In the early 20 th century, physicists discovered cosmic rays- energetic particles zooming through deep space. Many of these come from the sun, and can cause the northern lights. However, a few, very mysteriously, come from somewhere else with enormous energy. “The real puzzle is no one has any idea what in the universe is capable of doing that," said Corbin Covault, professor of physics at Case Western Reserve University. "There's some ideas, like massive black holes sucking material down in