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Quantum electrodynamics
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The theory of light and electrons.
QED describes the interaction of light and charged particles by exchanging photons. It predicts the electron's magnetic moment to 12 digits, the most accurate theory in science.
Lamb shift in hydrogen.
Needs renormalisation to remove infinities.
In more detail
Quantum electrodynamics describes how light and matter interact, with extremely precise predictions for quantities such as the electron's magnetic moment. It is the most tested theory in physics.
Real-world uses
- QED predictions match measured electron magnetic moments to many decimal places.
- It underpins technologies such as lasers and atomic clocks.
- Physicists use quantum electrodynamics to predict the magnetic moment of the electron with extraordinary precision.
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Frequently asked questions
Why is QED important?
It is one of the most accurate theories ever tested.
What does it describe?
Interactions between electrons and photons.
How accurate is QED?
It is one of the most precisely tested theories, matching measurements of the electron moment to many decimal places.
Related topics in Quantum Mechanics
Quantum statistics of light · Quantum field theory intro · Feynman path integral · Casimir effect · Quantum Hall effect · Superfluidity