There’s something deeply satisfying about the title of Marcus Chown’s book – it really catches the attention. This isn’t one of those collections of little scientific snippets – you know the sort of thing, the type of book that asks if penguins’ feet freeze – though it could be mistaken for one thanks to the look of the cover. Although it is a collection of different scientific theories, it is both a much deeper and more mind-boggling book than the “questions answered” type. It is subtitled “dispatches from the frontline of science”, and that frontline is the interface between scientific ideas and the deepest questions of the universe. For Douglas Adams fans, this is real Deep Thought territory.
Chown takes off with the relatively familiar but still mind boggling concept that our universe could be but a single bubble amid a myriad variant universes, so many in fact that there’s one out there where Elvis lives, and another identical to this, except you aren’t reading this review right now (spooky, but irritating behaviour by that other you). From there he moves on to Stephen Wolfram’s much attacked but still fascinating idea that the whole universe could be the outcome of a surprisingly simple computer program. Elsewhere you’ll find the really strange bits of the quantum universe, Chaitin’s amazing number Omega (which, Chown claims, is the real life equivalent of Douglas Adams’ 42), the chances of meeting up with an alien (and what an alien culture’s communications might be like), finally reaching the title story. This last one is the weirdest of the lot. The idea is that by the end time of the universe, there will be beings who are so technologically advanced that they can re-engineer the universe in a special way that will enable the end times to stretch for ever (subjectively), and that they will run a computer simulation so clever that we will all wake up after death in this electronic, everlasting heaven.
To be honest, I found this last topic a little tedious just because it was piling so much speculation upon speculation as to be practically meaningless. But the majority of the material in here is cracking stuff. Unlike Chown’s The Universe Next Door, although the sections are independent to the extent that some of the ideas contradict each other, and there’s an occasional slight overlap of information, there isn’t the same feeling that this is a collection of articles strung together – it reads as a book.
Throughout, Chown’s writing is superbly approachable. Over the years he has developed a laid-back tone well suited to getting across the most evilly complex science in an approachable way. The only slight concern here is that this can result in throwaway lines that don’t hold up to close scrutiny. At one point he says that Ockham’s razor is “invariably is true.” If this were the case there wouldn’t be a lot of point doing experiments, you’d just pick the simplest explanation. In fact a fair amount of the book is spent showing us scientific ideas that are anything but the simplest, but may be true. Another slight irritation is that, presumably in another attempt to be less frightening, instead of writing powers in the usual way, for example 108, he writes 10^8, as if entering it into a calculator. I find this much harder on the eye.
The only other problem here is the difficulty of handling such complex and far out concepts in a popular science book. Almost inevitably this leads to some statements that aren’t justified by the context that can be provided. For example, the first chapter states that in the model of an inflationary universe containing vast numbers of bubble universes, each seeded by a random start, because the overall universe is “effectively infinite in extent,” every possible arrangement must occur somewhere. (Hence Elvis and the other you, not reading this review.) This is flawed on two levels. Firstly there is an infinite (literally) difference between near-infinite and infinite. However many bubbles are postulated, you can take that number away from infinity and still have infinity left. You can’t apply arguments from infinity to a finite number. Secondly, even if there were an infinite set of bubble universes, it doesn’t follow that they provide every possible variant of the “real” universe – you could still have an infinitely varied set, none of which faintly resembled our own. This follows from the nature of quantum particles, each of which has properties that are effectively boundless, so in principle you could have an infinity of universes each featuring just one particle.
Another example of this difficulty that arises when you move from a complex science to a simple description arises in the last chapter, when talking about simulating the universe on a computer. We are told that “a perfect simulation of reality is a possibility.” If this were true, the simulation would have to be able to predict when a radioactive particle was about to decay – but this is definitively unpredictable. All we can predict is the probability of it occurring. According to quantum theory there is no hidden piece of information that will tell when it actually is going to decay, so such a simulation is beyond possibility.
This sort of problem is pretty well inevitable, though, with this kind of material, and it doesn’t really matter. What’s important is that this book opens up some of the leading edge physics thinking, explains lots of hot science superbly well, and will get readers thinking and talking about it, even if they don’t agree with it. Perhaps especially if they don’t. And that can’t be a bad thing.
Review by Brian Clegg
Marcus Chown’s The Never-ending Days of Being Dead is an energetic romp through the big ideas of leading-edge physics. There is enough technical detail to make the ideas credible, but not so much that they are incomprehensible; the prose is chummy; and the storyline is well-stocked with heroic renegade scientists leading their conservative colleagues into new and mind-bending realms. Chown’s aim is to find the most wacky, exciting answers to the deepest questions that physicists pose. One problem with this approach is that the wackiest, most exciting answers are not necessarily the true ones, and Chown’s enthusiasm for oddball science could sometimes benefit from less breathless awe and more reasoned scepticism. But it is hard to be rigorous and rollicking at the same time, and Chown achieves a pretty good balance between the two.
Breathless awe is no doubt an appropriate response to some of the topics that the book covers. The section titles tell us that Chown is not afraid of deep water: Part One is about The Nature of the Universe; Part Two concerns The Nature of Reality; and Part Three is modestly titled Life and the Universe. In 11 distinct chapters the book describes the most recent twists on big themes in physics and cosmology: the evolution of our (and other) universes; the search for alien intelligence; how to explain mass in its different forms; why we experience time as a “flow” from past to present; where the laws of physics come from; whether life can survive forever in the universe; and why ordinary objects behave differently from very small objects.
The questions are big and the answers unusual, and Chown is not afraid to say so. Occasionally he sounds more like a science publicist than a science expositor. If a discovery is not “profound”, “crucial”, “fascinating and intriguing”, “earth-shattering”, or “deeply connected” to some other discovery, it is “deeply, deeply subtle.”
Fortunately, Chown’s gift for superlatives is matched by his gift for drawing out more intriguing implications of scientific theories. It is truly odd and surprising to think there are a large number of other universes in which contain exact replicas of ourselves; or that at the end of the universe we will find ourselves reborn in a computer program. Other scenarios that Chown asks us to consider are that the “Creator” of our universe has encoded the laws of the universe in the cosmic background radiation; that the laws of physics arose because they are the laws that automatically apply to an empty universe; and that if our perceptive organs were set up differently, we might experience (say) the past as present, and vice versa.
If one takes Chown’s introduction literally, the point of the book is just to raise these intriguing possibilities. “I think this is the nature of science at the leading edge. It is ultimately about down-to-earth things we all care about — Where did we come from? Where did the universe come from? What the hell are we doing here?”
But to Chown’s credit and the reader’s pleasure, the book is much more about the process of arriving at the intriguing conjectures, rather than the conjectures themselves. Consider Steven Wolfram (a recurring hero in the book) and his idea that the physical world is best modelled by computer programs, not mathematics. In his chapter on Wolfram Chown eases the reader step by step into Wolfram’s unusual world, pointing out the pitfalls as well as the milestones along the way. For example, Wolfram thinks a program of a certain kind — “a cellular automaton” — is not just good at describing the natural world; it actually is the natural world. So Chown has the daunting task of making sense, for the general reader, of a universe that is a 3D grid of nodes and cells, with the each cell updating periodically depending on what its surrounding cells are doing. He makes a brave attempt, honing in on one specific problem with the theory, and Wolfram’s answer to it: how all cells in this giant array can update at the right time.
Chown is not afraid to say that Wolfram’s theory is a fringe idea. Nor is he afraid to say, when the occasion demands it: “this is a leap of faith”, or “this may seem a little woolly”. He assumes the reader is ignorant, but not that he is gullible. The result, in this and other chapters, is popular science that tells intriguing stories about why radicals believe what they do.
A conjecture has no intrigue if it makes no sense to the reader. So it’s a good thing that Chown’s story-telling is backed up by some skilled pedagogy. One of the most abstract chapters, on how physical laws rise out of symmetries, is a case in point. Chown starts with some history: in 1918 the German mathematician Emmy Noether realised that some fundamental physical laws — like the conservation of energy and of angular momentum — can be derived just from some basic symmetries — like the fact that physical laws are the same at all times, and in all directions. But how is this so? Chown gives an entry-level analogy. It’s like watching telegraph poles from the window of a car, he says: there’s a link between the telegraph poles all being the same distance apart, and the car having an unchanging momentum. So far so good. A second analogy pushes the reader up a level. Symmetries in space and time lead to laws, but so do symmetries in “space and time taken together.” A phrase like that is likely to shake the reader a bit, but Chown has a supporting metaphor to prop the reader up: he links the co-ordinates of space-time to co-ordinates on a normal map. Next, a second series of analogies takes the reader from centrifugal force (not a real force, as we all know); to general relativity (where gravity is not a real force — it just makes sure the laws of physics are the same for people who accelerate at different rates); to quantum mechanics and gauge theory (where electromagnetic forces make sure that the laws of physics stay the same when each point of a quantum wave rotates by a different amount).
In these passages, Chown doesn’t just use analogies: he uses the product of one analogy as the premise for next. The reader’s reward for climbing these analogical ladders is to understand what Chown means when he says something like: “Yet it turns out that everything Maxwell struggled to understand for more than a decade is merely the consequence of a simple symmetry principle: the laws of motion for a quantum particle must be the same under arbitrary rotations in complex space at different points in space.” This is a remarkable fact about physics — if you know what it means. We are lucky to have someone like Chown who can describe what it means.
Chown’s account of symmetry, general relativity, and gauge theory are of course wildly simplified. Take a closer look and the rungs of the ladder look less solid. For example, no doubt there is a link (as Chown says) between telegraph poles all being the same distance apart, and a car having an unchanging momentum. But isn’t this just another way of saying that speed is proportionate to distance travelled? And if so, does the example really cast any light on symmetry? To tell the reader what symmetry really means, Chown would need to answer these questions and many more like them. But at least he brings the reader to the point where the questions make sense.
Conclusion: if you know nothing about physics or maths, do read this book. You will learn and understand more than you thought you could learn or understand, and more easily. If you learnt some maths or physics at school or university, read this book even if you have no taste for popular science. You may learn something new; can admire Chown’s clever, colourful, accessible, explanations; and should enjoy your own attempts to poke holes in them.