Hi selfAdjoint,Originally posted by selfAdjoint
2) You have to have a specific event, such as a photon producing an electron and a positron. But in order to do that, the photon has to have enough energy to cover the masses of the two particles, 1022 electron volts. And the only photons with that kind of energy are up in the gamma ray range. Very few solar gamma rays (there are a few), make it down to the surface of the earth.