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Do photons relax?

  1. Jun 25, 2011 #1
    imagine a photon (travelling with the speed of light) is moving straight towards a huge mass say 10^10 Msun. what will happen to its speed/energy as it comes closer to it?
  2. jcsd
  3. Jun 25, 2011 #2


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    The speed remains constant, the energy increases as it falls into the gravitational potential well of the large mass.
  4. Jun 25, 2011 #3


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    As the energy increases the wavelength of the photon shortens. It blue shifts!
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