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EM waves

  1. Jun 13, 2009 #1
    My notes say that Heinrich Hertz was the first to generate and detect EM waves in the lab.
    ... Uhhh, this might seem really basic to you guys, but what exactly are EM waves?

    Because I thought they were any type of wave that appears on the electromagnetic spectrum, including visible light. So how is it that this guy was the first one to generate them in a lab? I mean, don't you just turn on a light??
     
  2. jcsd
  3. Jun 13, 2009 #2

    atyy

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    Science Advisor

    Yes, light is an EM wave, so that statement about Hertz can't be quite correct. When you light a candle you generate light, and when you see something, you are detecting EM waves.

    However, it wasn't known that light was an EM wave until Maxwell or later. So it's something like Hertz demonstrated that EM waves as predicted by Maxwell exist.
     
  4. Jun 14, 2009 #3

    jtbell

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    Staff: Mentor

    http://hyperphysics.phy-astr.gsu.edu/HBASE/Waves/emwavecon.html#c1

    Electromagnetic waves include visible light, but they aren't limited to visible light. They also include infrared ultraviolet, radio, microwave, etc. How you produce them depends on what part of the spectrum they're in. The waves Hertz generated were in what we now call the UHF radio/TV band. To see how he produced them, try Googling on something like "Heinrich Hertz radio waves".
     
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