Democritus's particle theory states that each organism in the universe is made up of particles so minuscule that nothing smaller is possible. Democritus regarded those particles, commonly known as atoms, as unchangeable ... More »

Democritus, an ancient Greek philosopher, was not the first to propose an atomic theory, as his mentor Leucippus originally proposed it. Democritus adopted the theory, developed it further, and provided a more detailed a... More »

Democritus lived and worked in Abdera in Thrace from about 460 B.C. to 370 B.C. He also traveled a great deal to places, such as Babylon, Egypt, Ethiopia, India and Greece. More »

Isaac Newton's theory of gravity states that every particle in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square... More »

The particle theory of matter states that all matter is made up of tiny particles, specifically atoms and molecules, and that these particles have inherent characteristics. A major part of the theory is the belief that a... More »

According to About.com Scuba Diving, the Venturi effect states that when air is forced through a narrow tube, the air particles leave the tube traveling at a greater speed than when they entered the tube. This results in... More »

String theory involves the view of the manifestation of all fundamental particles in the universe and the configuration of the fundamental strings. A string is regarded as a one-dimensional filament of energy and is thou... More »