‘I’m not really trying to say the present is without validity. Rather that it can’t have any validity in physics.’
‘Then physics isn’t everything? A big admission for a physicist, isn’t it?’
‘Remember the night we were out walking, back in Hawaii? I said then there were parts of our experience which simply defied physical law. I can develop those ideas a lot further. In a way I’d sooner get it off my chest now, rather than later. It sounds too crazy to put before a lot of people. Yet I’m sure something along these lines must be right. I’m going to put it in terms of a parable. Suppose you have a lot of pigeon holes, numbered in sequence, one, two, and so on… up to thousands and millions, and millions of millions if you like. In fact the sequence can be infinite both ways, if you prefer.’
I said that I didn’t mind. John went on, ‘All right, let’s come now to the contents of the pigeon holes. Suppose you choose one of them, say the 137th. You find in it a story, as you might find one of those little slips of paper in a Christmas cracker. But you also find statements about the stories you’ll find in other pigeon holes. You decide to check up on whether these statements about the stories in the other pigeon holes are right or not. To your surprise you find the statements made about earlier pigeon holes, the 136th, the 135th, and so on, are substantially correct. But when you compare with the pigeon holes on the other side, the 138th, the 139th,… you find things aren’t so good. You find a lot of contradictions and discrepancies. This turns out to be the same wherever you happen to look, in every pigeon hole. The statements made about pigeon holes on one side are always pretty good, those made about pigeon holes on the other side are at best diffuse and at worst just plain wrong. Now let’s translate this parable into the time problem. We’ll call the particular pigeon hole, the one you happen to be examining, the present. The earlier pigeon holes, the ones for which you find substantially correct statements, are what we will call the past. The later pigeon holes, the ones for which there isn’t too much in the way of correct statements, we call the future. Let me go on a bit further. What I want to suggest is that the actual world is very much like this. Instead of pigeon holes we talk about states.’
‘I understand what you’re saying. You have a division into a number of states. Choice of any one of them constitutes the present. My problem is, who decides which pigeon hole to look in, the one that constitutes the present?’
‘If I could answer that question I’d be a good half-way towards solving everything. Before I say anything about it let me ask you a question. Suppose that in each of these states your own consciousness is included. As soon as a particular state is chosen, as soon as an imaginary office worker takes a look at the contents of a particular pigeon hole, you have the subjective consciousness of a particular moment, of what you call the present. Think of the clerk in an office taking a look, first at the contents of one pigeon hole, then at the contents of another. Suppose he does this, not in sequence, but in any old order. What is the effect on your subjective consciousness? So far as the clerk himself is concerned, he’s jumping about all over the place among the pigeon holes. So your consciousness jumps all over the place. But the strange thing is that your subjective impression is quite different. You have the impression of time as an ever-rolling stream.’
We walked on for a while. I saw that if the contents of a pigeon hole could never be modified then John was right. It would be possible for his clerk to look into a particular pigeon hole a dozen times or more and you’d never know about it. All you could be aware of, on his idea, was the contents of a pigeon hole, not when or how it was sampled. But there was one thing that bothered me:
‘Doesn’t the idea of a sequence of choices on the part of your clerk itself imply the flow of time? If it does, the argument gets you nowhere.’
‘I’m sure it does not. A sequence is a logical concept in which time doesn’t really enter at all.’
I saw in a general sort of way what he meant. Yet I was troubled. ‘But if you have a rule that requires you to pass from one pigeon hole to the next, like passing from one number to the next, isn’t it really exactly the same as a smooth flow of time?’
‘If the rule were the one you say, yes certainly. But you could have rules that didn’t require the next number to be the succeeding pigeon hole. Look, suppose we do it this way. We could choose number 1, then number 100, then number 2, then number 99, and so on until we’ve had every pigeon hole from 1 to 100. Then we could do the same thing from 101 to 200. That would be a different kind of rule. In fact there are infinitely many ways in which you can lay down rules, if the sequence itself is infinite. Any particular rule establishes what we call a correspondence between the pigeon holes and the choices. If every pigeon hole is chosen exactly once we have what mathematicians call a one-one correspondence. If every pigeon hole is chosen many times we have a one-many correspondence. The crux of my argument is that you get exactly the same subjective experience whatever the correspondence you choose. It doesn’t matter what order you take the pigeon holes, it doesn’t matter if you choose some or all of them a million times, you’d never know anything different from the simple sequential order. All you can know is the original contents of the pigeon holes themselves.’
‘So really the choices could be an incredible hotch-potch. You could have youth and old age interlaced with each other and you’d never know?’
‘Not only that, but you could experience your youth a million times over and you’d never know. If the clerk were to put a note in a pigeon hole whenever he used it, then of course you could know you’d had a certain experience before. But as long as he leaves no note you can never know.’
‘I suppose so. Where have we got to now?’
‘Quite a way. We’ve got our sequence of pigeon holes, that’s the physical world. We don’t think of one pigeon hole as having any more significance than another, which agrees with what I said before. We don’t think of one particular state of the Earth as having any more significance than any other state of the Earth. We’ve completely eliminated the bogus idea of a steady flow of time. Our consciousness corresponds to just where the light falls, as it dances about among the pigeon holes. It lights up first one, then another, in some sequence that is quite irrelevant.
‘Now let’s come to the hard part. What is this light? I’m no longer talking in terms of a clerk in an office, because I don’t want to get bogged down in human images. All our pigeon holes are in darkness except where the spot of light falls. What that light consists of, where it comes from, we know nothing. It lies outside our present-day physics.
‘You remember I told you that it’s possible to defy our own present-day physical laws and still to make a clear gain in our assessment of the world. You remember the radioactive nuclei with the counters surrounding them? We wanted to know whether or not in a certain period of time a nucleus had undergone decay. I said there was only one way to find out. By looking. In other words by using the spot of light in our pigeon hole. My strong hunch is that it’s the spot of light that permits decisions which lie outside the laws of physics. This is why I’m so sure something else must be involved. It doesn’t need to be anything mystical. It may be subject to precise description, to law and order, the same as in our ordinary physics. It may only be mysterious because we don’t understand it.’
‘There’s certainly a lot of things I don’t understand. This light of yours, or whatever you like to call it, how does it decide that you are you and I am me?’