The cosmos and its laws have fascinated people since the ancient times. Many scientists and philosophers have used mathematics to formulate their ideas and compute predictions. Today, we have made huge progress in understanding the universe. In this lecture, you will hear about two of the most famous physicists of all time, Isaac Newton and Albert Einstein, and about their theories of the universe. You will learn about common features and central differences in their viewpoints and in the mathematics they used to formulate their theories.