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Photon and amplitude

  1. Jun 25, 2009 #1


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    Ok, i'm confused.
    Wavelength and frequency is basically the same thing, just different measures. Hight energy photon means that it has high frequency/ low wavelength.
    There are AM - amplitude modulators and FM - frequency modulators. (radio) Radio waves are photons, just really long ones.
    I don't get it: changing amplitude literally means how much energy you put in the wave, but changing frequency - the same. (??)
    When a photon is emitted in, for example, annihilation of electron and positron it is very energetic - high frequency photon is emitted (gamma ray). Whats the deal with amplitude? Can someone bring some clarity to this?
  2. jcsd
  3. Jun 25, 2009 #2
    One photon has the smallest amplitude - it is proportional to V-1/2, where V is the normalizing volume. A radio-wave with AM has different (varying) average number of photons of the same frequency, so it is the wave energy which is modulated.

    An FM wave has photons with different frequencies and possibly different amplitudes. An FM wave has also a variable in time energy and this is one of the ways to transmit (to code) information.

  4. Jun 25, 2009 #3


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    "Click", duh.
    Thanks, Bob! ;)
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