by PWrong » Sat Mar 27, 2004 12:40 pm
Actually, string theory says that there are 3 large dimensions, either 6 or seven (in supergravity theory) small curled up dimensions, and time is sometimes called the 10th or 11th dimension. All matter is made up of 1-dimensional strings (like infinitely thin rubber bands) that move through the 9 or 10 dimensions, and vibrate in a different manner depending on the type of particle they are.
We couldn't evolve into these dimensions, simply because we already occupy this space. More importantly, evolution can't really affect anything to do with subatomic physics, because DNA is too big.
However, this made me think about something else to do with string theory.
Part of The Elegant Universe deals with why the universe just happens to have three uncurled dimensions. Brian Greene's theory is that the universe began with 0 dimensions at the big bang, and the others gradually uncurled themselves, allowing the universe to spread out in 1 dimension, then 2, then 3.
This is where it gets confusing. Strings can constrict the dimensions, keeping them curled up. But when strings and antistrings collide and annihilate each other, this alleviates the constriction on the dimensions, allowing them to uncurl again. Unfortunately, (for people like us who want to be like Emily) an infinitely thin string is infinitely unlikely to collide with an antistring in 4D, but not in 3D. So when the 4th dimension tries to uncurl, the strings gain more freedom, can't annihilate each other, and constrict the 4th dimension again.
This is really interesting if you can understand it, and if the theory is correct, I think it provides us with an opportunity, given futuristic technology, to create small sections of 4D space in our own universe. I'll start a new thread on that subject.