The next time the sun is shining, go outside.... There may not be a cloud in the sky, but you will be standing in the middle of a spectral rainstorm. Cosmic rays, emanating from all sorts of high-energy entities, constantly bombard Earth’s atmosphere.... Trillions of muons are shooting toward the ground at close to the speed of light every single second. When muons encounter an object, some pass right through while others get stopped in their tracks....