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!

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?
    Thanks.
     
  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.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook