to choose a highly specialized, unrealistic form of interaction between branes. Moreover, Linde claims that the branes in the ekpyrotic model are not truly uniform in structure and therefore can't account for the large-scale uniformity of the universe.
"Instead of a theory, we have only wishful thinking," he says.
Steinhardt and his colleagues have posted responses on the Internet.
A slow process
Making a universe in ekpyrotic theory requires patience, notes Ovrut. Because the attractive force between branes is so small, they move at a snail's pace, and it could take an extraordinarily long time for a collision to occur, he says.
In effect, says Ovrut, the new theory replaces the very short growth spurt of inflation with a very long lead time for a collision.
As a bonus, he notes, the collision described by ekpyrotic theory not only generates cosmic structure, it also creates the known families of quarks and other fundamental particles.
"What's very beautiful about these brane models is that one can actually compute the spectrum of [elementary] particles, and what you get is something like our real world," notes Ovrut.
At least one empirical test of the ekpyrotic theory may soon be possible. The test would examine gravitational waves, the radiation produced when massive objects accelerate.
Big Bang plus inflation predicts that gravitational waves can have extremely long wavelengths, while the ekpyrotic theory does not. Long-wavelength gravitational waves would leave a distinctive fingerprint on the cosmic microwave background.
Future experiments with a new generation of space, balloon-borne, and ground-based telescopes may be able to detect that fingerprint, says Ovrut.
Other aspects of the ekpyrotic model are still being scrutinized.
"I worry a lot about the details," says Ovrut. "This is a theory that's really still in its infancy."
Letters:
I've just read your account of the "ekpyrotic model" of the universe. Although descriptive, "ekpyrotic" seems rather contrived and is hard to pronounce. Certainly it lacks the pizzazz of "Big Bang." And "Big Crunch" has been used previously to refer to the "anti-Big Bang" catastrophe thought to be awaiting the universe. How about the "Big Bump"?
Robert A. GorkinDover, Del.
/////////////////////Possible Cosmic Defect, Remnant From Big Bang, Discovered
ScienceDaily (Oct. 26, 2007) — Scientists from the Institute of Physics of Cantabria (IFCA) and the University of Cambridge may have discovered an example of a cosmic defect, a remnant from the Big Bang called a texture. If confirmed, their discovery, reported in Science, will provide dramatic new insight into how the universe evolved following the Big Bang.
See also:
Space & Time
Big Bang
Cosmology
Cosmic Rays
Astrophysics
Sun
Jupiter
Reference
Nucleosynthesis
Big Bang nucleosynthesis
Shape of the Universe
Subatomic particle
Textures are defects in the structure of the vacuum left over from the hot early universe. Professor Neil Turok of Cambridge's Department of Applied Mathematics and Theoretical Physics first showed how textures form in the 1990s, highlighting that some would survive from the Big Bang and should be visible in today's universe. Textures can be observed by the hot and cold spots they create in the cosmic microwave background radiation (CMB) which fills the universe and was released in the Big Bang 14 billion years ago.
The Big Bang theory proposes that the cosmos began in a very high density, high temperature state, cooling as it expands. In the early hot universe, physicists believe that the different types of elementary particle (particles such as a quark from which larger particles are created) behaved identically. As the universe cooled, the vacuum changed and the symmetry between the particles was broken, in a phase transition analogous to the freezing of water. During this kind of phase transition, quarks become distinct from electrons and neutrinos, for example.
Just as misalignments in the crystalline structure of ice lead to defects, misalignments in the symmetry-breaking pattern form cosmic defects. Textures, such as the one which may have been discovered, are one type of defect.
Professor Turok provides the following analogy: "Imagine a large crowd of people with everyone standing. To any person in it, the crowd looks roughly the same in all directions. Now tell them all to lie down. People would tend to lie in the same direction as their neighbours, but over large distances the direction chosen would vary. In some places, people would be unable to decide which was the best direction to lie in: if everyone lies down pointing directly away from you, you are forced to stand. You are now a defect in the symmetry, a texture."
It is believed that textures collapse and unwind on progressively larger scales, creating intense energy as well as gravitational potential. This unwinding also creates areas of extreme cold or hot, such as the very cold spot in the South Galactic Hemisphere discovered by the IFCA team in 2004.
Marcos Cruz and his colleagues, Dr. Patricio Vielva and Professor Enrique MartÃnez-González with the IFCA, pursued numerous possibilities for the existence of the cold spot. In particular, they thoroughly explored the possibility of being due to systematic effects, foreground contamination from our own galaxy or due to the scattering of cosmic microwave background radiation by large galaxy clusters.
Each time they came to the same conclusion: there were not any convincing arguments for any of these possibilities. They also hypothesised that it could be a texture and with the assistance of Dr Mike Hobson, a member of the Astrophysics Group at Cambridge's Cavendish Laboratory, and Professor Neil Turok, they were able to examine this possibility in detail.
Professor Turok performed large scale simulations using the COSMOS supercomputer at Cambridge to more accurately compare the theory with the event. Dr Hobson ranked the relative probabilities that the cold spot is due to a texture rather than just an extreme statistical fluctuation. The researchers concluded that the texture hypothesis is the most plausible explanation for the cold spot but acknowledge that additional tests are necessary.
"The possibility that this is a texture is very exciting," said Professor Turok. "If it is, it will revolutionise our understanding of how the fundamental symmetries between the particles and forces were broken as the universe emerged from the big bang. The current data is suggestive but not yet compelling. There are a number of follow-up tests which can be made with future data. It's a very testable hypothesis and we will know the answer within the next decade."
Dr Hobson said: "The prominent cold spot in the image of the cosmic microwave background taken by the WMAP satellite is a very puzzling feature that has attracted a lot of attention in the cosmological community, but has not as yet been convincingly explained.
"Our work investigates the exciting possibility that the cold spot is due to the presence of a cosmic texture; some current particle physics theories predict textures to be produced as the universe evolves, but they had never been observed. Somewhat to our surprise, we found that the cold spot, and in fact the cosmic microwave background radiation over the whole sky, is indeed consistent with such a texture model. Although the current data are not yet compelling, we suggest future observations that should be able to test our hypothesis definitively. If the cold spot is indeed proven to be a texture it will completely change our view of how the universe evolved following the Big Bang."
Reference: "A Feature in the Cosmic Background Radiation Consistent with a Cosmic Texture," by M. Cruz, P. Vielva and E. MartÃnez-González of the Instituto de FÃsica de Cantabria (CSIC, Univ. Cantabria) , in Santander, Spain; N. Turok of the University of Cambridge in Cambridge, UK; and M. Hobson of Cavendish Laboratory in Cambridge, UK, Science, October 25, 2007. This research was supported by the Spanish National Research Council (CSIC) and the Ministerio de Educación y Ciencia.
Adapted from materials provided by University of Cambridge.
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