Cosmic rays were first determined to be coming from outer space when...Victor Hess, in 1912, carried ionization chambers to high altitudes in a hydrogen balloon and detected an increase in radiation as he ascended (c). Hess's experiment on August 77th, 1912, was crucial in determining the extraterrestrial origin of cosmic rays. As he ascended, he noted that although the radiation levels initially decreased up to 2000 meters, they increased up to 5350 meters. Considering the times, it is amazing that Hess was even able to pull off the experiment, since he traveled to an altitude 1000 meters higher than Mount Ranier without an oxygen tank. A picture of Hess after the experiment is shown below.
Michelson and Morely did perform their famous interferometry experiment in 1887 (b), determining that there was no ether surrounding the earth, but this experiment had nothing to offer directly in the way of cosmic ray science. However, their experiment did help show that the speed of light is constant in all reference frames.
As far as we know, there was no sharp increase in cosmic rays observed with the release (or rerelease) of E.T. (a) and there was no reason that such an increase should have been expected.
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