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String Theory and The Uncertainty Principle

Posted: Fri Jan 02, 2009 1:25 pm
by ninjamidnight
What a cancer! If Einstein knew we were taught uncertainty principles and string theories, he would roll over in his grave. It seems as if physics detoured from evolution and regressed into our imaginative psychedelic delusions. When I hear someone talk about string theory, i hear the sounds of someone tripping on acid. If you graze the surface, you uncover a pitfall of irrational explanations that spiral into meaningless expressions which can not be disproven because it is too small for us to observe experimentally…what a coincidence. I am jealous I didn’t think of that one! I am reminded of a child’s fable concerning fairy dust, and when the child asks why or how, I say because it is magic, rather than, I’m not sure. It is better going to the grave searching for the truth or bearing the scars of failure, instead physicists are looking to exonerate due diligence for academic notoriety and purpose. For this, I truly respect Einstein; he could have written anything and made it a scientific proof…just because Einstein said so and no one would reasonably question it. Thank God he never succumbed to that temptation.
ULTIMATELY and physically, it is an inverted pyramid debacle scheme of confusion. “Let’s confuse congress into granting us more money for wasted experiments looking for extra dimensions that don’t exist”. I’m almost sure I can get grant money to find God’s home address if I put it into a theoretical mathematical equation. One day it will all come crumbling down. The mathematical equations are nice if you understand them, but they lack one important ingredient, purpose. They’re motivated by mathematical explanations that supports postulates of how. This is not how discoveries are made. For instance, I can’t disagree with species evolution, because it explains how and why. You can not backwards re-engineer physics to support how without why. In all my studies, evolutionary purpose precedes the existence of a physical phenomenon. If you took all of the possible anomalies sprouting from the math of string theory, we would tie ourselves in a knot…literally. We would evolve a universe with multiple consequences. Nothing like the one we live in. Imagine a law with several conditions and amendments. We would need judge, prosecutor and jury to walk and chew gum. This is what inspired Einstein’s search for a law without amendments….a “Unified field law”. Therefore, string theory is a huge waste of time…to many conditions…to many dimensions…. It literally takes on a life of its own…but it I really think it is the greatest science fiction trilogy since George Lucas’s “Star Wars”.

Re: String Theory and The Uncertainty Principle

Posted: Fri Jan 02, 2009 3:52 pm
by robertson
First of all, you should be really self-confident if you are the one that can say "String theory is a waste of time", and thousands of trully intelligent (I know nothing about you, but you are not more intelligent than Witten or Maldacena) cannot see this enlightening truth. At least, there has been some useful discoveries like AdS/CFT correspondence or mirror symmetries in Kalaby-Yau topologies. They have also bring some very interesting new ideas to physics, that might not be correct, but can help to find new inspiration for the new generation of physicist.

That said, I think you are right in some points. Lots of people think that too many bright physicist have been lost in this generation because they are trying to find something between the 7th and the 9th dimension, and we could have a better understanding of QCD and more serious GUT's. In my department there is only one teacher doing String Theory, and at least 10 doing phenomenology, lattice, flavor physics, neutrino... There are too many things that we do not know about nature to spend all our time in this beatiful but useless (so far) mathematical theory.

What can I say? I am applying to HEP and my rule to make a correct decision: run away from the stringy departments unless you have a very good reason. I hope we will see the end of this discusion before we die! I have heard that LHC can somehow discard (or at least discourage) String Theory. What will happen with the HEP departments of Princeton, Harvard... if this happens?

Any supporter of String Theory with true knowledge about this topic?

Re: String Theory and The Uncertainty Principle

Posted: Fri Jan 02, 2009 5:32 pm
by Fritz.Zwicky

do not feed the troll.

Crazy Fritz

Re: String Theory and The Uncertainty Principle

Posted: Fri Jan 02, 2009 7:57 pm
by abeboparebop
ninjamidnight wrote:If Einstein knew we were taught uncertainty principles

I especially like this line -- Heinsenberg's uncertainty principle was around for the last thirty years of Einstein's life.

Re: String Theory and The Uncertainty Principle

Posted: Sun Jan 04, 2009 5:03 pm
by Andromeda
robertson wrote:What can I say? I am applying to HEP and my rule to make a correct decision: run away from the stringy departments unless you have a very good reason. I hope we will see the end of this discusion before we die! I have heard that LHC can somehow discard (or at least discourage) String Theory. What will happen with the HEP departments of Princeton, Harvard... if this happens?

I wrote an article doing an overview of string theory once, and IRC the LHC might be able to disprove some versions of string theory but there will be no "smoking gun" either way on the issue. So those who want to study it will be free to carry on as usual on those theories that cannot be discredited with the LHC... Mind, you need an accelerator the size of Earth's orbit to definitively prove it one way or the other, hence the camp arguing against string theory as worthy of physicists' time due to lack of experimental verification.

Personally I always thought string theory was something better suited for the math department as it would solve the major arguments on either side- you could still study it if you liked, but it wouldn't be in physics where it's not experimentally verifiable. I'm an experimentalist from a pretty anti-string department however who is concerned about how much damage string theory has on a PR level for physics, so conclude what you will. :)

Re: String Theory and The Uncertainty Principle

Posted: Wed Jan 07, 2009 4:00 am
by YF17A
I'm applying for HEP theory. My philosophy: I have absolutely no right to judge the correctness (or lack thereof) of any theory until I've studied it in depth. This applies to string theory, LQG, etc. But pragmatically, since many top universities have string theorists and only Penn State and PI have LQG (in North America), the best route seems to be: study strings and make sure the string people have logically sound reasons why they think LQG is wrong. Also, LQG is essentially based in classical differential geometry, while string theory brings in infinite-dimensional Lie algebras and all sorts of topological and group theory subtleties, so studying strings will make one well-prepared for any future theory that uses the tools of modern mathematics.

Re: String Theory and The Uncertainty Principle

Posted: Wed Jan 07, 2009 4:30 am
by YF17A
Just another random of the strongest arguments in favor of string theory is its self-consistency. That is, once you assume supersymmetry and 10 dimensions, the theory stops spitting out contradictions and lots of things seem to magically fall into place.

A similar thing is true about supersymmetry by itself. There's absolutely zero experimental evidence for it right now, but it's required for self-consistency: if you want electroweak symmetry breaking, you need the Higgs, and if you want the Higgs mass to be reasonable, you need supersymmetry. I'd say 95% of particle experimentalists and theorists believe in supersymmetry despite the total lack of evidence - would anyone claim that they're wasting their time? Of course everyone could be wrong, in which case physics would suddenly get very interesting :)

Re: String Theory and The Uncertainty Principle

Posted: Wed Jan 07, 2009 9:28 am
by secander2!
Disclaimer: I'm doing my best to synthesize what I've learned from reading The Trouble With Physics and from having taken a course on the Philosophy of Science, but I'll honestly say that most of what I'm about to say is just my own bull, so please don't take offense at it, although I would be interested to hear opposing opinions and/or corrections to what I've said about Popper and String Theory.

If we take the philosophy of Karl Popper as being definitive of science (historically physicists tend to accept Popper and his philosophy of science even though many philosophers don't), i.e., that something is science insofar as it is falsifiable, then we are forced to admit that with each revision and change which has been necessary to keep String Theory from becoming falsified, String Theory has lost some of its credentials as a "science". In fact, referring to String Theory as a single theory is somewhat misleading. From my understanding, String Theory is actually composed of a virtually infinite expanse of separate "string theories", each of which predicts a completely universe. String Theorists have been studying a selected number of these "String Theories" and some of them have shown remarkable similarities to our own Universe. But if String Theory is just a mater of matching one of the "string theories" to our universe, then how can string theory be falsifiable? If any prediction of the currently accepted string theory is falsified by observation, one need only to pick another string theory which is not falsified by this observation. Perhaps science needs to move away from it's Popperian stance (and some are making the argument for this, I believe), but until it does, it seems to me that String Theory, for all its good and valid mathematical uses, will eventually loose its classification as science.

Re: String Theory and The Uncertainty Principle

Posted: Wed Jan 07, 2009 11:32 am
by YF17A
Well it's about time we started an interesting discussion on this forum. I'll start with an example called "gauge theory," where you describe your particles and interactions in terms of representations of compact Lie groups. Any Lie group will work, in fact Yang-Mills theory was formulated for SU(2) until they realized that there is no triplet of massless vectors in our universe. So technically there are an infinite number of solutions. But our universe is SU(3) x SU(2) x U(1). But wait! We've just hand-picked one solution out of infinitely many so we can describe what we see! Is the Standard Model no longer science?

OK, that was a little facetious. The reason we don't care about picking a particular solution is that it's a "model," not a fundamental theory. So I agree that the claims about string theory being a fundamental theory, THE END, are a little overblown. But if we treat it as more of a "framework," and notice that no one has yet found the Standard Model within that framework, we're back in business. What happens if we find a configuration of extra dimensions which gives rise to exactly the Standard Model, find a method for breaking supersymmetry that gives exactly the correct particle masses, and from that "handpicked solution," make one new prediction? Sounds like science to me. Of course, it may not be possible to find the Standard Model because there are so many solutions, but precisely because there are so many, if it's found it's likely to be unique. I would bet that if this happens, and that one prediction was in disagreement with observation, many would consider the theory to have been falsified.

P.S. @secander2: I'm interested in phenomenology precisely because I think concerns like yours are valid.

Re: String Theory and The Uncertainty Principle

Posted: Thu Jan 08, 2009 5:48 pm
by secander2!
Some very good points you make there, and in some ways I'm quite inclined to agree with you! Anyways, I'll try to restate my point and maybe even change it slightly :D I'm not saying that String Theory isn't important... however, String Theory seems (to me) to be very much like Group Theory before the advent of the Standard Model. As Frank Close put it when asked about String Theory: "String Theory is a very interesting branch of mathematics". It's not a fair criticism to say that we're handpicking SU(3) x SU(2) x U(1) out of all the possible gauge groups makes SU(3) x SU(2) x U(1) less scientific... what becomes less scientific is "Group Theory", but nobody is arguing that "Group Theory" is science to begin with.

In summary, my problem with String Theory is threefold:

1) Calling "String Theory" a scientific theory is misleading. String Theory is composed of numerous "string theories", it would be like calling "Group Theory" a scientific theory. Furthermore, even in this comparison, Group Theory comes out the winner. Specific gauge groups (i.e. SU(3) x SU(2) x U(1)) have made new testable predictions most of which have been verified. "String Theory" has yet to yield a single "string theory" which is not blatantly wrong or highly untestable. Furthermore, Group Theory was largely abandoned after SU(5) failed as a GUT due to a lack of proton decays. By contrast, "String Theory" has continued to be pursued despite the fact that every one of the "string theories" which is being studied differs from the real world in some quite substantial ways.

2) String Theory has yet to make [feasibly testable] scientific predictions despite having had (like you mentioned earlier) some of the smartest people in the world, such as Witten and Maldacena, working on it for many years.

3) String Theory is largely based on unproved conjectures. For instance, the string theories haven't even been proved to yield mathematically finite results. Predicating the careers of so many of the brightest physicists on a branch of study based on unproven conjectures seems highly risky indeed.

Anyways, sorry if that came across as overly belligerent. Part of my animosity towards String Theory may come from my experimenter's bias against theory. Either way, I too am really glad to be having an interesting discussion on this forum. Furthermore, whether or not String Theory should be considered a scientific theory or a mathematical framework, I don't know for sure... but I do believe that the work which is being put into it is DEFINITELY interesting and also potentially very useful. I agree that if string Theory is able to make a single [new] prediction, it will be redeemed. Furthermore, I definitely hope String Theory will work out ! It seems just too elegant to be wrong... but then I also think that SU(5) is just too elegant to be wrong too... who know? Maybe God not only plays dice with the Universe, but also laughs when we cry because things aren't as elegant as we'd like.

Re: String Theory and The Uncertainty Principle

Posted: Thu Jan 08, 2009 7:52 pm
by Andromeda
secander outlined it pretty well (experimentalists unite!). Frankly one reason I'm a bit piqued about string theory is all too often when I talk to people with non-scientific backgrounds and explain why science is different from, say, intelligent design or astrology or whatever I mention how important experiment is to us, and surprisingly often the person will pipe up "well, what about string theory?" I can explain why people study it of course, but there's this perception out there that all physicists do is stuff that isn't grounded in reality, string theory case in point, that really isn't healthy for our field.

Re: String Theory and The Uncertainty Principle

Posted: Thu Jan 08, 2009 11:09 pm
by YF17A

I'm confused as to what you mean by "Group Theory." I think my analogy is a good one, and I'm sticking with it. As I understand it, gauge theory is a theory of physics based on the principle that one's Lagrangian should be invariant under local gauge transformations. This principle doesn't specify which gauge transformations - to do that you have to pick a group, and use group theory to tell you what the Lie algebra looks like. You then interpret your results in terms of particles, interactions, etc. Currently, there is no principle that tells us which groups to pick. There are an infinite number of choices, each corresponding to a universe with different particles and interactions. If you thought gauge theory was a fundamental theory, you would be sunk. But as I argued before, the SM is a model, nothing more, and you're free to choose whichever groups match reality. If a similar perceptual shift were made among the string community (which would certainly require some humility on their parts), I see no reason why looking for SM-like solutions within the framework of string theory fails to be scientific.

As for your other points, I feel like you're just repeating the arguments in Smolin's book without really studying them in detail. Smolin's is a popular book, so there's very little math - but there are plenty of textbooks about string theory, so read a few and decide for yourself whether his claims are valid. From my own experience,

1) I don't quite know what you mean by "blatantly wrong." For the sake of argument, suppose that you mean the requirements of 10 dimensions and an infinite number of particles. Just because we don't see these things yet doesn't mean they're blatantly wrong. As an experimentalist, these things should excite you! An entire chapter of the CMS physics TDR is devoted to extra-dimension searches, so clearly some people do consider this "science."

2) I think some of the misconceptions about "testable predictions" come from not accounting for the low-energy consequences of the theory. For example, no one has ever seen a free quark. In fact, because of confinement, seeing a free quark is impossible even in principle! But if it looks and smells like a quark, as far as science is concerned, it is a quark: we see three point-like constituents inside nucleons, we measure BR(e+e- -> hadrons)/BR(e+e- ->leptons) and find N_c = 3, and everyone is happy. Of course we'll never see a string directly. But the low-energy predictions of string theory are fascinating; the topology of the extra dimensions is directly related to the number of fermion generations and the particle mass spectrum. If a match is found to the SM, it's easy to get testable consequences from, for example, the spectrum of KK modes of the massless particles.

3) Before t' Hooft proved renormalizability of the SM in the '70's, people had been dealing (crudely) with the infinities in QED and QCD for 30 years. The finiteness of that theory was certainly an "unproved conjecture" for Dirac, Feynman, Dyson, Gell-Mann, etc. etc. It may have been risky, but it was certainly worth it.

I don't think you're being belligerent at all, BTW. But I do wish there was more interest in the string community towards low-energy physics; by putting themselves on a pedestal, they have invited people to knock them off.

Re: String Theory and The Uncertainty Principle

Posted: Sun Jan 11, 2009 8:44 am
by secander2!

Yep, now I'm just beginning to make a fool out of myself due to my lack of knowledge of all this stuff. You're right when you say that I'm just repeating the arguments in Smolin's book, however, I'm doing a poor job at that even (which is why I said in my first post that most of what I'm about to say is just my own bull). If you've got any recommendations on good textbooks to read, I'd appreciate it, but I doubt that I'll have time to get through them for quite a while.

Anyways, back to the topic at hand. You're right, the analogy I tried to use doesn't really work with "Group Theory", I should have mentioned Gauge Theories (and even though my knowledge of theory is limited, I should have known this at least :oops: ). But even with all the mistakes I have made, I still feel that I have a bit of a point:

From my understand Gauge Theory is and of itself is not a testable scientific theory, it is merely a principle for creating scientific theories (you know more theory than I do, so please correct me if I'm wrong), yet gauge theories such as the SM have been formulated from the Gauge Principle that correspond to existing data and have been able to predict new measurements to high degrees of acuracy. As a result, the "Gauge Principle" gains legitimacy. Perhaps String Theory should be referred to as the "String Principle" to differentiate it from a tested scientific theory and to show that it has more in common with the Gauge Principle than it does with the Standard Model or something? My other point was that in a comparison between the "String Principle" and the Gauge Principle, the Gauge Principle comes out the winner because specific gauge theories have demonstrated substantial predictive power.

As for the three points which represent 'my' problem with String Theory:

1) By "blatantly wrong", I'm not referring to the extra dimensions or anything like that. In fact, I kinda think the extra dimensions are cool. I'm more referring to those theories which do predict things or which rely on certain seemingly (also, sorry for using "blatantly", I should have known that it's typically a bad idea to use such strong words) incorrect assumptions.

2) I'd be interested to know about these low-energy consequences, how they could be tested, and why they haven't been tested already. It seems that many of the predictions of String Theory are also predicted by other theories which make no recourse to strings (e.g., Supersymmetric particles are predicted by the MSSM among others which have no reliance on String Theory). Are these low energy consequences of String Theory unique to String Theory (I'm actually wondering, this is not a rhetorical question)? Of course, either way, their discovery would lend credence to strings, but it's hard to call String Theory "testable" on account of these predictions unless String Theory is unique in making these predictions.

3) And I'd be willing to admit that the SM was substantially more shaky, scientifically speaking, until these unproved conjectures were resolved. I'm not arguing that String Theory is damned to failure because it's based on things which are unproved. I'm merely saying that the more unproved assumptions upon which something is based, the more shaky it is. If I'm not mistaken, String Theory is based on a descent number of unproved assumptions which varies depending on the variant of String Theory you're looking at. Also, from reading The Trouble with Physics, it seems that the majority of breakthroughs in String Theory have been the addition of a cool new [unproved] conjecture. If this is true, then much of the promise of String Theory may be somewhat illusory.

@Andromeda, thanks :D however, I'm probably the worst person to be putting forward the "experimentalist" position, my only credentials are having read half of "The Trouble with Physics" ... I haven't even finished it yet :oops:

Re: String Theory and The Uncertainty Principle

Posted: Wed Jan 14, 2009 10:44 pm
by Juston
My favorite argument in favor of string theory is the one that Jacques Distler had on his blog. The idea is that its pointless to study quantum gravity by itself, because there's no limit where the other forces are weaker than gravity, so you have to consider a theory that takes into account the other fundamental forces.

While I used to be intrigued by the idea of loop quantum gravity, this argument caused me to shift my interests to string theory. I'm not completely sold on string theory though, but the fact that it may have a higher chance of giving me a graduate thesis topic ensures that I'll be doing something in ST, provided I get accepted into a grad program.

Hopefully, LHC will throw all the theories we have out the window and force us to start from scratch.