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Coupla questions

  1. Oct 30, 2003 #1
    1) Would the density of strings be constant throughout the universe,
    would they exist in a vacuum like the aether?
    2) Suppose I walk down the street. Do I carry the strings that make the particles of my body with me, or do strings along the way just vibrate to generate (new) identical particles.
  2. jcsd
  3. Oct 30, 2003 #2
    This appears to be a misconception. The strings replace the role of point particles in the Standard Model. You are made up of constantly vibrating strings, which behave (for the most part) just as point particles are supposed to. So, to speak of "me moving" is to speak of every particle (string), that helps compose your body, moving.
  4. Oct 30, 2003 #3
    misconception should be no surprise

    with this stuff. So the stuff I am made of is conjured by oscillating strings which I carry along with me (or they carry me along with them, whatever). I shine a light out into space and the energy which is light sends photons out into the void. The photons are also enerated by string oscillations, so strings are projected out from the beam?
    Am I being too mechanical about this?
  5. Oct 30, 2003 #4
    Re: misconception should be no surprise

    You're right. Some of the strings whose vibrations act like electrons in the flashlight break, and the new little bits of string that broke off vibrate to act like photons, and those strings fly off away from the flashlight, just as you would expect photons to do.
  6. Nov 1, 2003 #5
    Re: Re: misconception should be no surprise

    Nice way to give a non-technical explanation, Ambitwistor. Kudos. :smile:
  7. Nov 1, 2003 #6
    How about

    The first paragraph of a technical answer?
  8. Nov 1, 2003 #7
    Re: How about


    In quantum electrodynamics, you can write down the lowest-order Feynman diagram for the process of photon emission. It's a trivalent vertex, with one electron worldline coming in, and an electron and a photon worldline coming out. Slicing the diagram gives one or two points (depending on if you slice it before or after the emission), representing the particles at that instant of time. String theory's description of string emission is very similar: replace the points (particles) with line segments (strings). Over time, the string will sweep out a worldsheet (instead of a worldline for a particle), which branches into two worldsheets, one for the electron string and one for the photon string. If you look at time slices, you can see one string splitting into two, with the pieces travelling apart. That is where the original "electron string" breaks, leaving two strings: one is an "electron string" and another is a "photon string". One difference between this scenario and the QED scenario, other than the dimensionality, is that the photon is a fundamentally different particle from the electron, but in the string scenario, the resulting two strings are just pieces of the original string.
  9. Nov 1, 2003 #8
    Thanks, I could foller that

    It wern't too bad.
  10. Nov 2, 2003 #9
    boy, I don't think I know enough

    to respond to that, but speaking of "annihilating" how would the state of a string producing an electron differ from one producing a positron?
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