What does a physicist do?
Physicists are interested in finding out what makes the universe tick. There are different kinds of physicists that study very different things. For instance, astro-physicists study the stars and planets. They are interested in how the stars and planets are born and what causes them to behave the way they do. It was a physicist that discovered the first "black hole." Many astronomers are physicists. Then there are nuclear physicists. They are interested in observing the smallest particles which are called "quarks" and determining how they fit together and form different substances. All physicists are interested in discovering the unknown, whether it be a new star or planet or the nature of the particles that form the nucleus of the atom.
Bill Kozma, Accelerator Coordinator (Other answers by Bill Kozma)