If the expansion of the universe has slowed before, why is just assumed the the current acceleration will continue indefinitely? It seems to me a precarious assumption.
The working backwards to the era of inflation seems an incredible achievement to my puny Engineer's brain. But how do we know that the current laws of physics do not break down as we extrapolate back to the inflation era? That would seem to be more likely than to actually approach a...
First thank you for taking the time to answer.
ghwellsjr:
I still don't see the why based on whatever frame I use.
I think I need a more fundamental explanation.
pervect:
So you are saying the acceleration does have something to do with it?
But if say the clock is at...
I have always been confused about time dilation in General Relativity.
In the twins paradox, it is the traveling twin that ages slower. However, could you not just as easily say that it is the non-traveling twin that is moving away from the other?
So why is it the traveling twin and not...