nintendogs123 wrote:
It prolly won't be that every star burns out. I mean, it might be, but in theory, the way all life is going to end in the universe is by something they call "The Big Crunch". This is basically when matter density exceeds critical density. The universe, in theory, is expanding by an unknown force. Eventually, the expansion will be to much for the current phase, and the universe will collapse into itself. This could create a super dense state or even an unimaginably large black hole.
Then again, some people believe this could possibly cause another Big Bang, which would be pretty awesome.
There's a simpler theory called the Big Chill that says that the universe will expand so much that it will become absolute zero in all areas of the universe. This way wouldn't really END the universe, it'd just dwindle off.
I don't know why I told you all this.
I'm going to be an astronomy major, so I have the answers.
What happens is that yes, every star will burn out eventually, but how long it takes for the star to die depends on its mass. For example, huge supermassive stars like the Pistol Star will probably go supernova in the next few million years, class-G stars like the sun and Alpha Centauri live about ten billion years altogether, and red dwarfs like Barnard's star will probably burn for 300 billion more years before they finally die, so that means that no red dwarfs in the universe have died yet.
When a star goes supernova, it leaves behind a giant dust cloud, like the Crab Nebula, that eventually clumps together until it becomes dense enough in spots to form new stars. The thing is, every time a star goes supernova or just dies, some of its matter gets locked up in a white dwarf forever, which basically means that it can never be used for making new stars, unless it's close enough to a different star that it draws in enough matter to reach 1.4 solar masses, in which case it will explode again. But eventually, all the matter in the universe will be locked up in white dwarfs, which will eventually cool down into a black dwarf, and slowly lose matter due to proton decay for about 10^200 years until it disappears completely.
Also, they've discovered that there's not enough matter in the Universe for the gravity to pull the universe into a Big Crunch, so it'll expand forever, completely devoid of all matter and light. All that'll be there is the occasional photon and maybe a MACHO or two.
But since the Earth is going to be destroyed next month, it doesn't really matter to us.