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Re: Old Stars



On Fri, 5 Jul 1996 19:04:53 -0400 David J. Abineri said:

When we look at the oldest stars we can see, we are looking back to
a time just after the big bang. How is it that we (planet earth) have
arrived 'here' before the light that left those stars?

If we are viewing light from a star that is more than 4.6 billion light
years away then we arrived here after the light left the star. To look
back in time you have to look at distant stars. It's kind of like the
mail. If it takes 4 days to get a letter, you are reading 4 day old mail.
If it takes a billion years for the light to get here you are looking at
billion year old light. It is the time it takes the light to get here and
not the age of the star that counts. A star might be very old, but if it's
light gets here in 10 years you only get to see 10 year old light. Our best
guess is that our sun is a 4.6 billion year old star, but we don't get to
see the 4.6 billion year old light. However, anyone living 4.6 billion
light years away could be watching those first sun beams right now.