Robert Crease and Alfred Goldhaber, The Quantum Moment: How Planck, Bohr, Einstein, and Heisenberg Taught Us to Love Uncertainty, (New York, W.W. Norton and Company, 2014).
Adam Becker, What Is Real? The Unfinished Quest for the Meaning of Quantum Physics, (London, John Murray, 2018).
Ray Monk, Ludwig Wittgenstein: The Duty of Genius, (London, Vintage, 1990).
Nature is as screwy as she can be, so said Richard Feynman. That’s certainly the picture of nature that the quantum has left us with, although whether nature would agree with that is another matter. She may retort that she is under no obligation to comport to our conceptions of the reasonable. But that quantum mechanics is the implement we use to paint our picture of the world cannot be doubted. How that has come to be is one of the central themes of Crease and Goldhaber’s The Quantum Moment.
The authors are interested in accounting for how quantum physics has burrowed into our culture so much so that we find ourselves amid a “quantum moment.” This moment is relatively new, and has come to supplant a previous moment, the Newtonian moment, which reigned for all of 250 years. By a moment Crease and Goldhaber are referring to a period when our best physical theories transcend science to become, in a way, an encompassing metaphysical thesis a sort of weltanschauung if you will. Thus, we find complementarity, quantum leaps, Schrodinger’s cats, entanglement, principles both uncertainty and exclusion, as metaphorical concepts used in everyday discourse and which feature in our poems, our music, our films, our ideologies, the whole box and dice in fact. The book, I think, is a very useful first cut in explaining how that has come to be so.
One of the things that interests me about the quantum, and what brought me to purchase and read the book, is the idea that quantum mechanics represents a complete picture of nature. How did that idea develop and reach such dominance? One reason for being intrigued by this is that, in a philosophical sense as opposed to a technical within physics sense, there are two key pillars to the argument for why we need a quantum theory of gravity. The first is that quantum mechanics is complete and is as complete a picture of nature as is currently obtainable. The second is that general relativity, read gravitation, and quantum mechanics are incompatible. This leads to the conclusion that there must be a quantum theory of gravity. But if quantum mechanics is not complete then we have a problem. The quest for a quantum theory of gravity is now a 70 year one, but that quest has brought us, certainly thus far, no nearer to the old one. Perhaps that is because quantum gravity is a forlorn quest.
There is a significant problem to the book. The authors devote space, as they surely must, to describing and accounting for the prior Newtonian moment and then contrasting that with our own quantum moment. But that description and accounting won’t do. For Crease and Goldhaber Newton consecrated a mechanical world view, and one that was robustly deterministic. Newton in the Principia did not build a mechanical theory of nature. Far from it. Newton undermined the mechanical philosophy, in so far as central to the mechanical philosophy was a depiction of the world as a machine driven by contact mechanics. That conception was handed down from Descartes, Galileo and the natural philosophers of the early scientific revolution. This you will not find in Newton. What you will find instead is what Einstein, when speaking of the quantum, referred to as “spooky action at a distance.” Motion caused by forces acting on bodies rather than motion on contact of body upon body is not a mechanical theory. Newton himself in the Principia choose, rightly, to frame no hypothesis as to how spooky action at a distance could be made physically intelligible. That meant not only, from its very publication, that the Principia fatally tore asunder the mechanical philosophy but that the picture of nature it presented was incomplete.
Now Crease and Goldhaber do a good job of analysing how what is called Newtonianism, a mechanical and deterministic natural philosophy, came to permeate our culture in so a thoroughgoing way that it was elevated to a metaphysical doctrine transcending physics. Newton could account for not only motion but organs, tissue, politics, economics, indeed just about everything worth knowing. But in doing this they nonetheless miss the key part of the story, and that can’t but help to affect their reading of the quantum moment. Newton and Newtonianism are not the same, and Newton does not imply Newtonianism. That means the Newtonian moment has little to do with Newton nor the Principia. Rather, Newtonianism was a social and cultural construct developed for reasons other than intrinsically intellectual ones.
Such a rendering naturally invites us to consider the same of the quantum moment. There’s an interesting discussion, and dismissal, of the Forman thesis in the book. This is the thesis that, prior to the development of quantum mechanics, the wider intellectual culture of the German speaking lands began to exhibit an incredulity toward causality and determinism and that, therefore, a cultural paradigm shift preceded quantum mechanics and made quantum mechanics possible. This the authors reject, and it appears that they do so out of concern that it supports something akin to the strong programme in the sociology of science. I don’t see how it does, to paraphrase the logical positivists there’s a difference between the context of discovery and the context of justification. Crease and Goldhaber hold that it wasn’t a cultural quantum leap that led to a scientific version, rather causality went the other way. Physics was transformed for sound intellectual reasons and then, having torn asunder the Newtonian moment, quantum mechanics naturally led to a new quantum moment which came to dominate both our culture and our worldview. The quantum could increasingly be found everywhere not just in the Bohr model. One suspects there’s a good whiff of reductionism at play here. I would support Crease and Goldhaber’s dismissal of the Forman thesis, but not for their reasons. Quantum mechanics and the quantum moment are two different things much as Newton and Newtonianism are. I don’t think culture accounted for the science of the quantum, but I also, unlike Crease and Goldhaber, don’t think the science accounts for the quantum moment. The latter came about, I rather suspect, for its own reasons. That means any explanation of the quantum moment cannot be made dependent upon the science. When understood like so perhaps the considerations of Forman come to possess renewed relevance.
The irony in all that, of course, is that Newton left us with spooky action at a distance and so, in matter of fact, has quantum mechanics. The Quantum Moment is a good first cut in developing a full explanation of how the quantum has become a pervasive metaphysical doctrine. If you have come this far I think you should purchase and read it if you haven’t already done so.
Could we not then conclude that quantum mechanics is incomplete? This is a theme, by no means the central one, of Becker’s What Is Real? This hasn’t received good reviews, I think because they haven’t been much written by philosophers. I quite enjoyed it. The central theme of the book, you might want to argue, isn’t so much the meaning of quantum mechanics as what quantum mechanics means for the philosophy of science. The tug of war between logical positivism and scientific realism with respect to the quantum is well told. We have here a popular rendering of van Fraassen and co. There’s a little bit of irony here too for should quantum mechanics be the basis of a complete theory of nature one would expect it to be employed to settle such debates, yet the book discourages a completeness thesis. Becker draws a strong link, both historical and conceptual, connecting logical positivism to the Copenhagen interpretation. The discussion and elaboration of that link was a strong feature of the narrative, as was the explanation of Bell’s Theorem. Becker is a realist, and thinks the Copenhagen interpretation is not the last word on the matter hence the “unfinished quest” of the subtitle.
For me the business regarding the completion of quantum mechanics was the strongest aspect to the Becker book. The author goes at lengths to illuminate the position Einstein took on this matter. We often regard the experiments of Aspect, Zeilinger and the like as confirming quantum mechanics, especially entanglement and nonlocality, and so disconfirming Einstein’s critique of quantum theory. But as Becker reminds us, as do Crease and Goldhaber, subtle was the lord. Einstein would not have seen these experiments as addressing his fundamental issue with quantum mechanics. No matter how many such experiments are done they will always confirm quantum mechanics, much like experiment after experiment confirmed Newton’s inverse square law. Such experiments, however, do not address the completeness of the theory. No amount of experimentation could provide a definitive test of Newton’s theory explaining the physical mechanism behind the inverse square law because no such theory was offered by Newton to interrogate. No amount of experimentation confirming whatever be the relevant predictions of quantum mechanics settles the question of the physical mechanisms responsible for nonlocality and wavefunction collapse for quantum mechanics provides no theory amenable to experiment. Nonlocality and wavefunction collapse are part of quantum theory but the physical mechanisms behind them are outside of quantum mechanics so therefore quantum mechanics is incomplete. Should a theory of inflation conclude that there’s such a thing as the general increase in the price level of an economy, and how it might be measured to boot, that would be lovely but if it provides no reason why and under what circumstances inflation arises then the theory is incomplete.
Which returns us to quantum gravity, of course. This is often seen as a continuation of Einstein’s quest in his later years to develop a unified, complete, theory of physical reality. In a sense this is true, but only on the proviso that quantum mechanics is complete. Einstein himself, as we know, did not think quantum mechanics to be complete and so what he was searching for was a unified field theory which is not the same as quantum gravity. It seems to me that the ideas of Penrose are as close to those of Einstein in the contemporary era as one can find. Penrose still seeks to travel down the road to quantum gravity, his is a back road, but for Penrose incorporating gravity makes quantum mechanics complete, in that gravity is needed to explain wavefunction collapse, and so it is not necessarily general relativity that must wholly and only accommodate itself to the quantum. More give and take are required to consummate this marriage than hitherto supposed. The interesting thing about Penrose’s ideas is that spacetime is not taken to be as fundamental as previously thought. There could be something to this. One of the things arising from relativity is a dynamic picture of spacetime. Lorentz contraction, time dilation and so on imply a dynamic hence inherently physical conception of spacetime so perhaps there are more fundamental entities in the physical world that build spacetime. But, then again, perhaps Einstein was right all along. It could be that an entirely new conception of the physical is needed to develop a more complete theory of nature.
I suspect that Einstein was right about that.
Incidentally, Crease and Goldhaber say that the Newtonian moment, what with its machines and mechanisms, supplanted the Aristotelian moment with its goals and purposes. Aristotle was a keen observer of the biological world and his picture of matter to no small degree was organic. For this the modern scientific temper has no truck. But consider. What are living things, even mental things which properly belong to the biological sciences, if not forms of matter? For long I have regarded Darwin’s theory of evolution as incomplete in that it needs to be reduced to physics. There is growing recognition of this, with some physicists arguing that the laws of physics constrain the pathways of self organisation that evolution can take advantage of. I’m thinking now, however, it is not biology with evolution at the core that needs to be reduced to physics. Rather we need a revolution in our understanding of the physical to unify, not reduce, the physical sciences to the biological. If living things exhibit functions, goals and purposes it follows that a property of matter is that it can come to have functions, goals and purposes under certain configurations for reasons unknown. It could well be that such a unification and its attendant transformation in our notions of the physical will lead to renewed interest in Aristotle.
This, finally, brings us to Wittgenstein. When we come across a Wittgenstein or a Grigori Perelman our inclination is to declare them mad, but I wonder whether really it us that are mad. The Monk biography I read long ago and was fortunate to purchase cheaply recently. I have now read it a second time. One of the things that interested me was the manner the relationship between Wittgenstein and Bertrand Russell would be portrayed. The Monk biography is largely laudatory of Wittgenstein, much unlike the author’s biography of Russell. You get the impression with Monk that Russell, applicable to both the early and latter Wittgenstein, was too dimwitted to appreciate the subtlety and grace of Wittgenstein’s ideas. But he’s not alone. Russell finds good company in Moore, Turing, Ramsey, among others. I don’t buy it. That said, I think Wittgenstein is on to something when he argues that mathematical philosophy, including all of logicism, finitism-formalism, and intuitionism, is too mathematical. It seems to me the key concern for any philosophy of mathematics should not be foundational nor even be about mathematics as such. Instead the key concern should focus on what mathematics tells us about our relationship to the world, which is an altogether different question. Do we impose mathematics upon the world, or does the world impose mathematics upon us? Dealing with technical questions within mathematics or mathematical logic will tell us little about that and Wittgenstein was right to say so.
My own view is that the work of Frege, Russell, early Wittgenstein, Godel, Turing, Church, but also the prewar logical positivists represent “the heroic years” of 20th century philosophy on a par with the classical years of the early modern era. Certainty was not to be found, and the nature of mathematics is still puzzling and by far a settled matter. Yet this work gave us the tools to embark upon the second cognitive revolution, which might yet shed light on the relationship of mathematics to the world, computer science, information theory and so on. These are signal intellectual achievements and yet we regard philosophy as not progressive.
The major personal difference, according to Monk, between Russell and Wittgenstein was ethical. Should one primarily try and change the world for the better or should one try and change the self for the better? Russell was for the former, Wittgenstein the latter. Surely Russell was correct, and surely that is why Russell is reviled and Wittgenstein regarded as a saint. Monk relates a challenge posed to Wittgenstein by Russell that goes like this; should this commitment come at the expense of war and slavery for the rest would Wittgenstein still be committed to it? He replied in the affirmative. This is an odious view, and Wittgenstein did manage to discover himself as he meant to on the front in the First World War. Pity about the millions who died around him. Wittgenstein did come to hold pronounced left wing views, but he did little to promote them or act upon them in a political fashion. That is contrasted with Russell’s life of dissidence and activism. Despite all that there is something enchanting about Wittgenstein’s continued struggle to be a better person and the manner in which he gave up so much in the course of that struggle, but especially the degree to which he was prepared to be honest with himself as he struggled at it. Wittgenstein lived a rich life.
The second difference drawn between Russell and Wittgenstein was intellectual, especially with regard to the Wittgenstein of the Philosophical Investigations. Here we have Russell’s well known refrain that the latter Wittgenstein “seems to have grown tired of serious thinking and to have invented a doctrine which would make such an activity unnecessary.” What is being denoted by Russell is Wittgenstein’s ideas about the use of language. Monk has this as the central difference between Wittgenstein and those of his interlocutors with whom he most vigorously disagreed such as Russell. There are not so much innovations of thought as there are innovations of language. When Freud proposed a theory of the unconscious he was not providing a theory of the unconscious as a real entity but rather an innovative reconceptualisation of the meaning of the term. The same applies to Cantor and his use of infinity to encompass cardinality or the transfinite. The same applies to the concept number when we introduced imaginary numbers to signify the square root of negative numbers. The key question is whether these innovations are useful not whether they bare a relation to the world. The problems of philosophy become problems of language use. Wittgenstein is best interpreted as saying that the concepts of science are different to our every day concepts, so gravity in physics and gravity of the dictionary have two different meanings. That doesn’t mean that understanding the world does not involve real problems of knowledge rather than merely unravelling the tangles we weave through use of language. Notice that for all Wittgenstein’s influence this hasn’t caught on in epistemology. The knowledge of every day usage and knowledge as to be understood through a scientific theory of knowledge will have two very distinct meanings. Until this is recognised the prospects for epistemology appear dim. The reader might regard my take on Aristotle above to be another example of the species. It is evident that Wittgenstein’s ideas on language use are relevant to the way concepts are used in quantum physics as opposed to their usage in the cultural quantum moment.
Wittgenstein had very little interest in science, which is well contrasted to Russell’s attitude. Russell in his thinking, especially his latter philosophy, was quite attuned to the contemporaneous results of the sciences as any good philosopher should be. Disdain for scientific inquiry is not an intellectual virtue and we like to see Wittgenstein as especially intellectually pious. Such disdain is a marker of contemporary philosophy, but it wasn’t of the early modern period nor of the heroic years. It is true that Wittgenstein was the more influential philosopher but that’s not to say that he was a better philosopher, and this fact tells us more about ourselves than it does about the ideas of Russell. One aspect, highly important for us too, where Russell and Wittgenstein had some similarity regarding science was its impact upon society. Wittgenstein was concerned that science and scientific industry would lead to the destruction of civilisation. Russell, through his anti nuclear activism and dissidence, held similar views but it would be wrong to see them as being in accord with Wittgenstein’s. For Wittgenstein there was something intrinsic to science that threatens the good future of man. For Russell it was the pursuit of science under certain cultural, social and historical conditions that threatens the good future of humanity. Wittgenstein’s views here too have proved more influential among those who think about such problems, but it is Russell who is correct.
The header image was taken at Mallacoota, a remote, sparsely populated wonder of nature where water, both salty and fresh, the forest, and a rich diversity of life conjoin. Of Wittgenstein I read there, and the themes of the two earlier reviewed works I contemplated, among much else besides, while ensconced in the wilderness. Wittgenstein was on to something with the fjords of Norway. He would have been revolted to have learnt that tours are organised to the remains of his hut at Skjolden, and the fact that they are tells us something about why Wittgenstein has been so influential. Surely, he would have been disappointed to know of this for one gets the distinct impression that Wittgenstein would have liked to be remembered for his ideas rather than the way he lived.