What’s the difference between a discovery and a theory? Imagine a pirate searching long and hard on the hot sandy beach of a deserted isle, the tropic sweat oozing from his pores. He fiercely digs beneath the sand until he unearths a rusty treasure chest. He opens the ancient strongbox. If it contains gold doubloons, he has a major discovery in his hands. If it contains a parchment filled with differential calculus, all he has is a theory. So, while the Theories category honors the mathematicians, in the Discoveries category we pay homage to the lab rats.
The ACIS data suggests cosmic rays come not from the birth of atoms, as originally proposed by Robert Millikan, but from the death of stars.