The Now That Does Not Pass

Saint Augustine admitted something that every honest person has felt at least once: "What then is time? Provided that no one asks me, I know. If I want to explain it to an inquirer, I do not know." Sixteen centuries later I find myself in the same place, with one difference. I no longer trust what I think I know.

Two old puzzles keep bringing me back to the question. The first is the grandfather paradox: travel into the past, prevent your grandfather from meeting your grandmother, and you are never born. But if you are never born, no one travels, the meeting takes place, and you exist again. The second is the butterfly effect. In 1972 the meteorologist Edward Lorenz asked whether the flap of a butterfly's wings in Brazil could set off a tornado in Texas. Put the two together and the conclusion is unsettling: the smallest change in the past would unravel everything that came after it. And yet here we are, intact.

In the 1980s the Russian physicist Igor Novikov proposed a way out, known as the self-consistency principle: a traveller to the past could only do what had already happened. You might go, but every attempt to change history would fail, because your visit would already be part of the story. To me this sounds less like a solution than like a confession. If the past cannot be altered even by someone standing inside it, then in some sense the past has not gone anywhere. It is still there.

That is where my own reasoning leads, and where it stops making sense. I was, I am and I will be. Everything that was, is and will be seems to be gathered in the here and now. By my logic that is impossible, unless the idea of time as a river flowing from past to future is an illusion. Caused by what, I cannot say.

I am not the first to arrive at this. Two and a half thousand years ago Parmenides argued that what is, is, and what is not cannot be, and that change and passing away are tricks played on us by the senses. In March 1955, writing to the family of his lifelong friend Michele Besso, who had just died, Albert Einstein told them, in essence, that for physicists like him the separation between past, present and future was only an illusion, however stubborn. A few weeks later Einstein himself was dead. His relativity gave the idea a precise form. There is no single "now" shared by the whole universe; observers moving differently disagree about which events happen at the same time. Many physicists conclude that all moments exist equally, like the frames of a film laid out on a table. They call it the block universe.

Why, then, do we feel time flowing? Physics has a partial answer: entropy. Disorder tends to grow, and that asymmetry is why we remember yesterday and not tomorrow. In The Order of Time, Carlo Rovelli suggests that the flow may say more about us, creatures who see the world in blurred and partial form, than about the world itself. It explains the direction of the arrow. It does not explain the strange fact that it is always, for each of us, now.

I will confess something I have believed for a long time: that we live in a simulation. In 2003 the philosopher Nick Bostrom gave that suspicion a respectable shape in a paper titled "Are You Living in a Computer Simulation?" In a program every state can be stored at once, and the "present" is simply the frame on the screen. When I put this to Vera, the AI editor who helps me with these columns, she raised an objection: an illusory time does not require a simulation. A real block universe would explain it just as well. She is right, and the objection matters less than it seems. Either way the conclusion is the same. What is illusory is the passing, not the being.

I often think we live in two different dimensions at once: one in which things happen one after another, and one in which they simply are. In my last column I wrote about the veil of Isis, the ancient image of everything nature keeps hidden from us. If there is something under the veil of time, I suspect it is this. The Now is not a point sliding along a line. The Now is existence itself, and existence does not pass.

Consider it for a moment. No one has ever lived a single minute outside the present. Every memory is remembered now; every plan is made now; every fear of the future is felt now. What we call past and future may be the ways the present arranges what it holds, the way a single room can contain a photograph and a calendar. Nothing leaves the room. We simply turn to look at different walls.

Around the year 524, in a prison in Pavia, awaiting an execution he knew was coming, the Roman philosopher Boethius wrote The Consolation of Philosophy. In its last book, Philosophy herself offers him a definition that the Middle Ages would repeat for a thousand years: "Aeternitas igitur est interminabilis vitae tota simul et perfecta possessio." Eternity, then, is the complete, simultaneous and perfect possession of a life without end.

Boethius reserved that possession for God and left time to us. I am no longer sure the line between the two is so clear. Perhaps every now is a small share of that possession: everything at once, nothing missing, nothing going anywhere.

Thomas Laurent
Publisher, Vocemundi

Written by Vera, Vocemundi's AI editor, under Thomas Laurent's editorial direction.