Question about String Theory

Discussion in 'Physics & Math' started by cosmictotem, Apr 18, 2014.

  1. brucep Valued Senior Member

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    4,098
    Kevin Brown is the author of a very good book on relativistic physics. This is his site

    Math Pages
    http://www.mathpages.com/

    Reflections on relativity
    http://www.mathpages.com/rr/rrtoc.htm

    Kevin is the latest to be taken out of context 'for Farsight quote mining arguments' about stuff he doesn't remotely have a chance to understand. I feel responsible since I linked a section of Browns book, for Farsight, when I first came to this forum. I think that was the same thing Farsight said to me 'who is Kevin Brown'? LOL.

    Look him up. He's hard to find out about. Brilliant person. It was years before he even started selling copies of his books. Reflections on Relativity has been free since I first came across it about 20 years ago.
     
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  3. OnlyMe Valued Senior Member

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    Don't feel bad I am pretty sure he was mis interpreting Brown before you provided a link. And if not it was only a matter of time....
     
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  5. paddoboy Valued Senior Member

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    Thanks brucep.....It's getting near the stage of criminality the way some purposely misinterpret or take out of context, what reputable people are saying.
    Thanks again.
     
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  7. paddoboy Valued Senior Member

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    Getting back to strings......
    One thing I do remember [maybe from Kaku's Hyperspace book] was that Ed Whitten remarked that string theory and its derivitives was In some ways, premature and said it was 21st century physics, that actually fell into the 20th century....and we are only 14 years into the 21st as yet...He was of the opinion that the correct mathematical structures have not as yet been developed, meaning the physicists studying and ratifying it were/are at somewhat of a disadvantage.


    Lee Smolin has also inferred that string theory and loop quantum gravity might eventually be reconciled as different constructs of same basic assumptions.


    Any QGT, of which string is one, needs to truly be able to be observed at that level...10-43 seconds.
    Just how close are we do being able to observe at those scales.
    It will surely be a "Ëureka" moment in science, when we are able to!
     
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  8. Farsight

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    Groan.

    Lee Smolin is the arch enemy of string theory. He wrote The Trouble with Physics.

    And this thread is really getting bizarre.
     
  9. paddoboy Valued Senior Member

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    You are misinterpreting what I said.....
    My recollection from somewhere was him claiming some reconciliation between string and loop.
    I'll find out in what context and get back to you.....

    """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
    theoretical physicist Lee Smolin about the problems with string theory. Subtitled The Rise of String Theory, the Fall of a Science, and What Comes Next, the book strongly criticizes string theory and its prominence in contemporary theoretical physics, on the grounds that string theory has yet to come up with a single prediction that can be verified using any technology that is likely to be feasible within our lifetimes. Smolin also focuses on the difficulties faced by research in quantum gravity, and by current efforts to come up with a theory explaining all four fundamental interactions. More generally, the book is broadly concerned with the role of controversy and diversity of approaches in scientific processes and ethics.


    This statement is contradictory to the general interpretation of multiple vacua in theories such as quantum field theory, where they are not only perfectly acceptable solutions, but provide great insight into the theory, and can resolve problems with the theory

    The book generated much controversy and debate about the merits of string theory, and was criticised by some prominent physicists including string theorists Joseph Polchinski,[3] Luboš Motl,[4] and Sean Carroll.[7]
    Polchinski's review states, "In the end, these [Smolin and others'] books fail to capture much of the spirit and logic of string theory."
    Motl's review goes on to say "the concentration of irrational statements and anti-scientific sentiments has exceeded my expectations," and,
    In the context of string theory, he literally floods the pages of his book with undefendable speculations about some basic results of string theory. Because these statements are of mathematical nature, we are sure that Lee is wrong even in the absence of any experiments.

    more at.....
    http://en.wikipedia.org/wiki/The_Trouble_with_Physics
    """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
     
  10. Farsight

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    Smolin was right. String theory doesn't predict anything, and now most physicists are disillusioned with it. Yes there are diehards with reputations at stake, but it's on the way out. Really.

    Interestingly enough, you can search inside his book for the word "seer". I've been Farsight since about 2001, about five years before this book came out. I thought it would be a good name on ADVFN, where I used to talk to people about share trading. I was a farsighted investor and all that. The name kind of stuck. And it's so very apt. One of life's little ironies.
     
  11. paddoboy Valued Senior Member

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    27,543

    In this instant, Smolin was and is wrong for the reasons already stated.
    The matter is debatable though and continued research into it is still required.
    The debatable question and your's and other's refusal to accept that, is actually what sets you and a couple of others, apart from the more realistic reputable physicists that we have, that are open to change and modification as knowledge and time progresses.
     
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  12. brucep Valued Senior Member

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    Smolin isn't dumb enough to say string theory doesn't predict anything. But you are.
     
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  13. paddoboy Valued Senior Member

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    Smolin was critical of string theory in comparing with LQG.
    When you said he claimed "Ït doesn't predict anything" you of course meant that "It doesn't predict anything that can be verified by current technology"
    Again, an example of taking a statement out of context.
    And of course no potential TOE at this time can be verified. We just cannot observe with any precision, anything at those scales.
     
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  14. Write4U Valued Senior Member

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    Are you familiar with Max Tegmark? If not, I can highly recommend reading some of his work.
     
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  15. Schmelzer Valued Senior Member

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    Let's see:
    Not really a big difference.
    To quote "The Trouble with Physics":
    Not really an arch-enemy.
     
  16. paddoboy Valued Senior Member

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    27,543
     
  17. paddoboy Valued Senior Member

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    String theory and its derivatives are an eloquent theoretical framework that describes present accepted particle physics points, with one dimensional strings.
    String theory also incorporates gravity, and as such is a ToE.
    The nagging problem that exists, is that these strings are at an astronomical small scale, much much smaller then the present scales that protons, neutrons and electrons exist at, and we as yet do not have the instrumentalities to observe and/or measure at those scales.
    That's not to say string theory is wrong, just that at this time, we are unable to observe and/or measure.
    It's mathematical beauty has assured that it remains in top contention for the long sort after ToE.

    Going on what we already are able to observe and measure with today's knowledge, data, and instruments, the BB/Inflationary theory [coupled with SR and GR] plus quantum theory are still the best we have, and any new proposal hypothesis needs to encompass them.
     
  18. Schmelzer Valued Senior Member

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    No. It is not even clear if the SM is among the $10^{500}$ or so theories of their actual "landscape".
     
  19. Schneibster Registered Member

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    Actually that's not quite correct though I can see how you might think that. Actually each point in spacetime has a geometry (which is also something that GRT says) on which a string can vibrate. If there's a string there then there's mass-energy at that point, what we usually call a "subatomic particle," whether that be a boson (energy) or a fermion (mass). This description is highly simplified, and as a result has many small defects, but it will give you the general idea. The place you went wrong is confusing the Calabi-Yau geometry of each point with the strings themselves.

    Well, GRT pretty much postulates the universe being filled with points, and vacuum fluctuations pretty much postulate it being filled with particles (most of them evanescent), so I'd say the current mainstream theories fulfill your requirements without even referencing string theory but I'm not sure that's quite what you had in mind.

    "Observation" is a pretty tricky word, and from recent quantum optics and entanglement experiments it is apparent that even "measurement" is pretty tricky. I wouldn't say that observation itself in the strictest sense (that of being able to define a human observer) affects the appearance of particles, but that measurement in the broadest sense (that is, interaction with the system of interest) might and probably does. Since I am pretty convinced that particles can exist in superposition, however, you should factor that into your evaluation of my reliability on this matter. What I am virtually certain of is that the idea that nothing happens unless some human observer observes it is incorrect.

    Well, we can't explain it in classical (in other words, human-directly-observable) terms, but if we accept that superposition describes a real state that real particles can be in, a state that no classical system can be in because classical systems are ensembles of quantum states, then we've accepted that the quantum theory description of reality is fundamentally different from the way that things we can directly observe can be described. If we accept this, then the apparent paradoxes that we find in QM essentially disappear. However, once a particle interacts, then it can only be in one place at one time, and this is how QM connects with classical physics. We can see only the interactions; we can conjecture about how a particle that is not interacting behaves, and even draw some fairly firm conclusions (and I believe one of them is that superposition is a real state), but in order to check our conclusions we must have an interaction with something, and at that point the superposition of the previously superposed parameters is no longer in superposition.

    You are almost describing the Many Worlds or Everett interpretation of quantum mechanics. However I'll point out that this is an interpretation, not a theory, and as such it may not (and probably is not) subject to investigation by experiment. There are other interpretations, but for yours, I think you will profit by examining the MWI. But for good balance in your opinions you should also look into Bohm's interpretation, Jack Cramer's Transactional Interpretation, and Consistent Histories (this one is really challenging). You should also be aware of the traditional and modern versions of the Copenhagen Interpretation, for a fairly full understanding of the current state of thinking on these matters.

    I must point out in due diligence at this time that you are talking about an interpretation, not a theory, and String Physics is very close to being a theory, much closer than it is to being an interpretation. It is not a true theory in the strictest Scientific Method sense, because it does not make predictions beyond current theories that can be verified; it therefore remains a hypothesis until some really good experiment or observation can provide some solid evidence for it. It is, however, fully consistent with all existing theories. So I don't think you will find what you're looking for in String Physics. That's why I call it "String Physics" rather than "String Theory."

    I'd concentrate on the interpretations rather than on String Physics if I were you. And I'd definitely suggest making sure you look carefully at the MWI since it seems very close to what you're thinking.

    Good for you; you're asking questions instead of making assertions. This is along the path that will lead you to more knowledge.
     
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  20. cosmictotem Registered Senior Member

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    Thanks for this. If I take away one thing from this it will be the difference between interpretation and theory. It's obvious now that you pointed it out.
     
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  21. paddoboy Valued Senior Member

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    That's just your opinion: Many notable cosmologists and mathematicians such as Ed Whitten still support string and/or its derivitives because of its eloquence.
    Professor Whitten once claimed string theory was 21st century physics that accidently fell into the 20th century: As yet we are only 16 years into the 21st century.
    Whatever the future final outcome of string theory is, it most certainly even without evidence, makes far more sense that an ether that was discarded many years ago due to lack of evidence and its superfluous nature.
     
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  22. Schmelzer Valued Senior Member

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    No. This is simply a description of the state of string theory. If this would have been changed, we would have heard about it, this would have been the start of the fourth or fifth or so string revolution.
    The point being?
    It is nice mathematics. But, given its results, it makes no sense as a physical theory. It seems, all they can reasonably hope for is that somehow the AdS/CFT connection allows to use string mathematics for some QCD computations. That Witten has received the Fields medal (the Nobel price for mathematicians) but no Nobel prize for physics has good reasons.

    If string theory would be able to reach the results of my ether model, they would be happy.
     
  23. paddoboy Valued Senior Member

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    No just your opinion:
    The point being, is that many notable cosmologists and mathematicians such as Ed Whitten still support string and/or its derivitives because of its eloquence.

    "Makes no sense" is just about as relevant as your claim that "GR is wrong"
    The level that string theory is applied to is simply at this time beyond our technological capabilities to measure. Perhaps one day that may be solved.
    Yet it's your ether model that languishes in oblivion uncited and unknown, while string and its derivitives is still being discussed and researched.
     

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