? asked in Science & MathematicsPhysics · 6 months ago

Was Superstring Theory doomed all along?

So SST postulated that we replace point particles with string particles. Around the same time, the world of experimental physics was converging on the idea of Quantum Field Theory (QFT), which was the theory that was starting to come to the conclusion that particles don't actually exist, that they are just more constricted waves. QFT was less theoretically ambitious than SST, but more experimentally supported. It would seem that QFT was quietly converging on the right answer, but SST was going the exact opposite way, and turning particles into the main focus, and turning waves into an afterthought. When the experiments are saying one thing, and your theory is saying another, shouldn't the experimental theory win out? It seems that was a major problem with SST.

1 Answer

  • neb
    Lv 7
    6 months ago
    Favorite Answer

    No, QFT does not say that particles don’t exist. QFT says that particles are quantized disturbances in the underlying quantum field. Wave functions are (believed to be) non-physical mathematical representation so string theory can use wave functions just as easily as QFT.

    Keep in mind there is no accepted reality interpretation of quantum mechanics - that includes QFT. To try to say one theory represents reality and another theory doesn’t is a road you shouldn’t go down at this stage of the game.

    QFT is plagued with renormalization issues due to the fact that it treats particles as dimensionless points. It is doomed to have infinity problems. Because of that it’s an effective low energy theory - at high energies (short wavelengths) it is not effective.

    The biggest issue with string theory (it is now M-theory which merged the various string theories into a higher level theory) is that it’s not really testable because it would distinguish itself at levels that we don’t have the technology to probe. A great example is the strength of gravity at very short distances. One aspect of M-theory is the multiple dimensions that the closed string graviton would be allowed to ‘disperse’ in. Proof would be creation of micro black holes at energy levels far below that which would be predicted by general relativity. But, the LHC simply doesn’t have near enough energy to test this.

    Update: I should add that string theory really needs supersymmetry to be valid. The LHC so far has detected no evidence of supersymmetry at current energy levels. This is a big problem for M/string theory.

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