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Q & A: photon energy

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Most recent answer: 07/23/2010
Q:
If light has mass @ c but no mass at rest where did the mass go? Didn't Uncle Albert say matter cannot be created or destoyed? Which makes the statement that photons hitting a wall are destroyed very confusing.
- Keith F. (age 49)
Antrim , N.H. U.S.A.
A:
When photons are absorbed they no longer exist as photons but their energy continues to exist, often in the form of electrons being in higher energy states than they were initially. So the energy always goes somewhere. You can divide that sentence by c2 and say the mass always goes somewhere.

Mike W.

(published on 07/23/2010)

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