Astrophysicist, astronomer and science writer John Gribbin argues that “all the interpretations of quantum mechanics are myths”. He also states that it’s “hard to see quantum physics as anything but analogy”.
John R. Gribbin (who was born in 1946) is an astrophysicist, astronomer and a science writer. He earned his PhD in astrophysics from the University of Cambridge in 1971.
In 1968, Gribbin worked as one of Fred Hoyle’s research students at the Institute of Theoretical Astronomy. In 1984, Gribbin’s In Search of Schrödinger’s Cat: Quantum Physics and Reality was published: it became a bestseller. (Most of the passages from Gribbin in this essay are actually from his book, Schrödinger's Kittens and the Search For Reality.) The Spectator Book Club described Schrödinger’s Cat one of the best popularisations of physics to precede Stephen Hawking’s A Brief History of Time. The Spectator also described Gribbin as “one of the finest and most prolific writers of popular science around”. In 2009, at the World Conference of Science Journalists, the Association of British Science Writers awarded Gribbin its Lifetime Achievement award.
A list of Gribbin’s papers and articles can be found here — complete with links to the original sources.
Introduction
It can be assumed that even a few laypersons (or beginners) have quickly noted the obvious and strong distinctions which can be made between quantum mechanics (or quantum theory) and its many and various interpretations. (Wikipedia cites 15 “influential interpretations”!) That said, there have been far more laypersons (or beginners) who’ve strongly conflated the interpretations of quantum mechanics with quantum mechanics itself.
So now it can be argued that all the interpretations of quantum mechanics are in the same ballpark for the obvious reason that each one is an … interpretation. This means that the fact that the interpretations are interpretations of the physical data and the mathematics doesn’t really make any difference in this respect. And that’s because all the interpretations — almost by definition — still go beyond the data, mathematics, predictions, experiments, observations and tests.
And it’s — at least partly — because of all the above that John Gribbin takes his radical position on such interpretations.
Gribbin writes:
“You are free to choose whichever of the quantum interpretations most appeals to you, or to reject all of them, or to purchase the entire package and use a different interpretation according to convenience, or the day of the week or whim.”
And, elsewhere, Gribbin adds:
“I stress, again, that all such interpretations are myths, crutches to help us imagine what is going on at the quantum level and to make testable predictions. They are not, any of them, uniquely ‘the truth’; rather, they are all ‘real’, even where they disagree with one another.”
Prima facie, Gribbin’s position seems to be one of scientific relativism. Or, at the very least, one of scientific pluralism. Indeed when Gribbin states that “[r]eality is in very large measure what you want it to be”, he actually seems to be venturing into (a subjective or even solipsistic) idealism.
[Many scientists are pluralists when it comes to scientific theories, concepts and models.]
Alternatively, is all this a scientist’s very own version of some kind of (postmodern?) constructivism or constructionism? (Sure — that’s a hell of a lot of isms!)
Now, despite that last (as it were) charge of constructivism, it’s worth nothing that there’s a chapter called ‘Constructing Quarks’ in Gribbin’s book Schrödinger's Kittens and the Search For Reality (1995). This chapter — and perhaps many of Gribbin’s other words on quantum mechanics — is strongly inspired by the ideas of the sociologist and historian of science Andrew Pickering (1948-) and his book of (almost) the same name, Constructing Quarks: A Sociological History of Particle Physics (1984).
Gribbin even gets all psychological and aesthetic when he concludes (at the end of one of his books) that we “are free to choose whichever one gives you most comfort, and ignore the rest”.
Still, Gribbin immediately concludes the passage above with the following (as it were) acknowledgement:
“Still, though, almost everybody wants to know ‘the answer’. The quest for a really real model is what drives theoretical physicists.”
Gribbin even confesses that he “still had this hankering” for the really real himself — “even though the logical part of [his] mind tells [him] that the search is fruitless”.
But what of scientific pluralism?
Is it automatically a good thing?
Take the physicist David Finkelstein’s words on the problem we (especially laypersons or beginners) have with so many different interpretations of quantum mechanics.
Finkelstein firstly tells us that “[q]uantum theory was split up into dialects” and that this was the case because “[d]ifferent people describe[d] the same experiences in remarkably different languages”. (Finkelstein’s last point is a good expression of the underdetermination of theory by the data thesis.)
Yet that widespread pluralism may still seem to be commendable and even productive… except for the fact that all this is (Finkelstein continues) “confusing even to physicists”.
So there are three (among other) alternatives we (or at least physicists) can take:
(1) Pick a particular interpretation.
(2) “Buy the lot” (i.e., “purchase the entire package”) — as John Gribbin suggests.
Or:
(3) Reject the whole lot.
So now take the words of physicist N. David Mermin (1935-), which can be interpreted as a suggestion to “buy” option (3).
Mermin tells us that quantum theory
“is so beautiful and so powerful that it can, in itself, acquire the persuasive character of a complete explanation”.
[It can, of course, be asked what Mermin means by “complete explanation”.]
More broadly, a person who’s against all the interpretations of quantum mechanics can argue that we have no need, right or philosophical justification to interpret the mathematical formalism/s, observations, data, experimental results and tests at all.
It can now be asked if it’s ever possible — even in principle — to completely bypass all interpretation in quantum mechanics. Indeed can we even say what quantum mechanics is (i.e., beyond the mathematics) without relying on at least a degree of interpretation?
So, in that case, we’d need to be specific as to what the interpretation is and what precisely it is that’s being interpreted.
In any case, Gribbin believes that
“none of [the interpretations of quantum mechanics] is anything other than a conceptual model designed to help our understanding of quantum phenomena”.
Gribbin’s primary reason for stating the above is that all the interpretations he considers “make the same predictions”. What’s more, Gribbin refers to John G. Cramer’s position on his own interpretation (i.e., Gribbin’s favoured transactional interpretation — see later) when he writes that
“Cramer is at pains to stress that his interpretation makes no predictions that are different from those of conventional quantum mechanics”.
Now that really does clarify the situation here.
Indeed, if one is very uncharitable, the words above may possibly show us the utter redundancy of all the interpretations of quantum mechanics. (Hence the oft-quoted words “Shut up and calculate!”.)
Of course stating that the many different interpretations of quantum mechanics “make no [unique] predictions” is hardly an original point. Commentators have been stating this since at least the 1950s.
Yet despite all of Gribbin’s words above, he states that many (or even all?) of the interpreters of quantum mechanics believe that their own interpretations are true…
The True Interpretation!
… That’s right — true.
Gribbin writes:
“[T]he interpreters and their followers will each tell you that their own favoured interpretation is the one true faith, and all those who follow other faiths are heretics.”
The passage above comes straight after Gribbin had already told us that “[a]t the level of equations, none of these interpretations is better than any other”. And, conversely, that “none of the interpretations is worse than any of the others, mathematically speaking”. (Much of this may hinge on precisely how we’re to take the phrases “at the level of equations” and “mathematically speaking”.)
Gribbin also referred to the book The Ghost in the Atom: A Discussion of the Mysteries of Quantum Physics, which was edited by the physicist and writer Paul Davies. Gribbin claims that in that book “the experts can each be seen solemnly claiming that one particular interpretation is correct while the others are impossible”. Gribbin continues:
“Utterly sure of themselves, and with few exceptions, they all plump for different versions of reality and dismiss the others.”
Theoretical physicist Steven Weinberg (1933–2021) seemed to concur with Gribbin when he wrote the following:
“[M]any physicists are satisfied with their own interpretation of quantum mechanics. But different physicists are satisfied with different interpretations.”
Scientific Models
John Gribbin’s position on the interpretations of quantum mechanics is very similar to his position on scientific models. Indeed his position on what models are is fairly standard within science itself.
Gribbin writes:
“All models are deliberately simplified, by our choice of which degrees of freedom to use as handles on reality; and all models of the world beyond the reach of our immediate senses are fictions, free inventions of the human mind.”
What Gribbin says is almost — or even literally — true by definition. (The clue is in the word “model” itself.) More relevantly, what Gribbin stated above can be rewritten in this way:
All interpretations of quantum mechanics are deliberately simplified, by our choice of which degrees of freedom to use as handles on reality; and all interpretations of quantum mechanics beyond the reach of our immediate senses are fictions, free inventions of the human mind.
Gribbin also writes:
“All models of the atom are lies in the sense that they do not represent the single, unique truth about atoms; but all models are true, and useful, in so far as they give us a handle on some aspects of the atomic world.”
Here again the above can be rewritten in order to make it apply to the interpretations of quantum mechanics:
All interpretations of quantum mechanics are lies in the sense that they do not represent the single, unique truth about reality; but all interpretations are true, and useful, in so far as they give us a handle on some aspects of the quantum world.
One would hope that Gribbin was being rhetorical and/or poetic when he used the word “lies” about scientific models. (That applies to the words “truth” and “true” too.) Pedantically speaking, a single model can’t be true, a lie or false. That’s because a model isn’t a statement or even a set of statements. So a model can’t literally be a lie; or, strictly speaking, either true or false. It can, however, be accurate, useful, helpful, etc.
As for Gribbin’s words “unique truth”.
In order for a model to be the unique truth about any given x, then it would actually need to be x. (“The best model of the world is the world itself.”)
Gribbin also seems to put a pragmatist position on truth. That is, he associates a model’s truth with its being (what he calls) “useful”. Thus a model is true only if it is useful. (Incidentally, Gribbin says almost exactly the same thing about the interpretations of quantum mechanics.)
Yet this pragmatist and/or pluralist position on models inevitably leads to this question:
What is the model a model of?
Let’s say that it’s a model of a given x, which isn’t itself a model.
Yet what is this x when (as it were) stripped of its (or any) model?
The English theoretical physicist and cosmologist Stephen Hawking (1942–2018) got to grips with that problematic question in the following passage:
“There is no picture- or theory-independent concept of reality. Instead we will adopt a view that we will call model-dependent realism: the idea that a physical theory or world picture is a model (generally of a mathematical nature) and a set of rules that connect the elements of the model to observations. This provides a framework with which to interpret modern science.”
If you can’t picture, describe or even access “reality” without a model (as Hawking suggests in his philosophical position of model-dependent realism), then Gribbin’s pluralism may well have a lot going for it.
So it’s fairly clear that Gribbin pretty much puts the interpretations of quantum mechanics in the same — or at least a similar — box as models in science generally.
So what about analogies?
Analogies
In the following passage Gribbin uses the words “analogies” and “model[s]” interchangeably. He writes:
“With [] great analogies to draw on — the nuclear model of the atom [] the QED theory of light [] the quark model of protons and neutrons and the QCD theory of the strong interaction [].”
As already stated, the above is more or less a standard take on models in physics: it’s what Gribbin argues next which is more radical:
“‘Analogy was not one option amongst many,’ says [Andrew] Pickering [the constructivist mentioned earlier]; ‘it was the basis of all that transpired. Without analogy, there would have been no new physics.’
“The same is true of quantum mechanics itself. Indeed, it is hard to see quantum physics as anything but analogy [].”
And, as with the question about models earlier, some readers may now ask the following question:
Analogies… of what?
In other words, don’t we have models and analogies of things which aren’t themselves models and analogies?
It may even seem that Gribbin is talking about analogies of analogies — full stop. After all, he does use the words “anything but analogy”. But if analogies (as well as models) are literally all we have, then how can they be analogies at all? That said, it may only be through analogies — or models — that we can arrive at things which aren’t themselves analogies (or models). And this is certainly what Hawking believed (as shown earlier) about scientific models.
All Interpretations are Equal?
When it comes to the interpretations of quantum mechanics, John Gribbin suggests that one helpful possibility (or suggestion) is to “buy the lot”. He suggests this because
“each of the interpretations is a viable model, and each of them provides us with useful insights into the way the world works”.
Gribbin seems to have been influenced by the American physicist Heinz Pagels (1939–1988) when it comes to buying this bulk-buy pluralism. Gribbin refers to Pagels’ own position, in which Pagels argued that
“we should learn a little about the quantum world from each of the interpretations, considering all of them together in a kind of superposition of possibilities”.
And then (referring to a situation mentioned earlier) Gribbin continues:
“Few of the experts, however, are broadminded enough to take this view. Instead, you tend to find that individual physicists (those who bother to think about these things at all, that is) cling stubbornly to the notion that their own favoured interpretation is correct, and that all of the other interpretations are ‘obviously’ wrong.”
There may well be an argument that all interpretations are superfluous when it comes to predictions, (quantum-based) technology, etc. However, that certainly doesn’t mean that all interpretations are “equally good”. They may be equally good in the sense that they don’t make the slightest bit of difference when it comes to the mathematical theory, predictions and technology. However, are they all equally good in literally every respect?
Of course being a pluralist doesn’t mean one needs take all the interpretations to be equal. More strongly, it doesn’t mean that they actually are equal. So one must assume that an outrightly silly interpretation would be rejected by Gribbin.
Another way of putting this is to argue that even if we accept the essential limitations of all the interpretations (and that no single one gives us a complete picture), then that doesn’t also mean that all interpretations must be treated equally.
In detail. What if Interpretation A (or its “useful insights”) outrightly contradicts Interpretation B? That said, it can be supposed that if one chooses A on one (as Gribbin puts it) “day of the week”, and B on another day of the week, then any contradictions between them simply may not matter. Alternatively, A and B may be being bought for different reasons, rather than on different days.
More mundanely, take a murder that hasn’t be solved and which has engendered numerous interpretations (or, at least, explanations). Does that mean that all these explanations/interpretations of the murder should be treated equally?
All the above seems to lead to this question:
So how truly pluralist is John Gribbin’s pluralism?
Gribbin’s Faves: The Many-Worlds and Transactional Interpretations
At some points in his books Gribbin seems to argue that all interpretations of quantum mechanics are equal. At other points… he doesn’t. One can therefore conclude by saying that Gribbin believes that some interpretations are more equal than others. (Actually, he believes that about two interpretations — the many-worlds interpretation and the transactional interpretation.)
Gribbin admits this when he states that “[t]he time has come for me to nail my colors the mast”. He also writes:
“[The many-worlds interpretation] is still my favourite among the traditional interpretations, and if I were forced to offer a ‘best buy’ from all the ideas outlined so far this would be it.”
Moreover, Gribbin’s pluralism seems to be contradicted by his strong criticisms of the Copenhagen interpretation (which he’s expressed many times in many books) — and that’s alongside his strong commitment to the many-worlds interpretation and the transactional interpretation.
For example, Gribbin is partly factual and partly judgmental when he tells us that it is
“an historical accident is that [the Copenhagen interpretation] was the first interpretation that could be made to work, in the sense of providing recipes that quantum cooks who did not want to bother with the deeper mysteries and the philosophy could use to bake quantum cakes”.
He then says that the Copenhagen interpretation doesn’t care “[h]ow you choose to interpret [because] what is going on is largely up to you”. Indeed Gribbin continues by stating that “[t]here is no official ‘interpretation’ at this level”. All we have is (in basic terms) loads of experiments and probabilities.
As already stated, Gribbin favors John G. Cramer ’s transactional interpretation.
Cramer’s Transactional Interpretation
Interestingly enough, it turns out that Cramer is somewhat of a pluralist himself.
According to Gribbin, Cramer believes that his own interpretation is (simply)
“a tool which is likely to be particularly useful in teaching, and which has considerable value in developing intuitions and insights into otherwise mysterious quantum phenomena”.
And then Gribbin tells us exactly why he favours Cramer’s interpretation. He writes:
“The only valid criterion for choosing one interpretation rather than another is how effective it is as an aid to our way of thinking about these mysteries — and on that score Cramer’s interpretation wins hands down.”
Technically, in the transactional interpretation
“[t]here is no need to assign a special status to the observer (intelligent or otherwise), or to the measuring apparatus”.
Moreover, because the transactional interpretations is
“going beyond the debate about the role of the observer [it] really does resolve those classic quantum mysteries”.
Yet even after these eulogies to Cramer’s interpretation, Gribbin can still be seen to be deflating it when he states the following:
“There is no problem at all with the mathematics of Cramer’s interpretation of quantum mechanics, because the mathematics, right down to Schrodinger’s equation, is exactly the same as in the standard Copenhagen Interpretation."
And finally:
“The difference is, literally, only in the interpretation.”
So even though many people may know that all interpretations (including Cramer’s) basically use the same maths and makes the same predictions, I personally — at least at first — still strongly suspected (or simply assumed) that the different interpretations did offer at least some additions (or slight tweaks) when it comes to the maths, predictions, etc. Yet this simply isn’t so — at least (according to Gribbin) when it comes to Cramer’s own interpretation of quantum mechanics.
