From what I have gathered, whether or not decoherence has solved the measurement problem is still a matter of debate. But to those who say that it does, my question is: how does it solve it? Does it actually cause the collapse of the wavefunction? These questions are actually pieces of a larger puzzle I am trying to put together: Has the superposition of states of quantum entities which are not being observed by a conscious mind collapsed, or not? E.g. are the photons of light from a light bulb in a superposition of states when noone is looking, or has decoherence already caused the collapse? If anyone can help me in trying to put the pieces together I'd appreciate it! P.S. I know that I could gather alot of info on this topic via an engine search, but as a non-scientist I find the accompanying mathematical formulae too hard to understand. I would appreciate if people could keep explanations simple. Thanks!