What is physics?

This passage from an article written by John J. Hopfield, who served as President of the American Physical Society in 2006, is a beautiful summary of "what is physics". I hope you enjoy reading it and come to understand a little bit more of the world I get to play in every day. :)

What is physics? To me—growing up with a father and mother both of whom were physicists—physics was not subject matter. The atom, the troposphere, the nucleus, a piece of glass, the washing machine, my bicycle, the phonograph, a magnet—these were all incidentally the subject matter. The central idea was that the world is understandable, that you should be able to take anything apart, understand the relationships between its constituents, do experiments, and on that basis be able to develop a quantitative understanding of its behavior. Physics was a point of view that the world around us is, with effort, ingenuity, and adequate resources, understandable in a predictive and reasonably quantitative fashion. Being a physicist is a dedication to a quest for this kind of understanding.

—John J. Hopfield, APS News, 16 (8), Aug/Sep 2007, p.8.