Written in 1944, a newly surfaced document reveals Erwin Schrödinger held deep beliefs about universal randomness long before modern quantum theory took shape.
Erwin Schrödinger Document Found in Austrian Library
A lost document authored by one of the creators of quantum physics has emerged from more than eight decades of obscurity inside an Austrian library archive. The short text contributes directly to the debates of the 1940s known as the collapse of determinism.
While Schrödinger is commonly remembered as a critic of quantum randomness, the newly surfaced notes show he believed certain aspects of the universe remained fundamentally unpredictable. This perspective stretched back before the formulation of quantum mechanics itself in the 1920s.
In the unpublished manuscript, the physicist wrote The strongest argument in favor of indeterminism is older than quantum mechanics
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Quantum Mechanics Introduces Probability to Classical Determinism
In classical physics, true randomness does not exist. Although rolling dice, computer random number generators, or flipping a coin involve complex physical forces and imperfections, those outcomes are theoretically predictable if all preceding conditions are known. This deterministic view holds that every event in the classical world is governed by prior physical rules. Quantum mechanics, however, operates on entirely different principles.
At the subatomic level, the behavior of photons and electrons can only be charted through probabilities. Physicists can calculate the statistical likelihood of a specific result with immense precision, but they cannot definitively predict what an individual particle will do. This gap fueled a historic debate over whether the universe is genuinely random at its core or if hidden variables—undetected properties or conditions—dictate particle behavior beneath the surface of current measurements.
Schrödinger Builds a Hidden Variable Model
During the scientific debates of the 1940s, Schrödinger developed a mathematical model designed to address the controversy. His framework relied on a combination of particle-specific hidden variables and surrounding environmental conditions to reproduce the probabilities predicted by quantum theory without requiring every separate interaction to be random by default.
Experimental evidence and logical deduction can never prove that the deterministic or indeterministic view is impossible.
Erwin Schrödinger
Despite constructing this model, Schrödinger never published the manuscript. Del Santo suggests that when physicist Heinrich Pelzer published a similar hidden-variable model in 1944, Schrödinger likely learned of the work and concluded the question had already been resolved.
Tracing Schrödinger Early Philosophical Influences
Long before drafting his 1944 manuscript, Schrödinger viewed classical determinism with skepticism. Influenced by physicist Franz Exner during the 1920s, Schrödinger dismissed classical determinism as a philosophical prejudice and an a priori conviction, arguing that nature’s laws might be fundamentally statistical rather than rigidly mechanical.
Why the three-page document remained shelved for over 80 years before being shared on the preprint server arXiv is still not known, leaving researchers to examine how these private writings reshape our understanding of quantum mechanics’ foundational thinkers.