My general question is: can high energy photons convert into many lower energy photons? Could the reverse reaction occur spontaneously?
Let's say we have a single photon that was emitted from a distant supernova. We detect it here on Earth. The photon hasn't converted into multiple lower...
I've been writing a lot recently about whether the reason for the increase of entropy over time (i.e. the second law of thermodynamics) is the time irreversibility of the weak nuclear force. I would like to get some people's thoughts on this topic (perhaps links to important papers on this...