Physicists and philosophers fight it out

I have lately spent rather too much time and effort catching up on a controversy concerning reactions to a book by physicist Lawrence Krauss (A Universe from Nothing, published last year), and, in particular, concerning a muscularly negative review of the book by philosopher David Albert.

The controversy has been recently reignited by the withdrawal of Albert's invitation to join a prestigious panel (including Krauss) for a public discussion at The American Museum of Natural History.

As Jason Streitfeld makes clear, one of the underlying issues relates to the status of philosophers vis à vis scientists (in this case physicists).

The demarcation lines and motivational factors in this disinvitation dispute are not all that clear, however. It should be noted, for instance, that David Albert, as well as being a philosopher, also has a PhD in physics, and that attitudes to religion are playing a key role.

Albert's main contention is that Krauss's 'nothing' (relativistic-quantum-field-theoretical vacuum states) are particular arrangements of elementary physical stuff, and therefore far from nothing as generally understood.

But Albert is particularly scathing about what he sees as Krauss's facile rejection of religion. He writes:

"When I was growing up, where I was growing up, there was a critique of religion according to which religion was cruel, and a lie, and a mechanism of enslavement, and something full of loathing and contempt for everything essentially human. Maybe that was true and maybe it wasn’t, but it had to do with important things — it had to do, that is, with history, and with suffering, and with the hope of a better world — and it seems like a pity, and more than a pity, and worse than a pity, with all that in the back of one’s head, to think that all that gets offered to us now, by guys like these, in books like this, is the pale, small, silly, nerdy accusation that religion is, I don't know, dumb."

Krauss called Albert's review "moronic", by the way.


Physicists have a history of disparaging philosophers. Some months ago, one of the most reflective of contemporary physicists, the (then) 88-year-old Freeman Dyson ruffled a few feathers by disparaging contemporary philosphers in an essay published in The New York Review of Books.

I read it at the time, and intended to do a piece on it, but didn't get around to it. Strangely, the expression "the fading of philosophy" – used by Dyson – must have lodged in my subconscious, and I used it as the title for a post last month without realizing its source.

I am in sympathy with much – though not all – of what Dyson says, and I am attracted by his somewhat world-weary tone and contrarian instincts.

There is something of the amateur and the dabbler about him, and he has (or had) one of those almost freakishly clever mathematical minds which can sometimes lead to a certain kind of hubris about one's own abilities and judgements as well as to an overestimation of the power of technologies to solve problems.

Dyson balances these tendencies with a genuine sort of wisdom, however. His little anecdote about a disappointing encounter with Wittgenstein, and then the story of his accidentally coming across Wittgenstein's grave in the course of a winter walk fifty years later, is quite moving.

Dyson's essay is a series of reflections on (rather than a review of) a book by Jim Holt based on interviews with various thinkers (philosophers, physicists and cosmologists) on why there is something rather than nothing. (In fact, Holt has been invited to join the panel from which Albert was disinvited. The world of public scientific intellectuals is a very small one. Even our old friend Massimo Pigliucci plays a part in the controversy.)

Dyson was not impressed with the calibre of Holt's philosopher interviewees. Dwarfs, he calls them, in stark contrast to the philosophical giants of the past. Only one, John Leslie (retired and living on Canada's west coast), gets a favorable mention.

"Philosophers became insignificant," Dyson wrote, "when philosophy became a separate academic discipline, distinct from science and history and literature and religion. The great philosophers of the past covered all these disciplines."

I too have been arguing against philosophy as a stand-alone discipline, and see philosophical thinking as being something which arises naturally in the context of the pursuit of the various sciences.

But I have to say that I find Dyson's way of expressing himself at times vague and imprecise. The last sentence quoted above, for example, could be read as suggesting that all of the great philosophers of the past covered all of these disciplines, or, alternatively, that some covered one or some disciplines and some covered other disciplines. Also, religion is not a discipline. This is just poor writing.

I have some reservations also about Dyson's view of philosophy as a literary phenomenon, and I tend to see, for example, the Book of Job more as literature with a religio-philosophical slant than as philosophy as such. But this is perhaps little more than a semantic – or definitional – question.

My more serious disagreement with Dyson relates to his obviously religious tendencies, which I don't share. But I will concede that, of all the possible religious outlooks I have considered (and rejected), Dyson's Platonic and mystical approach ranks amongst the least unappealing.

Dyson's key point about philosophers having become insignificant relates directly to the disinvitation controversy, and, though Dyson and Krauss are about as different from one another as two physicists could be, it is interesting that they are both dismissive – albeit for different reasons – of contemporary philosophy.

Perhaps the best thing I read in all the pretty wild and woolly discussion associated with the Krauss/Albert dispute was – apart from Albert's original review – a little joke in the comment thread of a blog post I didn't make a note of.

It was a brief mock-warning to scientists about the dangers of being rude to philosophers of science. They had better be careful because the philosophers might go on strike, and where would the scientists be then?

Physics, metaphysics, religion and social thought

Are sciences like physics relevant to social and political thinking? Arguably they are, not directly, but as they influence one's general view of the world - one's metaphysics, if you like.

Consider relatively recent developments in physics - particularly those relating to our clearer understanding of the notion of quantum entanglement, and the realization that information is physical and a more basic physical concept than matter or energy.

These discoveries and new ways of thinking allow us to reassess various older traditions of thought. Personally, I am led to look again with increased respect at philosophers like F.H. Bradley (a 19th century philosophical idealist) who, entirely innocent of mathematics and formal logic, articulated a view of the world in which everything was related to everything else, everything was ultimately inseparable from the whole. Schopenhauer (drawing on Indian philosophy) had a similar view. Spinoza was an important source for Bradley's thought - indeed there is a rich tradition of thinkers in this vein. Some were religious, others less so or not at all. The wholesale rejection of idealism by philosophers in the early 20th century occurred just when physics was beginning a revolution which would vindicate important elements of philosophical idealism.

I am not suggesting a return to philosophical idealism, however. Any metaphysics of the future needs, in my opinion, to be firmly based in physics and quantum information theory.

Issues of politics and society can of course be dealt with without reference to physics or information theory; but they cannot be dealt with in any comprehensive way without reference to religion. This is because so many Western institutions and ideas and modes of thinking are influenced so profoundly by Christian and classical (especially Platonic and Stoic) thought. Even people who don't think of themselves as religious continue to hold beliefs which derive directly from religious traditions. This applies to value systems (humanism could be seen to be a Christian value system) and also to more general ways of thinking about oneself. Religious ways of thinking (e.g. the mind as something different from the body) come naturally to us, whereas scientific truths are often counter-intuitive.

My views on science and my (very limited) scientific knowledge form the basis of my secular view of the world; and this secular view clearly affects my political and social views. Physics and information theory may not have direct applications to social philosophy, but indirectly - by helping to form a secular view of reality - they influence profoundly my social thinking.

Through a crystal darkly

In previous remarks on randomness and computation, I mentioned the work of Gregory Chaitin, a mathematician and theorist who has written and spoken (he is a brilliant speaker) extensively for both specialist and general audiences. Chaitin's technical work is highly regarded, but his interpretations and extrapolations are sometimes a little idiosyncratic and he is inclined to sound a bit New Agey at times. (He is rumored to receive help in his thinking from a giant crystal!)

Paul Davies (a physicist and writer) is, by contrast, sober and restrained - even a little pedestrian by comparison - but he is a reliable guide within his areas of expertise. I recently came across a foreword by Davies to a book of Chaitin's essays* in which Davies gives his perspective on the significance of Chaitin's work and its implications for physics and our view of the world generally.

Chaitin (who had been obsessed from his childhood years with Kurt Gödel's incompleteness theorem) "greatly extended the scope of Gödel's basic insight," writes Davies, "and recast the notion of incompleteness in a way that brings it much closer to the real world of computers and physical processes. A key step in his work is the recognition of a basic link between mathematical undecidability and randomness. Something is random if it has no pattern, no abbreviated description, in which case there is no algorithm shorter than the thing itself which captures its content. And a random fact is true for no reason at all; it is true 'by accident' so to speak ... Chaitin was able to demonstrate that mathematics is shot-through with randomness ... Mathematics, supposedly the epitome of logical orderliness is exposed as harboring irreducible arbitrariness." (p. vi)

"[M]athematics contains randomness - or accidental, reasonless truths," Davies explains, "because a ... universal Turing machine [an idealized computer], may or may not halt in executing its program, and there is no systematic way to know in advance if a function is computable (i.e. the Turing machine will halt) or not." (p. viii)

But this limitation on what we can know or predict (known as Turing uncomputability) applies not just to mathematics and computers but also to scientific theories. On Chaitin's view, a scientific theory is like a computer program that predicts our observations (the experimental data).

Indeed, in the words of Paul Davies, " ... we may regard nature as an information processing system, and a law of physics as an algorithm that maps the input data (initial conditions) into output data (final state). Thus in some sense the universe is a gigantic computer, with the laws playing the role of universal software." (p. viii)

And if the laws of physics are computer algorithms, there will be randomness in the laws of physics stemming from Turing uncomputability. But, according to Davies, the randomness will, in reality, be "even more pronounced than that which flows from Turing uncomputability." (p. viii)

He points out that the real universe differs in a crucial respect from the concept of a Turing machine. "The latter is supposed to have infinite time at its disposal: there is no upper bound on the number of steps it may perform to execute its program. The only relevant issue is whether the program eventually halts or not, however long it takes. The machine is also permitted unlimited memory ... If these limitless resources are replaced by finite resources, however, an additional, fundamental, source of unknowability emerges. So if, following Chaitin, we treat the laws of physics as software running on the resource-limited hardware known as the observable universe, then these laws will embed a form of randomness, or uncertainty, or ambiguity, or fuzziness - call it what you will - arising from the finite informational processing capacity of the cosmos." (pp. viii-ix)

There are, it seems, different forms or levels or randomness. The 'mild' form which - as chaos theory shows - is implicit even in classical, deterministic physics; the pseudo-randomness which can be generated by simple computer algorithms; the well-known randomness inherent in quantum mechanics; and perhaps the deepest levels of all stemming from proven features of idealized computers (Turing machines) and from seeing the universe itself as a giant computer - one with specific limitations on its processing capacities.

These are difficult (and to some extent speculative) ideas. But I think they are worth pursuing and may even have profound implications for how we see ourselves and our world.

It is, of course, impossible to draw definitive political or metaphysical conclusions from them, but, if the ideas are sound, there will be such conclusions to draw.

Let me just mention two thoughts which come immediately to mind: Chaitin's and Davies' notions are utterly incompatible with any political ideology which attempts to predict, plan and control human affairs; and they also appear to undermine perspectives which incorporate notions of a providential force operating behind the scenes and impinging on natural processes, historical events and/or individual destinies. 


* Thinking about Gödel and Turing: essays on complexity, 1970-2007 (World Scientific, 2007).

The unity of science

I have always disliked the idea that there is some kind of dividing line between the human sciences and the so-called 'hard sciences' like physics and chemistry. In the 1920s and 1930s the thinkers of the Vienna Circle pursued the 'unity of science' ideal, sensing in the division between the human and other sciences traces of a dualism of mind and matter.

But the unity of science project was strenuously resisted, and attempts (often rather crude) to apply the methods of quantitative science to human questions were - and still are - attacked as 'scientism'. Even the scientifically-minded thinker and  economist Friedrich von Hayek used the term 'scientism' to describe what he saw as misguided attempts to turn economics into a science like classical physics.

But (and I take my cue here from Nassim Nicholas Taleb) Hayek and others who maintain "a hard and qualitative distinction between the social sciences and physics" * are working with an outmoded notion of physics.

The 'hard sciences', we now know, go well beyond the traditional engineering-oriented mentality and the approaches of classical physics - they are far more complicated and shot through with predictive uncertainties (randomness) than was appreciated in the past.

So the idea of the unity of science is given a new lease of life as the nature of science (and reality) is better understood.

Furthermore, socialistic notions of central planning - once claimed to be 'scientific' - are clearly exposed as being based on an inadequate view of science; while the conservative's traditional skepticism about government action and awareness of the dangers of unintended consequences is given (rather belated) scientific support and vindication.



* The black swan: the impact of the highly improbable (Penguin, 2008), p. 181.

The randomness at the heart of reality

Is reality ultimately based on randomness? How one answers this question ultimately colors one's outlook (I suggest) in deep and subtle ways. Of course, there are many ways one could approach the issue and there are ambiguities in the question itself. But I am drawn to such questions as this (as a moth to a flame?) and, since I read and think about them, I might as well write about them here from time to time.

Here, then, are a few notes about Vlatko Vedral's view of the issue ...

Vedral draws a distinction between "classical superficial randomness" (e.g. coin tosses) and "quantum fundamental randomness" (see Decoding reality (OUP, 2010), p.163). Randomness approximates to unpredictability and much in our world appears random because it is impossible to predict in practice even if in theory one could do so using the methods of classical physics (if one had all the relevant data etc.). But the quantum world is different. No prediction can be made (even in theory) of certain quantum events. Quantum theory embraces randomness, and sees some quantum phenomena as random in a fundamental sense.*

We can think of scientific theories, Vedral writes (p. 166), as computer programs "with the output being the result of whatever experiment we are trying to model. We say that our theory is powerful, if we can compress all sorts of observations into very few equations."

But any theory will be finite and will (as Gregory Chaitin first fully realized within information theory) only produce a finite set of results. "In other words, there will be many experimental outcomes that could not be compressed within the theory. And this effectively implies that they are random." (p. 167)

Is the randomness in quantum theory due to the theory's incompleteness - our lack of knowledge of a more detailed deterministic underlying theory - as some people think? Or is "randomness inherent in the Universe, and therefore ... [an essential] part of any physical description of reality? Randomness could simply be there because our description of reality is always .... finite and anything requiring more information than that would appear to be random (since our description could not predict it)." (p. 167-168)

Vedral states what he sees as a "very profound conclusion" that this view implies: "that randomness in quantum physics is far from unexpected - in fact according to this logic it is actually essential. Furthermore, it would mean that whatever theory - if any - superseded quantum physics, it would still have to contain some random features." (p. 168)

To me it matters (or seems to matter) whether or not randomness is at the heart of things. Does it matter to you?

* I have revised this passage slightly in response to a comment.

Out of my comfort zone

Further to my recent post on intellectual curiosity... (This is where it takes me sometimes.)

There is a very commonly held view that each era's key technology tends to be incorporated into cosmological and other explanations (e.g. the mechanistic, 'clockwork' universe of the 17th and 18th centuries). Supposedly, we project our technology onto reality and mistake a mere metaphor for reality.

So what of recent attempts to explain the ultimate workings of the universe in terms either of a classical computer/computation, or, more recently, in terms of quantum computation?

Seth Lloyd, who works in the area of quantum computing, wrote a little book four years ago called Programming the universe. Lloyd claims that the universe is a quantum computer and we (and everything in it) are the computation. If this is true, then we are very privileged to be the first humans to have (half?) understood some very profound things about reality.

Lloyd recently reviewed in New Scientist a new book by Vlatko Vedral (Decoding reality) which makes the same claim and is clearly annoyed that Vedral does not acknowledge his book.

These issues are extremely complex and all I mean to do for the moment is to raise them. In my private reading I'll be following them up and I will report my progress (if any) from time to time. But I won't be writing on this sort of thing very often - others can do it better.

As things stand I am impressed with the view that information is a fundamental concept of physics, more fundamental even than the concepts of matter and energy. And if information is physical, then Seth Lloyd's arguments must be taken seriously.