From Science Fiction to Physics: Does Time Actually Exist? | James Gleick | Big Think

There is a sort of funny things that you hear people say that time doesn't actually exist. And it's something that physicists argue about. I mean, physicists actually have symposia on the subject of, is there such a thing as time? And it's also something that has a tradition in philosophy going back about a century.

But I think it's fair to say that in one sense, it's a ridiculous idea. How can you say time doesn't exist when we have such a profound experience of it, first of all? And second of all, we're talking about it constantly. I mean, we couldn't get – I can't get through this sentence without referring to time. I was going to say we couldn't get through the day without discussing time.

So obviously, when a physicist questions the existence of time, they are trying to say something specialized, something technical. Einstein offers, Einstein or maybe I should say more properly Minkowski, his teacher and contemporary, offers a vision of space-time as a single thing, as a four-dimensional block in which the past and the future are just like spatial dimensions. They're just like north and south in the equations of physics.

And so you can construct a view of the world in which the future is already there. You can say, and physicists do say something very much like this, that in the fundamental laws of physics, there is no distinction between the past and the future. And so if you are playing that game, you're essentially saying time as an independent thing doesn't exist. Time is just another dimension like space.

Again, that is in obvious conflict with our intuitions about the world. We go through the day acting as though the past is over and the future has not yet happened and might happen this way or it might happen that way. We could flip a coin and see. We tend to believe in our gut that the future is not fully determined and therefore is different from the past.

But physicists will say, and it's certainly true that a lot of things that we feel in our gut turn out not to be right. We feel in our gut that we're sitting on a flat plane on the surface of something that's immobile. And if a scientist came along and told you that no, you're actually on the surface of a giant sphere that's spinning at high speed and hurtling through space, and by the way, there's no difference between up and down except any illusion that's created by the force of gravity, well you'd have to do some radical readjustment of your understanding of the universe to accept that your first intuitions weren't correct.

And so if a physicist comes to me and says, do some readjustment. Face it, the future looks different from the past to you, but actually physics tells us it's the same. I at least acknowledge that I have an obligation to take that seriously, to listen to it. And physicists do argue about these things, and it's fair to argue about it.

And it's an argument that I take a position on in my time travel book because I felt I had to, or maybe I had a position and yet it's got to be a qualified position. And that's what I recommend to readers of science fiction and to physicists: remember that your views of these things are provisional.