Lost Schrödinger manuscript challenges view of quantum pioneer

Unearthed 1944 draft reveals physicist argued for the possibility of determinism

By LineZotpaper

Published20 October 2026

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A long-lost manuscript by quantum pioneer Erwin Schrödinger, unearthed in an Austrian archive by physicist Flavio Del Santo of the University of Geneva, is reshaping understanding of the Nobel laureate's philosophy. The three-page document, written in response to a heated 1944 debate in the journal Nature over the 'collapse of determinism,' reveals Schrödinger actively critiquing arguments against hidden variables, offering insight into a philosophical position more complex than his popular image as a champion of determinism.

The debate that prompted the manuscript began in the mid-1940s. Physicist Edmund Whittaker argued in a May 1943 lecture that quantum mechanics had finally proven classical determinism impossible. Satyendra Nath Bose made a similar case in January 1944, prompting a flurry of responses in Nature throughout the year.

Whittaker's central argument involved a thought experiment with photons and a polarising filter. He contended that if a photon carried a hidden variable determining its behaviour, changing the filter's angle while the photon was in flight would render that instruction useless, proving hidden variables could not exist.

Schrödinger, following the debate, identified a critical flaw. Whittaker had assumed the hidden variable could only take one of two values. Schrödinger constructed a mathematical model where a photon's hidden variable could take any value between zero and one, with a deterministic rule updating it after each interaction. This model reproduced quantum mechanics' probabilistic predictions without requiring pure randomness.

The manuscript's discovery sheds light on Schrödinger's own position. He is often painted as a champion of determinism, but the manuscript shows his views were more complex. Influenced by physicist Franz Exner, he described classical determinism as a 'philosophic prejudice' as early as the 1920s. 'Experimental evidence + logical deduction can never prove that either the deterministic or the indeterministic view is impossible,' he wrote.

Why the manuscript remained unpublished for over 80 years is a mystery. Del Santo suggests Schrödinger may have learned of a similar, if less complete, model from physicist Heinrich Pelzer in 1944 and decided the point had already been made.

Analysis

Why This Matters

The manuscript reframes the historical narrative around one of quantum mechanics' founders, showing him engaged in a deeper philosophical debate than usually credited.
It revives a decades-old discussion about the nature of quantum randomness that is central to how physicists interpret the theory.
Highlights the importance of archival research in uncovering the nuanced positions of historical scientific figures.

Background

The question of whether quantum mechanics is fundamentally random or governed by hidden variables is one of the deepest in modern physics. The indeterminate, or 'Copenhagen,' interpretation became the dominant view through the 20th century. The minority hidden-variable position, which this manuscript supports as a logical possibility, has seen periodic revivals and continues to motivate foundational research today.

Key Perspectives

Historians of Physics: The discovery by Flavio Del Santo is a significant archival find, revealing a previously unknown and substantive engagement by Schrödinger in a critical mid-century debate.
Proponents of Hidden Variables: The manuscript provides a new historical reference point, showing a founder of quantum mechanics developing a mathematical framework consistent with deterministic underlying laws.
Interpreters of Standard Quantum Mechanics: May note that Schrödinger himself was not arguing for determinism as a belief, but was critiquing the logical arguments against it. The manuscript reinforces that the debate was deeply nuanced even for its central protagonists.

What to Watch

Academic publication and detailed analysis of the full manuscript text.
Whether this discovery influences contemporary foundational physics research or historical narratives of quantum theory.
Further archival searches in the same collection for related documents from the 1940s debate.

Sources

A Lost Schrödinger Manuscript Reveals a Surprising Twist in Quantum Physics · ScienceAlert

Checked

10 claims in this story checked against 1 source: 6 supported.

Show each claim

SupportedThe lost manuscript challenges the view of Schrödinger as a champion of determinism.ScienceAlert: “Although Schrödinger is often portrayed as a champion of determinism, his own philosophical position was rather different.”
SupportedThe manuscript is a 1944 draft arguing that determinism was possible.ScienceAlert: “sometime after November 1944, he penned a response of his own”
Partly supportedThe document was unearthed by physicist Flavio Del Santo of the University of Geneva.ScienceAlert: “brought to light by physics historian Flavio Del Santo of the University of Geneva”
Partly supportedThe manuscript is reshaping understanding of Schrödinger’s philosophy.ScienceAlert: “it offers a surprising insight into what Erwin Schrödinger himself believed about the nature of reality”
Not in the sourcesSchrödinger was a Nobel laureate.
Partly supportedWhittaker’s and Bose’s arguments prompted a flurry of responses in Nature throughout 1944.ScienceAlert: “In July 1944, mathematician Henry Piaggio published an article in Nature titled “ Collapse of Determinism ,” reporting on Bose's arguments. It prompted a flurry of responses”
SupportedWhittaker argued that changing the polarizer’s angle while photons were in flight would make a hidden instruction useless.ScienceAlert: “changing the angle of the polarizer while the photons were in flight would render that instruction useless”
SupportedSchrödinger’s model allowed a photon’s hidden variable to take any value between zero and one and reproduced quantum probabilities without random interactions.ScienceAlert: “What if it could take any value between zero and one? He then constructed a mathematical model”
SupportedSchrödinger wrote, “Experimental evidence + logical deduction can never prove that either the deterministic or the indeterministic view is impossible.”ScienceAlert: ““Experimental evidence + logical deduction can never prove that either the deterministic or the indeterministic view is impossible ,” he wrote.”
SupportedDel Santo suggested Schrödinger may have learned of Pelzer’s similar model and decided the point had already been made.ScienceAlert: “Schrödinger may have learned of Pelzer's work and decided that the point had already been made.”

Correction

20 October 2026An earlier version of this story said the manuscript challenged Schrödinger's popular image as a defender of quantum indeterminism. The image it challenges is of him as a champion of determinism.