The Prediction Graveyard

resolved · Earned

A previously unobserved anti-electron should have the electron’s mass and the opposite charge.

Source-backed summary; not presented as a verbatim quotation.

Paul A. M. Dirac
Theoretical physicist · United Kingdom

Made: 1931-09-01Resolved: 1932
Original conceptual trajectory diagram illustrating No cause of death assigned
Reasoning and outcomes. Original illustration for The Prediction Graveyard. Aniruddh Jangid, 2026. Original digital diagram. CC BY 4.0. Changes: none. This is a conceptual diagram, not an archival image.

The world at the time.

Dirac’s 1928 equation generated troublesome negative-energy solutions. After an unsuccessful proton interpretation, his 1931 paper proposed a distinct anti-electron.

What happened.

Carl Anderson discovered the positron in 1932. Subsequent pair-production observations supplied further confirmation.

Predicted vs actual.

MetricPredictedActualVariance / caveat
Anti-electronEqual mass, opposite chargePositron discoveredProperties confirmed

The counter-signal.

The proton was far heavier than the electron, and Weyl’s symmetry analysis ruled out treating a hole as a proton. That contemporary objection changed Dirac’s hypothesis before the positron was observed.

Verdict.

Reasoning: sound · Outcome: right

Credit attaches to the corrected 1931 prediction, not a claim that he unambiguously predicted a positron in 1928.

The 1931 explicit anti-electron claim is used, avoiding the common backdating to 1928. Day-level publication date comes from the bibliographic record; discovery kept at year precision.

Cause of death / explanatory lens.

No cause of death assigned

The lesson.

Should a successful forecast be dated to a precursor equation or to the explicit testable claim?

Sources.

  1. Quantised singularities in the electromagnetic fieldprimary · 1931 · explicit anti-electron prediction
  2. Quantised singularities bibliographic recordbibliographic · 1931-09-01 · publication date
  3. Dirac biographicalinstitutional_history · Date not established · 1932 discovery
  4. Hermann Weylscholarly_history · 2011 · contemporary mass objection

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