In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object. Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton.
It is important to realize that in physics today, we have no knowledge of what energy is. We do not have a picture that energy comes in little blobs of a definite amount.
Richard Feynman, in The Feynman Lectures on Physics (1964) Volume I, 4-1
If by free market one means a market that is autonomous and spontaneous, free from political controls, then there is no such thing as a free market at all. It is simply a myth.
Michael Hardt and Antonio Negri, in Multitude, p. 167
