But there's so much unexplained stuff. I don't quite understand the scientific explanation of the placebo effect. What is the core of that? The fact that the placebo effect exists is a fact, but what is it? We have no idea. I love that. I even love that with regard to the home-court advantage in sports. What is that? It's connected to a belief system. Both things, the placebo and the home-court effect, are a belief system that we can turn thought into actual biological function. In and of itself, that's something that science says is not possible. But you can document it.

It's interesting you say that. Most people, if you just stop them on the street, would say that science has always got the answers to things. But if you stop most scientists in their laboratories, they would say the exact opposite: how little they know about the world. Science as an act of humility. And I think you had Elliot say something very similar to that.
Right.

Do you see some of these "acts of nature"—in the film you brought up red tide and colony collapse—as forever beyond our capacity to explain? Or is it something that, with enough thought and enough effort, we can explain?
It'll either get thrown into some tentative, tenuous explanation or it'll be thrown into the pile of the placebo effect: "Okay, it's fact, but we have no idea." There's another one: When the tsunami came, the animals all ran, sensing it happening. What is it that's in their primitive—we'll call it "primitive"—biological makeup, that we've forgotten? It would seem that would be quite an asset for a species to have what they have—knowing something's wrong and we better get out of here. We don't have that, and yet we're supposed to be higher-functioning. So what happened? We don't even understand that. What is it about the intuitiveness of animals? Is it some microscopic shift in the atmosphere that they're sensing? What is it, exactly?

There's so many of those amazing things that tie us to each other, that make us all one system. I think the basic thing about the movie is that we're pretending we're not part of the system.

You said you had drawn inspiration from Einstein's recent biography, the Isaacson biography. What were some of the things you pulled out and tried to instill into what you did?
It's the same type of thing. I get that feeling of what drives you to say that there's an answer: the beauty of simplicity. What is the beauty of simplicity? That is, there's something that binds everything. To keep looking for that, that drive is almost the holy grail. I can totally relate to that on an intuitive level. That's somehow tied to some mystical thing—I don't know if "mystical" is the correct word. It's beyond logic; it's the evidence that all things come from one simple thing.

Fundamental physics, as Einstein practiced, is always at that boundary between physics and metaphysics, or the mystical and the material.
Yeah, what was that whole thing he was struggling with when he said that God doesn't roll the dice? It's random, where a thing is?

Yes, in quantum mechanics you've got that kind of irreducible randomness.
He doesn't like that—and I don't like that, either. At the end of the day, things can't be random.

That was Einstein's point of view. Some people wonder whether that was right or whether there is this randomness that we'll never be able to explain, that's inherent in the world.
That would be counter to, at least, our primitive understanding.

It's interesting what you say about the beauty of simplicity, because I think you had that embodied in the character of the math teacher. Facing an inevitable death as they drive through Princeton, he tries to bring that out in his fellow passengers in the car. Here they are, they're about to die, and to give their death some nobility they went back to a math problem: the beauty of simplicity.
Exactly. Just talking about how amazing that is, what we think of it as a small thing: the principle of doubling, which in a very short order makes an incredible magnitude. I told John when he was doing that scene that he sees beauty in those numbers and that he's always found this kind of awe at it. There's a great satisfaction that comes from understanding that you do this, this and this, and it comes out to that. It's amazing. It's the thing that's driven him and makes him connect with Elliot, who sees that in science. That's why they're so close. And then he's in that room and he just wants one thing: This is my joy, what I see, this is the joy of life for me. Just one more time, just teach one more kid that joy.