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Photon direction

  1. Jun 9, 2014 #1
    So I'm trying to figure out something I don't understand about the direction of radiation when a charge is accelerated. I know that when a charge is accelerated it gives off EM radiation, which I kind of picture as the electric field of the charge 'wiggling' spherically all around it. If that picture is right, how does the photon know which way to go if say the charge is accelerated to the right. The disturbance in the electric field is spherically symmetric, is a photn emitted in all directions?

    I'm trying to relate this to what I know about atoms, I figrue if an electron drops down an energy level in an atom you can tell the direction of the photon emission by measuring the recoil of the atom. But I figure the electric field must wiggle in a similar way in that case, since the electron dropping down is similar to an accelerating charge.

    I guess it comes down to what determines the direction of a photon emission in either case? Tried not to be too confusing.
  2. jcsd
  3. Jun 9, 2014 #2
    In both cases the photon is emitted in some random direction. If you get many photons than they will distribute themselves along many different directions around the accelerating atom. That won't really be a spherically symmetric distribution since the acceleration has a direction in space which breaks the symmetry, but the distribution will be axially symmetric around that direction.
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