"A quantum is the smallest amount of energy that a system can gain or lose," explains Sam Rae, editor of the physics.org website.
Max Planck first started using the term in 1900 as part of a theory of physics at the sub-atomic level. In this theory light could be thought about as tiny lumps of energy as well as just a continuous wave, says Jim al-Khalili, professor of physics at Surrey University.
This idea of energy as tiny discrete particles was a major departure from classical physics and quantum theory was taken on by other notables such as Albert Einstein.
"It forms the foundation for most of modern physics and chemistry," says Prof al-Khalili "We wouldn't have CD players, iPods and mobile phones if quantum theory hadn't been. It is the most powerful theory in science."
adapted from bbc.newson release of quantum of solace this October 31
