The Expansion of the Universe... ahem

Here's a response to my pal Yogi, who responded to my previous post with the portrait photo of Edwin Hubble:

The galaxies are like raisins randomly distributed in a loaf of unbaked dough. You bake the loaf, and it rises and expands, and the raisins move apart from one another. The raisins are not moving into new regions of formerly raisinless dough; the whole loaf, raisins and all, is expanding.

There is no space outside the universe. There is no space, empty or otherwise, outside the universe. The universe is the totality of space-time.

The universe, as Galileo taught, is "finite but unbounded." It is getting "larger" in the special sense that its constituent parts are getting further from one another -- not because they are objects moving into formerly empty space, but because spacetime (which has objects in it) is expanding.

also...
I believe one ought never to bash the dime-a-dozen pigheaded scientists without praising the more rare and imaginative scientists who recognize the limitations of human endeavor. Their efforts in the face of those limitations really are breathtaking. The good guys are aware that it has become clear in the past 15 years that the universe is not only expanding, it's expanding at an accelerating rate. Nothing we know so far can explain that, and the good guys are thrilled. They prefer to work on cosmic problems like those than on building bigger bombs. They are our friends. I should add that I also respect Big Bang skeptics, but so far their arguments have not persuaded me. Then again, Twinkletoes (that's me) doesn't really know beans about astrophysics. I am just a dilettante; literally, I take delight in it. And fricking Saturn is two light-hours away, a silky sultry factoid which sends a pleasant flutter through my 'nads.

Hendrix, Hubble, and Homer, folks!