The expansion of the universe and the intensity of cosmic rays

Abstract

It was pointed out by Zwicky(1) that the distance which a light quantum can travel is, perhaps, limited. Its frequency v and energy hv are affected by the astronomical red shift and may be reduced to the vanishing point if the distance is sufficiently large. Experimentally the dependence of the red shift upon the travel time t – t0 follows very nearly (within the limits of error) a linear law up to t – t0 = 10^(8) years and amounts to k = -▲v/v = 0.56 X 10^(-9) per year. If it is permissible to extrapolate the linear law to larger distances, the light quantum will vanish for t – t0 = 1.8 X 10^(9) years. All the radiation received by a terrestrial observer must, in this case, be derived from a space limited by this radius and this involves serious difficulties for the explanation of the rather high intensity of cosmic rays.