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EM waves

  1. Jan 26, 2010 #1
    Can man-made EM waves produce physical vibrations of objects? Can man-made EM waves vibrate powders like sand or talc?
    I'm trying to understand if any types of electronic frequencies can cause physical vibrations...thanks.
  2. jcsd
  3. Jan 26, 2010 #2
    Light and other em waves carry a (small) momentum, so they 'push' on things very slightly but you need a lot of light.
  4. Jan 26, 2010 #3
    Hmmm, makes sense since light has mass.....
    What about inaudible radio waves such as ULF, ELF, LF? Can they cause physical vibrations?
  5. Jan 26, 2010 #4
    Photons don't have rest mass but they do have momentum. Any frequency em radiation is the same basic phenomenon as light.
  6. Jan 26, 2010 #5
    * Light (and other EM radiation) actually is mostly likely massless (or at least absolutely-ridiculously small).

    * 'Vibrations' is vague. EM radiation can heat substances and 'push' substances. Heat is a form of 'vibration' if you will. (EM radiation can also obviously do other stuff too)

    * Inaudible radio waves? I wasn't aware any EM waves were 'audible'.

    * Not all substances absorb / reflect all em waves.

    So, for the things that do absorb / reflect ULF, ELF, LF will in return be imparted heat, or a 'push'. But I need to reiterate how small this force is... and heat is your most likely return... the material would have to be reflective to get a 'push'.
  7. Jan 26, 2010 #6
    Ok, thanks.
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