Supersymmetry Theory Dealt a Blow 143
Dupple writes in with some news from the team at the Large Hadron Collider. "Researchers at the Large Hadron Collider have detected one of the rarest particle decays seen in Nature. The finding deals a significant blow to the theory of physics known as supersymmetry. Many researchers had hoped the LHC would have confirmed this by now. Supersymmetry, or SUSY, has gained popularity as a way to explain some of the inconsistencies in the traditional theory of subatomic physics known as the Standard Model. The new observation, reported at the Hadron Collider Physics conference in Kyoto, is not consistent with many of the most likely models of SUSY. Prof Chris Parke, who is the spokesperson for the UK Participation in the LHCb experiment, told BBC News: 'Supersymmetry may not be dead but these latest results have certainly put it into hospital.'"
Re:And? (Score:3, Interesting)
Gravitons. Gravitinos are the supersymmetric partners of gravitons, which might not exist at all.
That's not the fundamental problem. If you could consistently describe quantum gravity without space curvature and recover GR in the classical limit, physicists would happily put space curvature where they haver put absolute time: A nice approximation which works well under certain conditions, but breaks down when you get to extremes. No, the real problem with quantum gravity is that the straightforward theories simply don't work.
Re:And? (Score:5, Interesting)
I expect a petition by string theorists to turn off the Large Hadron Collider any day now.
Re:Bad summary (Score:4, Interesting)
Yes, but "supersymmetry" isn't "a theory", it's not the science. It's a label that is applied to the whole family of putative theories that are trying to be science, and which share a common core feature. It's not "general", it's "several". I hate to stand up for supersymmetry, as none of its expressions show the elegance that I like in science (et gustibus non disputandem est), but thinking of it as one single target that can be shot down is in error.
Not long before Newton some other guy (Galileo?) proposed the acceleration of objects falling under gravity such that the speed was proportional to the disance already moved. Newton as we know modelled it differently. The other guy's theory fell down when it was realised that an object would never start to fall. So they shot it down, and Newton's took over. That didn't mean that "gravitational acceleration" was so general it couldn't be disproved and wasn't a science.
> it makes it less interesting science
In some ways, definitely - yours seems to overlap somewhat with my 'elegance' point of view. If there is enough room to be making many many different models, then it looks like there's more guesswork involved than insight. Anyone can roll their own supersymmetric theory - download the new SuSy model GUI-based wizard trial version, and generate your own model in only 10 clicks! First 20 models free!
NOT a moment of insight! (Score:5, Interesting)
Einstein's revolution was sparked by a moment of insight.
Wrong, it was the result of long hard work by several people.
It all started when Maxwell's equations gave results that did not agree with newtonian physics. In an attempt to get at the root of things, Michelson and Morley [wikipedia.org] created an experimental setup to measure the speed of light in different directions in a very precise way. To everyone's astonishment, these experiments indicated that the speed of light is a universal constant, which does not depend on either the movement of the light emitter nor the movement of the detector.
Which was exactly what Maxwell's equations had predicted to begin with! If there was a true intellectual giant here, it was Maxwell.
Several scientists started creating equations that made the results of the Michelson-Morley experiment compatible with classical mechanics. Einstein was just the most successful one, because his equations were more elegant and simpler than those of the others.
However, this does not mean Einstein was absolutely right, his theory was only the best one for that particular period. Today we know things he didn't know, just as Newton didn't know that the speed of light is constant.
For instance, there IS a fixed frame for the whole universe, the one in which the cosmic background [wikipedia.org] is symmetrical. This background was discovered only in 1965.
There's also the horizon problem [wikipedia.org], which was discovered only in the 1970s. If we look at the sky in opposite directions, we see the same characteristics. We are looking at different regions of the universe that never had contact with each other since the creation of the universe. They are so far apart that even light couldn't have reached one from the other during the universe's lifetime. To solve this problem in a way that's compatible with einsteinian relativity, cosmologists came up with cosmic inflation [wikipedia.org], a rather ugly and contrived kludge.
Besides, relativity does not give results that are compatible with quantum physics, this has been demonstrated experimentally [wikipedia.org].
It's rather unfortunate that Einstein's theory is so elegant and precise, because it's certainly wrong when your size scales too much up or down.
Re:And? (Score:4, Interesting)
I'm not a physicist, and to me, a lot of this seems like wishful thinking : building on a model of a model, without any actual proof that any of it is actually correct.
We have an enourmous amount of experimental evidence that a huge number of predictions of the Standard Model are correct to ridiculous degrees of precision. No matter what happens, that mountain of evidence is not going to go away.
You can't literally "prove" physical theories; proof is for math. You can only acquire evidence based on observation. And there is precious little else in all of science that has as much hard quantitative evidence for it than the Standard Model.
Accepting that you meant "proof" in the sense that is applicable to physics, it's just ludicrous to say we're building on a model "without any actual proof".
The theory also isn't perfect as there are phenomenon it does not explain, but given its enourmous success, doesn't it make sense to build on it to iron out the imperfections? It's not like this is being done to the exclusion of complete reworks. Physicists around the world are working on the problem from various angles. It would be outright stupid to ignore the "Standard Model is basically correct but needs extending to cover the new phenomenon" angle.
It seems like a lot of fun, but why does it surprise anyone if it comes crashing down one day ?
Two different answers:
1) Because if the theory was really that bad that it was going to come "crashing down", then it wouldn't have been so fantastically successful up to this point.
2) It wouldn't be a surprise if the next-better-theory does away with the Standard Model completely as the most accurate description of reality, because this has happened before and will probably happen again. However, just like with the theories those two supplanted, the Standard Model would not so much come "crashing down" as be shown to just be an approximate model that works extremely well for a broad range of conditions and to extremely high precision. It is essentially impossible for this not to be the case because we've already tested it in that range. Any replacement theory must give the same predictions for the same conditions, or that theory is not a good replacement.