Einstein liked Quantum Mechanics

“In my opinion, this theory [quantum mechanics] contains without doubt a piece of the ultimate truth.“ Einstein, in 1931.

“Quantum Mechanics represents an important and in some sense even conclusive advance in physical knowledge.” Einstein, in 1948.

Follow-up to my blog post last month about the EPR paper, in which I griped about a pet peeve of mine, the persistent myth that Einstein disliked (sometimes it is said that he hated) quantum mechanics. Einstein disagreed with Bohr and Heisenberg and others about the conclusions one should draw from the success of quantum theory, and he disliked the Copenhagen philosophy (or philosophies), but that’s not the same as disliking quantum mechanics. All the evidence I know of indicates that he appreciated as much, or more, as anyone else what a significant advance in physics the theory was.

It is true that one can find some negative comments in some letters. For example, one finds, in a letter to Ehrenfest, in January 1927, “My heart does not warm to Schrödingerei—it is uncausal and altogether too primitive” (quoted by Fine 1986, p. 27). But to put this in perspective, this is mild compared to Heisenberg’s comment on Schrödinger: “The more I reflect on the physical content of Schrödinger’s theory, the more disgusting [abscheulich] I find it” (letter to Pauli, June 8 1926, in Pauli 1979, letter 136). 

In his Dialectica article (1948), Einstein wrote, “Quantum Mechanics represents an important and in some sense even conclusive advance in physical knowledge.” But perhaps this was a public pronouncement hiding private loathing?

One place to look for Einstein’s sincere attitude is in his recommendations for Nobel Prizes. These were confidential, to be seen only by the Nobel Prize committee, and they were influential; as we shall see below, the committee took Einstein’s recommendations very seriously. So, we can assume that Einstein is recommending for honours only the people that he really thinks deserve the honours. Abraham Pais, Einstein’s biographer, was given permission to see Einstein’s letters to the Nobel prize committee, and he reports what he found in an appendix of his biography, ‘Subtle is the Lord…’. 

Let us confine our attention to the recommendations made after the crucial period 1925-1927, which saw the genesis of quantum mechanics as we know it, primarily at the hands of Heisenberg and Schrödinger. Let us focus on his recommendations for theoretical physics, putting aside recommendations for experimental work and his numerous recommendations for Peace Prizes.

In 1928 he recommended that the prize be awarded either to de Broglie, Davisson, and Germer, for the proposal of electron waves and its experimental verification, or to Heisenberg and Schrödinger jointly. Other possibilities he floated were a prize to be shared between de Broglie and Schrödinger, for wave mechanics, or one to Heisenberg, Born, and Jordan, for matrix mechanics.The 1929 prize went to de Broglie.

In 1931 he recommended individual prizes for Schrödinger and Heisenberg. In his letter, he wrote,

“In my opinion, this theory contains without doubt a piece of the ultimate truth. The achievements of both men are independent of each other and so significant that it would not be appropriate to divide a Nobel prize between them.”

There was no prize awarded in 1931. In 1932 Einstein’s recommendation was a prize for Schrödinger. In 1932 the prize was awarded to Heisenberg, and in 1933, jointly to Schrödinger and Dirac.

His next recommendation for theoretical physics was in 1945, for Pauli, and in 1945 Pauli got his Nobel prize, for the exclusion principle.

And that’s it, in terms of recommendations for prizes in theoretical physics, after 1927. Once quantum mechanics existed, Einstein, in his recommendations for Nobel prizes in theoretical physics, had no other concern than to honour its founders.

References

Einstein, Albert (1948). Quanten-mechanik und wirklichkeit. Dialectica 2, 320–324. 

Fine, Arthur (1986). The Shaky Game: Einstein, Realism, and the Quantum Theory. University of Chicago Press.

Pais, Abraham (1982). ‘Subtle is the Lord…’: The Science and the Life of Albert Einstein. Oxford University Press.

Pauli, Wolfgang (1979).  Wissenschaftlicher Briefwechsel mit Bohr, Einstein, Heisenberg, u.a./Wolfgang Pauli, Scientific Correspondence with Bohr, Einstein, Heisenberg, a.o.  A. Hermann, K. v. Meyenn, and V.F. Weisskopf, eds.  Springer.