George S. Greenstein (Section 01)
In recent years, astronomers have come to realize that the view of the universe we get through telescopes is not telling the whole story. Rather, in addition to all the astronomical objects that we can observe, the universe contains an enormous number of unseen things: objects which we have never directly detected and, in some cases, which we never will. Some of these objects are black holes, some are planets orbiting nearby stars, and the nature of the rest-the mysterious "dark matter"-is entirely unknown. First semester. Professor Greenstein.