Wilczek, Frank Anthony (1951-...), an American physicist, won a share of the 2004 Nobel Prize in physics for his research into the force that binds together particles in the nucleus of an atom. Wilczek shared the prize with the American physicist David J. Gross, who was Wilczek's professor at the time the research was conducted. A share of the prize was also awarded to the American physicist H. David Politzer, who studied the same topic independently. The three scientists studied the behavior of quarks, tiny particles that make up protons, neutrons, and various other particles. Quarks are attracted to one another by a force called the strong interaction, one of the four fundamental forces of physics. The strong interaction is sometimes called the strong force or strong nuclear force.