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Old 01-06-2014, 05:41 PM
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sheeny (Al)
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Join Date: Jun 2005
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Quote:
Originally Posted by mithrandir View Post
Yes and yes.
If they weren't traveling at c they would have no mass/energy and not even exist.
Yes.

When a photon is created, it has finite energy (E = hv) and no mass, so the energy must move at c.

Think about it from the photon's POV: it does not experience time (because it moves at c in our reference frame) so only exists as a vector of energy from the start to where it is absorbed for an "instant". There is no option for it to exist at rest in our reference frame.

Al.
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