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On John Barrow (1952-2020)

Peter Coles, who is a professor of theoretical physics at Maynooth University in Ireland, tells an anecdote about John Barrow, who died recently at the age of 67. Barrow had been Coles’ thesis supervisor and a profound influence on his work as well as a good friend. As Coles tells it in his In the Dark blog, Barrow had an engaging and sometimes slightly morbid sense of humor, dry enough to tease out the ironies abundant in life’s accomplishments. Thus his reaction to being made a Fellow of the Royal Society, which was to point out in an email that his joy was tempered by having received as his first communication from the Society not only a fat bill for his subscription, but also a form upon which to enter the details of his future obituary.

How saddening that Barrow’s obituary materials had to be put to use so soon. The man was 67, felled by cancer. As Coles notes, he was “one of cosmology’s brightest lights.” I can glance across my office to the nearest of many bookshelves where I see various Barrow titles, including of course The Anthropic Cosmological Principle (Oxford University Press, 1986) and The Left Hand of Creation (Oxford, 1983), the latter of which was my introduction to Barrow and the reason I snapped up the former. Along the way, Barrow produced numerous popular science titles and, of course, hundreds of papers in the journals.

Image: Cosmologist, mathematician and physicist John D. Barrow, who died on September 26. Credit: Tom Powell.

You can learn an extraordinary amount of physics from reading (and re-reading) The Anthropic Cosmological Principle, which Barrow wrote with Frank Tipler, and while theoretical astrophysics dominates the tome, you’ll come out of it steeped not only in cosmology but also philosophy and the history of ideas, from Johann Fichte to Henri Bergson, with a healthy dose of Teilhard de Chardin. None of that means you have to buy into anthropic cosmological principles in the way Barrow and Tipler framed their consequences, although the case is made with vigor and verve. The book is a treasure house of accumulated ideas; the reader can move among them learning, questioning, arguing. I wish I had had the chance to talk to Barrow, preferably over a leisurely dinner, for he was both a raconteur and a wit who spoke with a polymath’s elegance.

As to the anthropic cosmological principle, let’s say that parts of it are self-evident though sometimes productive. Drawing on Brandon Carter, the authors laid out the fact that the physical constants we study in the cosmos have to be such that life can exist within the universe they support. But let me quote Ethan Siegel’s recent piece on anthropic matters, as he’ll say it better. Two forms of the principle emerge in The Anthropic Cosmological Principle:

1) The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exists sites where carbon-based life can evolve and by the requirement that the Universe be old enough for it to have already done so.

2) The Universe must have those properties which allow life to develop within it at some stage in history.

All of which seems self-evident until you absorb the implication in the second item: A universe without life is not allowed. Now we’re in the realm of teleology, making this take on the principle controversial, to say the least. To push the pedal down all the way, Barrow and Tipler introduce a Final Anthropic Principle (FAP) which points to the necessity for information processing to emerge and insists that once present, it will never disappear. Tipler would take these ideas and run with them in his own The Physics of Immortality (Doubleday, 1994). Martin Gardner was less impressed, calling the notion of an ‘Omega Point’ the Completely Ridiculous Anthropic Principle (CRAP). I would say it is entertaining metaphysics and leave it at that.

But the weak anthropic principle still resonates. Paul Davies calls it “a familiar part of the theorist’s arsenal” and Siegel discusses its use in Stephen Weinberg’s 1987 calculation of the energy density of empty space, which must be at least 118 orders of magnitude smaller than what scientists had derived from quantum field theory or we would not be here to calculate it (measurements now indicate the actual figure is 120 orders of magnitude smaller). How it can be used and sometimes abused is, in fact, the subject of the Siegel essay I referenced above. I’m not comfortable enough going through the intellectual thickets here to say more. I always wanted to ask Barrow about his current thinking on the matter to satisfy my questions, though as fate would have it, I never had the chance to meet the man.

What appealed about the dinner idea was Barrow’s interest in wine and cuisine. In the course of my checkered career, I labored as a wine critic and restaurant reviewer for a local paper, and the thought of engaging this wide-ranging intellect on issues ranging from early music to the fine structure constant while sipping, say, a Vosne-Romanée (I would have pulled out all the stops for Barrow!) was enticing. But I have to read the reminiscences of others to reinforce my sense of the man. Paul Davies’ has noted his sartorial elegance (all those trips to Italy), his quick wit, his grasp of literature and the visual arts. Much of which I had more or less inferred from his books.

I mention Italy because Barrow loved the country and I learned from Davies that his stage play Infinities saw its premiere in Milan (it went on to win the Italian Premi Ubu award for the best play in Italian theatre in 2002), and it was consoling to find out that Barrow and his wife Elizabeth had made one last trip there no more than weeks before he died. While we of course remember him here as a scientist, and an extraordinarily influential one at that, style manifests itself in many ways, from the elegance of a new suit to the figures on a physicist’s chalkboard. On his defining intellectual style, let’s turn back to Davies:

More recently, Barrow was interested in the possibility that the fine-structure constant—an unexplained number that describes the strength of the electromagnetic force—might not be constant at all but rather vary over cosmological scales. He produced a theoretical basis for incorporating such a phenomenon in physical law while also remaining open-minded on the observational evidence. His adventurous choices of research problems typified Barrow’s intellectual style, which was to challenge the hidden assumptions underpinning cherished mainstream theories. Fundamental problems in physics and cosmology may appear intractable, he reasoned, because we are thinking about them the wrong way. It was a mode of thought that resonated with many colleagues, this writer included, who are drawn to reflect on the deepest questions of existence.

Indeed, Davies’ many books display the kind of intellectual bandwidth that Barrow tapped so effortlessly, and which is on display in Barrow’s numerous books. He wrote, both in his professional work and his popular science titles, with a crisp, unaffected clarity. I appreciated, as I do with Davies, his willingness to engage with the public, to whom he communicated an obvious joy in the acquiring of knowledge. That’s quite a range, to move from analysis of the early universe and the nature of its physical constants to the reader on the underground, riding home from a harried day with book in lap explaining how mathematics gives shape to the cosmos. How cosmologists slide from the micro to the macro scale will always astonish me.

But practicality has played a hand in this. Go back to the early 1980s and consider, as Barrow often did, the changes that have occurred in how we communicate science. Public discourse on their research and its consequences was relatively rare among researchers until more recent times, when university science departments began to determinedly reach out not only for new students but for the visibility that attracts good faculty. Barrow would win the Royal Society’s Michael Faraday Prize for excellence in communicating science to UK audiences, a subject he further embraced through his involvement as director of the Millennium Mathematics Project, which seeks to spread mathematical skills broadly outside the boundaries of the academy. The latter seems to have inspired his 100 Essential Things You Didn’t Know You Didn’t Know About Maths and the Arts (Bodley Head, 2014), a series of short riffs on the subject.

Image: John Barrow receiving the Queen’s Anniversary Prize on behalf of the Millennium Mathematics Project. Credit: Centre for Theoretical Cosmology News.

Barrow could never have been accused of being a blinkered academic. Even so, he would write over 500 research papers in astrophysics and cosmology, much of the time asking how astronomical observations could inform our understanding of fundamental physics. I’ve mentioned the fine-structure constant and the possibility of variation in earlier cosmological epochs. But he also explored cosmic inflation and probed extremes of nature, the singularities suggested by the nature of the Big Bang. His honors and awards are too numerous to list in the space of this article. His over 20 books have been translated into 28 languages.

What a fine spirit he inspired in those around him. I caught that sense of quest and possibility early, from The Left Hand of Creation, which Barrow wrote with Joseph Silk. The book’s final paragraph is worth quoting:

Could there be any shortcuts to the answers to the cosmological questions? There are some who foolishly desire contact with advanced extraterrestrials in order that we might painlessly discover the secrets of the universe secondhand and prematurely extend our understanding. Such a civilization would surely resemble a child who receives as a gift a collection of completed crossword puzzles. The human search for the structure of the universe is more important than finding it because it motivates the creative power of the human imagination. About 50 years ago a group of eminent cosmologists were asked what single question they would ask of an infallible oracle who could answer them with only yes or no. When his opportunity came, Georges Lemaître made the wisest choice. He said, “I would ask the Oracle not to answer in order that a subsequent generation would not be deprived of the pleasure of searching for and finding the solution.”

Dinner with Barrow would have been just the ticket. A toast, then, to the man who said “A universe simple enough to be understood is too simple to produce a mind capable of understanding it.” Here’s to a universe of complexity so rich that it could inspire the life of such a man.


Comments on this entry are closed.

  • Christian G October 16, 2020, 16:43

    Given the interlocking nature of theory, technology, and experiment, it’s much more likely the only answer an advanced civilization could give us would be “Sorry, your mathematics and instruments aren’t up to providing the complete picture yet”. And anyone who thinks the scientific community wouldn’t want to verify the answers for themselves understands neither scientists nor people.

    A pity such an evidently great mind would fall into the fallacy of the excluded middle, but the article certainly made me want to check his books out.

  • Geoffrey Hillend October 16, 2020, 17:15

    I absolutely agree with the idea that an ET civilization which is very technologically advanced will not give us their technological secrets since it would deprive us the opportunity of the feeling of new discoveries, and learning it for ourselves. The creative mind and scientific intuition are important because these give a civilization intellectual freedom and independence of thought, so we can think for ourselves and not be too dependent on another civilization. Giving a more primitive, violent civilization advanced technology is also unethical since technology can be used for wars according to Jung.

    Nature does not give away her invisible secrets easily. It is only when the level of consciousness is high enough do we discover something new. I toast John Barrow and teleology.

    • ljk October 19, 2020, 10:03

      This is why I have always been skeptical of Carl Sagan’s idea that an advanced ETI would beam the equivalent of the Encyclopedia Galactica about the Cosmos, sharing their knowledge with less sophisticated species in order to uplift them.

      You do not go around sharing your most valuable assets with strangers, especially ones who have the potential to take that information and use it against you. Unless you are already nihilistic and suicidal.

      I am certainly not against enlightening others, but not at the expense of my own well being and those of my kind. At the least it is unwise to just send everything you know out into the void and hope for the best. History on this planet at least has shown otherwise.

      The only realistic time I could see this happening is for the same reason ETI beamed all their knowledge and history to Earth in the SF novel The Listeners by James Gunn: The Capellan race was dying, they did not possess interstellar travel capabilities, and they wanted to preserve something of themselves and their species, so they sent all their information via radio waves to our world and probably others. Since they would be gone by the time humanity and anyone else picked up their transmissions, it would not matter if they gave away the keys to their home, so to speak.

  • wdk October 16, 2020, 18:05

    Faced with such a passing, this itself is quite a memorable and thoughtful
    reflection. Thank you providing this for our more than momentary consideration.

  • David Herne October 16, 2020, 23:59

    So, so sad his passing. Also however, the cause. Professor Barrow died of what we should consider today a preventable form of cancer. I urge all (men in particular) over 50 years of age to undergo the procedure that would very, very reliably detect the form of cancer that was his undoing. (A quick search will tell you what it was.) Too young, too early.

  • Mike Serfas October 17, 2020, 15:53

    There is much I don’t know in this philosophy, but I feel resistance to a weak anthropic principle that speaks of a particular composition of life. The principle seems to presume a theory of consciousness that we have not truly provided. In other words, what explains how a chimpanzee, houseplant, asteroid, or sunspot lacks the consciousness to “perceive” the universe, but humans do not?

    A related issue is why we should assume that the boundary conditions for the universe are set at the beginning. Quantum mechanics is largely time-reversible, so couldn’t the “cause” for the values of physical constants and other events be situated in the middle or at the end?

    • Robin Datta October 18, 2020, 5:58

      The only conscious entity that one is aware of is oneself. It is through unwitting Turing tests that one assigns other entities to the conscious category. Infants and small children often do this imperfectly (or not at all), hence assigning inanimate objects to the conscious category.

      Inquiries into the nature of the universe do not proffer any information about the enquirer.

      • Mike Serfas October 18, 2020, 9:54

        Ah, but how can you be confident you are aware of yourself? The brain is a physical object that can and unfortunately sometimes is divided up by surgery and stroke. Its atoms are continually exchanged with the external environment, its connections continually rewired as a necessary step in cognitive function. Are you aware of yourself, or are you aware only of memories that were laid down by someone else?

        (As inconvenient as this argument is, it at least renormalizes our expectations of the consciousness of other people – we may know as much about them as we do ourselves…)

        • Alex Tolley October 18, 2020, 19:03

          There problems with the “you are your memories that may be falsely created every second ago”.

          1. The memories have to be created every tiny fraction of time.
          2. One can start an external process that would jar if memories were changed. This then requires not just the memories, but the external world to be changed.
          3. The same process has to be done for every other person, indeed every other organism with some sort of information processing organ that can store state even temporarily.

          The problems make even the idea of a multiverse being created with every decision simple by comparison, because for every individual, the newly created brain state would have to be consistent with all teh others. The constraints that implies suggests to me that even if this was the case, it would have to be such that the consistency between state changes would be no different than if there were no recreated new state.

          Hence applying Occam’s Razor, the simplest explanation that there is no recreation of new brain states (memories) between clock ticks is the most likely correct conclusion.

          • Mike Serfas October 19, 2020, 10:20

            I wasn’t saying the memories were false – only that you don’t know they were “the same person”, or indeed a conscious person. This isn’t purely theoretical – do you really have any idea if you are a conscious entity during a familiar walk or freeway commute, when abruptly you find yourself at a destination? The memories are very likely consistent with external events, but you have little if any more evidence to infer you were a conscious person five minutes ago or will be five minutes from now than you do that someone else is. Moreover, if you surmise you are “the same person” as that past or future self despite differences in composition, you should logically surmise you are the same person as those other individuals per the traditional philosophy of atman.

            • Alex Tolley October 20, 2020, 2:27

              A better example is losing consciousness during some phases of sleep. We also know that you lose consciousness during anesthesia in surgery. So we know that loss of consciousness does happen, and has even been measured with fMRI.

              The trickier question is whether you are the same person after regaining consciousness. I see little reason to doubt this.

              However, we also know that that brain damage does appear, behaviorally at least, to result in a different person. Whether the individual feels that they are a different person is less clear. Anecdotally, if we just alter brain chemistry with drugs, people describe themselves as different, although they know their memories are retained. OTOH, as we age, we lose memories (or at least recall), but do not feel different. Dementia and Alzheimers result in both memory loss and brain damage, and behaviorally the person does seem different, although by the time it becomes severe, the person may no longer be able to communicate whether they are different or not.

              My personal view is that consciousness is not relevant. What counts is behavior, and we can change behaviors with drugs, surgery, even by changing environments. In that view, people can be made to be different. I tend to agree with teh view that consciousness is an illusion created by the brain with circuits monitoring other circuits. The brain confabulates a “story” that we perceive as consciousness. It is similar to dreaming, except that during sleep, we have little control over the sensory circuits that are triggered during memory consolidation.

  • Thomas W Hair October 18, 2020, 16:49

    By the looks of some of these comments we seem to have second tier navel gazers commenting on a first tier navel gazer. I, for one, shall have a beer as it is about 5 o’clock in my somewhere and not ponder for a second this untestable and wholly unscientific proposition. Now, all of you science and engineering types, go build a bridge or something…or I shall have to taunt you a second time;-}

    • Mike Serfas October 19, 2020, 11:41

      But we haven’t even gotten started! You’ll know we’re properly underway if I start going on about how knowledge of the immutable future of the indeterminate universe defines free will. :) Philosophy is the basis of natural philosophy, the arts, religion and ethics, and per longstanding tradition the most central question of philosophy is the nature of the self. By relating to that, the anthropic principle therefore bridges the boundary between scientific and unscientific, and challenges us to tackle the hard problem of consciousness… if only to the minimum degree possible to propose why physical constants have the values they do.

      • Thomas W Hair October 19, 2020, 22:04

        Mike, you are spot on. I was just being flippant, sorry. Your words are prescience.

  • Henry Cordova October 19, 2020, 7:12

    “I think I think, therefore, I think I am.”

    Maybe we are not conscious. Perhaps consciousness is an illusion, maybe we just simulate consciousness. Our only “test” for consciousness is the Turing Test, and as the film Ex Machina so cheekily points out, the Turing Test can be inconclusive.

    Still, thinking about these issues is not a waste of time. We may not be able to learn anything about the Nature of Reality, but at least we might learn something about ourselves.

  • wdk October 20, 2020, 21:48

    Mike Serfas,

    Way back there in this thread you said:

    A related issue is why we should assume that the boundary conditions for the universe are set at the beginning. Quantum mechanics is largely time-reversible, so couldn’t the “cause” for the values of physical constants and other events be situated in the middle or at the end?

    There is one aspect of this “reversibility” that struck me the other day.
    In a textbook I was reading that an electron, say in the hydrogen Balmer sequence can be pumped up from an energy level, say 2, to 5 with the absorption of a photon. And then it can drop down with the emission of a photon. But it could stop off at an intermediate location, say 4 or 3 and then go to 2, a cascade.

    What have we got there? Freedom of will?

    • Mike Serfas October 26, 2020, 11:26

      Well, if a quantum event is truly random, I would say it’s not free will. No “decision” was made – the choice can’t be tied to anything but that one particle doing a truly random coin toss. (though I don’t understand Bohmian mechanics nearly enough to argue about whether the coin can cheat, but “hidden variables” remain out of favor so far as I know) You don’t know what it will do but you can at least predict how often it will do it, and argue there’s no significance or detectable pattern to when one choice is made over another.

      True free will should be a choice without a cause that can’t be predicted. For example, suppose you figured out a way to make a very transient mini Tipler cylinder that could hold up to two electrons going round and round in a closed spacetime loop. You find you’re able to measure they’re there without changing the state – indeed, you can’t change the state however you try because any electron in the present is due to turn up in the past. But when you look in the cylinders some can contain 0, 1, or 2 electrons. The pattern might look random, or it might be all the same, and there’s no law of physics telling you what to expect, because you don’t see any event that determines how many are present. What that means is the universe has a fixed set of physical laws … but there is a boundary condition defined at each cylinder, namely how many electrons are present. And that would match what we intuitively expect from free will: the power to actually decide what happens in the universe.

  • Akexander Kaucz November 14, 2020, 0:34

    So interesting to read the comments. Progressing from memories of a departed scholar to a discussion of arguments he highlighted.
    I remember John Barrow as a schoolmate at primary school and secondary school. Fellow Barham primary schoolmates recall his athletic ability.
    He was captain of the football team and as a fellow teammate recalled he scored most of the goals. The Barham school football team won the local schools championship the year John played. Also he won the 60 or 80 yard race at the district sports and helped his school win the championship.
    John together his mother took me to the local Methodist Church they attended. Having been brought up in a Roman Catholic and Church of England background I was struck by the lack of symbolism and emptiness of the church compared with the other churches. A nothingness to me. It could have been this simplicity that influenced John to be a reductionist.
    For reasons I don’t know John invited me to join him at the annual Christmas lecture for children. Years later John gave the Christmas lecture.