The Nothing That Has the Potential to Be Anything

Quantum mechanics reveals that even an empty box is far from empty.

Published on Feb. 15, 2026

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Quantum mechanics shows that even when a box is completely emptied of all visible contents, gases, and dark matter, it is still filled with ground-state or zero-point energy. This unavoidable residue is associated with fields like the electromagnetic field, as well as with discrete objects like atoms and molecules. The existence of zero-point energy has been used to explain various phenomena, from the vibrations of molecules to the failure of liquid helium to condense into a solid. While physicists have come to terms with the infinities involved, the gravitational effects of zero-point energy remain a mystery.

Why it matters

Zero-point energy is a fundamental concept in quantum mechanics that challenges our intuitive understanding of emptiness. It reveals that even the most seemingly empty spaces are filled with an invisible, ever-present energy that has profound implications for our understanding of the universe and the nature of reality.

The details

Zero-point energy arises from the fact that, according to quantum mechanics, particles and fields cannot be completely at rest, even in their lowest energy state. This is due to the Heisenberg uncertainty principle, which forbids precisely specifying both the position and momentum of a particle. As a result, particles exhibit a spread of values in their positions and velocities, even when they are in their ground state. This jittering motion is the manifestation of zero-point energy. Experiments have observed this effect, such as the recent study that found correlated motions in an organic molecule cooled almost to absolute zero.

  • In 1911, Max Planck first introduced the concept of zero-point energy.
  • In 1948, Hendrick Casimir predicted the force between two uncharged parallel plates, which was later observed in 1997.
  • In 1946, Wolfgang Pauli realized that the infinite or gargantuan amount of zero-point energy should create a powerful gravitational field, a mystery that still puzzles physicists.

The players

Max Planck

The physicist who first introduced the concept of zero-point energy in 1911.

Hendrick Casimir

The physicist who predicted the force between two uncharged parallel plates in 1948.

Wolfgang Pauli

The physicist who realized in 1946 that the infinite or gargantuan amount of zero-point energy should create a powerful gravitational field, a mystery that still puzzles physicists.

Peter Milonni

A theorist at the University of Rochester who studies the quantum vacuum.

Rebecca Boll

An experimental physicist at the European X-Ray Free-Electron Laser Facility near Hamburg.

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What they’re saying

“After that, 'it was Einstein, I think, who took it seriously for the first time,'”

— Peter Milonni, theorist (Quanta Magazine)

“That was not initially the main goal of the experiment. It's basically something that we found.”

— Rebecca Boll, experimental physicist (Quanta Magazine)

“All forms of energy gravitate. That includes the vacuum energy, so you can't ignore it.”

— Sean Carroll, physicist at Johns Hopkins University (Quanta Magazine)

What’s next

Physicists continue to investigate the nature and implications of zero-point energy, particularly its relationship to gravity, which remains a mystery.

The takeaway

Zero-point energy, the unavoidable residue that remains even in an apparently empty box, is a profound and counterintuitive concept in quantum mechanics that challenges our understanding of emptiness and the nature of reality. Its existence has been used to explain various phenomena, but its full implications, especially for gravity, are still being explored by physicists.