Something to look forward to: There’s a good article in today’s New York Times about string theory. As you probably know, string theory is the biggest thing in physics since the Big Bang; it’s the leading candidate for the “theory of everything”, the grand theory that will explain all the forces and dynamics of the universe, from the quantum hijinks of sub-atomic particles to the whirling of black holes. Well, turns out that string theory is getting the physics people into some rough terrain these days. It seems to have a million or more different versions, any one of which could be right for all we know. To make things more difficult, it requires more than four dimensions.
Most string theories require ten dimensions. So where are the other six? Rolled up into little knots or something. Not exactly in service, as far as we are concerned. But one day that all might change. One of the biggest surprises of the past 10 years was the discovery that all the stars and galaxies in the universe are accelerating, speeding up as they spread apart from each other. Scientists had expected them to be slowing down from gravity. But no, something is still pushing them. Can string theory explain this cosmic acceleration?
Yes, it can. But if string theory is correct, the pushing and accelerating is a side effect of the other six dimensions being all rolled and wound up. And someday that’s going to change. Eventually (who knows when) the extra dimensions are going to start forcing their way back into the picture as they “unwind”. And at that point, things are going to change big time. The basic rules of physics that allow there to be atoms and molecules and planets and stars and galaxies and life as we know it will all go out the window. If there is any kind of life left at that time, no matter how advanced, it will probably not be able to survive.
Well, that could still turn out to be wrong. But one thing for sure, the astrophysicists are really in strange territory these days. Just when they thought the big picture was coming together, it all blows up. More and more brilliant scientists these days are being quoted as saying “we don’t know” (the more brilliant they are, the more honest they seem to be about this). Strange times these are.