Schrödinger's 1944 manuscript reveals hidden-variable model
A newly analyzed 1944-45 manuscript by Erwin Schrödinger details a hidden-variable model, showing it was a proof of principle for quantum randomness, not evidence of his belief in determinism.
A three-page handwritten manuscript by Erwin Schrödinger, discovered in an Austrian library after 80 years, sheds light on his views about determinism. Physics historian Flavio Del Santo of the University of Geneva brought the unpublished document, titled 'Collapse of Determinism,' to light from the Schrödinger archive at the University of Vienna. Written sometime after November 1944, the manuscript remained hidden for over eight decades and is now available on the preprint server arXiv.
Schrödinger's model
The manuscript details a model where particles have hidden values between zero and one, with a deterministic update rule after photon passage through polarizers. Schrödinger's model assigned particles a range of possible hidden values, not simple yes-or-no instructions. It proposed that hidden variables could take any value between zero and one, not only two values, and included a deterministic rule for updating the hidden variable after a photon passed through a polarizer. Del Santo's calculations confirmed the model matched quantum mechanics predictions. The model worked when light passed through multiple filters in sequence.
Historical context
Written between November 1944 and 1945 during the debate over the collapse of determinism, the manuscript remained unpublished until recently. Schrödinger had argued as early as the 1920s that the laws of nature might be fundamentally statistical, not governed by an underlying clockwork of perfectly predictable events. His position on indeterminism remained unchanged through the 1940s and beyond. The manuscript serves as a proof of principle against claims of the impossibility of hidden variables, not as a dogmatic commitment to determinism. The analysis suggests Schrödinger shelved the manuscript after learning of Edmund Taylor Whittaker's 1943 argument.
Schrödinger's stance
Schrödinger maintained that experimental evidence and logic could never prove determinism or indeterminism impossible, viewing classical determinism as a 'philosophic prejudice.' He argued that quantum mechanics does not prove determinism is impossible. Erwin Schrödinger said: "experiments and logic could never prove either view impossible." He described classical determinism as a 'philosophic prejudice' and an 'a priori belief.' The manuscript remains available on arXiv preprint server for further study.
