virtual photon

physics

Also known as: virtual particle

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July 14, 2026

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A virtual photon is a theoretical particle that mediates the electromagnetic force between charged particles. These photons are not directly observable because their existence briefly violates the conservation of energy and momentum. This temporary violation is permitted by Heisenberg's uncertainty principle, allowing energy to be "borrowed" for a very short time.123

Virtual photons are central to quantum electrodynamics (QED), a highly successful theory describing the interactions of charged particles and the electromagnetic field. In QED, charged particles interact by emitting and absorbing these virtual photons, which causes them to change speed and direction. While real photons constitute observable electromagnetic radiation like light, virtual photons are the unseen force carriers in interactions between charged particles.124

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quantum electrodynamics
These photons are “virtual”; that is, they cannot be seen or detected in any way because their existence violates the conservation of energy and momentum. The photon exchange is merely the “force” of the interaction, because interacting particles change their speed and direction of travel as they release…
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These photons are “virtual”; that is, they cannot be seen or detected in any way because their existence violates the conservation of energy and momentum. The photon exchange is merely the “force” of the interaction, because interacting particles change their speed and direction of travel as they release…
Read More

subatomic particle
Electromagnetism
…borrowed photons are called “virtual” photons to distinguish them from real photons, which constitute electromagnetic radiation and can, in principle, exist forever. This concept of virtual particles in processes that fulfill the conditions of the uncertainty principle applies to the exchange of other gauge bosons as well.
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…borrowed photons are called “virtual” photons to distinguish them from real photons, which constitute electromagnetic radiation and can, in principle, exist forever. This concept of virtual particles in processes that fulfill the conditions of the uncertainty principle applies to the exchange of other gauge bosons as well.
Read More