In this clip from Genius by Stephen Hawking, the volunteers get to grips with the Machine of Life to understand the systems of the body. The machine is made up of lots of moving parts; it works by transferring an impulse from one place to another, sustained by the input of energy. Each moving part follows the laws of physics and together they keep the impulse moving. It's very much a chain reaction. The volunteers will come to terms with the similarities behind this process and what is going on inside their bodies. Where the machine features dominos and pool balls the human body has molecules, chains of atoms of carbon, oxygen, hydrogen, and other elements. The volunteers must work hard to keep the machine working.