1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Coherent waves?

  1. Jul 18, 2011 #1
    is it necessary ffor coherent waves to be of same frequency? bcoz everywhere i read its written dat they must have a constant phse difference. but cant they have frequencies dat are simple numerical multiples of each other?
    like 256 512
     
  2. jcsd
  3. Jul 18, 2011 #2

    Drakkith

    User Avatar

    Staff: Mentor

    That depends on what you mean by coherent. Coherence just describes the correlation of the properties of waves. See here: http://en.wikipedia.org/wiki/Coherence_(physics [Broken])
     
    Last edited by a moderator: May 5, 2017
  4. Jul 19, 2011 #3
    i think yes.. being multiples makes waves beat at the frequency that is HCF of both the frequencies.
     
  5. Jul 19, 2011 #4

    sophiecentaur

    User Avatar
    Science Advisor
    Gold Member

    There is a constantly changing phase difference between a fundamental and second harmonic. 2πf radians per second, actually. It just happens that, every cycle of the fundamental, the phase is a whole number of cycles.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook