Mysteries of the Universe

1900: We know the distances to 70 of the nearest stars. There are no galaxies except for the Milky Way, although some astronomers do believe that some of the fuzzy "nebulae" seen in the night sky are separate, very distant galaxies. The universe is unchanging. Newton's laws are used to explain all physical phenomena. The elements that have been identified are believed to be built of indivisible atoms that are the "essence" of the element. Physicists believe there is little more to be discovered in their field. However, there are a few nagging issues, such as the behavior of light, which will spur a revolution in the field as the new century begins.