Thread: Black hole rips star apart

Just read an interesting book on black holes, event horizons, string theories, worm holes etc. The book was recently written and it seems to indicate that Einstein's Theory of Relativity may need modification, as very recent observations of black holes and dark matter in the universe appear not to completely covered by the Theory of Relativity............but observations are continuing with newer and more powerful telescopes. Makes interesting reading if you are into that sort of stuff.

Just as an aside............the Universe was created 13 billion years ago and with modern telescopes the furtherest that can be seen with the latest telescopes is 13 billion light years away. Does the Universe extend beyond that to infinity or is the 13 billion light year barrier mark the extent of the Universe?????????????

We are actually looking back in time so the galaxies at the 13 billion light year mark are as they appeared at the Big Bang, the creation of the Universe.

Sorry Bob, I don't mean to hijack your Thread, but you have me going off at a tangent, because there are many unanswered questions about the Universe including Black Holes.

Originally Posted by Ausfree

Just as an aside............the Universe was created 13 billion years ago and with modern telescopes the furtherest that can be seen with the latest telescopes is 13 billion light years away. Does the Universe extend beyond that to infinity or is the 13 billion light year barrier mark the extent of the Universe?????????????

Not strictly true, telescopes can just see some galaxies as they were around 13B years ago. There is no evidence that they are at the edge of anything, therefore any observer in those galaxies would seem to be in the centre of the observable universe, just like us. In any case the universe is somewhat older than the oldest observed galaxy, by at least 300K years, the time when the universe became transparent to ordinary light. The cosmic background radiation is a remnant of this point in time.

Farthest Known Galaxy in the Universe Discovered

The Cosmic Distance Scale

Originally Posted by bee utey

Not strictly true, telescopes can just see some galaxies as they were around 13B years ago. There is no evidence that they are at the edge of anything, therefore any observer in those galaxies would seem to be in the centre of the observable universe, just like us. In any case the universe is somewhat older than the oldest observed galaxy, by at least 300K years, the time when the universe became transparent to ordinary light. The cosmic background radiation is a remnant of this point in time.

Farthest Known Galaxy in the Universe Discovered

The Cosmic Distance Scale

So what you are saying is......the Universe is infinite. The 300k years is a mere blip in the overall scheme of things and that I believe is the time it took from the initial "Big Bang" to when the primeval dust started to coalesce into stars that started to shine. If the Universe spread out from an initial "Big Bang" there must be a finite point where the Universe ends. The problem is you can't see past 13 billion light years away, because thats when the Universe began. So it is difficult to prove that somebody observing in a galaxy 13 billion light years from us can see further out.

This article argues that the Universe is infinite and that the light from the furtherest galaxies will never reach us.....

http://curious.astro.cornell.edu/abo...t-intermediate

ps. By the way I'm not arguing for one side or the other, I have an open mind on the problem.