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Radiant heat energy

  1. Nov 27, 2009 #1
    why does your hand not feel the radiant heat energy from a fireplace if you place it behind a sheet of glass, even though you can see the fire very easily?
  2. jcsd
  3. Nov 27, 2009 #2
    I've never noticed that. Do you know the greenhouse effect?
  4. Nov 29, 2009 #3
    Really? I doubt it.
    Why can my hand feel the radiant heat from the sun if we place it under glass?

    And what is the relation between the question and the greenhouse effect?
  5. Nov 29, 2009 #4
    If you have a barrier (glass or atmosphere) that is opaque to infra-red but transparent to visible light, it will let plenty of energy in during the day, and still block much of the heat-loss during the night. (The key is the differences between the radiation spectra from either side.)
    Last edited: Nov 29, 2009
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