Bill Nye explores the most important discoveries leading to our understanding of the universe. The theories of Einstein and Galileo led to significant breakthroughs in understanding the universe. Additionally, the work of Aristotle, Copernicus, Kepler, and modern day astronomers, Paul Butler and Saul Pelmutter led to significant breakthroughs in astronomy. The great discoveries of astronomy have helped us begin to understand our vast universe. The more we learn, the more we have to question. One thing is certain: there are still many astonishing discoveries in astronomy to come and it willbe exciting to see themunfold.