Before Newton was born, René Descartes raised a nightmarish prospect. How do I know, he asked, whether anything exists? Is some malignant demon conjuring up my thoughts and experiences? Perhaps there isn’t any world. How can we be sure of anything? Descartes famously argued that we can at least be certain of our own existence. Cogito ergo sum: I think, therefore I am. In fact, this did not get him very far, and his main argument for a real world was that God would not deceive us on such a fundamental matter.
Modern science has a better answer to the solipsists – those who, like Descartes in that extreme moment of doubt, deny existence outside their own thoughts. The starting point is that we do observe a great variety of phenomena. We can then ask whether we can postulate a world and laws that lead to the phenomena. If this is so, it does not explain how or why the world is there, but it does provide grounds for taking its existence more seriously.
You may think that time capsules and a brain preserved in aspic aware of seeing motion are getting dangerously close to solipsism and the machinations of a demon. Without anticipating the rest of the book, an outline may still be helpful. There are only two rules of the game: there must be an external world subject to laws and a correspondence between it and experiences.
Apart from the fact that Newton placed the material objects of the universe in an arena, my things are his things. They are Nows, the relative configurations of the universe. Newton’s Nows form a string, brought into being by an act of creation at one end, called the past. It is usually assumed that our experiences in some instant reflect the structure in a short segment of the string at a point along it. It is a segment, rather than one Now, because we see things not only in positions but in motion. However, a single Now contains only positional information. It seems that we need at least two Nows to have information about changes of position.
Newtonian history, as modified by Big Bang cosmology, translates into a path in Platonia. It begins at a certain point with a creation event, after which the laws of nature determine the path. Many paths satisfy the same laws, but the laws by themselves do not tell us why one path is chosen by the creation event in preference to others.
The alternative picture, suggested by quantum mechanics and proposed in this book, is quite different. There are no paths with unique starting points conceived as creation events. Indeed, there are no paths at all. Instead, the different points of Platonia, each of which represents a different possible configuration of the universe, are present – as potentialities at least – in different quantities. This matches what we found in the Timeless Theory bag: many different triangles present in different quantities. It will be helpful to represent this in a more graphic way. Imagine that Platonia is covered by a mist. Its intensity does not vary in time – it is static – but it does vary from position to position. Its intensity at each given point is a measure of how many configurations (as in the previous example, with triangles in the Timeless Bag) corresponding to that point are present. All these configurations, present in different quantities, you should imagine for the moment as being collected together in a ‘heap’ or ‘bag’.
So, Platonia is covered with mist. Its intensity cannot change in time (there is no time), but it does vary from point to point. In some places it is much more intense than in others. A timeless law, complete in itself, determines where the mist collects. The law is a kind of competition for the mist between the Nows. Those that ‘resonate’ well with each other get more mist. The outcome is a distribution of mist intensity. This, as I have just explained, is simply another description of the Timeless Theory bag – for mist intensity read numbers of triangle copies. But the Nows of this Platonia are much more complex than triangles.
This opens up possibilities. Triangles tell no stories, they are too simple. But if the Nows are defined by, say, the arrangements of three large bodies and of many thousands of small bodies, things are different. For example, the three large bodies could form the tenth triangle from the right in Figure 1. The remaining small bodies could be arranged in such a way that they literally create the pattern of the first nine triangles from the right of the sequence. This may seem contrived, but it is possible. It is a Now in a greatly enlarged Platonia. Shown such a Now, what could we make of it? One interpretation is that the small bodies record what the large bodies have done: the Now is a time capsule, a picture of a Newtonian history. As soon as a sufficient number of bodies are present, the possibilities for creating time capsules are immense.
I believe the sole reason we believe in time is because we only ever experience the universe through the medium of a time capsule. My assumptions are:
(1) All experience we have in some instant derives from the structure in one Now.
(2) For Nows capable of self-awareness (by containing brains, etc.) the probability of being experienced is proportional to their mist intensity.
(3) The Nows at which the mist has a high intensity are time capsules (they will also possess other specific properties).
Thus, the one law of the universe that determines the mist intensity over Platonia is timeless. The Nows and the distribution of the mist are both static. The appearance of time arises solely because the mist is concentrated on time capsules, and a Now that is a time capsule is therefore much more likely to be experienced than a Now that is not. (Please remember that this is only an outline: the detailed arguments are still to come.)
Of the three assumptions, the second is the most problematic. The first and third may seem strange and implausible, but they can be made definite. If correct, their significance and meaning are clear-cut. Both could be shown to be false, but this is good, since a theory that cannot be disproved is a bad theory. The best theories make firm predictions that can be tested. The main difficulty with the second assumption is in saying what it means. We encounter, in a modified form, the difficulty that Descartes raised. It is acute.
In a Newtonian scheme, the connection between theory and experience is unambiguous. There is a path through Platonia, and all the Nows on it are realized: sentient beings within any Nows on the path do experience those Nows. In the alternative scheme, the distribution of the mist over Platonia – its intensity at each Now – is as definite as the line of the Newtonian path. The difficulty, which is deeply rooted in quantum mechanics, is how to interpret the intensity of the mist. When we get to grips with quantum mechanics, I shall explain my reasons for assuming that the mist intensity at a Now measures its probability of being experienced. Perhaps some cosmic lottery is the best way to explain this.
Each Now has a mist intensity. Suppose that all the Nows participate in a lottery, receiving numbers of tickets proportional to their mist intensities. Nows where the mist is intense get tickets galore, others very few. By assumption (1), conscious experience is always in one Now. If a Now has a special structure, it is capable of self-awareness. But is it actually self-aware? Structure in itself, no matter how intricate and ordered, cannot explain how it can be self-aware. Consciousness is the ultimate mystery.
Perhaps it is a mystery that makes some sense of the mist that covers Platonia. If there is a cosmic lottery, clearly the Nows with the most tickets will have the best chance. If a ticket belonging to a Now capable of self-awareness is drawn, this can, so to speak, ‘bring to life’ the Now. It is aware. The consciousness potentially present in Nows structured the right way is actual in those that are drawn. Two questions about this cosmic lottery may well be asked: when are the tickets drawn, and how many are drawn?
The first question is easily answered: it has no meaning. Think of the brain preserved in aspic, or the unfortunate brain-damaged patient who believes that Harold Macmillan is Prime Minister and Dwight Eisenhower is President. The structure capable of making a Now self-aware is eternal and timeless. Structure is all that counts. Self-awareness does not happen at a certain time and last for some fraction of a second. Yesterday seems to come before today because today contains records (memories) of yesterday. Nothing in the known facts is changed by imagining them hung on a ‘line of time’ – or even reversing their positions on that line. The instant is not in time, time is in the instant. We do not have to worry when the draw is made, only whether our number comes up.