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What IS an em wave?

  1. Jul 28, 2013 #1
    i think i've asked this a number of times on different posts stemming from various discussions but i don't think this question was in the wrong thread. so i've decided to make a new thread for this.

    so what 'IS' an EM wave? i understand that the acceleration of charges could produce a wave (disturbance) in the E-field, and hence a sinusoidal oscillation of the charge would produce an EM wave; if all EM radiation are the same, except for their wavelengths, then this implies that EM radiation is just a transverse wave in the electric field right? ie, it is a transverse wave of the electric field?

    the process i gave describes the production of RF, which is radiated radially (in 2-D) from the antenna. but if you put a photodetector around the antenna, would it detect individual photons?
  2. jcsd
  3. Jul 28, 2013 #2


    Staff: Mentor

    It is a transverse wave in the electroMAGNETIC field. In an EM wave the magnetic field is perpendicular to the electric field and they are of equal magnitude (in units where c=1).

    It would be very hard to detect individual photons in the RF range, their energy is extremely small. In principle, it could be done, but in practice I think it would be undetectable.
  4. Jul 28, 2013 #3


    User Avatar

    Staff: Mentor

    No, as a photodetector doesn't work in the microwave/radio frequency regions. The energy of each photon is simply too small to cause the photodetector to detect them.
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