Is String Theory really a theory?

  1. Hey guys. This is my first post.

    I don't have any background in physics so please don't just throw equations and stuff at me and expect me to understand.

    So is string theory really a theory? It seems to me that theories need to have evidence to back them up. You need to be able to look and see how it is applied. For the Big Bang theory we can see that the universe is expanding. For evolution we can see that new species arrive, there's mutations in genes, etc.

    For string theory we have what?

    Isn't it more of a conjecture or a philosophy?

    Well just gotta say that you guys seem pretty hardcore from what I've been reading. Hopefully I'll learn some stuff. :confused:
     
  2. jcsd
  3. jeff

    jeff 658
    Science Advisor

    When you're just a beginner, it's easy in this particular forum to get fooled into believing people here know more than they actually do. Truthfully there's hardly anyone here who knows what they're doing. Unfortunately some of them post with a misleading air of authority. So remember to ask questions in a way that forces them to give you clear, detailed and unambiguous physics answers, and not vague or overly broad statements which try to hide the fact that they don't really understand all relevant sides of the issue. Really try hard to recognize when someone is trying to brainwash you into worshipping the same gods they do so they can avoid discussions of ideas - I have in mind string theory - that they hate simply because they are too complex and technical for them to understand.
     
  4. Some other advice, watch out for the following all too typical behavior of string theory proponents:

    1. Evasion of questions that they don't have an answer for, or for which the answer is embarassing to their cause. You don't seem to have gotten an answer to the question of whether string theory is really a theory in any conventional sense of the term. The reason
    for this is the answer is that it's not, it's a set of ideas that people would like to believe can
    someday be turned into a real theory. But they've been trying without success for twenty years. For more fun along these lines, try asking string theorists to write down the equations for string theory, or to give even one experimental prediction of string theory. You'll get all sorts of incorrect answers (equations whose solutions are known not to correspond to the real world, "predictions" about what might happen, not what will happen), obfuscation, and attacks on non-believers.

    2. The arrogance of string theory advocates is pretty mind-blowing. Many of them are convinced that they are brilliant since they have learned something about string theory and that anyone who doesn't believe must just be too stupid to understand. I have a Ph.D in particle theory from Princeton and have taught graduate courses in mathematics and quantum field theory at Columbia, but I've more than once heard from undergraduate string theory fanatics who inform me that I'm just too stupid and ignorant to understand the true wonderfulness of string theory. Not all of them grow out of this youthful arrogance.
     
  5. Peter,

    For one , I do not think you are stupid.

    Could we not put this aside for a minute. I mean if we wanted too, could we not ask what your alliance is with Smolin, and whether this positon is more reputable? If we did this, and you answered, then we'd have to conclude there was some bias? :smile:

    Well I know better then, to present such characteristics of people's nature in regards to theoretical positions then, because we indeed know the important criteria, and that has to do with experimentation, right? I assume everyone is on the same wave length? :confused: We have seen enough disrespect to the Grandfathers, even though we are building on their mistakes?

    What are your thoughts on probing dimenisons in context of what I have shown in regards to the graviton(energy in energy out-where has it gone if not equal?) in regards to the colliders? Do you have another explanation?
     
  6. What's a graviton?

    Exactly. :D
     
  7. A quantizied gravitational wave...........

    I'm not a string theorist.......so if my answer is vague.....

    its for a good reason so you build with what you got, and see who siad what and hopefully.......you come up with the right answer.

    Maybe Jeff can respond as he pays a lot of lip service but does not contribute much. Or Peter, and we can expect a direct answer.
     
  8. Oh, I know that much. They're just a bit of wishful thinking at the moment though I believe because we know bugger all about gravity.

    I think they just have a graviton because it would make sense.
     
  9. jeff

    jeff 658
    Science Advisor

    whydoyouwanttoknow,

    All current approaches to the problem of how to quantize gravity or how to integrate all fundamental interactions into a single unified framework are more research program than theory. This is an inevitability when experiment isn’t able to keep up with imagination. The question is then how worthwhile a given research program is. This is a physics and not a politics question, and the one you should put to me, notevenwrong, and everyone else who posts in this thread.
     
  10. On the contrary we know lots about gravity.

    Check out Taylor and Hulse and tell me how this energy is being lost and you will understand why Mercury rotation give off information.

    The question I ask Peter is legite, about energy in and energy out? Looking at the examples I just gave you, will help you undertand what I mean.

    Hopefully Jeff or Peter will respond appropriately and not with some politcal jargon.
     
  11. marcus

    marcus 24,274
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    Gold Member
    2014 Award

    Sol, I was really astonished when you replied to this with misinformed innuendo. AFAIK Peter has never once urged anybody to study Loop Quantum Gravity. I have never seen any signs of an "alliance" with Smolin.
    You talk as if you thought there was a conspiracy to discredit String :rolleyes:

    I have followed Peter's blog since it's beginning several months ago and
    his occasional criticisms of String hype, confusion, and triumphalism have been straight and disinterested-----not slanted towards the LQG alternative.

    Peter is one of the few objective observers who speaks his mind and your unfounded hint that he might be a "crypto-Looper" with an ax to grind comes across to me as a smear tactic.

    this is what I am referring to:
    Sol: "I mean if we wanted too, could we not ask what your alliance is with Smolin, and whether this positon is more reputable? If we did this, and you answered, then we'd have to conclude there was some bias?"

    I think you should retract that.
     
  12. jeff

    jeff 658
    Science Advisor

    My experience at PF has taught me that the only questions worth my time in answering are those that are well-posed and addressed directly to me.
     
  13. you mean....like about your knowledge of holography?

    It's not nice to use other peoples excuses(Chroot) :smile:
     
  14. I know what Peter is like, and in the second paragraph I dismiss this feature. Please read again.




    Let's think about the beginning of this thread then and hoepfully people are not thinking I am hijacking because of a question asked. It has diverged now into something else? I have gone to the heart of the original question.


    Peter or Jeff can answer with "credibitly" as to what is being done in the colliders. String theory developed out of the need to comprehend where this energy was going, and pushing for great energy requirments, found limitations.

    No, just putting everyine on the same playing field :smile:

    Anyone can correct here. I'd appreciate it.
     
    Last edited: Aug 5, 2004
  15. My interests and background are rather different than Smolin's. He has been doing quantum gravity from the beginning of his career more than 25 years ago (he and I
    overlapped at Harvard where I was an undergraduate, he was a graduate student). He approaches quantum gravity often by trying to dig into the deep conceptual and philosophical problems that it raises. My background is in quantum field theory and mathematics, and to the extent that I think about quantum gravity it is from a particle physicist and mathematician's point of view, which is rather different than Smolin's. One thing he and I agree on though is that the current state of fundamental theoretical physics is quite disturbing, with a dangerous "group-think" about string theory. He and I have met and correspond every so often, but I correspond with a lot of people on these topics. The recent behavior of Susskind in response to Smolin's serious criticism of the unscientific nature of "anthropic" reasoning is an example of the all too common way in which some string theorists react to any criticism of what they are doing.

    I'm not a proponent of LQG, although I find it a more promising idea about quantizing gravity than string theory. Unlike string theory it seems to me to be a healthy part of physics, with a reasonable number of people working on it and slowly making progress. Someday we'll know enough to see how well some of the LQG ideas work.
    No one knows the right answer to the question of how to quantize gravity. Physics would be a lot healthier if there were many different research programs going on in this area, not just one huge dominant one with one small challenger.
     
  16. marcus

    marcus 24,274
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    I mean that kindly, sol. It would be better if you retracted the innuendo.

    I think you have a problem with anyone criticising Leonard Susskind and the emotion shows when you use phrases like "respect for the Grandfathers" or "disresepect for the Grandfathers".

    We should try to deal with this problem humanely.

    I believe Susskind's influence is harmful to String research program---it distorts it, takes it in unscientific directions, and damages respect for it.
    It is a case where one needs to amputate a limb to save the patient.
    Someone in arXiv recently rejected a paper submitted by Susskind and IMO this did Susskind a great favor and was protective of String research interests.

    Think about what that means. ArXiv never rejects stuff from established academic people but they made an exception in Susskind's case---probably the only time in the dozen or so years ArXiv has been running. He has gone wacko and must be muzzled for his own good and the good of String research.

    But I also believe in respecting Grandfathers, and indeed even ordinary grandfathers and grandmothers! We should all treat each other with respect expecially distinguished old scholars. So what do you do?

    For starters, sol, you could amputate the Anthropic Principle from your own thinking. It is the basic diseased member that needs excision. Susskind started damaging String interests the day he began appealing to it. It doesnt matter what you can say about different kinds of AP or different philosophical justifications for this version or that---the whole thing is in bad odor. It is, unfortunately, a question of biting the bullet.

    the String/LQG debate is a whole other business, almost forgotten what with all this AP noise. Once Susskind is retired or under control we can all have a cup of tea and discuss the Loop vs. String prospects politely, as they did in Berlin last October.
     
  17. So, um, the answer is that it's not a theory?
     
  18. marcus

    marcus 24,274
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    the P word: phenomenology

    Two separate aims jeff mentions.
    A. quantize gravity
    B. integrate all fundamental interactions

    Loop people address problem A.
    String people want to do B and get A as a bonus or byproduct.

    What distinguishes a theory from a theory-under-development or a Bright Hope of a theory or, to put it more carefully a "research program" is
    phenomenology: does it make predictions you can test?

    the latest conference on this was in Poland in February 2004
    the topic of WS-2004 was "Quantum Gravity Phenomenology"
    It lasted 10 days from 4Feb to 14Feb and had talks by a dozen or more experts. Several people doing observational work---the best known
    was Ted Jacobson. Lee Smolin, a theorist who has make some predictions
    that the observation people are trying to shoot down, was there and
    gave 3 of the talks. I will get the link.

    Looking over the talks from this 10-day symposium is a good way to
    gauge the progress in Loop Gravity from being just an untestable "research program" to becoming a real physical theory that can either be confirmed or proven wrong by astronomical observations (the leading type is gammaray burst astronomy, discussed at WS-2004).

    [edit: here's the link to that symposium]
    http://ws2004.ift.uni.wroc.pl/html.html
    click on "lectures"

    I dont say LQG has reached maturity, I am saying look for yourself and gauge the progress. (then equate it with String if you want to)
     
    Last edited: Aug 5, 2004
  19. This reference is in regard to the predecessors who have lead our thinking.

    Here we might inject, Penrose, or Wheeler, and even Kip? I think you have to be sixty and over to qualify:smile:

    Einsteins position on EPR, and what did John Bell do for us? Now we have these crazy people who talk about quantum entanglement? And now imagine.......teleportation :smile:

    Theoretical positions change the way we percieve things, although indeed, must be grounded in some reality? In order to delve into those theoretcial positions it mght be a philosophy that begins the creation of this math or that math? There had to be some logical reasoning applied to the pursuate of any of these directions.

    Again, Einstein did not like the spookiness, but things have changed. Penrose saw this when he presented the quanglement issue? I showed Wheeler's Geon, for this specific reason also. There was thinking behind these postions, although not always right, they lead to other conclusions :smile:
     
    Last edited: Aug 5, 2004
  20. Thanks Peter for being honest.

    Did you see the importance of the question I asked in regards to a anomaly that exists in the colliders?

    I am a outsider, looking in, and wondering what lead these thinkers to conclude these extra dimensions, and to demonstrate a philsophical position, is much more deeply considered, then being past off as, flights of fancy.

    regards,
     
  21. The gravitational waves were already quantizied in the graviton.

    I have concistently showed that the integral approach is being implored right now from a LQG perspective in Glast.

    If you change the question around in terms of Gamma ray detection, you would ask, what is revealed in a photon interaction going through a gravitonic gathering?

    But this could hurt Strings? :smile:

    I must admit Urs wasn't to forth coming when I asked the question.


    We all know I have lots to learn :smile:
     
    Last edited: Aug 5, 2004
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