Kind: captions
Language: en
and now for some final thoughts on Aging
in the cosmos it wasn't until a century
ago that we began to apply the methods
and tools of astrophysics to learn just
how old the Sun and the rest of the
stars might be which leads to questions
such as do all stars live to the same
age and are some immortal when we
carefully study their properties such as
their mass and Composition combined with
some basic laws of physics we learn that
just like us not all stars will die at
the same age some the high mass ones
live life in the fast lane they run
through their fuel supplied prodigious
rates lasting a mere million years our
Sun is just an average star unremarkable
in almost every way it's been shining
steadily for about half of his 10
billion year life expectancy and other
stars the low-mass ones are so efficient
and so slow in the rate they make energy
that they'll live for trillions of years
a thousand times the current age of the
universe we know all this because the
galaxy has a hundred billion stars
enough to catch some being born they
catch most living through their middle
age and still others in the act of dying
of course if we live to a hundred or
even a thousand that's still a mere
moment in cosmic time insufficient by
far to watch the Sun or any other star
live out their lives even as they watch
us live out hours and that is the cosmic
perspective
you