FAO: Theory of relativity buffs

Arcade Fire · 11 Jul 2007 at 18:23

Kronologic said:
1) IIRC you will have infinite mass and be traveling forward in space but backward in time
2) You travel to work every day and go home every night. Does time ever travel backwards during this journey?
3) Its a cycle, kind of like the chicken and egg question. Which came first the big bang, the big collapse? where did the matter come from in the first place?

To the OP: Please pay no attention to any of these answers, for the sake of your understanding.

iraiguana · 11 Jul 2007 at 18:37

Chicken and the egg is solved easily, You would have an animal extremely closely related to a chicken ( but its not!) and then a mutation would occur in the growth of the chick whilst in the egg. So the Egg came first if you class the egg and chick as the same entity, or the chicken if you say the egg is not apart of that chick.

Energize · 11 Jul 2007 at 18:52

Dj_Jestar said:
2. As the French would say: Le Big Bang. Universe started as some single point (singularity) that exploded. The Universe as we know it, is expanding. Will it eventually collapse, back into it's original singularity state? What will happen when it transfers from expanding to collapsing? Will time stop, then turn around and go backwards? Is this possibly what has been happening repeatedly since the beginning of everything - Continuous expansion, collapse, expansion, collapse, rinse repeat, etc.? (A friend dubbed this the "Slinky Effect")

It's thought that the universe won't continuously expand and collapse, rather that because our universe appears to be flat it will undergo a heat death, big freeze or a big rip.

Fusion · 11 Jul 2007 at 19:00

It's when pondering what initiated the big bang that I start having trouble. If someone could simplify brane cosmology for me, I'd be very grateful.

Arcade Fire · 11 Jul 2007 at 19:12

Fusion said:
It's when pondering what initiated the big bang that I start having trouble. If someone could simplify brane cosmology for me, I'd be very grateful.

I don't think there are many people around here who can even pretend to understand brane cosmology. I certainly don't, and I don't have any motivation to find out really. Maybe GordyR can tell you something about it.

One thing I do know is that not many people take the ekpyrotic universe too seriously - certainly in the theoretical physics group at Cambridge it's viewed as a little bit of a joke; the 'pet theory' of Neil Turok and a couple of other guys who just won't let it go. I gather that it's a nice mathematical theory, but has basically zero evidence to support it.