a reply to:
Ravenwatcher
Astronomers have labelled suns like our own G2 class stars and in a more friendly title Yellow Dwarf stars, our sun will live for approximately eight
to ten billion years give or take and is about halfway through its life cycle according to some theory's.
Rather than getting cold the sun will get warmer, much, much warmer so that within just two billion years our earth will likely be uninhabitable to
life as we know it, the sea's will evaporate into the atmosphere and over time the water will lose its hydrogen to space turning our earth into a true
twin of what Venus is today.
But that is a very long time off so I would be more afraid of asteroids and comets than the sun going out.
And when it does finally go out it will be when it has consumed most of its hydrogen (there is plenty left) and starts to use up heavier and heavier
elements as fuel swelling as it does so into a red giant whose outer atmosphere may even reach beyond the orbit of the earth so consuming the by then
ancient planet but once again don't worry it is very long time off.
Finally, the core of the sun no longer able to fuse the heavier and heavier elements will collapse within thousands to just a few million years at
most of it becoming a red giant, at this point it will explode violently throwing out it's outer atmosphere and whatever remains of the planets that
were consumed by its expansion creating a small nebula leaving only a white dwarf star the core of our own sun which will eventually go cold but only
after an extremely long time.
Time is vast, even trying to comprehend a million years is hard so trying to comprehend a billion even harder.
And you know there could possibly have been other earth like worlds long, long ago and scientists recently discovered the grave of one such solar
system that may have been like our own once very, very long ago in which the remains of its ancient planets apparently may still be orbiting the dead
star that was once their sun.
bgr.com...
But thinking about this WILL depress you, better to live in the light of the day, see the beauty and uniqueness of our world which we take for
granted, the miracle of life itself and the greater miracle of a mind that can ask these questions.
Once long-ago scientists DID think the sun would burn out but that was before they had a better grasp on nuclear physics but still many ancient
science fiction and even newer science fiction stories revolve around that ancient idea.
As the sun ages it's solar winds will become stronger, it's hydrogen will deplete to be replaced first by helium then it will turn that into heavier
and heavier elements.
Every element in your body, indeed the world around you were made from Hydrogen in the core of long dead stars mostly giant stars, there the hydrogen
atoms were squeezed together in the heart of the star in a process known as nuclear fusion, this released energy, light and heat but it also created
heavier and heavier element's and some of the largest stars created the heaviest elements, some stars got so big that when they went nova and blew off
there outer atmospheres the core had turned into a mass of pure neutron's so dense and heavy a tea spoon of it would weigh than the titanic did and
some stars even bigger collapsed into things called brown holes which, somewhere out there some stars may even have become true black holes were time
all but time stop's as time and gravity seem to have an inverse relationship and even light can't escape there immense gravitational presence.