Deep Time

The Sun takes two hundred and fifty million years to go once
around the Milky Way. A galaxy collision might take four times
as long, or one billion years.

For comparison:
-- Recorded human history spans about five thousand years.
-- Human beings evolved about half a million years ago.
-- The dinosaurs became extinct about sixty million years ago.
-- Fish evolved about five hundred million years ago.
-- Life evolved about four billion years ago.
-- The Earth and Sun are about five billion years old.
-- The Universe is about thirteen billion years old.