I was reading Scientific American tonight (November '07 issue) and they had an article on multiple universes, string theory, and "branes" ("The Great Cosmic Roller-Coaster Ride"). The article is available online, but it unfortunately lacks the illustrations that inspired me; you'll have to go to the library and look at the paper copy to see the artist's rendition of a "Calabi-Yau space." There's a picture of one here, and also in Wikipedia, along with many mathematical formulae; but the picture in SciAm had long stringy appendages sticking out of the central mass. It looked familiar; it looked strangely familiar, and then I realized:
It's the Flying Spaghetti Monster in disguise! These scientists are covert Pastafarians! "String theory" indeed - what better to make strings than spaghetti? The Universe is a physical manifestation of the FSM and the cosmic strings are His Noodly Appendages. All is now clear.
Actually, I've been reading the cosmology articles in SciAm for 30-odd years now, and as time has gone on they've gotten farther and farther out, to the point that I ask myself: do these people have any work to do?? I realize this is a serious branch of science, but the basis of science is that you establish a theory, and then you make a prediction, and then you create an experiment to test the prediction, after which you either declare victory and start writing up the article for Science, or you go back and tinker with the theory some more. (The scientific method in a nutshell.)
The trouble with cosmologists, and especially string theorists, is that they've been trying for 20 years to devise experiments that would validate their theories, and they can't do it. They'd have to create the conditions that existed within nanoseconds after the Big Bang, and then be able to stand back outside the inferno and analyze the process. I don't know why they think the experiment wouldn't incinerate the experimenter. They plan to work on very small scales, of course: just a minuscule inferno.
As I read about strings, and branes, and scalar fields, and dark matter, I get a whiff - just a whiff - of the "ether" which filled interplanetary space only about 125 years ago. The scientists of that day could no more sample the atmosphere (or lack of it) in interplanetary space, than today's cosmologists can collect a piece of dark matter in a test tube and weigh it. But they were just as convinced that it was there. Today's scientists have much better equipment and much better experimental data. But until they can verify a prediction, they're no better off than the people who believed in ether. They'll tell you the mathematics makes it work; maybe it does. Mathematics is a language I never mastered, and this is a pretty esoteric dialect. I'd still like to see a verified prediction.