We know its age and size are two sides to the same coin.(relative) We
know one way to find its age is to measure the decay of its radioactive
elements.,and this gives a very good measurement of the oldest earth
rocks.. They are 3.8 billion years old. dating our solar system we have
meteorites that are 4.6 billion years old. We really have to start
guessing when trying to measure the age of nebula,and old stars. read
the oldest stars might have a life span of 12 billion years I think if
we could find stars with very little or no heavy elements immerged in
them they would have to be created out of hydrogen and helium the only
stuff around,and to start up their fusion core would be a longer time
processes. Posted it would be great if we could find a white dwarf that
was nearing its end and ready to shut of its light. Have a gut feeling
my guessing the universe's age at 22 billion years kind of fits
Go figure bert