Who is Max Planck from A Brief History of Time and what is their importance?

Max Planck introduces the idea that light is emitted in packets that he calls quanta. This idea leads to quantum mechanics, a theory that explains how very small particles, such as electrons, behave. A critically important part of the theory is the uncertainty principle, where the position and velocity of any given particle could be a number of possibilities, and that probability plays a part in how the universe works. Hawking combines quantum mechanics with relativity and proposes a very different view for the origination of the universe: the universe may have always existed, and may do so forever.