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String Theory a Disaster for Physics?
BlueCup writes "Mathematician Peter Woit of Columbia University describes string theory in his book Not Even Wrong,. He calls the theory 'a disaster for physics.' Which would have been a fringe opinion a few years ago, but now, after years of string theory books reaching the best sellers list, he has company."
I think ST is a very interesting and peculiar theory. I'm not sure it's a disaster. Even if ST is proved wrong in some way the math that resulted from ST is still worthwhile. However I think Woit's point is metascientifical, in that string theorists get more funding than those who are trying to provide alternatives to ST. That ST has become somewhat of a marketing term. This is surely damaging but again science is not excluded from human frailty.
The best education consists in immunizing people against systematic attempts at education. - Paul Feyerabend
I am a cosmologist, albeit one who works "close" to string theory (I am not a string theorist, but many of my collaborators are), and I am familiar with Woit's arguments (and have met the gentleman himself several times).
However, my impression -- and I speak as someone who works inside a particle theory group, and who has served on faculty-level particle physics search committees -- is that string theory is far from having a "lock" on theoretical particle physics today. In the article, Woit is quoted as follows: "By his count, of 22 recently tenured professors in particle theory at the six top U.S. departments, 20 are string theorists." Looking at the Particle Physics Rumor Mill (http://physics.wm.edu/~calvin/) which assembles the short lists for faculty jobs in particle theory many of (and perhaps most) the people getting offers are not "hard core" string theorists. Many of them will have written papers with some string content, but have wider interests in cosmology, particle phenomenology, and/or physics "beyond the standard model".
This statistic differs from Woit's, in that it is not just counting "top" physics departments, and looks at Assistant Prof hires, and not tenured faculty (although *outside* the top six, most Assistant Profs can expect to be promoted to tenue). However, I suspect that the "twenty out of twenty two" statistic is either over a very carefully chosen interval, or reflect a very broad definition of who counts as a "string theorist".
My feeling is that string theorists have a *hard* time getting jobs. In general, many places outside the top ten (ande most of the jobs are outside the top ten) do not have string theorists on their faculty, and string theorists have a hard time differentiating themselves from other people in their field, which makes it hard for them to get hired -- especially as they are competing against other, very smart people.
The real issue here is that particle physicists have received no "surprises" in many years -- perhaps the only genuinely unexpected recent data point being the non-zero value of the cosmological constant. And this did not create a new problem, since the challenge for the theoretical community was always to explain why the CC was around 10^120 times smaller than its "natural" value, which is not much easier than explaining why it is actually slightly different from zero. In this enviroment, we have no good way to "prune" theoretical ideas, and the hope of many is that the LHC (Large Hadron Collider) will yield results that cannot be explained within the context of the so-called "standard model" of particle physics. In this sense *any* theoretical framework that had been worked on since the mid 1970s would risk falling into the same trap as string theory, since there is no data we can't explain with existing models -- if it was incompatible with the standard model it would have been dead on arrival, but any model which yields the standard model in some limit is not falsifiable with current data.
On the other hand, string theory does provide a rich mathematical structure with some very surprising results. The so-called "AdS/CFT" correspondence sets up a completely unexpected relationship between gravity and a particular class of field theories, and some calculations in QCD (the theory of the "strong" nuclear interaction) can be "organized" and performed using string theoretic ideas. This does not "test" string theory, but it does show that there are deep and unexpected consequences to what is ultimately a very simple idea and, in the absence of data, this motivates theoriests to keep working in this area.
Well, you forgot one other thing about science: If my science says that a "cat" by definition has a tail, then these things you call "cats without tails" aren't actually "cats" at all, but something else, perhaps yet to be named.
I have no idea why I felt the need to bring that up.
-- thinkyhead software and media
Both God and String Theory have the same problems for the scientific method - neither of them is falsifiable - and neither makes predictions about things we don't already know that we can actually go out and test.
So (as a scientist) there is very little point in thinking about either of them for very long because they simply don't get you any further in making workable personal jet packs, or any of the other fun stuff that science is generally so good at.
Falsifiability is a reasonable requirement. It says: "OK Mr. Proponent of God/StringTheory. tell me one experiment I could reasonably consider doing that (if it hypothetically failed) would prove that God/Strings definitely doesn't exist." But there IS no such test for either thing. String theory is just so very flexible that it can accomodate almost any failed experiment by picking another one of the ten-to-the-power-500 possible variations on how space is wrapped up, and experiments that might manage to disprove it appear to require more energy than the entire universe contains in order to perform them. Meanwhile, God is claimed to be utterly omnipotent - so any experiment we think up to prove that he's not there, could merely be written of as him "testing our faith".
Lack of falsifiability doesn't prove or disprove a theory - it just makes the theory worthless for science.
So it's fine to believe in God and be a scientist - so long as you realise that your theory of the universe isn't going to help you make personal jet packs (which you still owe me by the way!).
If somewhere in all the religious texts it said "God can do absolutely anything EXCEPT make purple stars" - then we could all get out our telescopes and go look for purple stars. If we ever found one then the case would be closed. If we never found one - then we still wouldn't know for SURE that there was a God - but ultimate proof isn't something science can ever really provide. But as it is, we are told by the proponents of the God theory that he can do absolutely anything he likes - and we know that if he does exist then he has no compunction in planting REALLY convincing bogus evidence for the big bang just to "test our faith". So we can't make ANY predictions about God whatever and any theory that includes him in any way whatever is useless for our progress. If we employ our belief in God, we can't make a computer that works reliably because God might decide he doesn't like us calculating PI to a bazillion places so the machine would be useless for all practical purposes. We can't find out whether there was life on Mars because he does stuff like burying really convincing solid stone dinosaur bones to try to cheat us into a belief in evolution when he knows full well that it's not true. A world with a God in it is simply not open to doing any kind of useful science - so if we'd like to have personal jet packs (sorry to keep harping on about those - but really, they are a bit overdue), we'd better put God theories to one side while we're designing them. If we used a God-based universe as our model, the only really plausible way to get jet packs is to sit on our backsides and pray for them to materialise out of thin air.
String theory has similar problems - and I could understand why people are beginning to think it's a waste of time for such a large proportion of Physicists to be working on it. The theory is at the point where it certainly COULD be true - but if it doesn't tell us anything we don't already know and there's no way for us to ever disprove it - then it's just not very useful.
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