Essential Insights
- An unpublished Schrödinger manuscript challenges claims that hidden variables are impossible.
- His photon model reproduced quantum probabilities and accounted for successive measurements deterministically.
- Yet Schrödinger personally favored indeterminism, viewing classical determinism as philosophical prejudice.
- Rediscovered decades later, his work urges openness in debates about quantum reality.
A newly uncovered three-page manuscript complicates the familiar story of Erwin Schrödinger as a critic of quantum randomness. Written in the 1940s but never published, it argues that physicists could not rule out hidden variables—unknown factors that might shape the behavior of individual particles.
The document does not show that quantum mechanics is wrong. Instead, it challenges a claim that determinism is mathematically impossible.
A brief case for hidden variables
Quantum mechanics predicts the behavior of particles in probabilities. It can tell scientists how likely an outcome is, but not exactly what a single particle will do. That leaves a lasting question: Is randomness built into nature, or do hidden conditions govern outcomes?
A 1932 argument by mathematician John von Neumann was widely taken as proof that hidden-variable explanations could not work. In the 1940s, physicist Edmund Whittaker offered a separate argument using photons and polarizing filters. He said a photon could not carry a fixed instruction for passing through a filter, because changing the filter’s angle could make that instruction fail.
Schrödinger challenged the setup. Whittaker had limited the hidden information to two possible values, but Schrödinger saw no reason it could not take a continuous range. He devised a model in which the result depended on that value and the filter’s angle. He also proposed a rule for updating the value after a measurement, allowing the model to address later measurements.
Possibility is not proof
The manuscript’s central point was measured: evidence and logic alone could not prove that either determinism or indeterminism was impossible. Schrödinger was defending the possibility of a deterministic model, not declaring that nature must follow one.
That distinction also reframes his own views. He had questioned classical determinism before quantum theory took shape, and the manuscript suggests he continued to accept that nature might be fundamentally unpredictable. His argument was not a conversion to certainty, but a warning against closing off alternatives too soon.
The episode offers a useful lesson for science and technology: a model can show that an idea is possible without proving it describes reality. Schrödinger’s proposal did not settle the debate, and quantum mechanics remains exceptionally successful. But it reveals how assumptions built into a model can shape what scientists consider possible.
Continue Your Tech Journey
Explore the future of technology with our detailed insights on Artificial Intelligence.
Explore past and present digital transformations on the Internet Archive.
QuantumV1
