Time is the bookkeeping of change, written by entropy and read by memory.

 A

Short answer:
Time comes from change as registered by memory and entropy.

Bullet gist (sources of time):

• No change → no time: without processes or differences, time has no meaning.

• Entropy gives direction: the increase of entropy supplies the arrow that distinguishes past from future.

• Memory gives existence: the past exists only as records—traces in brains, fossils, photons, marks.

• The present is a process: not an instant, but an ongoing updating of states.

• Time is relational: it is not a substance but an ordering of events.

• Physics + experience converge:

  • Physics: time emerges from correlations among changing systems.

  • Experience: time emerges from consciousness stretching across memory and anticipation.

• No universal “now”: relativity shows time is local, not absolute.

• Time is emergent, not fundamental: many modern theories treat time as arising from deeper, timeless structures.

Tagline:

Time is the bookkeeping of change, written by entropy and read by memory.

One-line answer:

• Time arises from irreversible change plus the records that preserve it.