Impossibility by John D. Barrow

barrowjd-impossibilityThe subtitle of this book is what really attracted me to it: “The Limits of Science and the Science of Limits”. As a philosopher, I’m fascinated by the idea that there are not only things we don’t know, but things we can’t know. Some scientists are searching for a theory of everything – a set of equations that will account for everything in the Universe. I don’t believe such a thing is possible for us, because it’s not possible for, say, a goldfish. Mankind is just another branch on the evotionary tree, subject to much the same limitations of perception and cognition. I read this book as an attempt to get some additional clarity on this issue.

The content of the book is diverse and deep, covering many areas, from language to mathematics to cosmology, and more. There’s a great deal packed into 250 pages. The most memorable section, for me personally, was a discussion on how complexity occurs on a particular fractal level of the Universe (terrestrial life), not at the extremes of the very large (stars and galaxies) or the very small (atoms and sub-atomic particles). The human brain is the most complex structure in the known Universe, and this gives us reason to speculate that the very function of the Universe could be to bring about the likes of us. We tend to assume that size equals importance, and the images from the Hubble Space Telescope certainly make us feel very unimportant. But what if complexity equals importance?

The book also contains a fascinating discussion on how the speed of light restricts us from ever getting a complete view of the Universe. When we look into deep space, we see it as it was billions of years ago, not as it is today, because it takes so long for light to reach us. And we can’t see the more distant parts of space at all, because the light emitted by very distant stars hasn’t yet had time to reach Earth at all. This puts us in a fishbowl of sorts and it causes us to make assumptions about what is beyond our knowledge. Since we are able to identify inflexible laws of nature in the part of the Universe that we can see, we assume that these laws apply across the entire Universe. But we simply don’t know, and furthermore, we can’t know.

Some of the content of the book was beyond me, particularly the more mathematical parts. Also, some of the content struck me as irrelevant to anything of practical value, such as a section on time travel paradoxes. If anything, this illustrated the importance of philosophy alongside science. It’s very easy to think of time as something physically real, but the only place that time exists, in the sense of a recording of events, is inside brains. Hence, no time travel paradoxes are possible, because there is no time. There is only an ever-changing now. Any discussion of time travel involves a misperception of time as a literal thing making a literal recording of the cosmos as it moves. This material in the book was a waste of time – no pun intended. The book culminated in a discussion of hidden problems in the voting process, which was a bit flat for an ending.

Overall, I felt this was an important book for me to read. The author has a very rational mind and a broad range of knowledge.

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4 thoughts on “Impossibility by John D. Barrow

  1. Dr. Macaw says:

    Your comments on time, though currently in command of wide popular assent, are completely unscientific, Darryl. The idea that time is a construction of our human brain is an eighteenth-century notion, forwarded by Immanuel Kant in his book Kritik der reinen Vernunft. It was categorically destroyed by Einsteinian Relativity, which demonstrated that time and space belong to a single continuum: this idea remains fundamental to modern theoretical physics. Time is a physical event, subject to measurable alteration by local contingencies such as gravity & mass. (This has been proved by an experiment using exact-to-the-nanosecond atomic clocks, related by Stephen Hawking in A Brief History of Time).

    Of course, it is common to confuse the highly scientific notion that time as experienced here on our planet is a local event, produced by our local gravity and space, with the idea that time as such is an effect of human sequencing, and, as such, a pure creation of our collective imagination. Time on earth is perfectly REAL; it just happens to be purely LOCAL. Human constructions of time (such as those related to the subjectivity of our orbital cycle) also exist, of course, and have been studied by such eloquent modern philosophers as Martin Heidegger. These studies actually EXPLAIN your seductive metaphor of the goldish in its bowl, by suggesting sound environmental reasons why humans have asked questions about time from the very dawn of their history. Time as experienced here on our planet has no descriptive relevance to remote reaches of our universe, any more than local conditions of space produced by a medium-small planet circling an average star do; these are mostly not applicable even to the observable universe! However, this does not mean that space does not exist, or that travel through space is impossible (this last idea was put forward by ancient Greek sophists, but has found no welcome in modern science). Relativity does imply the possibility of time travel, as his friend Kurt Gödel proved to Einstein. Though bedevilled by paradoxes, the idea of time travel is therefore not really ridiculous, much less irrelevant; personally, I trust Einstein & Gödel (one of the best examples of a great scientist working alongside a great philosopher – plus Einstein literally masterminded Gödel’s rescue from Nazi Germany) and would guess that there will turn out to be some trick to time travel; i.e., it will be possible. It is really no different from the idea of travelling through vast reaches of space: which I guess will also happen one day, in spite (or perhaps because) of the luminal speed-limit. It is certainly not true, as you claim, that “Any discussion of time travel involves a misperception of time as a literal thing making a literal recording of the cosmos as it moves”, since no modern physicist holds this concept of time (I recommend Hawking’s book). Meanwhile, as Roger Penrose expounds in The Road to Reality, neither space nor time are probably key to the fundamental underlying equations that might compose a grand unified theory of the universe…which is only to say that evey serious physicist I know is perfectly aware that a Theory of Everything would not explain everything, and would in fact open more doors than it closes.

  2. Darryl says:

    My view on time is an awful lot older than Kant. You could trace it to Buddhism and probably farther. It is not at odds with relativity whatsoever, at least not my understanding of it.

    There is only the present moment and an eternal flux of change. We use the idea of “time”, conceived of as past, present and future, to make measurements regarding the present that was, present that is, and present that will be.

    When, say, World War II happened, it happened as the present. When the big bang happened, it happened as the present. Right now, you are in the present. If you count to ten, you’re still in the present. If you remember something from childhood, you’re doing that in the present, and you’re recalling an event that you originally experienced as the present. There’s only ever the present, as a singular moment that takes on new shapes. There is no cosmic recording device for a literal past-present-future. That’s just a function of human brains.

    You’re making something of a knee-jerk reaction here, and I’m not going to be able to convince you of that with a mere anecdote. But I’m strongly advising you that there’s something I’m seeing here that you’re not. And it takes quite a bit of effort to wrap one’s mind around it. But it’s quite a eureka moment when it happens.

  3. Dr. Macaw says:

    I’m sorry, Darryl, if I sound less than persuaded, but my arguments here seem to operate on just another level from yours. (For example, in your reply you don’t bother answering any of them). The concept of “question begging” is something I feel you should reflect on deeply.

    Meanwhile, attempting to have a rock-solid concept in “the present” won’t wear philosophically (and hasn’t done so). Your statement “When, say, World War II happened, it happened as the present. When the big bang happened, it happened as the present” is touchingly fervent, but also simply wrong. When World War II “happened” (as you blithely put it) it happened in the way of all events, by definition: as an uncertain flux from a partly-known past to a future that, as Heidegger put it, contains the only certain event. This flux between them is often referred to as “the present”, but then that by definition has no more stability than the other two parameters of which it exists as the corrollary. Your attempt to contradict this is no more than an appeal to naive reality.

    As far as the big bang goes, dude, you are clearly unaware of modern theoretical physics, from which you appropriate this concept. Your self-confidence in this connection raises a smile. Try reading “The Grand Design” by Hawking and Mlodinow. The big bang didn’t “happen”: there is a point of the space-time continuum where space and time break down under extreme conditions, and some laws of the universe are correspondingly altered. We call this location “the big bang.” But it didn’t “happen”: any more than the North Pole happened. Hawking and Mlodinow precisely argue that time behaves like space under these circumstances. There is certainly no grounds for postulating any space OR time anterior to the big bang, so it couldn’t “happen.” But while trying to score on me for talking about time, you yourself explicitly cling to a naive perception of time which I don’t hold to & which physics long ago abandoned.

    “My view on time is an awful lot older than Kant. You could trace it to Buddhism and probably farther. It is not at odds with relativity whatsoever, at least not my understanding of it”…dude, what understanding is that ? Please explain what you understand by Einstein’s relativity. You desperately need to, for the sake of the argument. As far as your position on time goes, it is Kantian to claim that time is a product of human sequencing, period. In intellectual history, it is a known fact that Kant originated this outlook. He didn’t emphasize an eternal present – probably because he was an astoundingly able thinker. Ask some friend or other who has studied philosophy at a university. Did Buddha say anything like this? I think there must be some problem with your interpretation of Buddha if you think that. I would bet on that being the explanation.

  4. Darryl says:

    I don’t see any contradiction between relativity (or anything I’ve read in physics, including The Grand Design) and the concept of an eternal present. If you see one, explain it, because they both fit fine to me. Perhaps you’re projecting your own misperception of this philosophical position onto me – just saying.

    Regarding relativity and time travel, let’s posit that it’s possible to take a spacecraft into deep space and return to Earth in a few years. Obviously the people on earth will have aged more than you have. But this is not time-travel in any weird sense. The bending of space-time is simply different on the craft from what it is on Earth. While in space, if the people on the craft were somehow able to observe Earth directly, they would see them moving in fast motion. If the Earth dwellers were somehow able to observe you in deep space, they would see you moving in slow motion. But both parties are experiencing the natural flow of the present. Both are in the same present at all times.

    The Big Bang did happen as an event. You seem to be conflating the initial inflation of space-time with the singularity before the inflation.

    As for postulating space-time prior to the Big Bang, I have no problem with that in theory, because we simply don’t know why the bang happened. An eternal succession of universes is a possibility. You have far too much confidence about stuff that we can’t possibly know for sure.

    There’s nothing philosophically immature about the understanding that all events happen in the present. You’ve never known it to be any other way in experience. And experience is your only window on the universe. Having equations that allow for time travel is not the same thing as time travel being possible in the real world, because mathematics allows for all sorts of possible realities that don’t correspond to what is.

    As for my philosophy coming from Kant, perhaps you should listen to some Alan Watts on Buddhism.

    Finally, I should let you know, I’m not really interested in fencing with you. This will probably be my last response. You project a huge amount of arrogance that makes you very difficult to actually listen to, because my gut reaction is to metaphorically poke you in eye right back. Just saying. You’re more well read than I am on science, and that gives you an opportunity to offer helpful corrections, but that’s not what you appear to want from this.

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