25 questions · 14 almanac · 0 findings

Quantum Electrodynamics

The quantum field theory of light and charged matter.

Almanac The Proton Misbehaved on Purpose
  • Why did the measured magnetic moment of the proton come out nearly three times higher than the simple Dirac prediction?
Almanac A Crack in Dirac's Perfect Equation
  • What discrepancy did Willis Lamb find between Dirac's equation and the measured energy levels of hydrogen?
  • What wartime radar technology let Lamb make microwave measurements precise enough to catch the Lamb shift?
  • How did Lamb and Kusch's small experimental anomalies lead to the development of quantum electrodynamics?
Almanac No Law Forbids the Very Small
  • What question did Feynman ask about whether physical laws prevent building machines at the molecular or atomic scale?
  • What cash prizes did Feynman offer for miniaturization challenges, and were they ever claimed?
  • Why is Feynman's 1959 lecture considered the founding document of nanotechnology even though it proposed no specific technique?
Almanac Why Anything Weighs Anything
  • What contradiction in gauge theory made it necessary to explain how the W and Z bosons could have mass?
Almanac A Hair's Width From New York to LA
  • Why had quantum electrodynamics been producing infinite, unusable answers before renormalization fixed it?
  • How precisely do QED's predictions match experimental measurement, and what does that precision actually mean in physical terms?
  • What are Feynman diagrams, and why did they make QED calculations easier for other physicists to use?
  • How did Freeman Dyson show that Tomonaga's, Schwinger's, and Feynman's independently developed approaches were equivalent?
Almanac All Scales at Once, Finally
  • What does it mean for fluctuations to occur 'at every scale of length simultaneously,' and why did that break the standard tools of physics?
  • How did Wilson's renormalization group get adopted outside condensed matter physics, into quantum field theory?
Almanac Taming the Infinities in the Standard Model
  • What made the electroweak theory's calculations produce unusable infinities before 1971?
  • How did 't Hooft's renormalisability proof turn the Standard Model into a mathematically trustworthy structure?
  • Why does the mass of the Higgs boson trace back to work done in Utrecht in the early 1970s?
Almanac A Synthesiser, Not a Student
  • What did Freeman Dyson's 1949 paper prove about the three competing formulations of quantum electrodynamics?
  • Why was Dyson's contribution described as synthesis rather than original discovery?