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Strings Link the Ultra-Cold With the Super-Hot
gabrlknght writes "Superstring theory claims the power to explain the universe, but critics say it can't be tested by experiment. Lately, though, string math has helped explain a couple of surprising experiments creating 'perfect liquids' at cosmic extremes of hot and cold. 'Both systems can be described as something like a shadow world sitting in a higher dimension. Strongly coupled particles are linked by ripples traveling through the extra dimension, says Steinberg, of Brookhaven. String math describing such ripples stems from an idea called the holographic principle, used by string theorists to describe certain kinds of black holes. A black hole's entropy depends on its surface area — as though all the information in its three-dimensional interior is stored on its two-dimensional surface. (The 'holographic' label is an allusion to ordinary holograms, where 3-D images are coated on a 2-D surface, like an emblem on a credit card.) The holographic principle has value because in some cases the math for a complex 3-D system (neglecting time) can be too hard to solve, but the equivalent 4-D math provides simpler equations to describe the same phenomena.'"
The thing is, "God did it" doesn't give you any equations or principles. String theory, while it may turn out to be completely wrong, at least gives us something to test.
...all claiming that String theory is not testable.
To these people, I'd like to point out that:
1] Not being testable with current technology is not the same as not making any testable predictions. Technology advances, after all, and there are predictions that were made by Einstein that are still being tested today.
2] It's flat out wrong to say there is no work being done to test String theory. The LHC will begin to unlock a number of answers in this regard.
My non-technical mother in law is interested in string theory but she has no clue what it's about, except that everything in the universe is made out of tiny "strings" that go into another dimension. She is a retired grade school teacher and knows what atoms and subatomic particles are, and she understands the idea of a line having zero width and a plane having zero thickness. I'm trying to come up with an analogy that will get across the basic idea.
Say the universe is two-dimensional, like the surface of a drum. No thickness, just a plane. Then say somebody outside of the universe pokes a needle through the drum head and pulls a piece of thread through it. The thread is one-dimensional, with no actual thickness, so the place where it goes through is just a point. Nobody who lived in the 2-dimensional surface could see the point because it has no thickness. But what if the thread vibrates like a guitar string... as it moves back and forth, the point where it goes through the drum also moves back and forth. The spot becomes a little line. If the string didn't vibrate exactly back and forth but kind of wandered around in a fuzzy pattern, the point would look like a hazy dot.
Because the string vibrates so fast, the people in the plane of the drumhead would never perceive it as a point, but only as a blurry spot (assuming they could see things that small).
That's what a subatomic particle is in our universe, except in 3 dimensions. Wherever a vibrating cosmic string passes through our universe, it forms a hazy dot-like pattern in space, which to us is a subatomic particle.
I know this is far from exact, but does it give enough of the general idea?