The Salmon of Doubt: Hitchhiking the Galaxy One Last Time (14 page)

Then to my surprise I discovered that it was converging with my growing interest in computers. There was nothing particularly profound about that enthusiasm—I just unashamedly love playing with gadgets.

The connection lies in the counterintuitive observation that complex results arise from simple causes, iterated many times over. It’s terribly simple to see this happening in a computer. Whatever complexities a computer produces—modeling wind turbulence, modeling economies or the way light dances in the eye of an imaginary dinosaur—it all grows out of simple lines of code that start with adding one and one, testing the result, and then doing it again. Being able watch complexity blossom out of this primitive simplicity is one of the great marvels of our age, greater even than watching man walk on the moon.

It’s much more difficult to see it happening in the case of the evolution of life. The time scales are so vast and our perspective so much complicated by the fact that it’s ourselves we’re looking at, but our invention of the computer has for the first time let us get a real feel for how it works—just as our invention of the hydraulic pump first gave us an insight into what the heart was doing and how the circulation of the blood worked.

That is also why it’s impossible to divorce pure science from technology: they feed and stimulate each other. So the latest software gizmo for transferring an mp3 sound file from one computer to another across continents is, when you peer into its innards and at the infrastructure that has given rise to it and that it, in turn, becomes part of, is, in its way, every bit as interesting as the way in which a cell replicates, an idea is formed within a brain, or a beetle deep in the heart of the Amazonian rain forest digests its prey. It’s all part of the same underlying process that we in turn are part of, it’s where our creative energies are being poured, and I’ll happily take it over comedians, television, and football any day.

OCTOBER 2000

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Present somebody with a questionnaire clipboard, and they lie. A friend of mine once had a job preparing a questionnaire for people to fill in on the Web. He said the information they got back was enormously heartening about the state of the world. For instance, did you know that almost 90 percent of the population are CEOs of their own companies and earn over a million dollars a year?

Is There an Artificial God?

This was originally billed as a debate only because I was a bit anxious coming here. I didn’t think I was going to have time to prepare anything and also, in a room full of such luminaries, thought, “What could I, as an amateur, possibly have to say? So I thought I would settle for a debate. But after having been here for a couple of days, I realised you’re just a bunch of guys! It’s been rife with ideas, and I’ve had so many myself through talking with and listening to people, that I’d thought what I’d do was stand up and have an argument and debate with myself. I’ll talk for a while and hope sufficiently to provoke and inflame opinion that there’ll be an outburst of chair-throwing at the end. Before I embark on what I want to try to tackle, may I warn you that things may get a little bit lost from time to time because there’s a lot of stuff that’s just come in from what we’ve been hearing today, so if I occasionally sort of go ... I was telling somebody earlier today that I have a four-year-old daughter and was very, very interested watching her face when she was in her first two or three weeks of life and suddenly realising what nobody would have realised in previous ages—she was rebooting!

I was thinking about this earlier today when Larry Yaeger was talking about “What Is Life?” and mentioned at the end something I didn’t know, about a special field of handwriting recognition. The following strange thought went through my mind: that trying to figure out what is life and what isn’t, and where the boundary is, has an interesting relationship with how you recognise handwriting. We all know, when presented with any particular entity, whether it’s a bit of mould from the fridge or whatever—we instinctively know when something is an example of life and when it isn’t. But it turns out to be tremendously hard exactly to define it. I remember once, a long time ago, needing a definition of life for a speech I was giving. Assuming there was a simple one and looking around the Internet, I was astonished at how diverse the definitions were and how very, very detailed each one had to be in order to include

“this” but not include “that.” If you think about it, a collection that includes a fruit fly and Richard Dawkins and the Great Barrier Reef is an awkward set of objects to try to compare. When we try to figure out what the rules are that we are looking for, trying to find a rule that’s self-evidently true, that turns out to be very, very hard.

Compare this with the business of recognising whether something is an A or a B or a C. It’s a similar kind of process, but it’s also a very, very different process, because you may say of something that you’re “not quite certain whether it count as life or not life, it’s kind of there on the edge, isn’t it, it’s probably a very low example of what you might call life, it’s maybe just about alive or maybe it isn’t.” Or maybe you might say about something that’s an example of digital life, “Does that count as being alive?”

Is it something, to coin someone’s earlier phrase, that’ll go squish if you step on it? Think about the controversial Gaia hypothesis; people say, “Is the planet alive?” “Is the ecosphere alive or not?” In the end it depends on how you define such things. Compare that with handwriting recognition. In the end you are trying to say “Is this an A or is it a B?” People write As at Bs in many different ways; floridly, sloppily, or whatever. Its no good saying, “Well, it’s sort of A-ish but there’s a bit of B in there,” because you can’t write the word “apple” with such a thing. It is either an A or a B. How do you judge? If you’re doing handwriting recognition, what you are trying to do is not to assess the relative degrees of A-ness or B-ness of the letter but trying to define the intention of the person who wrote it. It’s very clear in the end—is it an A or a B?—ah! it’s an because the person writing it was writing the word “apple” and that’s clearly what it means. So, in the end, in the absence of an intentional creator, you cannot say what life is, because it simply depends on what set of definitions you include in your overall definition. Without a god, life is only a matter of opinion. I want to pick up on a few other things that came around today. I was fascinated by Larry (again), talking about tautology, because there’s an argument that I remember being stumped by once, to which I couldn’t come up with a reply, because I was so puzzled by the challenge and couldn’t quite figure it out. A guy said to me, “Yes, but the whole theory of evolution is based on a tautology: Where does the idea of God come from? Well, I think we have a very skewed point of view on an awful lot of things, but let’s try to see where our point of view comes from. Imagine early man. Early man is, like everything else, an evolved creature and he finds himself in a world that he’s begun to take a little charge of; he’s begun to be a toolmaker, a changer of his environment with the tools that he’s made, and he makes tools when he does, in order to make changes in his environment. To give an example of the way man operates compared to other animals, consider speciation, which, as we know, tends to occur when a small group of animals gets separated from the rest of the herd by some geological upheaval, population pressure, food shortage, or whatever, and finds itself in a new environment with maybe something different going on. Take a very simple example; maybe a bunch of animals suddenly finds itself in a place where the weather is rather colder. We know that in a few generations those genes that favour a thicker coat will has come to the fore and we’ll come and we’ll find that the animals have now got thicker coats. Early man, who’s a toolmaker, doesn’t have to do this: he can inhabit an extraordinarily wide range of habitats on earth, from tundra to the Gobi Desert—he even manages to live in New York, for heaven’s sake—and reason is that when he arrives in a new environment he doesn’t have to wait for several generations; if he arrives in a colder environment and sees an animal that has those genes which favour a thicker coat, he says, “I’ll have it off him.” Tools have enabled us to think intentionally, to make things and to do things to create a world that fits us better. Now imagine an early man surveying his surroundings at the end of a happy day’s toolmaking. He looks around and he sees a world that pleases him mightily; behind him are mountains with caves in them—mountains are great because you can go and hide in the caves and you are out of the rain and the bears can’t get you; in front of him there’s the forest—it’s got nuts and berries and delicious food; there’s a stream going by, which is full of water—water’s delicious to drink, you can float your boats in it and do all sorts of stuff with it; here’s cousin Ug and he’s caught a mammoth—mammoths are great, you can eat them, you can wear their coats, you can use their bones to create weapons to catch other mammoths. I mean this is a great world, it’s fantastic. But our early man has a moment to reflect and he thinks to himself, “Well, this is an interesting world that I find myself in,” and then he asks himself a very treacherous question, a question that is totally meaningless and fallacious, but only comes about because of the nature of the sort of person he is, the sort of person he has evolved into, and the sort of person who has thrived because he thinks this particular way. Man the maker looks at his world and says, “So who made this, then?” Who made this?—you can see why it’s a treacherous question. Early man thinks, “Well, because there’s only one sort of being I know about who makes things, whoever made all this must therefore be a much bigger, much more powerful and necessarily invisible, one of me, and because I tend to be the strong one who does all the stuff, he’s probably male.” And so we have the idea of a God. Then, because when we make things, we do it with the intention of doing something with them, early man asks himself, “If he made it, what did he make it for?” Now the real trap springs, because early man is thinking, “This world fits me very well. Here are all these things that support me and feed me and look after me; yes, this world fits me nicely,” and he reaches the inescapable conclusion that whoever made it, made it for him. This is rather as if you imagine a puddle waking up one morning and thinking, “This is an interesting world I find myself in—an interesting hole I find myself in—fits me rather neatly, doesn’t it? In fact it fits me staggeringly well, must have been made to have me in it!” This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it’s still frantically hanging on to the notion that everything’s going to be all right, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rathejf by surprise. I think this may be something we need to be on the watch-out for. We all know that at some point in the future the universe will come to an end, and at some other point, considerably in advance from that but still not immediately pressing, the sun will explode. We feel there’s plenty of time to worry about that, but on the other hand that’s a very dangerous thing to say. Look at what’s supposed to be going to happen on first of January

2000—let’s not pretend that we didn’t have a warning that the century was going to end! I think that we need to take a larger perspective on who we are and what we are doing here if we are going to survive in the long term.

I rather love that notion, and, as I was discussing with someone earlier today, there’s a book I thoroughly enjoyed recently by David Deutsch, who is an advocate of the multiple-universe view of the universe, called The Fabric of Reality, in which he explores the notion of a quantum multiple-universe view of the universe. This came from the famous wave/particle dichotomy about the behaviour of light—that you couldn’t measure it as a wave when it behaves as a wave, or as a particle when it behaves as a particle. How does this come to be? David Deutsch points out that if you imagine that our universe is simply one layer and that there is an infinite multiplicity of universes spreading out on either side, not only does it solve the problem, but the problem simply goes away. This is exactly how you expect light to behave under those circumstances. Quantum mechanics has claims to be predicated on the notion that the universe behaves as if there were a multiplicity of universes, but it rather strains our credulity to think that there actually would be.

This goes straight back to Galileo and the Vatican. In fact, what the Vatican said to Galileo was, “We don’t dispute your readings, we just dispute the explanation you put on them. It’s all very well for you to say that the planets sort of do that as they go round and it is as if we were a planet and those planets were all going round the sun; it’s all right to say it’s as if that were happening, but you’re not allowed to say that’s what is happening, because we have a total lockhold on universal truth and also it simply strains our personal credulity.” Just so, I think that the idea that there are multiple universes currently strains our credulity, but it may well be that it’s simply one more strain that we have to learn to live with, just as we’ve had to learn to live with a whole bunch of them in the past.

The next age of sand is the microscopic one. We put glass lenses into microscopes and started to look down at the microscopic view of the universe. Then we began to understand that when we get down to the subatomic level, the solid world we live in also consists, again rather worryingly, of almost nothing and that wherever we do find something it turns out not to actually something, but only the probability that there may something there.

One way or another, this is a deeply misleading universe. Wherever we look, it’s beginning to be extremely alarming and extremely upsetting to our sense of who we are—great, strapping, physical people living in a universe that exists almost entirely for us—that it just isn’t the case. At this point we still divining from this all sorts of fundamental principles, recognising the way that gravity works, the way that strong and weak nuclear forces work, recognising the nature of matter, the nature of particles and so on, but having got those fundamentals, we’re still not very good at figuring out how it works, because the maths is really rather tricky. So we tend to come up with almost a clockwork view of the way it all works because that’s the best our math can manage. I don’t mean in any way to disparage Newton, because I guess he was the first person who saw that there were principles at work that were different from anything we actually saw around us. His first law of motion—that something will remain in its position of either rest or motion until some other force works on it—is something that none of us, living in a gravity well, in a gas envelope, had ever seen, because everything we move comes to a halt. It was only through very, very careful watching and observing and measuring and divining the principles underlying what we could all see happening that he came up with the principles that we all know and recognise as being the laws of motion, but nevertheless it is, by modern terms, still a somewhat clockwork view of the universe.

As I say, I don’t mean that to sound disparaging in any way at all, because his achievements, as we all know, were absolutely monumental, but it still kind of doesn’t make sense to us.

Now there are all sorts of entities we are also aware of, as well as particles, forces, tables, chairs, rocks, and so on, that are almost invisible to science; almost invisible, because science has almost nothing to say about them whatsoever. I’m talking about dogs and cats and cows and each other. We living things are so far beyond the purview of anything science can actually say, almost beyond even recognising ourselves as things that science might be expected to have something to say about.

I can imagine Newton sitting down and working out his laws of motion and figuring out the way the universe works and with him, a cat wandering around. The reason we had no idea how cats worked was because, since Newton, we had proceeded by the very simple principle that essentially, to see how things work, we took them apart. If you try to take a cat apart to see how it works, the first thing you have in your hands is a nonworking cat. Life is a level of complexity that almost lies outside our vision; is so far beyond anything we have any means of understanding that we just think of it as a different class of object, a different class of matter; “life,” something that had a mysterious essence about it, was God-given—and that’s the only explanation we had. The bombshell comes in 1859 when Darwin publishes the Origin of Species. It takes a long time before we really get to grips with this and begin understand it, because not only does it seem incredible and thoroughly demeaning to us, but it’s yet another shock to our system to discover that not only are we not the centre of universe and we’re not made of anything, but we started out as some kind of slime and got to where we are via being a monkey.

It just doesn’t read well. But also, we have no opportunity to see this stuff at work. In a sense Darwin was like Newton in that he was the first person to see underlying principles really were not at all obvious, from the everyday world in which he lived. We had to think very hard to understand the nature of what was happening around us, and we had no clear obvious everyday examples of evolution to point to. Even today that persists as a slightly tricky problem if you’re trying to persuade somebody who doesn’t believe in all this evolution stuff and wants you to show him an example—they are hard to find in terms of everyday observation. So we come to the third age of sand. In the third age of sand we discover something else we can make out of sand—silicon. We make the silicon chip—and suddenly what opens up to us is a universe not of fundamental particles and fundamental forces, but of the things that were missing in that picture that told us how they work; what the silicon chip revealed to us was the process.

The silicon chip enables us to do mathematics tremendously fast, to model the—as it turns out—very, very simple processes that are analogous to life in terms of their simplicity; iteration, looping, branching, the feedback loop that lies at the heart of everything you do on a computer and at the heart of everything that happens in evolution—that is, the output stage of one generation becomes the input stage of the next.

Suddenly we have a working model—not for a while, because early machines are terribly slow and clunky—but gradually we accumulate a working model of this thing that previously we could only guess at or deduce—and you had to be a pretty sharp and a pretty clear thinker even to divine it happening when it was far from obvious and indeed counterintuitive, particularly to as proud a species as we.

So, suddenly, evolution ceases to be such a real problem get hold of. It’s rather like the following scenario: One Tuesday a person is spotted in a street in London, doing something criminal. Two detectives are investigating, trying to work out what happened. One of them is a twentieth-century detective and the other, by the marvels of science fiction, is a nineteenth-century detective. The problem is this: The person who was clearly seen and identified on the street in London on Tuesday was seen by someone else, an equally reliable witness, on the street in Santa Fe on the same Tuesday. How could that possibly be? The nineteenth-century detective could only think it was by some sort of magical intervention. Now, the twentieth-century detective may not be able to say, “He took BA flight this and then United flight that”—he may not be able to figure out exactly which way he did it, or by which route he traveled, but it’s not a problem. It doesn’t bother him; he just says, “He got there by plane. I don’t know which plane and it may be a little tricky to find out, but there’s no essential mystery.” We’re used to idea of jet travel. We don’t know whether the criminal flew BA 178, or UA 270, or whatever, but we know roughly how it was done. I suspect that as we become more and more conversant with the role a computer plays and the way in which the computer models the process of enormously simple elements giving rise to enormously complex results, then the idea of life being an emergent phenomenon will become easier and easier to swallow. We may never know precisely what steps life took in the very early stages of this planet, but it’s not a mystery.