Amplitude and frequency dependence on energy of a wave.

  1. Hello all,

    I have learned that the energy of a wave is proportional to the square of its amplitude. I have also learned (by the Planck relation) that the energy of a wave is proportional to the frequency of the wave. Doesn't this imply that the frequency of a wave is proportional to the square of its amplitude? I know this deduction is wrong; what am I messing up here??

    Thanks for your help and time,
    F2
     
  2. jcsd
  3. The energy of a photon is proportional to its frequency. Eγ=hv where h is Planck's constant and v is the frequency.

    The energy of an EM wave is indeed proportional to the square of its amplitude. But this wave is made of many individual photons. An EM wave coming from a blue light can have the same energy as an EM wave coming from a red light, but the red light will consist of more photons to make up for a smaller energy per photon.
     
  4. So is a photon a wave packet, and an EM wave a composition of wave packets (photons)?
     
  5. davenn

    davenn 3,884
    Science Advisor
    Gold Member
    2014 Award

    Hi Famwood2

    that's my understanding, Yes tho through reading I understand that a photon doesn't have to be restricted to a wave packet

    here's a couple of articles you may find interesting :smile:

    Photon wave functions, wave-packet quantization of light, and coherence theory
    http://arxiv.org/ftp/arxiv/papers/0708/0708.0831.pdf


    Focus: Shaping Single Photons
    Published September 5, 2008 | Phys. Rev. Focus 22, 8 (2008) | DOI: 10.1103/PhysRevFocus.22.8

    cheers
    Dave
     
  6. Thanks!
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook

Have something to add?

0
Draft saved Draft deleted