What is Real?

“…epistemology-soaked orgy…”

Dear reader, I have set myself a goal: I aim to burn the phrase above – it is a quote – into your mind. If you forget everything else from this essay but remember that quote, I will die a happy essayist.

You might be wondering why this goal. I will not tell you that, neither here nor later. But you will more than understand by the end of the essay.

You might now be wondering whose words those are. That, I will tell you: they are Einstein’s.

No, not the late Bob Einstein – common mistake – Bob is justly famous – but Albert Einstein.

Of course, the latter is also fairly famous, but he is less famous than he deserves to be – something happened along the way.

What is that something, I hear you ask, that undeservedly lessened the great Albert’s fame? Also, why did Albert say those words? To which orgy was he referring? Who all participated? Did all participants get a big bang?

Well, it is literally a century-long tale. And it is told, wonderfully, by Adam Becker in his book ‘What is Real?’.

This essay reviews that book, and tells in brief said tale.

1. The Process of the Review

I had listened to the audiobook and then listened to Becker’s interview by Sean Carroll – this interview is on Carroll’s podcast ‘Mindscape’ – a while ago. To write this review, I listened to the audiobook and interview again so as to refresh the details and dates. And I referred to the physical book to get the page numbers of certain interesting parts – these are called out later.

Given the times we live in, let me state that no AI wrote any part of this essay. Nor was it given to an AI to read for feedback.

The words – also the em dashes – are all mine, typed on a comfy couch or in an uncomfy cafe chair.

Yes, I use em dashes – I always have – in fact, I rather enjoy using them – I also enjoy them as a reader – I am hoping you do too – and I will continue using them, whether or not LLMs do. AIs are welcome to also use them of course.

If you don’t believe me and are thus inclined to pan this essay, just Pangram it.

Right then, onwards.

2. The Focus of the Book

Becker’s book is a book about the field of Quantum Physics, not the topic of Quantum Physics (QP). So, it is not complex, or at least it is manageably so. More specifically, it is about, to quote the subtitle, “the quest for the meaning of Quantum Physics”.

What does that mean, you ask. Consider a person who knows that QP is a sound theory, in that its Maths works to predict phenomena to a staggering degree of precision, and who wants to understand what it says about reality – wants to nail down ontological commitments.

So, putting it in my own words, the book is about working towards an Ontology, and not just stopping at Epistemology. Becker is frightfully keen on that – rightfully so. Perhaps that gives you a slight hint about what Albert was saying – more in a bit.

3. The Capsule Review

I am really glad I read this book. I learnt a fair bit – a number of new things – and it helped me correct two misunderstandings specific to the history and domain of QP. One of those misunderstandings was rather significant – you will see. The book also helped me in a general way, that is, not regarding QP – this too, you will see.

I am grateful to Becker for this book. It must have been a huge task to collect and sift the details and then present them in the form he did, and he did it well.

4. THE REVIEW

Those in the ACX community who have read Eliezer Yudkowsky’s ‘Quantum Physics Sequence’ will find in the book some technical material they already know.

What they will also find in the book, which they won’t in the Quantum Physics Sequence, is a fully detailed idea-by-idea, blow-by-blow, physicist-by-physicist and physicist-versus-physicist account of how things developed, across several decades, from the first hints of ‘not all is well in classical Physics’ to ‘Physics is crazily unintuitive, but we now have the right tools’ to the current sorry default of ‘shut up and calculate’.

Becker lays out said development wonderfully, talking about the various physicists, explaining their personal QP-journeys, their knowledge – who knew what when – their thought-processes – – some handwavy, others not – their professional roles, their personalities, their public interactions and their behind-the-scenes discussions/letters. All in all, fascinating stuff.

Some of the happenings I learnt about from his book are just staggering – you will see.

Becker is quite clear early in the Introduction that ‘shut up and calculate’ – the Copenhagen Interpretation (CI) – is not a tenable position. He says that it involves “papering over a hole in our understanding of the world”.

With that said, Becker himself is entirely agnostic about how to fill that hole. On the second-last page of the book – this is page 287 – he states he does not know what the right ontology is. But he is quite clear that said hole needs to be filled – that it is a consummation devoutly to be wished.

Also on page 287, he states that “solipsism and idealism” are not what QP is about. Quite.

While he is never shy about his opinion of CI in the book, he is not unfair to it, from what I can see. You may disagree once you read the book, and that’s fine – its author and this reviewer are, like you, human, and may have blind spots.

Another thing he is not shy about is that the progression – regression – from ‘Physics is crazily unintuitive, but we now have the right tools’ to the current sorry default of ‘shut up and calculate’ is a failure to insulate the “human process” of Science from “big money and military contracts” and also a “failure to live up to the ideals of the scientific method”.

Those are some fairly heavy phrases. You will see why he says all that.

By the way, the phrase ‘shut up and calculate’ was originated by David Mermin. He wrote it in 1989, as a summary of what he understood CI to be saying to him. After coming up with that memorable summary, he proceeded to add that he wouldn’t, you know, shut up. Good man. Becker is clearly cast from the same mould.

Right then, let’s get to the book proper.

4.1 Clear as a Bell

After the book’s introduction, Becker kicks off things in the Prologue by talking about John Stewart Bell. The student Bell had found QP – it was basically CI at that point – to be a “vague mess”. You see, Neils Bohr and Werner Heisenberg, the biggest boys behind CI back then, were “maddeningly unclear” about the boundary between the quantum and classical worlds.

But then, in 1949, Bell read about John von Neumann’s proof – he did not read the proof itself because it was only in German, but read about it from Max Born’s book – which showed that CI, with all the lack-of-clarity that Bell found unsatisfactory, was the only way of understanding QP.

So, for Bell to be right in his unease, either QP itself was wrong, or von Neumann was wrong. Or, of course, both.

Presumably, the three facts that 1) QP clearly worked well empirically, 2) von Neumann was, you know, von Neumann, and 3) others had read the von Neumann proof in German led Bell to put his unease aside. He went on to work on other things, and then life got in the way, or at least went another way.

By the time he took up the task again, it was well over a decade later.

What – and this is me talking – a loss for the world. That on so small a thing as the lack of an English translation turned even the most elite of Physics is one of those things that I could not have imagined, but it happened. On the bright side, at least Bell took up the task again. It could have been worse – it can always be worse.

Becker closes this part of the book by saying that Bell made the “most profound discovery… since Einstein”.

Just to be clear, he too is referring to Albert, not Bob. His closing sets a beautiful hook for later in the mind of the reader who does not know Bell’s insight – his cleverness. And thus ends the book’s Prologue.

4.2 The Early Days

Chapter 1 kicks off with Becker talking about the early days of QP – it kicked off in the latter half of the 1920s. He explains how QP, unlike Relativity, was a collaborative effort, and Bohr was basically the Godfather of it in those early days – it is due to Bohr and collaborators working in Copenhagen at the Neils Bohr Institute that the term CI came about.

He – Becker, not Bohr – explains that Bohr’s and Heisenberg’s stance – CI – was that QP has nothing to say about the lowest level of reality – that the smallest objects are not as real as the objects of daily life – and that all that we get from QP is the abstract description of the world which allows us to make probabilistic predictions about macroscopic outcomes.

“…epistemology-soaked orgy…”.

He then explains, with various glorious quotes, Albert’s stance on CI, and this is where Albert’s quoted phrase comes in – Albert used it in a letter to Erwin Schrödinger in 1935. He was referring to CI, and you can see what he meant.

But the thing is people thought von Neumann had proven that it was CI-or-bust for QP – this proof was from 1932 – and this assured those people – almost all the people not named Albert Einstein and Erwin Schrödinger – that Bohr’s and Heisenberg’s stance was the way to go.

Well, such is life – Science, even Physics, involves humans. It is true that the humans doing elite Physics are super-humans, but that super-ness is not necessarily in all aspects.

Becker quotes Paul Feyerabend talking about his firsthand experience of this dynamic at a talk given by Bohr. Bohr gave his talk and left. The attendees continued discussion and some attacked his arguments, but his/CI supporters referred to the von Neumann proof and that “silenced the objectors”.

And thus, CI, which dominates to this day, won the day that day.

Read about that episode in full in the book – it is on page 15.

To be fair – and this is me talking – if you did not go along with Bohr and von Neumann back then, you would have had to be singularly strong-minded, and you would also have had to be committed, as Becker is, to wanting Physics to answer ‘What is Real?’, not just make predictions.

As in, you could be strong-minded but if you were philosophically content with just an “epistemology-soaked orgy”, you would keep quiet. Similarly, you could be philosophically aghast at the “epistemology-soaked orgy” of CI but if you were not strong-minded, you would keep quiet. Because Bohr and von Neumann.

Then the book recounts a remarkable tale.

In 1935 – this is just three years after von Neumann’s proof – someone showed that his proof was wrong.

Yes, you read that right, assuming what you read is that someone showed von Neumann’s proof was wrong.

Someone read von Neumann’s work, did not take his words to be the one small step below the word of God, assessed the work, and found an error within. Not a trivial error, but an error which invalidated his proof that it was CI-or-bust.

Consider: Bell had read about the proof in Born’s book in 1949 and swallowed his unease. But that proof had been shown to be not-a-proof in 1935.

The person who found the error by von Neumann was Grete Hermann, a Physics “outsider” and a lady, which led to her being ignored. No, I am not making this up. Becker explains that, because of those two factors, “nobody listened to her”.

I imagine this does not mean – and this is me talking – literally nobody listened to her. I imagine there must have been people who saw she was right – imagine their frustration as they saw things unfold for decades after – but nobody who was somebody in Physics listened.

And thus, CI continued to dominate.

But it did not do so unchallenged. There was a “rebellion” against it, led by Albert and Schrödinger, and, as far as Physics goes, those are some pretty good lead-rebels.

Sitting here a century after the start of QP, I wonder whether Albert would have spotted the error in von Neumann’s proof had he read it – it seems he was not aware of it. Luckily, the error was later re-discovered by– but I am getting ahead of the book’s unfolding. Back to the book.

And there ends chapter 1.

4.3 A Danish Sir Humphrey

Chapter 2 gets into details of the early QP milestones in terms of ideas/hypotheses, the reactions to them of various physicists and their discussions.

Becker devotes some time to talking about Bohr and relaying stories about him, which are both endearing and surprising.

He mentions that Bohr had a “remarkable charisma” which was – and this made me sit up – further boosted by his “institutional power”.

He then switches to talk about how “plodding and obscure” Bohr was – he quotes George Gamow remarking on the “slowness” of Bohr’s “thinking”.

He then stresses how unclear Bohr’s writing was – “torturous and obscure” – unlike Albert’s, which was quite clear. He quotes a sentence by Bohr – one of his “shorter and more straightforward sentences” – regarding quantum-jumps. It takes forever to read out in the audiobook, and it makes Sir Humphrey look like a model of concision and clarity.

Note this is one of Bohr’s shorter written sentences. I am definitely not going to type it out here. Read the book to get the full flavour. It is on page 33.

All I can say is that Bohr sounds like the kind of chap who would have made an absolutely world-class bureaucrat. In case Physics had not worked out for him – to be very clear, Physics worked out very well for him – his views regarding CI aside, he was a great physicist, in fact, a Nobel – the civil service would have been a lock.

But then Becker explains that Bohr was even less clear in his speech than he was in his writing, sometimes unintelligible and with incomplete sentences. Ok, so maybe not suitable for quite the top levels of the civil service – those chaps are polished speakers.

The part that struck me most in chapter 2 is the recounting of how Heisenberg+Bohr argued with Schrödinger about the relative merits of matrix-mechanics and the wave-equation, these being alternate approaches to the Maths of QP. Bohr invited Schrödinger over specifically for this discussion.

The outcome was that neither budged an inch, and each was absolutely convinced of their right-ness and the other’s wrong-ness. Again, such is life – Science involves humans.

Note, this stalemate had nothing to do with CI-or-Not – that was a different matter entirely.

And so we arrive at chapter 3.

4.4 Third Time’s the Charm

You remember Becker talked about Bohr’s lack of clarity in writing and speech. In this chapter, he shares that Bohr’s writing was so unclear that, even now, it is unclear what he believed. He shares – and I found this staggering – that there is a “cottage industry” of figuring out what Bohr was thinking and why he was thinking what he was thinking.

After some detail – this is on page 47 – he concludes by saying that said industry has not reached a conclusion, but that most agree that part of the answer to the ‘why’ is the influence of “Kant’s writing”. I am not making this up.

I had no idea there was such a thing as a cottage industry for analysing way old Physics writings, and I would not have imagined that it was possible for such an effort to not arrive at consensus almost a century after the relevant writings.

Becker then talks about how various members of the CI-camp contradicted each other, and sometimes themselves, in their claims regarding CI. I found the recounting entertaining but I can imagine parts of it might make some people grit their teeth – it certainly would have made the old me grit his.

He then mentions that the CI-camp did agree on a few things, specifically that what mattered was making predictions about the world, not what was “really happening” – that QP was a tool, not a theory of the world.

“…epistemology-soaked orgy…”.

Albert of course disagreed with that entirely and passionately. You already know wherefrom came the orgy-quote.

Now, you are about to find out why I said that something happened due to which Albert is less famous than he deserves to be.

That something was a comedy of errors made by the CI-camp – three errors, to be precise, with all three pointing in the same direction – and said errors are recounted in chapter 3.

Let’s take a look.

You may have seen the famous photo from the 1927 Solvay conference, in which there are more eventual Nobel laureates than there are non-laureates.

That conference is where the first of the three errors happened. Albert presented a simple thought experiment, which was about the non-locality implied by CI. But Bohr misunderstood it to be about the uncertainty principle. Not just Bohr, but the other chaps – those absolute top minds – also misunderstood what Albert was saying. Becker says that the response was “muted incomprehension”. And the whole thing thus went nowhere.

Note, here it is not important to understand the precise meaning of locality or the substance of the uncertainty principle. It suffices to know that they are quite different concepts. From my minor understanding of Physics, they are about as different as, say, the conservation of momentum and the nature of a black hole.

The issue Albert raised regarding non-locality does not seem hard to understand – take a look at page 50 – and I cannot imagine why it was confusing/hard for the attendees. I mean, I am not an Einstein – this is literally true since my surname is different, and it is also figuratively true – but I grasped his point about non-locality. Frankly, it is sort of surprising that someone in the CI-camp had not already noticed this issue themselves. Yet again, such is life – Science involves humans.

So, to sum up, this was the most elite gathering ever in Physics, attended by the absolute best and brightest. Two of the heaviest heavyweights squared off (so to speak). The challenger led with a beautiful jab, right to the chin. But the judges marked it as a miss, and then lost interest in the contest. Thus, the champion retained his title by default.

So, that was error 1 of 3. Now for the 2nd.

Albert didn’t give up. Having failed in 1927, he tried again in 1930 at the next Solvay conference: he presented a different, more nuanced thought experiment, again to do with the non-locality implied by CI. And, again, Bohr misunderstood it to be about the uncertainty principle.

I found this rather entertaining, but I can see how reading this might make someone gloomy.

I can only imagine how Albert himself might have been feeling at this point. Probably gloomily wondering if there was even any point in getting out of bed with the dawn, or burning the midnight oil.

Now for the 3rd error.

In 1935, Albert came up with yet another thought experiment – talk about persistence and patience. This is the most famous of the three – it is the substance of the EPR paper – and it is, yet again, about non-locality.

This time – third time’s the charm – the CI-camp got what Albert was saying, precisely and in full. Progress – Albert’s patience had paid off. Bohr then responded with a paper which had a detailed and clear counter-argument representing the CI-position.

I am fully kidding. Bohr did respond – that small part of the paragraph above is true, but all the rest of it is not.

Becker shares that there has been an “enormous amount of ink spilt” by people who have tried to figure out what Bohr wrote in response to EPR, but there is no consensus, and it is not even clear whether Bohr thought QP was local/non-local. I was absolutely staggered when I learnt this.

There is more on this by Becker. But you really should read it yourself – see page 58. I promise it is worth the read. I also recommend listening to his interview by Carroll regarding this specific topic – there are details in there that are worth a listen.

So, while Bohr’s response to EPR was, with the benefit of hindsight – also without the benefit of hindsight – useless at best, the mere fact that it existed assured physicists that CI was fine and things could proceed, kind of how von Neumann’s earlier proof assured people who knew of its existence. For the fourth time, such is life – Science involves humans.

Becker concludes the chapter by mentioning that Albert opined that Physics had gone “astray by following” Bohr. And he quotes Albert saying that CI “avoids reality…”.

“…epistemology-soaked orgy…”.

A personal but relevant digression: until I read Becker’s book, and listened to his interview, I had no idea of this full background and context.

And it is not just that I did not know all this staggering stuff. What is also staggering to me is that the impression I had received from some reading back in high school was that Albert was out of his depth in the brave new and weird world of QP, and thus wrong, while Bohr was right, and that this was the opinion of everyone who mattered in Physics.

Thanks to Becker – and he has my eternal gratitude for this – I now know that this was not the case at all.

I remember, quite clearly, reading about the second and third of Albert’s thought experiments – they are famous enough for even me to have come across them way back in high school – and coming away with the impression, based on that other author’s words, that Bohr had refuted Albert in both cases.

Now I know from Becker that this was not the case – that Bohr had misunderstood the second thought experiment – same as he had the first – and his response to the third one was so muddled that we are not even sure whether he misunderstood it as well.

That is to say, what I read in high school was a piece of fiction.

History is written by victors, even if undeserving. And ‘shut up and calculate’ clearly won. The thing though is that undeserved victories are fragile. At the very least, there is progress by the funeral.

As James Hacker, the Prime Minister in ‘Yes, Prime Minister’, once observed – this was in a hilarious context – death is a “wonderful thing”. He had his reasons for saying that. And here is mine: death weeds out those who are wedded to wrong ideas – only death can do them part – and who insist on dragging the rest of us down with them.

Becker mentions at the start of chapter 3 that there is this inaccurate narrative regarding Albert and QP, and that it has been passed down over generations. That matches what I saw. And given that I got the impression I got, I am sure others would have too.

[Becker explains this in his interview too. The first time I heard it, I literally nodded, so precisely did his description of the inaccurate narrative match my impression.]

All this is why I said at the start of this essay that Albert, famous as he is, is less famous than he deserves to be. If generations of people hear that a chap was out of his depth once Physics moved on from the classical approach to the more correct but less intuitive quantum approach, it kind of damages his reputation as a thinker.

To close this section, I have two comments:

1. I am very curious: who was the first non-physicist to promulgate this fictional narrative? Anyone know? Let me know. Thanks.
2. If such a nonsense consensus can arise in the most demanding and objective of fields, at the absolute top level, where the persons involved – both the primary actors and the secondary observers – have brains the size of Saturn, imagine what the situation might be in other fields. Consider consensuses in fields where the persons – offense is not intended but I cannot prevent anyone from taking it – are not as formidable as those in elite Physics. If you did not already know all this about QP/Albert, surely you are now a bit less sanguine about other consensuses.

On we go to chapter 4.

4.5 Epistemology, What Is It Good For? War

Chapter 4 is about WW2 and the Manhattan project, and their effects on the physicists, many of whom moved countries, and some of whom played critical parts in said project and thus in WW2. There is not much to say about it – it is of course interesting to read about the madness of those times.

What I found notable was the part where Becker talks about a massive boom in Physics research funding after the war. This then led to a lot more students, which led to much expanded classrooms, and textbooks “nearly dropped questions” about foundations, that is, questions of ontology took a very distant back seat.

I can understand that, during wartime, people may not have been seized with an urgency to figure out the nature of base-reality, and more than happy to engage in an orgy of epistemology – that is in fact what won the war, or at least ended it – but that this became the post-war norm due to a deluge of funding is, with hindsight, rather a pity.

But these things happen – you win one global war with your epistemology and soon, that is all anyone wants to fund, and thus all thinkers want to think about, and teachers teach.

A neat feedback loop: epistemology was good for war, and the War was good for epistemology.

Let’s go to chapter 5.

4.6 A Valiant Effort

You recall von Neumann’s 1932 proof that it was CI-or-bust for QP. You recall that Hermann had shown it was wrong, but was ignored.

Now, we jump to 1952. Two decades later, said proof was still accepted by Physics as a field, and Albert was still considered to have come out worse in his debates with Bohr.

It was at this point that someone literally came up with a theory that had an ontology – it didn’t have the vagueness/handwaving of CI – and was consistent with QP’s predictions.

This brave chap was David Bohm.

Becker makes it clear in the book that Bohm knew of von Neumann’s proof. That is, Bohm knowingly defied it by trying to come up with his own approach. And the reason he did that was because he started teaching QP and even wrote a book about it, in which he tried to explain CI. As a result of trying to explain it, he found CI unacceptable. That is, he thought for himself, and then acted on it.

By the way, even if he hadn’t known about von Neumann’s proof, the fact that he offered an ontology after nearly three decades of CI-dominance – this included apparent dominance over Albert – is quite sufficient for me to consider him brave.

Consider the situation: here was a chap offering an actual ontology and his theory’s predictions were no different. A triumph, at least of imagination and inventiveness. So, what do you think happened?

Well, the work was presented on his behalf by Max Dresden – Bohm was stuck outside the country due to reasons – to whose attention it was brought by his students. Dresden initially rejected their queries by referring to, yes, von Neumann’s proof, but he finally took a look and was impressed enough that he decided to share it with an elite audience at Princeton’s Institute for Advanced Study.

After he had concluded his presentation, there was a stunned silence – you could have heard an ontology drop – and then there was a slow clap in the corner. Turning to it, he saw that it was one of the bigwigs of the CI-camp. The clapper stood up, looked over at Albert – this was in Princeton, remember – and said in a loud carrying voice: “I was wrong. I am going to take a long hard look at von Neumann’s proof and see where he went wrong.”

Did I lose you? Where? Was it the ‘slow clap’? Too dramatic?

That is to say, that is not what happened. What happened was that– no, I want you to read Becker’s text on page 90 for yourself to find out the full details of the reaction. I will share just the crowning portion of the reaction because it is too good not to relay.

After various people had said various choice things about the absent Bohm – they commented about his intellect and also his morals – and some had implied that Dresden was not-smart for having “taken Bohm seriously”, Robert Oppenheimer, the head of the institute, said to the room that “if we cannot disprove Bohm, then we must agree to ignore him”.

Yes, this is a thing that we have every reason to believe happened. Talk about dropping a bomb on an innocent, and blowing up the commons.

For the fifth time, such is life – Science involves humans.

It is a good thing – and this is me talking – that Oppenheimer did not have this attitude towards inventive efforts when leading the Manhattan project, or perhaps it is not a good thing – I suppose it depends on your stance regarding the successful development of the bomb – but such an attitude probably wouldn’t have helped develop a working bomb.

By the way, here is something to know and note: Bohm had been Oppenheimer’s student.

Becker then goes into some detail about Bohm’s life, following which he talks about his ontology. Bohm’s idea was that there is a reality at the lowest levels, it is quite sensible to talk about it and it comprises particles guided by pilot waves.

I realise this will not satisfy anyone interested in a full intuitive grasp of how this solves the mysteries that CI’s handwaving left open but, in my humble opinion, this kind of thing requires either a deep inspection or a fairly superficial one. The middle ground is both taxing and unsatisfying.

Becker provides a broad picture of it in the book – see pages 99-102. The important thing is to know that, in Bohm’s theory, the Maths was equivalent to the wave equation, and so gave the same predictions, while also providing an ontology – a stance on reality.

I am not a physicist, so I am curious: how hard a piece of work was Bohm’s? I ask because this was after more than two decades of CI, during which QP hung in the ether (so to speak) with no tether to reality. Was Bohm’s a rare work of genius – was it something only someone absolutely elite could have done – or could a top-100 physicist of the 1950s have managed it?

Becker points out that Bohm’s idea was quite similar to de Broglie’s work from the 1927 Solvay, but that Bohm had addressed the challenge raised at the conference that had, at least then and there, stumped de Broglie. Good going by Bohm.

There is a paragraph on page 106 which is a bit saddening. Becker shares that Bohm of course found out about the reaction at Princeton. Imagine hearing that your past teacher had told physicists, in so many words, that your work must be ignored if it cannot be disproved. And then imagine that said teacher is Oppenheimer.

And this wasn’t even regular Oppenheimer, but the post-Manhattan Oppenheimer. Thus, imagine the effect his words would have had on those physicists. Plus, there was of course von Neumann’s proof in the background.

So, any such well-read physicist had two choices: ignore Oppenheimer, take von Neumann to be wrong, and take Bohr to be wrong, OR, take Bohm to be wrong.

In a technical sense, it was a choice but, in a human sense, it was not much of a choice. What was extremely likely was what happened. And so, QP carried on with CI.

Here is something I found hilarious: Becker explains that younger physicists dismissed Bohm’s work because they noticed that it implied non-locality, and thus they considered it inferior to CI.

It is hilarious because CI is also non-local – that was the point Albert had made, over and over and over again via his thought experiments. The third one was even published, and also mentioned in mass media. Such is life…

You might wonder – I did – how Albert and Schrödinger reacted to Bohm’s work. Becker goes into that. Schrödinger was busy with other things, including finding a wave-only ontology for QP, and did not engage. Albert had issues with the work, including of course the non-locality. He did not consider it radical enough and was working at the time on uniting Relativity with the Maths of QP.

Eventually, Bohm abandoned his theory – he became convinced it was wrong because it turned out to not work with Special Relativity – and started looking for a new one.

4.7 Killing a Philosophic Monstrosity

Chapter 6 starts with Albert’s final lecture. It was in April 1954, at Princeton, on Relativity, but the discussion turned to QP. At that lecture was present a student who noted Albert’s remarks about CI.

The student, Hugh Everett, had read both von Neumann’s book – the one with the proof – and Bohm’s work. He had noted the “problem lurking” in QP, that is, he found CI entirely unacceptable – he considered it a “philosophic monstrosity”.

A digression: appreciate how well these chaps wrote back in the day – we saw examples from Albert and Everett – at least when they were being critical.

So, there had been Bell in 1949 with his unease, Bohm in 1952 with his unease and thus effort, and then Everett in 1954, also uneasy.

Did he make an effort too, I hear you ask. Yes – yes, he did.

Everett was smart and strong-minded, and he did what such people do in such situations: he ignored the prestige of those who were promulgating what he considered a “philosophic monstrosity” and came up with a new approach.

He came up with an ontology – an ontology that was free of the vagueness that had made Bell uneasy – by treating all of reality as being subject to the same laws of Physics, with no handwaving differentiation between classical objects and the quantum world. His stance was that the same laws that governed an electron governed an electric appliance, and that was that.

Now comes the most entertaining part of chapter 6 – the part that would have made the old me grit his teeth – all 25 of them.

Everett had a draft of his thesis ready in January 1956, less than two years after Albert’s lecture. His professor was John Wheeler and Bohr was Wheeler’s mentor and friend. Wheeler did not want to endanger his relationship with Bohr – career reasons – and he knew that Bohr would not be thrilled with Everett’s stance.

So, Becker explains, Wheeler decided to try and “secure Bohr’s… blessing for Everett’s work” before he endorsed it as a thesis. Good God.

Consider the task Wheeler took on: Everett considered CI – Bohr’s baby – a “monstrosity”, and Wheeler wanted to get Bohr to smile upon Everett’s evisceration of his baby.

Dear reader, try to imagine what happened.

When I first learnt what follows, I almost laughed in disbelief. Here are the highlights in chronological order:

1. Everett readied a draft of his thesis in January 1956.

2. Wheeler told Everett at some point after that that his thesis would be accepted and his degree granted by summer 1956.

3. In mid-1956 – this was several months after the draft was ready – Wheeler sent the draft to Bohr.

4. He then discussed the ideas with Bohr and gang in person, and then told Everett that he needed to “thrash” out the all the “issues of interpretation” with Bohr by visiting him for several weeks, and added that while the thesis was done, the “hardest part” was “just beginning”.

   1. I am not making this up. See the book. Page 129.

5. Given #2 above, Everett already had a job lined up by then, and he was to start it in three weeks.

6. Worse, Wheeler had misread how favourably the CI-camp looked upon Everett’s ideas. He got further feedback from them at this point and realised this.

7. Wheeler then told Everett that it would “take a lot of time” to resolve the issues the CI-camp had raised and proposed two months of “day by day argument” with Bohr to have a meeting of the minds, not on the formalism but on the “words” of the thesis.

8. He then wrote to the CI-camp – and this is a masterpiece – that Everett accepted CI and only meant to generalise it.

   1. See page 131.

9. He then wrote to Everett and indicated that the thesis “must” be heavily revised in terms of “words” but not the Maths before he would recommend it for acceptance.

10. But Everett didn’t go to meet Bohr. So, in the end, Wheeler sat down with him and “told him what to say” in his thesis. The revisions did not change the Maths/formalism but “downplayed” the many-worlds aspect of it, that is, its ontology, that is, the thing that puts the ‘many’ – also the ‘s’ – in ‘Many Worlds’.

11. Thus, about six short months after Wheeler had first sent the thesis to Bohr, its words were in a state that Wheeler could accept.

12. I take it he thought that the revised thesis would not give rise to whatever downsides he had imagined the original draft would have.

13. The thesis was published as a paper in 1957 along with a companion paper from Wheeler saying that Everett’s work did not aim to replace CI.

Imagine being Everett and going through this process. What would you think? Imagine.

[I rather wish that Everett had written a memoir or left behind a detailed diary – I checked – he did not – so that we could hear directly from him on this. Ah well.]

But there is more – there was a cherry on top of this comedy-cake: even after all that work, with Wheeler literally telling Everett how to change his words, the CI-camp still disagreed with the Wheeler-approved contents of Everett’s thesis, and Bohr had someone else write a response to Everett.

Dear reader, you should open the book to page 132 and read the excerpts of the CI-camp’s response – they are quoted by Becker. Then, read Becker’s analysis of same – it will be well worth it.

Then, read Everett’s counter-response to the CI-camp from back in the day. Also well worth it.

Though Everett responded, and with decent points, the CI-camp did not respond to him – they probably had more important things to do – and the exchange ended there.

In 1959 – this is two years after the publication of his thesis – Everett happened to meet Bohr and his colleagues, and they discussed Physics. After, one of those colleagues wrote about Everett that “he was undescribably (sic) stupid”. Such is life…

The rest of chapter 6 describes a bit of Everett’s career and the very occasional mentions of Many Worlds by physicists over the next decade. In brief, the idea didn’t even get as much attention as Bohm’s had back in the day. And on we go to chapter 7.

4.8 Saved by The Bell

You remember John Bell from earlier. He had swallowed his unease in 1949 and got on with life. Then, in 1952, he came across Bohm’s idea. It seemed sound, and this indicated to him that von Neumann’s proof needed to be checked, which seems like the obvious conclusion. But what is obvious – clear as a bell – to a John Bell may not be so to another, or to all others.

He went looking for the proof but it was still only in German. It came out in English in 1955, by which time Bell was busy with PhD-work.

It was apparently in 1963 that Bell got round to reading von Neumann’s proof.

You remember this from earlier:

Sitting here a century after the start of QP, I wonder whether Albert would have spotted the error in von Neumann’s proof had he read it. Luckily, the error was later re-discovered by– but I am getting ahead of the book’s unfolding.

It was Bell who re-discovered – remember Grete Hermann – von Neumann’s error. In a memorable quote, Becker relays Bell saying that said proof “falls apart in your hands”.

So, a proof from 1932, relied upon in its specifics by several elite physicists and relied upon vaguely by many, many top physicists, was found to be flawed in 1963.

Of course, it had been found to be flawed back in 1935 but no one had cared. This time though, the world sat up and noticed when Bell found the error, and then proceeded to do some further clever work which led to his now-famous insight – his theorem: Bell’s Theorem.

I am again kidding. Sorry.

Literally nothing happened for about five years after Bell published his now-landmark paper in 1964. Bell might as well have communicated his theorem via drums or smoke signals for all the response he got.

And there ends chapter 7.

4.9 Chapter 8

Becker kicks it off with Thomas Kuhn’s interview of Bohr, in which they revisited the Albert-Bohr debates, and Bohr was of the opinion that Albert had had much the worse of it and that his criticisms had been groundless. Bohr even lamented the time Albert had spent coming up with his thought experiments.

Yes, this is a thing we have every reason to believe happened. I can of course imagine how things would have seemed from Bohr’s shoes but, still, wow.

There is some relief provided by this chapter, due to Becker’s description of the demise of Logical Positivism. This is relevant in that aspects of CI are positivist, and both ideas had arisen from the same cultural context. While the primary CI-chaps did not start from positivism as the basis and thus come up with their CI-claims regarding QP, the two shared “common inspirations”: the ideas of Ernst Mach.

Bohr himself was not a positivist but he did once state that his reply to the EPR paper – the text about the meaning of which people are still not quite sure – was kind of based on positivist reasoning. Also, CI was defended from criticisms using positivism-derived reasoning by other CI-chaps.

Becker states plainly that the CI-camp had “embraced a knockoff version” of positivism, which was useful for their goals. After all, for example, most didn’t believe that electrons don’t exist. He also calls the CI-camp’s stance a “caricature of the positivist attitude” and a “cartoonish parody of positivism”. Jolly well put.

He then explains the demise of positivism, the persons involved who did the demise-ing, their arguments, etc. If you find this stuff interesting, see page 179 onwards.

My main thought upon reading this part was gratitude at having been born in a post-positivist culture. Because I just know I would have swallowed the positivist party-line whole.

Then, Becker talks about “scientific realism” – ah, the joy – and its ascent.

That then links to a section on the scientific realists who knew of QP and its ontological vacuum due to CI, and who wondered about what may arise there.

Becker talks about Hilary Putnam as an example. Putnam knew of von Neumann’s proof but he did not know of Bell’s error-spotting, thus he thought Bohm’s idea was ruled out. He didn’t even know about Everett’s idea, but, if he had had, I am guessing he would have thought it was ruled out too.

Then, Becker makes an important point. He explains that philosophers had rid the world of positivism and some of them clearly understood the ontological vacuum in QP, but physicists of that new generation were not schooled in philosophy as much as say Albert had been because the post-war specialisation had affected this aspect of physicists’ education. They were, happily, or perhaps unhappily – I don’t know – busy with large grants due to the boom in post-war funding for Physics, and their work comprised “hard-nosed calculations”, not philosophising about what is real.

“shut up and calculate” “…epistemology-soaked orgy…”

And thus ends chapter 8.

4.10 Green Shoots, Shot

This chapter is the most staggering of all. In it, Becker talks about the chaps who pushed QP forward from its local maxima of the non-local CI.

He starts off with John Clauser. Clauser was unimpressed with CI, and then he came across Bell’s paper by chance. In a moving passage, Becker quotes Clauser’s recounting of his reaction – see page 194.

As it happened, Clauser was an experimental physicist and thus wondered about testing Bell’s Theorem. He checked and found such a test had not been done. He then went to his advisor who was “pissed” about Clauser poking around in this stuff. Luckily, he told Clauser to write to Bell, et al. which Clauser did – this was in 1969.

And that was the first correspondence Bell had received about his 1964 paper – the paper which is now considered brilliant.

The book then moves onto Dieter Zeh, who, as a theoretical physicist thinking for himself, did a sort of thought experiment, where he treated the entire universe, including the macroscopic device that measures the result of a quantum experiment, as a quantum system from top to toe, and came up with what is now known as Decoherence. In the process, he also independently discovered Everett’s approach.

A digression: for those who do not know, the Many Worlds approach of today comprises both Everett’s approach and Decoherence.

He wrote it up and took it to his mentor. It was quite a remarkable piece of bad luck for Zeh that his mentor sent his work to the same chap who had called Everett “undescribably (sic) stupid”.

So, as you can imagine, his response was not flattering. He called it “a concentrate of the wildest nonsense”. And the rest of his response is remark-able for another reason too. Do see page 198.

A digression: having read those passages multiple times, and having had time to reflect, I think that chap – the critic of Everett and Zeh – seems to be one of those second-level academic operatives which are not uncommon in today’s world either. After all, there is nothing new under the Sun – nothing new within the wavefunction.

I spend a fair bit of time on Twitter and, there, I see experts who are wedded till death-do-them-part to someone else’s influential but idiotic idea. Thus, they respond with venom if someone critiques the idea logically, even if only parenthetically.

There is a still worse case though – and I have seen examples of this on Twitter too – where an expert is wedded-till-death not to some specific influential but idiotic idea, but to some influential idiot in general.

Such is life – truth-seeking involves humans, and some humans are not all they could be. Or, perhaps, they are.

The mentor did not share the response with Zeh but told him that working further on that topic would “extinguish” his career.

But Zeh was a stubborn man and submitted it to journals. Some declined with reasons – one called it “senseless”, another said that QP did not “apply to macroscopic objects” – and the rest just declined, sans reason.

So, Zeh sent it to Eugene Wigner who he knew was interested in QP’s foundations. After some interesting back-and-forth with the CI-camp – see page 200 – Wigner had the paper published in a new journal where he was on the editorial board. By this time, Zeh had discovered Everett and referenced him in his paper. Nice.

Becker then talks about a student of Wigner’s, Abner Shimony. Shimony was, like Clauser, unimpressed with CI and in 1964-65, he came across Bell’s paper. Like Clauser, Shimony was impressed: “something very great” were his words. So, like Clauser, he wanted to test Bell’s Theorem.

Dear reader, did you notice the consistency across Clauser and Shimony? Probably because of not being wedded till death-do-them-part to CI, they didn’t reject Bell’s Theorem at first glance. They were thus able to see that it was insightful, that it would be good to test, and that they should test it.

Here is the happy part of this chapter. The two chaps found out about each others’ intentions and decided to collaborate. Very nice, or as Shimony wrote, “a civilized way” to proceed, given that they had independently arrived at the thought.

They co-wrote a paper – the CHSH paper – which described an experiment that could be performed to test Bell’s Theorem.

Just consider the potential consequences: either the experiment would show that QP was non-local (or something at least as weird was going on) – a great Physics result – or that QP was wrong – an even greater Physics result.

Also consider: the CHSH paper was in 1969, about five years after Bell’s paper. That is, slowly but surely, progress was being made.

But, this progress almost remained on paper. It was touch and go that Clauser could get hold of equipment and manpower to do the experiment, and even after he got access to manpower and most of the required equipment, it took him another two years to scrounge up the rest of it. Geez.

But, he got it done, got the results, and published in 1972, showing that QP was fine which meant that reality was either non-local or something at least as weird was going on.

Now, that’s progress.

Remember, this significant progress happened in spite of Clauser’s mentor being “pissed” at his interest in the topic.

Then, Becker gets to the most staggering part – yes, “pissed” mentors and assessments of “wildest nonsense” are not the lowest points of this century-long tale.

He explains the effects on Clauser’s and Zeh’s careers, and on the careers of Zeh’s students. The latter could not get jobs for a long time because they had not done “real Physics”.

Ironic, is it not, that the CI-chaps were the ones participating in the orgy, but it was these two curious and capable chaps who got ****ed.

There is a horrifying section where Becker mentions that a letter of recommendation, written by Clauser’s PhD advisor to help him with his job-search, said that his Bell-experiments were “junk science”. Really – see page 209.

Then, Becker explains further general reasons that physicists stayed away from questions of ontology. These are in addition to the reasons of ‘funding towards usable outcomes’ and positivism being in the air. He says that American Physics was ascendant and it was more “pragmatic”, and that theories which were non-CI were associated with communism which would risk the large Physics-funding from the military for usable outcomes.

Yet another staggering part is when he quotes Clauser saying that students up to postgraduate level were taught in so many words that Bohr was right and Albert wrong – end of discussion – and questioning it could be career-ruin.

I thus consider it a minor miracle that the CHSH paper and Zeh’s Decoherence paper were ever written in the first place. God bless them.

This was followed by the also good work of Alain Aspect who also found Bell’s Theorem fascinating, and pushed the field forward both via experiment and his social approach.

Becker explains that, as a cumulative result of all these efforts, some – not many, and definitely not the majority, but some – physicists began to “openly question” CI in the 1980s.

Oh, I say, open dissent! That too in the hardest science. Be still, my heart.

So, six decades from the start by Bohr and gang, half a century from von Neumann’s proof and Albert’s thought experiments, three decades from Bell’s paper and a decade from Clauser’s experiment, the world of Physics reached a point where some physicists began to openly question CI.

If that is not blinding-fast progress, I would like to know what is.

Like all progress, this one had a cost: the careers of some curious and capable chaps. But these things happen.

There was another cost, which was hidden even though it may have been wider spread: the chaps who used to bully the physicists who asked ‘what is real?’ could no longer do so.

Imagine. Consider. It reads like something from Victor Hugo in mid-season form, does it not. In fact, I imagine Hugo would have been rather chuffed with himself to have come up with a scenario this sad. Jean Valjean’s life-story was tragic, sure, but he never had to suffer the heart-rending indignity of being unable to bully people.

Fact is sadder than fiction.

4.11 A Noble Man

Chapter 10 gets into further work by Bell and how more physicists were becoming aware of his insight, and even spreading it. It mentions some potential practical effects of taking Bell’s Theorem seriously.

Then, it gets into further progress on the Decoherence front, with the idea receiving more work and also attention, sans hostility.

But two steps forward were matched by approximately two steps back when one of the main proponents tried to reconcile CI with Everett, kind of like Wheeler trying to reconcile Everett with CI.

Remarkably, the chap who did this, Wojciech Zurek, was a student of Wheeler’s – the apple’s ontology did not fall far from the tree’s.

Skipping over some material, we then arrive at the introduction of another ontology – this is different from Bohm’s and Everett’s – named ‘Spontaneous Collapse’. I won’t get into details here, but it is one of the ontologies that Becker lists towards the end of the book when he claims agnosticism about which one is right, while also unshyly stating that CI is untenable.

Bell died in 1990 of a stroke, never having won a Nobel, but having done work which clearly deserved one. More importantly, he displayed a courage and a commitment to where his curiosity took him that many contemporaries, including various Nobels, never did. He wasn’t a Nobel, but he was more: a Noble.

4.12 The Bigger Picture Informs the Smallest

Becker shares that, before Bell died, he made the perceptive observation about Many Worlds that the existence of all possible worlds was interesting, given that our own world was “highly improbable”. To be fair, he found Many Worlds extravagant and vague, and wanted it to be made precise. But he did not dismiss it outright and opined it may have “something distinctive to say” about EPR once made precise. Not bad.

Chapter 11 gets into progress in the Physics world regarding Many Worlds and Everett’s idea getting some positive attention, thanks to Bryce DeWitt.

Hilariously, as a result of the attention, it attracted critics, one of whom referred to it as the “Everett-Wheeler interpretation”. Wheeler, who had originally tried to walk the line between not alienating the CI-camp while also accepting Everett’s thesis, then “publicly distanced himself” from the Everettian approach, and proceeded to come up with an alternate approach which he considered compatible with CI.

Due to Cosmology rising, Many Worlds gained even more popularity, both conceptually and practically, and CI fell a bit out of favour. Why, you ask.

To explain the workings of the early universe, when it was very small in size, QP had to be integrated with General Relativity (GR). That is, there was a reality there to contend with, and it could not be handwaved away in classic CI-style.

Hilariously, the same chap who called Everett “undescribably (sic) stupid” and Zeh’s work “wildest nonsense” had said in the 1960s that no QP-GR unification was required as the effects could not be seen. A classic case of handwaving reality away.

“…epistemology-soaked orgy…”

But, to be fair, there was a very good reason he had said that. You see – I found this out from Becker of course – said chap was a positivist.

Dear reader, if you ever desire an exchange of ideas with a positivist but don’t know any, find the nearest epistemology-soaked orgy and throw a stone at it – you will likely hit a positivist. If at first throw you don’t succeed, throw again. You will hit one soon enough – the odds are in your favour.

Becker then describes the trainwreck of falsifiability as a criterion for Science, due to which people resisted the idea of multiverses, both in quantum and cosmological domains. He then takes it apart.

Everett died in 1982 and did not get to see the progress, but it seems he would not have much cared. He had achieved his goals with his thesis, and gone on to do what interested him, which was not a career in Physics academia.

4.13 The Mayhem Remains

In the final chapter, Becker goes into some detail on the current dynamics of the field, and the proposed ontologies. This is where he expresses his agnosticism about which ontology is right, and his unshy stance that CI is not.

He explains that CI receives a plurality of votes when physicists are now asked about their preferred take on QP. And that the real fraction is probably higher because of sampling bias. Such, still, is life.

He mentions that philosophers of Physics are almost unanimous that CI is wrong, but leading physicists seem ignorant of philosophy and are quite happy to go with CI. It seems like a hopeless situation. And it is – in our short run.

Things will not change tomorrow, nor tomorrow’s tomorrow, but they will change. Petty as the pace of change is, it is positive and the effects will cumulate.

Let CI strut and fret its remaining hours upon the stage, on the way to dusty death, to then be heard no more.

An influential but idiotic idea, full of sound and fury, signifying nothing.

And when I say ‘nothing’, I mean that literally: CI has nothing to say about the lowest level of reality – it blithely leaves what Becker calls a “hole” in our understanding of reality.

“…epistemology-soaked orgy…”

In Closing

Dear reader, as I end this essay, I would like Zeh to have the last word on CI. Why? Because of what he and his students went through as a result of their work on Decoherence.

Zeh considered CI to be the “…greatest sophism in the history of science”.

I checked and found out that he died recently, in 2018. May he reap rewards, deserved but denied him in life, in the afterlife.

Becker closes his book with what is essentially a common-sense statement of scientific realism but which, due to the last hundred years of ontological chaos in QP, comes across almost as an aesthetic appeal.

He says that there is “something real, out in the world” and the “job of Physics” is to find out what that something is. Put another way, one uses Physics to find out what is real_._

Be well.