Tuesday, April 3, 2012

This is goes Along with My Comment on Expanding into What?

3 comments:

James R said...

Wow! Thanks, Pete. Not that I can understand it all. General relativity is still generally beyond me.

I guess for me the explanations (and my lack of understanding) reinforce it for me as most astounding.

Big Myk said...

All I know about this is the raisin bread analogy. As you bake the loaf, the raisins move further apart, not because some force has acted upon them, but because dough itself is expanding. I've heard it said this way: the big bang was not an explosion in space but an explosion of space.

The universe includes all of space, time, matter, energy, and so than there can be nothing outside of it, nothing for it to expand into. I suppose that there could be some higher-dimensional space in which the universe were embedded and into which it expands (like a two-dimensional balloon expanding into three-dimensional space). But we could have no way of ever measuring the existence or characteristics of such a space.

James R said...

I like your explanation and analogies too. All this is making it sound "most astounding."

Like Pete's video I think that one needs to understand General Relativity to understand the expansion of space-time. I guess General Relativity could also qualify as someone's "most astounding" thing about the universe. At least there are a few who understand it.