Theoretical physicist Brian Greene moderates this fascinating program exploring the fundamental principles of Quantum Physics.
PARTICIPANTS: Mark Van Raamsdonk, Gerard ’t Hooft, David Wallace, Birgitta Whaley
MODERATOR: Brian Greene
Event Date: JUNE 2, 2017
BRIAN GREENE: Good to see all of you.
You see a quote up there by Niels Bohr, one of the founding figures of quantum mechanics:
“Anyone who thinks they can talk about quantum mechanics without getting dizzy hasn’t yet understood the first word of it.”
Now, why would that be? What did Niels Bohr mean by that? Well, basically he meant that we all have a good intuition for classical physics. Right?
And by that, I mean, you know, if I was to take any little object, right, and give it a catch. Nice! Did a one-handed catch right there. Throw this a little bit further back. Here we go, two for two. Nope, we’re still one-for-two. They’re still back in the dark ages –- here we go. You have that one over there? Good.
Right now, each one of the people who caught, so that would be the two of you over here, is really an evolved human being. Now, you see, when we were out there in the Savannah trying to survive, we needed certain skills, we needed to be able to know where to throw a spear or how to throw a rock to get the next meal.
We needed to dodge some animal that was running toward us. And therefore we learned the basic physics of the everyday macroscopic so-called classical world. We learned that intuitively. And that’s why when I throw an object, you don’t have to go through some elaborate calculation to figure out the trajectory of that stuffed animal. You just put out your hand and catch it, right? It’s built into our being.
But that’s not the case when we go beyond the world of the everyday. If we explore the world, say of the very small, which is what we are going to focus on here tonight, we don’t have experience in that domain. We don’t have intuition in that domain. And in fact, were it the case that any of our distant brethren way in the past, if they did have some quantum mechanical knowledge and they sat down to think about electrons and probability waves and wave functions and things of that sort, they got eaten! Their genes didn’t propagate, right?
And therefore we have to use the power of mathematics and experiment and observation to peer deeper into the true nature of reality when things are beyond our direct sensory experience. And that’s what quantum mechanics is all about. It’s trying to describe what happens in the micro-world in a way that is both accurate and revealing.
And the thing to bear in mind is that even though our focus here tonight will really in some sense be in the microworld, the world of particles, we are all a collection of particles. So any weirdness that we find down there in the microworld, in some sense it has an impact even in the macroworld and maybe suppresses –- we’ll discuss. But it’s not like there’s a sharp divide between the small and the big.
We are big beings made of a lot of small things. So any weirdness about the small stuff really does apply to us as well. And in this journey into the micro-world, the world of quantum mechanics, we have some of the world leading experts to help us along, to figure things out. And let me now bring them on stage.
Joining us tonight is a professor of philosophy at the University of Southern California who spent 22 years at the University of Oxford as a student, researcher, and faculty member. He is the author of a book on the Everett interpretation of quantum mechanics titled the Emergent Multiverse. Please welcome David Wallace.
Also joining us tonight is a professor of chemistry at the University of California, Berkeley, co-director of the Berkeley Quantum Information and Computation Center and faculty scientist at the Lawrence Berkeley National Laboratory. She’s a fellow of the American Physical Society and recipient of awards from the Bergmann, Sloan, Alexander von Humboldt Foundations. Please welcome K. Birgitta Whaley.
Our third participant is a professor of physics at the University of British Columbia, a Simons Investigator and member of the Simons Foundation “It from Qubit” collaboration. He was a Canada research chair and Sloan Foundation fellow and was awarded the Canadian CAP-CRM medal for theoretical mathematical physics in 2014. Please welcome Mark Van Raamsdonk.
Our final participant is a professor of theoretical physics at Utrecht University in the Netherlands and winner of the 1999 Nobel Prize in Physics for work in quantum field theory that laid the foundations for the standard model of particle physics, one of the greatest minds of our era, please welcome Gerard ‘t Hooft.
All right, so the subject is quantum mechanics, and part of the evening will involve some challenge to the conventional thinking about quantum mechanics. And so before we get into the details, I thought I would just sort of take your temperature. Get a sense of where you stand on quantum mechanics. Is it, in your mind, a done deal? It’s finished, we completely understand it? Is it a provisional theory? Is it something which 100 years from now we’re going to look back on with a quaint smile? “How did they think that that’s how things worked?” So, David, your view.
DAVID WALLACE: Well I don’t think we fully understand it yet. I think it has a lot of depth left to plumb, and who knows it might turn out to be replaced. But right at the minute, I think we don’t have either empirical or theoretical reason to think that anything will take its place.
BRIAN GREENE: Good. Birgitta?
BIRGITTA WHALEY: I think it’s here to stay. There may be extensions, modifications, there may be something more complete, but this will still be part of it, in my view.
BRIAN GREENE: OK, Mark.
MARK VAN RAAMSDONK: Yeah, so there’s a frontier in quantum mechanics that I work in, and this is the frontier. It’s like the wild west of theoretical physics, where we’re trying to combine quantum mechanics and gravity, and we need to do that to understand black holes and hopefully eventually understand the big bang. And there’s a lot to do, and we don’t know if we’re going to have to modify quantum mechanics, or it will all be the same quantum mechanics all the way down.