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Light and Matter interaction

  1. Aug 30, 2012 #1
    How does light cause matter to move? For example, when a photon collides with an atom, an electron absorbs the photon and moves to a higher energy state. If the energy is not used then the electron falls back to a lower energy state and emits radiation. I am unsure of how the photon in the above example causes the motion of an atom. A more specific question is how does sunlight increase temperature, or speed up the motion of the gas particles in the atmosphere.
  2. jcsd
  3. Aug 31, 2012 #2


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    Staff: Mentor

    Light is an EM wave whose fields have what's called vectors. This means that an electric charge that the wave passes over will feel a force from the electric field of the EM wave in a particular direction. It is this force that causes an interaction. Each individual interaction takes a specific amount of energy based on the frequency of the wave. We call these "photons".
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