Recent content by freetheparticle

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    Undergrad How can a photon "stimulate emission" if it really does (Einstein coefficients)

    Okay, but how does an external photon cause the particle to emit a photon of the same state? I don't see how it can encourage the particle to radiate a different photon.
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    Undergrad How can a photon "stimulate emission" if it really does (Einstein coefficients)

    Einstein coefficients tell us that there is some probability for an atom to go from E_1 to E_2 given by the coefficient of absorption. This is fine, but why is there only one coefficient (absorption) going from E_1 to E_2 and two for the transition E_2 to E_1? Spontaneous emission makes sense...
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    Undergrad How can photons interact if they travel at the speed of ligh

    I was listening to a podcast about the solar neutrino problem, and they discussed how we have deduced that neutrinos are not massless due to the fact that they interact with other particles (even if this interaction occurs rarely). I paraphrase: "a particle traveling at the speed of light is...