Zero Point Energy
Classical physics says that a body may have zero energy. The kinetic energyof a body is zero ifand the heat energyis zero if the absolute temperatureis zero. Quantum mechanics however predicts the energy of a body may never be zero. A body must have energy at least equal to some minimum energy, called the 'zero point' energy.
In conventional quantum physics, the origin of zero-point energy is the Heisenberg uncertainty principle, which states that, for a moving particle such as an electron, a more precise measurement of position demands a less precise measurement of momentum or velocity and vice versa. A parallel uncertainty exists between measurements involving time and energy. This minimum uncertainty is not due to any correctable flaws in measurement, but reflects the wave nature of matter in quantum physics. This leads to the concept of zero-point energy.
Zero-point energy is the energy that remains when all other energy is removed from a system. As the temperature of liquid helium is lowered to absolute zero at normal pressure, helium remains a liquid rather than freezing to a solid, owing to the irremovable zero-point energy of its atomic motions. Increasing the pressure sufficiently may cause the helium to freeze.
A mass on a spring can always be brought to rest classically, but a quantum mechanical spring will always retain a small non zero motion due to the requirements of the Heisenberg uncertainty principle, resulting in a zero-point energy.
Quantum physics predicts that all of space must be filled with electromagnetic zero-point fluctuations (also called the zero-point field) creating a universal sea of zero-point energy. The photons are virtual and their lifetime is limited by the uncertainty principle:
With the decreasing size of electronic circuits, quantum mechanical effects will become more important. One of these effects will be that the zero point energy will appear as a background noise against the electronic signals that pass around the circuit.