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Thread: String/particle properties

  1. #1 String/particle properties 
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    In string/superstring theory, different particles are different vibrational modes of the strings(?). What properties of the string gives rise to particle properties such as charge, mass or spin?


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    Forum Junior TheDr.Spo's Avatar
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    String Theory gives rise to eleven dimensions, ten of space and one of time. These extra seven dimensions are thought to be compactified inside of the four dimensional world we experience. Charge and spin come from the particle's momentums in other dimensions. For example, an electron's negative charge comes from its momentum in one of those hidden dimensions. Likewise, its spin comes from its momentum in another one of those hidden dimensions.

    Mass comes from the energy of the string (e.g. Rotational energy, quantum "jitters").


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  4. #3  
    . DrRocket's Avatar
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    Quote Originally Posted by TheDr.Spo
    String Theory gives rise to eleven dimensions, ten of space and one of time. These extra seven dimensions are thought to be compactified inside of the four dimensional world we experience. Charge and spin come from the particle's momentums in other dimensions. For example, an electron's negative charge comes from its momentum in one of those hidden dimensions. Likewise, its spin comes from its momentum in another one of those hidden dimensions.

    Mass comes from the energy of the string (e.g. Rotational energy, quantum "jitters").
    Not quite right, but string theory is not well-defined, and difficult to popularize. There is a recent book The Shape of Inner Space: String Theory and the Geometry of the Universe's Hidden Dimensions by Yau and Nadis that ought to be interesting. I have not yet finished it.

    The additional compactified dimensions of string theories (the number varies with the particular string theory) are associated with Calabi-Yau manifolds (the Yau of the book). Yau is a roaring genius and well worth listening to. I suggest a careful reading of the book.

    The phrase "momentum in a hidden dimension" is an oxrmoron. That is not how "dimension" works. You may need some help in understanding what "dimension" means, particularly in the context of a manifold. There are some good books on manifolds and geometry available. There are some impenetrable books on string theory -- understandable sice no one can yet clearly define what it is.
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    Forum Junior TheDr.Spo's Avatar
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    Calling out my knowledge on this is merited, because the last book I read on String Theory is a bit out-dated at this point. Thanks for the reference to a more updated version, DrRocket.
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