Lost Schrödinger manuscript reveals his hidden-variable quantum model

Overview

Updated 1 hour ago

A three-page draft by Erwin Schrödinger sat unnoticed in the University of Vienna archive for 82 years. The quantum pioneer wrote it in late 1944 to show that determinism couldn't be ruled out — a position he refused to abandon even though he leaned toward indeterminism.

Physicist Flavio Del Santo at the University of Geneva transcribed the manuscript for the first time and posted his analysis on arXiv. The draft contains a working hidden-variable model for photons, and it reframes the 1940s debate over 'the collapse of determinism' — a debate that connects directly to today's questions about what quantum randomness means.

Why it matters

Schrödinger's 1944 draft shows quantum mechanics' founders never settled whether the universe is deterministic — a question physicists still debate today.

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Key Indicators

Years manuscript sat unpublished

Drafted in late 1944, the three-page response remained in Vienna's Schrödinger archive until 2026.

Manuscript pages

Schrödinger's handwritten response ran three pages.

0–1

Range of Schrödinger's hidden variable

His model gave each photon a hidden value anywhere between zero and one, not just two choices.

Voices

Curated perspectives — historical figures and your fellow readers.

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People Involved

Erwin Schrödinger

Nobel Prize-winning physicist, author of the lost manuscript

Deceased (1887–1961); manuscript rediscovered in 2026

Flavio Del Santo

Physicist at University of Geneva, analyzed the manuscript

Active; posted analysis on arXiv in October 2026

E.T. Whittaker

Mathematician whose 1943 lecture opened the determinism debate

Deceased (1873–1956)

Satyendra Nath Bose

Physicist whose 1944 address fed the debate

Deceased (1894–1974)

Heinrich Pelzer

Physicist who published a competing hidden-variable model in 1944

Deceased

Organizations Involved

University of Vienna

University

Holds the Schrödinger archive containing the lost manuscript

The Schrödinger archive at the University of Vienna held the unpublished three-page manuscript for 82 years.

University of Geneva

University

Institution of the researcher who analyzed the manuscript

Flavio Del Santo conducted his analysis of Schrödinger's manuscript at the University of Geneva.

Nature

Scientific journal

Venue of the original 1944 debate

The journal where the 'collapse of determinism' debate played out in 1944.

Timeline

May 1943 October 2026

7 events Latest: Yesterday

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October 2026
Manuscript's contents revealed to the public
Latest Publication

ScienceAlert and other outlets publish detailed accounts of Del Santo's study, bringing the lost draft to wide attention.
Yesterday
Del Santo posts analysis on arXiv
Research

Flavio Del Santo publishes the first transcription and analysis of Schrödinger's manuscript, reconstructing the debate's history.
October 2026
November 1944
Schrödinger drafts hidden-variable response
Manuscript

Schrödinger writes a three-page response giving photons a continuous hidden variable and a rule for updating it. He never publishes it.
November 1944
July 1944
Nature reports Bose's address
Publication

Mathematician H.T.H. Piaggio writes up Bose's address for Nature under the title 'Collapse of Determinism,' reaching European physicists.
July 1944
January 1944
Bose addresses Indian Science Congress on determinism
Address

Satyendra Nath Bose delivers his presidential address to the Indian Science Congress in Delhi, arguing determinism had collapsed.
January 3rd, 1944
1944
Pelzer publishes hidden-variable model
Publication

Heinrich Pelzer publishes a model showing Whittaker's argument that photons can't carry hidden instructions doesn't hold.
1944
May 1943
Whittaker argues quantum mechanics ended determinism
Lecture

E.T. Whittaker gives the Guthrie Lecture in London, arguing quantum mechanics destroyed the classical idea of a predictable universe.
May 1943

Scenarios

Del Santo's analysis clears peer review and publishes in a journal

Likely Resolves by End of 2027

Discussed by: The paper is currently an arXiv preprint; Del Santo's prior work has appeared in peer-reviewed venues in quantum foundations.

Del Santo submits his transcription and analysis of Schrödinger's manuscript to a peer-reviewed journal in the history of physics or quantum foundations. Acceptance would make the study the canonical reference for the episode and likely draw further scholarly attention to the manuscript.

Vienna archive digitizes the Schrödinger manuscript

Possible Resolves by Q2 2028

Discussed by: Del Santo's study relies on archival documents; digitization typically follows scholarly interest.

The University of Vienna's Schrödinger archive releases a digital scan of the three-page draft, making it accessible to researchers and the public. This would allow independent verification of Del Santo's transcription and broader study of the document.

Schrödinger's model enters the living determinism debate

Possible Resolves by End of 2027

Discussed by: The sanjaysays.com analysis notes that Bell's later work suggests Schrödinger had the better of the argument against impossibility proofs.

A paper in a major physics or foundations journal cites Schrödinger's 1944 model in the current debate over hidden variables and quantum randomness, beyond purely historical treatment. The sanjaysays analysis argues Schrödinger's 'caution stands' against later impossibility proofs, making such a citation plausible.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1952

Bohm's pilot wave theory (1952)

David Bohm published a fully deterministic hidden-variable theory, the pilot wave, that reproduces all quantum mechanics predictions. It was largely ignored for decades before gaining attention.

Then

Bohm's theory demonstrated mathematically that a deterministic reformulation of quantum mechanics was possible, contradicting the prevailing orthodoxy.

Now

It became the leading example of a viable hidden-variable theory, revived in modern foundations-of-physics debates.

Why this matters now

Bohm's work shows deterministic models of quantum mechanics were viable, echoing the proof-of-principle approach Schrödinger took in his lost manuscript.

1932–1935

Von Neumann's impossibility proof and Grete Hermann's critique (1932–1935)

John von Neumann's 1932 book claimed to prove that hidden variables were impossible. In 1935, philosopher Grete Hermann identified a flaw in the proof, though her critique went largely unnoticed until Bell's 1966 paper dismantled von Neumann's argument.

Then

Von Neumann's proof was widely accepted, and Hermann's critique was ignored for decades.

Now

Bell's 1966 analysis confirmed Hermann's objection, showing that a celebrated impossibility proof was wrong.

Why this matters now

The episode supports Schrödinger's 1944 refusal to call determinism impossible — a well-known 'impossibility proof' later collapsed under scrutiny.

1964

Bell's theorem (1964)

John Bell published a theorem showing that no local hidden-variable theory can reproduce all predictions of quantum mechanics. Subsequent experiments confirmed the inequalities he derived.

Then

Bell's work ruled out local hidden variables, a major constraint on deterministic reformulations.

Now

It showed that while determinism might not be impossible, local hidden variables cannot match quantum mechanics. Experiments continue to test the boundaries.

Why this matters now

Bell's work validated Schrödinger's caution that no proof can settle the determinism question, even as it closed off local hidden-variable models.