The strong force is a fundamental force that acts across the short range of the atomic nucleus to bind it together. The strong force reflects an interact between quarks that is mediated by the carrier particle (boson) termed the gluon. In addition to binding nucleons (i.e., neutrons and protons), the strong force controls interactions between mesons and baryons.

At the end of the nineteen century, two fundamental forces were known, the electromagnetic force and the gravitational force. As physicists began to study atoms and sub atomic structure, however, they discovered more forces at work. The first new force to be found was the strong force, responsible for binding protons and neutrons into atomic nuclei. Initially, the nucleus presented a puzzle to physicists because, according to electromagnetic theory, nuclei with larger numbers of protons should not be stable. The positive charges would repel each other, and...