Since these other forces are not the main focus of this project, they will not be described in great detail.

In short, this theory basically stated that light is just a disturbance caused by the rippling of the fifth dimension, which is too small for us to detect. This is similar to a theory stated by a German physicist named Riemann, who believed that electricity, magnetism, and gravity are caused by the crumpling of our three-dimensional universe into the unseen fourth dimension. According to the Kaluza-Klein theory, the fifth dimension was rolled up into a space of 10^-33 cm. However, this theory was unable to be proven correct because of the large amount of energy (10¹⁹ billion electron volts) needed to actually probe such a small distance.

This theory is very detailed and complicated. It deals mainly with subatomic particles such as quarks, leptons, muons, and neutrinos. Quantum Mechanics is based mainly on four concepts.

1. Forces are created by the exchange of discrete packets of energy, called quanta.
2. Different forces are caused by the exchange of different quanta.
3. We can never know simultaneously the velocity of a subatomic particle and its position (the Heisenburg Uncertainty Principle).
4. There is a measurable probability that particles may "tunnel" through or make a quantum leap through impenetrable barriers.

The Standard Model is probably the most successful theory in the history of science, because it can explain every piece of experimental data concerning subatomic particles. Basically, the theory states that all matter consists of quarks and leptons, which interact by exchanging different types of quanta. There are three forces created:

1. Strong Force - protons, neutrons, and other heavy particles consist of smaller particles called quarks which are held together by small packets of energy called gluons.
2. Weak Force - "leptons" such as electrons, muon, tau mesons, and neutrinos interact by exchanging quanta, called W and Z bosons.
3. Electromagnetic Force

Superstring theory states that all matter is made up of tiny vibrating strings that are composed of six dimensions curled up into a space of 10^-33 cm, a distance which is referred to as the Planck length. Particles of matter are actually represented by different modes of vibration of these strings. The strings interact by breaking into smaller strings and by joining with other strings, and this causes forces such as gravity to occur.