Professor Susskind opens the lecture with one of the fundamental questions in cosmology: why are there more protons than anti-protons in the universe today? The answer lies in theory of baryogenesis in the very early universe. This theory leads to the Sakharov conditions, and the fact that the only general symmetry requirement under all conditions is complete charge-parity-time (CPT) symmetry.
Professor Susskind then introduces the concept of inflation in the early universe. He derives the basic equations of motion for inflation by starting with the equations for a falling particle in a gravitational field and a viscous fluid.