The Four Fundamental Forces
THE FOUR FUNDAMENTAL FORCES
The interactions between matter can be explained by four forces:
Gravitational: The weakest of the four forces, the gravitational force is the mutual attraction between masses. Although its effect is small in the realm of subatomic particles, it has great cosmic power, and is the force that holds solar systems and galaxies together.
Electromagnetic: This force explains the magnetic field and the electron-nucleus structure of an atom.
Strong: Some 100 times stronger than the electromagnetic force, the strong force holds together the protons and neutrons within an atomic nucleus.
Weak: This force is associated with the radioactive beta-decay of some nuclei. The electromagnetic and weak forces have recently been shown to be part of an electro-weak force.