Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: CZARCAR on 27/11/2011 13:15:15
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i dont get it. if mass=0, then photon has no energy?
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That's only the correct equation when you're calculating the energy of something that is sitting still. Light always moves at light speed, so the correct equation in that case is:
E2=(mc2)2+(pc)2,
where p is momentum. A photon has no mass (m=0), but it has momentum, (p≠0). Therefore, it has energy.
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thanx