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How far have they delved into String and M- Theory?

  1. Jun 7, 2004 #1
    Im curious to see how far physicists have delved both into Superstring Theory and M-theory? Have they gotten the exact equations of both theories yet? And has an equation of both theories presented itself yet that has some hope of becoming the one inch equations that physicists want to find?
  2. jcsd
  3. Jun 7, 2004 #2
    I am not expert on this, so I'll just try to share what I have learned about string theory. As far as I know, the exact equations of M-Theory have not been found yet (i.e. there is not yet a complete description of the theory). I think that once M-Theory will be fully understood it will lead to the one-inch equation that physicists are after. Also, I have come to understand that lately string theory has jumped the barrier of being "unfalsifiable" and now makes some predictions which can be verified experimentally. In an interview posted with Witten on these boards I read that Witten said one of string theory's most important predictions was that supersymmetry existed and therefore if the LHC at CERN proves the existence of these supersymmetric particles it could definitely be a very strong proof for string theory. Also, another of the aims of the LHC is to discover some of the 7 other hidden dimensions, which would provide another strong proof for string theory.

    Recently, I came across a news article stating that Yale scientists had also found a way to test string theory. This is the link to it:


    Just as a question, it seems that quite a few people on these boards believe string theory is unfalsifiable, but with these experiments that can't be claimed anymore?
  4. Jun 7, 2004 #3
    Just as another point, in one of Michio Kaku's articles on his website, "M-Theory: The Mother of All Superstrings" it makes a point stating that the obstacle M-Theory faces is that the theory has to be solved non-perturbatively and then it can reduce to a theory about different particles such as electrons, protons and atoms for which there is already a large amount of experimental data.
  5. Jun 7, 2004 #4
    not a falsifiable prediction of string theory

    Read the article carefully:

    "Easther stressed it is a long shot that string theory might leave measurable effects on the microwave background"

    string theory doesn't predict the size of these effects since you don't even know the string scale. As the author says, it is unlikely you will ever see these effects, and you certainly can't falsify string theory by not observing them.
  6. Jun 7, 2004 #5


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    Supersymmetry is not a prediction of string theory. It was an idea that developed independently. String theory happens to require supersymmetry, but not the other way around.

    And as stated by notevenwrong, most (all?) predictions are extremely vague.
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