Zerpa

Meet Zerpa, a quantum oscillator who can never be perfectly still, even at absolute zero.

A mass on a spring in classical physics can have any energy, including zero. In quantum mechanics a harmonic oscillator can only have energies E_n = ħω(n + ½), for n = 0, 1, 2 and so on. The levels are evenly spaced by ħω. And the lowest level, n = 0, is not zero but ħω/2: the zero-point energy.

The reason is the uncertainty principle. To have zero energy, the oscillator would need to sit exactly at the bottom with exactly zero momentum, and quantum mechanics forbids pinning down both. The ground state is the best compromise, a small spread in position and momentum.

Zero-point motion is real and measurable. It is why liquid helium does not freeze at normal pressure even near absolute zero, and it shifts the vibrational energies of molecules, which shows up in their spectra.

Zero-point energy is sometimes misrepresented as a source of free power. It is the lowest possible energy, so no energy can be extracted from it.