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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."
String Theory attempts an actual prediction and then gets it correct.
Till then, it's a bunch of fancy gobbedly gook as far as I'm concerned.
Well, yes, because that's not how science works. Theories have to be put forward which make predictions which can be meaningfully tested. If there is no way to actually test it, then it is, in effect, impossible to develop - by definition it cannot be wrong, and therefore is effectively complete, and science is 'finished', more or less. If such an idea ends up being the dominant trend, then yes, it would be something of a disaster.
I suppose we should stop looking for what started the universe, since we can't disprove the existance of God or anything. What a load of BS.
Would you class the statement "Everything happens because God says so" as scientific? I would hope not - such a statement is inherently impossible to scrutinise or critique, as "God did it" is, in this theory, a perfectly valid response. Science does not advance by pursuing ideas of that sort, but rather putting forward testable theories, and working out ways to stress them and see if their predictions hold, and refining them as a result.
That some ideas cannot be disproven is not a problem for science - instead we content ourselves with studying those that can be.
ST is an attempt to unify QFT with GR. In that setting QFT and GR are a consequence of ST. However string theorists have discovered something called the landscape. In which not only is QFT and GR possible but so are 10^500 other types of universes and the theories that describe them.
This is a huge problem. Of course there is the possibility that finding the ultimate theory of everything is impossible and this would be the physics dual to Godel's incompleteness result. Which I'm sure sure scares the shit out of many physicists.
The best education consists in immunizing people against systematic attempts at education. - Paul Feyerabend
"Untestable! Unfalsifiable!" This is a common refrain from string theory critics, and even from many string theory fans - and it really bugs me. I'm a philosopher of science, and I say: forget falsifiability!
Well, don't completely forget falsifiability - but don't let it be the whole story. Falsifiability was already outdated philosophy of science 50 years ago. Its main problem is what's sometimes called the "Quine-Duhem Thesis" - roughly speaking, any treasured theory can be made to fit any evidence, as long as you're willing to adjust enough auxiliary hypotheses. Here's an ordinary example: when your high school science lab experiments didn't fit predictions, your results didn't get published in Science for falsifying the theory at hand. Instead, quite reasonably, you drew the conclusion that something wasn't quite right with the instruments, etc., and you kept the original theory. The tricky question is to figure out when it's reasonable to excuse recalcitrant data, and when you're unreasonably trying to rescue a theory that's just wrong. Intelligent design advocates can lay out all sorts of falsification criteria, and then make similar excuses should unhappy data come their way. So does that make ID a science? (If on the other hand you insist that only actual falsification makes something a science, then only theories we no longer believe can count as scientific!)
It's too easy in all sciences - not just string theory - to make theories "supported" by the data. Given this problem, the name of the science game is to find the simplest explanation that fits the data. It's very hard to say exactly what counts as a simpler theory, but some theories are clearly less simple. Compare the hypothesis that "the butler did it" to the hypothesis that "unknown sneaky aliens planted all that evidence to make it look like the butler did it." Both hypotheses fit the evidence equally well, but the latter is clearly less simple, and we normally never even consider it for a moment.
String theory explains all the data, from quantum physics to relativity, with a simplicity that's hard to beat. (Its elegance is so good, we're apparently willing to posit 11 dimensions for it!) That's what makes it a legitimate scientific theory. Of course it would be great to have more relevant data, to see if string theory can accommodate them simply too. But just because we can't get such data (now, or maybe ever) doesn't spoil the current scientific status of the theory.
I am a theoretical physicist. I am educated in Supersymmetry, Riemannian geometry, and the original Kaluza-Klein theory. I am educated in field theory in curved space time, but not Supergravity, nor do I care to be.
I have only one thing to say about all of this. Everytime I sit in a talk on strings or branes all I can think is one thing.
Extra dimensions are the epicycles of Modern Physics
That's all I have to say. If you understand this, it is profound.
American's shun science careers because they are so punishingly expensive. Conside the lifecycle of someone who want's to go into String Theory:
4 years undergrad ($40-$120k in cost)
5-7 years grad school (making $15k per year)
2-6 years postdoc (making $40k per year)
7 years pre-tenure (making $60-80k per year)
tenure (making $80-$100k per year)
Oh, and if you fail at any point along the line, you have no career. Since you are looking at 18-24 years to get to tenure, that's a HUGE
investmet to make. You are basically looking at not knowing whether you have a career or not until you are 36-42 years old.
Compare this with the career track of an equally bright student going into CS, and getting a job in tech.
4 years undergrad ($40k-$120k in cost)
starting job ($60k-80k)
5 years experience ($80k-$120k)
move into management ($100k-$150k)
etc... notice how the CS grad going into IT hits the $60-$80k range 7-13 *years* before the scientist?
Plus, while there is less risk of being laid off as a tenured professor, the risk of having your career evaporate as an IT person (please note, IT person who could have hacked being an academic scientist) is MUCH lower. Sure, you may loose your job, but there are plenty of other jobs.
Few American's go into science because the economics of science is so bad. I don't know how to fix that, but the cause is pretty clear.
Oh... by the way, I am an American who was on the academic track in String Theory and got off the merry-go-round. Everytime I talk to my friends who stuck it out I am overjoyed I left. My friends are at the mid-potsdoc stage right now. They are trying to scrape by living on $40k a year in ultra expensive locals like Boston, and live in terror that the only jobs they will be available will be in middle of no-where universities in unpleasant places. By way of contrast there are tech jobs to be had in a variety of nice locals to meet most peoples tastes. It's particularly hard on the women, who are starting to hear their biological clocks tick VERY loudly, and who are still years away from being settled in enough to take a break to have children. It's also very hard for both genders to find a long term mate, as they face the aforementioned prospect of having to move a lot to unpleasant places (like Norma, OK, middle of nowhere PA, middle of nowhere plains states, etc) if they want to continue their careers. And let's not even start talking about the two body problem (two romantically entwined academics).
So basically, if you want more Americans to go into science, make it suck less.