Professor Susskind introduces the topic of modern Cosmology, which started with the discovery of cosmic microwave background radiation in 1964. However, this lecture focuses on the classical or Newtonian view of the universe. Beginning with the assumption of an isotropic universe with gravity as the only significant cosmic-scale force, Professor Susskind derives the equation for the Hubble constant, and demonstrates that the universe cannot be static - that it must be expanding or contracting.