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Infrared Wavelength

  1. Jan 31, 2012 #1
    Do different materials (i.e. granite, steel, water, etc.), all at the same temperature, emit the same infrared wavelength?
  2. jcsd
  3. Jan 31, 2012 #2
    For the most part, yes. See 'kirchoff's[/PLAIN] [Broken] law'

    They will emit the same radiation if you think of them as perfect 'black bodies' (basically the simplest model of a thermal emitter). But materials are not perfect black bodies, and thus exhibit some differences in their spectra---largely from emission/absorption lines
    Last edited by a moderator: May 5, 2017
  4. Feb 2, 2012 #3
    Thank You.
  5. Feb 6, 2012 #4
    But they may not be observed [measured] as such when viewed from a distance, [redshift,blue shift] etc..
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