So suppose you stumble across a packet of four index cards. They read as follows:
#1: “At E there is evidence of M, L, F, and D”
#2: “At M there is evidence of D and F”
#3: “At G there is evidence of D, E, L, and M”
#4: “At T there is evidence of G, L, and F”
If you are a little bit of a puzzle nerd, and you have some urge to interpret these cards as representing moments of time, you can eventually deduce their sequence:
2 -> 1-> 3 -> 4
But this sequence is something you have deduced from the information on each of the cards, and the cards themselves of course exist simultaneously. The temporal sequence is an interpretation of the available evidence.
Okay, this idea is basically what Julian Barbour is proposing in his book The End of Time. Instead of index cards, he begins with a huge quantity of temporal slices of the universe (“Nows”), many of which (“Time Capsules”) contain structures which can be interpreted as implying facts about a temporal sequence. Any structure in which you and I exist, with the active and functioning meat in our heads, is a Time Capsule because of whatever it is about us that encodes our memory. So we end up believing there is a flow of time, since each Now we inhabit is filled, from our point of view, with all sorts of implications about what has happened and will happen. So at every moment, it seems to us there is time. But there isn’t any. Not really.
It is a trippy idea, but Barbour is led to it by reasons most sober. I skimmed most of the details, but the gist is that nothing known by physics today explains why there should be any flow of time. That is, physics talks about different events existing in time, and talks about what happens over time, but why time should be moving in one direction rather than another is unexplained. Moreover, as is widely deplored, the two big camps of physics today, QM and GenRel, do not seem to have ever met one another. Barbour proposes a solution to both of these puzzles: just get rid of time. (Note: in this sense, Barbour is just finding new reasons to agree with McTaggart, in his 1908 essay.)
The idea is exciting to me because of how closely it approaches an idea I’ve been flirting with, balls-to-the-wall skepticism. According to B2WSk, it is perfectly possible that the universe is nothing but random noises, except for a few little islands in which there appears something like WHAT YOU ARE EXPERIENCING RIGHT NOW with your ordered perceptions and memories and feelings of temporal continuity and anticipations of the future. But every seemingly ordered moment is only an island. There is no past, and no future, and precious little present. It only seems like there is, right here, right now; but don’t worry, it will pass.
B2WSk, in my mind, is solipsistic (now that’s a nice phrase!), but Barbour thinks each well-ordered Now is a state of the whole universe. Actually, Barbour goes even broader, and includes the Nows of possible states of the universe — all Nows of all possible worlds — and then arranges some sort of probability distribution over them which makes some of the Nows more likely to exist than others (in accordance with QM).
Does this all mean we should start ignoring our beliefs in the past and our memories. No, according to Barbour. His book concludes:
[Ernst] Mach once commented that ‘In wishing to preserve our personal memories beyond death, we are behaving like the astute Eskimo, who refused with thanks the gift of immortality without his seals and walruses.’ I am not going without them, either. I cannot even if I wanted to: they are part of me. Like you, I am nothing and yet everything. I am nothing because there is no personal canvas on which I am painted. I am everything because I am the universe seen from the point, unforeseeable because it is unique, that is me now. C’est moi. I am bound to stay. We all watch – and participate in – the great spectacle. Immortality is here. Our task is to recognize it. Some Nows are thrilling and beautiful beyond description. Being in them is the supreme gift.
Except for the little bit at the end there, I think Barbour has managed to come up with the only metaphysics that could compete with Nietzsche’s eternal recurrence as a means of affirming the value of the here and now. It’s not the thrill or the beauty that makes a Now valuable. It is, I would suggest, it’s uniqueness, the sheer improbability of something like this ever cropping up in existence, no matter what beauty, ugliness, thrills, or banality it includes. And it is no gift, if ‘gift’ implies a giver. It comes from nowhere, and then goes back home.