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Stadium Wave as Longitudinal Wave in Terms of Transmission

  1. Jul 18, 2010 #1
    So, the common high school physics example of a transverse wave is a "stadium wave" ... but, I'm wondering if this is actually longitudinal in terms of particle transmission. Each particle (audience member) is only standing up/down. The particles/audience stay in place and don't propagate/run down the seats.

    Light is (almost trivially) referred to as a transverse wave, but how do the photons "move"? In sound, the particles are disrupted... are the photons disrupted?
  2. jcsd
  3. Jul 20, 2010 #2
    No the stadium wave is purely transversal. If you plug a guitar string it is also purely transversal. The wave may propagate back or forth or in a circle, but as long as the amplitude is perpendicular to the propagation direction, it is transversal. That is the whole point of the definition. The equivalent of a longitudinal wave for people is http://www.youtube.com/watch?v=iQOYRr1ijrg" (look at the audience and enjoy the corny music :rofl: )

    Edit: http://www.youtube.com/watch?v=8rRL3BwcoF8"

    Photons work very different from other waves there is no medium and you shouldn't imagine one.
    Last edited by a moderator: Apr 25, 2017
  4. Jul 20, 2010 #3
    You're confusing some things. The people in the audience are not particles, they are the medium through which the wave travels. The "particle" is the bulge in the medium - the people standing - which propagates through the audience.

    For light, photons are not - like gas atoms for sound - a medium. They are wave packets, like the bulge moving through the audience, and as such they propagate.
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