Schrödinger’s View

Erwin Schrödinger

Schrödinger with ladies

Schrödinger’s view on quantum mechanics is described as follows in the book Erwin Schrödinger, An Introduction to His Writings by William T. Scott:

  • Erwin Schrödinger held a view of quantum mechanics which was, or appeared to be, radically different from that of most of his contemporaries in theoretical physics. He attacked the notion of quantum jumps, those discontinuous transitions that defy any space-time description yet seem to be implied by a wealth of experimental evidence. He expressed considerable dissatisfaction with the statistical interpretation of the wave function that Max Born introduced.
  • On some occasions he even seemed to deny the existence of the particles themselves.
  • Throughout his life Schrödinger was committed to the ideal of a rational and realistic theory of events in the atomic world. In an obituary notice, Max Born described the tenor of Schrödinger’s thought as essentially classical, as the hope of finding the way back to the classical physics of clearly comprehensible events.
  • No sudden or discontinuous transitions (jumps) are involved. This is the reason why Schrödinger said that quantum jumps will go the way of astronomical epicycles as outmoded, obsolete concepts. Schrödinger gave a strong argument for continuous rather than discrete transitions in atoms.
  • Was Born right that Schrödinger sought a return to the classical physics of clearly comprehensible events? Undoubtedly Born was correct. 

From the book Erwin Schrödinger by Dieter Hoffman et al, we quote:

  • Für Erwin Schrödinger war diese Wende zu einer statistischen Interpretation der Quantentheorie, die mit der sogenannten Kopenhagener Deutung auch schon bald (1927) eine relativ abge- schlossene und widerspruchsfreie Form erhalten sollte, zutiefst unbefriedigend. Gegenüber Bohr hatte er während seines Aufenthaltes in Kopenhagen verzweifelt erklärt:
  • Wenn es doch bei dieser verdammten Quantenspringerei bleiben soll, so bedaure ich, mich überhaupt jemals mit der Quantentheorie abgegeben zu haben.

From the book Schrödinger’s World View edited by Johan Götschel we quote:

  • The reason was the apparent impossibility of describing nature on the atomic scale in the classical way, i.e., by giving an account of what is actually going on at every point of a continuously connected region of space- time. Schrödinger realized that the phenomena embraced by the so-called wave-particle dualism presented a serious difficulty that somehow had to be overcome. But he was not ready to accept the orthodox solution in this respect: The renouncement of the classical spacetime description – the intrusion of discontinuity, of quantum jumps and the new kind of identity of particles – destroyed the ideal of nature as something understandable.
  • There are – Schrödinger says – as it were, gaps in our picture. However, possibly with the exception of a period around 1930, he firmly believed that the gaps could be eliminated. Already in one of his original papers on wave mechanics, SchrOdinger speculated whether the processes in the atom can be integrated into the space-time form of our thinking. In an almost Wittgensteinian manner he says:
  • From a philosophical point of view I would consider a definite decision in this sense to be a complete surrender. For we cannot really alter the forms of thinking. and whatever we cannot understand within them we cannot understand at all. There are such things, but I do not believe that atomic structure belongs to them.22
  • In a similar vein, in his last paper of 1958 he emphasizes:We do feel a yearning for a complete description of the material world in space and time, and we consider far from proven that this aim cannot be reached.
  • Schrödinger’s wave mechanics was his attempt to reach the aim.

From the book Schrödinger’s Philosophy of Quantum Mechanics  by Michel Bitbol, we quote:

  • The generally accepted view is that he (Schrödinger) never really recovered from his interpretative failure of 1926-1927, and that his late reflections (during the 1950’s) are little more than an expression of his rising nostalgia for the lost ideal of picturing the world, not to say for some favourite traditional picture.
  • Schrödinger expressed an almost naive realist position in his seminal papers on wave mechanics of 1926, and then a more sophisticated scientific realist attitude in his writings of the 1950’s. Schrödinger’s first interpretation of quantum mechanics was sketched out in January and February of 1926, in the pioneering papers entitled “Quantization as a problem of proper values I and II”. It amounted to taking the /psi-function at face-value and treating it as a direct description of wave-like processes occurring within the boundaries of atoms.
  • From 1928 on, Schrödinger resigned himself to teaching quantum mechanics according to the mainstream “Copenhagen interpretation”. The year 1935 marked a noticeable turning point. A few weeks after the publication of the Einstein-Podolsky-Rosen paper and the burst of correspondence with Einstein which followed, Schrodinger published both his “cat-paper” and a more technical article concerning the “entanglement” of wave- functions. In these two papers, Schrödinger expressed a skepticism about the current interpretation of quantum mechanics, which was grounded in a deep understanding of the issues involved, even though he admitted his inability to offer any satisfactory alternative. Finally, in the late forties and the early fifties, he became increasingly self-assertive, and declared his attachment to an idiosyncratic conception of quantum mechanics which, to many, appeared as a mere revival of his first 1926 wave-interpretation.
  • It is no exaggeration to say that this later development was unanimously rejected by the scientific community. True, some isolated physicists of renown, such as Einstein and de Broglie, welcomed both Schrodinger’s renewed “realist” approach and the valuable support which he was now giving to their own struggle against the current “dogma” (as they called the cluster of Copenhagen-like interpretations commonly accepted at that time). But they did not approve, let alone accept, Schrödinger’s wave- interpretation. Moreover, the apparent convergence of the three thinkers on the issue of “realism” was mostly epistemological, partly verbal, and certainly not metaphysical; for they did not even agree about the meaning of the word “reality”.
  • As for the former Göttingen-Copenhagen physicists, their reception of Schröinger’s late interpretation of quantum mechanics was quite hostile. Pauli went as far as denouncing Schrödinger’s “neurotic” regression, and accusing him of entertaining the “dream of a way back, back to the classical style of Newton-Maxwell, that is hopeless, off the way, bad taste and not even a lovely dream”. Many physicists rejected Schrödinger’s proposals, without even bothering to examine his arguments with any care.

In short, Schrödinger never accepted the Copenhagen Interpretation because he viewed it to be unphysical, but he was crushed by the Göttingen-Copenhagen school. What Schrödinger was searching for was a model for the atom which is Anschaulich, that is possible to picture in 3d. realQM is such a theory. What would Schrödinger have said about realQM?

Here are some quotes by Schrödinger:

  • Ich möchte nicht den Eindruck hinterlassen, mich hätte nur die Wissenschaft interessiert. Tatsächlich war es mein früher Wunsch, Poet zu sein. Aber ich bemerkte bald, dass Poesie kein Geld einbringt. Die Wissenschaft dagegen offerierte mir eine Karriere.
  • I insist upon the view that ‘all is waves’.
  • I am no friend of probability theory, I have hated it from the first moment when our dear friend Max Born gave it birth. For it could be seen how easy and simple it made everything, in principle, everything ironed and the true problems concealed. Everybody must jump on the bandwagon [Ausweg]. And actually not a year passed before it became an official credo, and it still is.
  • I don’t like it (Copenhagen Interpretation), and I’m sorry I ever had anything to do with it.
  • Bohr’s standpoint, that a space-time description is impossible, I reject a limine. Physics does not consist only of atomic research, science does not consist only of physics, and life does not consist only of science. The aim of atomic research is to fit our empirical knowledge concerning it into our other thinking. All of this other thinking, so far as it concerns the outer world, is active in space and time. If it cannot be fitted into space and time, then it fails in its whole aim and one does not know what purpose it really serves.
  • What we observe as material bodies and forces are nothing but shapes and variations in the structure of space.
  • Bohr’s standpoint, that a space-time description is impossible, I reject a limine. Physics does not consist only of atomic research, science does not consist only of physics, and life does not consist only of science. The aim of atomic research is to fit our empirical knowledge concerning it into our other thinking. All of this other thinking, so far as it concerns the outer world, is active in space and time. If it cannot be fitted into space and time, then it fails in its whole aim and one does not know what purpose it really serves.
  • (To Bohr while visiting in Copenhagen September 1926): Surely you realise that the whole idea of quantum jumps os bound to end in nonsense. You claim first of all that if an atom is in a stationary state, the electron revolves periodically but does not emit light, when, according to Maxwell’s theory, it must. Next, the electron is said to jump from one orbit to the next and to emit radiation. Is this jump supposed to be gradual or sudden? If it is gradual, the orbital frequency and energy of the electron must change as well. But in that case, how do you explain the persistence of fie spectral lines?….In other words, the whole idea of quantum jumps is sheer fantasy.
  • With very few exceptions (such as Einstein and Laue) all the rest of the theoretical physicists were unadulterated asses and I was the only sane person left…The one great dilemma that ail us… day and night is the wave-particle dilemma… So unable is the good average physicist to believe that any sound person could refuse to accept the Copenhagen oracle. (Schrödinger in a letter to Synge 1959)

Here some quotes about Schrödinger:

  • You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality — if only one is honest. (Einstein)
  • You are the only person with whom I am actually willing to come to terms. Almost all the other fellows do not look from the facts to the theory but from the theory to the facts: they cannot extricate themselves from a once accepted conceptual net, but only flop about in it in a grotesque way. (Einstein to Schrödinger on the Copenhagen Interpretation 1935)