Maybe Av's reservations are caused by the fact that
everything humans do can be done badly just as easily as well, and
is perhaps just as frequently. All this about gravity gives examples of both.
Who in history has ever thought outside the box as brilliantly as Einstein? For crying out loud, he realized time is not the same in different situations! An utterly preposterous thought. But if
true, it would explain some weird things. So he tried to work it out on the abacus. And sure enough, the math worked.
Does that prove time passes at different speeds under different circumstances? Of course not. It just proves Einstein was able to invent a theory that could hold up in the mathematical world. But
is he right? Can it be proven? Here's a very short bit of reading that shows how it can be proven in a way that actually has bearing on many of our lives:
www-astronomy.mps.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
OTOH... Einstein, of all people!, blew it. His calculations
also told him that our universe is expanding. And
somehow, the guy who could come up with the idea of relative time couldn't see past the assumption of his day that the universe was static. But gravity is an undeniable part of the universe. And if all planets and stars always remain the same distance from each other, something must be countering gravity's influence. So he figured there must be some unknown force, which he called the cosmological constant, that does the opposite of gravity.
NOW the math works!! Yee Haa!! When they discovered the universe is expanding, Einstein said this was his biggest blunder. (The fact that there is reason to believe some force similar to what Einstein concocted really
does exist does not change the fact that he assumed something that was untrue, and invented something so that the math would work.)
But where are we now, with this M stuff? After all this time, the math isn't able to fit gravity into the theory that unifies the nuclear forces and electromagnetism.
Avatar wrote:Now that is the part I don't get. As far as I'm concerned, they postulate first, then "prove."
The previous super-string theories weren't working out, right? Couldn't be unified.
So they started imagining all sorts of crazy things, throwing them into the mix, to see what would happen. Standing waves colliding in other realities, all sorts of stuff. Nothing balanced.
So one guy said, "how about we add another dimension?" So they did. That time, the equations seemed to balance.
They added the extra dimension, then did all the math as though it was there, and got an answer that matched their postulate.
You're not appreciating what they have been doing all along. Yes, they "imagined all sorts of crazy things." But you said it yourself: nothing balanced.
The math would not support them. So, one by one, those things were thrown out. There is no question that gravity exists, and there isn't any reason to suspect that we can't understand its relationship with the rest of the universe much more deeply than we currently do. So let's try different ideas, and see if any of them hold. A? No. B? No. C? No. But do any of these things fail in a way that helps us learn? That suggests anything? Did somebody
really come up with an 11th dimension entirely out of left field??? If there was no hint of such an outlandish idea, how long would it be before somebody came up with the idea out of nowhere? We'd probably get Shakespeare out of those monkeys sooner.
And if the math holds, is that the end of it? Certainly not.
Avatar wrote:If the experience comes first, math is nothing more than an explanation of the way we think it works. It's "made up" / formulated/whatever to account for the observable and testable phenomenon, based on our perception it. The math is not the phenomenon.
It's one thing to see certain phenomena, and come up with math that will initially support the crazy notion that matter is not infinitely divisible, but made up of atoms, which, in turn, are made up of protons, neutrons, and electrons. It's another thing to see the implications of that math, and invent things like atomic bombs. As with relativity and navigational satellites, the math does more than merely explain what we
do see; it also tells us what we
should be able to see - and
do. If these
shoulds don't pan out, we know the math was just a pretty picture derived from a false premise. Time to find another premise, and see if
its shoulds work.
) myself on the subject once I get my hands on at least one of Brian Greene's books: The Elegant Universe or The Fabric of the Cosmos. I've watched the PBS Nova special based on The Elegant Universe and hosted by Greene, and he's pretty good at it. Something as seemingly esoteric as string or M-Theory certainly benefits from having a visual medium (and all sorts of cool computer graphics!) convey its concepts. I wish we had more of these kinds of quality science shows on TV and less pseudo-science and sensationalistic crap. 
