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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.'"
Dimensions can have all sorts of zany topologies going out to infinity.
The World Wide Web is dying. Soon, we shall have only the Internet.
"Ultracold" here refers to degenerate Fermi gases, not Bose-Einstein condensates (BEC).
Here's a layman article:
A Fermi gas of atoms
Deborah Jin
Physics World, 2002
And the original publication by the Duke group:
Observation of a Strongly Interacting Degenerate Fermi Gas of Atoms
K. M. O'Hara, S. L. Hemmer, M. E. Gehm, S. R. Granade, J. E. Thomas
Science Vol 298, p 2179 - 2182 (2002)
Yes there are tests but the tests won't be definitive. One of the problems with string theories is that there are a multitude of them and they very very mutable. The collider will only rule out (likely) or confirm (doubtful) a subset of the possible string theories. However, the remainder of the string theories will be safe from falsifiable experimentation. What is needed but lacking is way to winnow out candidate string theories that a) describe our/the universe, b) solve current quandaries of physics like why certain physical constants have the values that they do, c) make predictions which are practical to confirm, d) are parsimonious as string theories are notorious for introducing several new constants and constructs for every one they explain.
Now I may not be a PhD but I am a taxpayer who is happy to see some of his taxes go to funding basic scientific research. And I agree with those who say that the current fashionability of string theories preclude other approaches from being funded and that string theories are getting a free pass on standards of prediction, observation, and experiment that other branches of science are held to.
Incidentally, a hallmark of all other good theories in physics to date is that all can be represented by fairly simple systems of equations which an Asimov, a Sagan, or for that matter a good HS science teacher can explain to an interested (and research funding...) public. Be they Newtons Law's, Special and General Relativity, or Maxwell's Equations, good theories tend to have a parsimonious tightness to them that practically shout out what experiments one should do next. Now I realize that in the end, that the universe need not conform to such beautiful systems but the fact that to date that it has and string theories most certainly are not give me pause.
The FA at least holds out some hope for winnowing out more implausible string theories (and no the idea that all string theories describe a possible universe cuts zero ice until someone finds a way to observe/test that) at least and maybe showing the way to an actual viable theory that is more than pretty math.
This article really is not about string theory. The article is really about the math developed as people have explored string theory. It is this math that has been applied in explaining "perfect liquid" experiments.