Physicist Lisa Randall

The Harvard professor and author of Knocking on Heaven’s Door addresses the ongoing debate between science and religion and shares why she feels there has been a loss of respect for science.

Lisa Randall’s scientific endeavors have made her one of today's most cited and influential theoretical physicists. A physics professor at Harvard, she's received numerous honors, including being named one of Time's 100 Most Influential People. She's also a best-selling author, who makes an impassioned argument for the significance of science in her latest text, Knocking on Heaven’s Door. Randall earned her Ph.D. from Harvard and was the first tenured woman in physics at Princeton and the first tenured woman theorist in science at Harvard and at MIT.


Tavis: Lisa Randall is a professor of physics at Harvard and a member of the “Time” 100 back in 2007 of the most influential people in the world. Her new book is called “Knocking on Heaven’s Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World.” Professor Randall, an honor to have you on this program.

Lisa Randall: It’s an honor to be here. Thank you.

Tavis: Glad to have you. Let me start by asking a pretty straightforward question  – why do you do what you do, and why do you think it matters?

Randall: Well, part of it, honestly, is probably selfish. It’s just a lot of fun. I actually like seeing how the world  – trying to figure out how the world works, how it all fits together. Also, it makes me happy when I feel like things are consistent, when there’s some sort of order to the universe. There’s something very nice about finding some truth that might actually have some internal nature to it.

But I just think it’s a very valuable way of thinking as well, and so  – but I think it’s important that we keep making progress. What I do is very theoretical. It won’t necessarily have implications for anything anyone is doing tomorrow, yet you know that there’s a sense of progress in science, and as we understand more it just turns out that somehow, the world evolves with us.

Tavis: You spend a good part of the book, thankfully, I think, at least to my satisfaction, a decent part of the book talking about this debate, which seems to be ongoing between science and religion.

I just, on my radio show the other day, had a conversation with Professor Mlodinow and Deepak Chopra, who have a book out debating science and religion.

Randall: Right, right, yeah.

Tavis: So everywhere you look there’s this debate between science and religion. Topline for me how you see that debate these days.

Randall: Well, first of all I want to make clear that it isn’t the main focus of my book.

Tavis: Exactly, admittedly.

Randall: What I wanted to do was explain the nature of science, and it is part of the story of explaining the nature of science, to distinguish it from other ways of thinking about the world.

So really what I wanted to do was just get it so that the issues were on the table, so people can just take it for what they are. So the two questions I had are really where is the difference and also why do we care. Those were the questions, and it was part of a general discussion of how science builds up on itself.

So for me, I distinguished religion as involving a deity that comes in and changes the world today in any way, whether it’s by changing the physical universe or by changing my decision, and I just distinguish that from the way that scientists think about this.

Religion can have psychological and social roles, but in terms of really explaining how things work, science works differently. Science is based on material elements at the core. Doesn’t mean we necessarily understand how everything works based on those material elements, but we know they’re there, and we know that there are mechanical properties, that things interact or things react to forces.

So it’s a very different way of thinking about the universe, and so people can feel happier thinking of it as some kind of external force. But for science, it’s all internal. The ingredients are there, and we’re trying to piece them together. We’re trying to build from what we know about the universe, how things work, and trying to go beyond that step by step.

Tavis: To your point now, I wonder whether or not you think that necessarily or just thinking differently, which I think has a value innately in and of itself, there’s a value in thinking differently, oftentimes, but does thinking differently about these issues lead up to make better decisions?

Randall: Well, depends what you mean by thinking differently. Some people think  – what do you have in mind, exactly?

Tavis: Thinking differently about the scientific issues that you’re working on, the research that you’re working on.

Randall: I really do think that science has an internal structure and it makes sense and we can test it. It doesn’t mean we’re answering all questions, and we’re certainly not answering all questions right away, but I think it’s very useful that science has these parameters that  – and it’s not  – I think what happens is people get this very limited view of science. They think set of rules, and then we derive it.

Of course when you’re working on science it’s a much more amorphous process. That was one of the things I really want to make clear. It’s not like we know all the answers right away. You’re trying to put it together. You’re trying to put together data, you’re trying to put together what theories can  – how it can all fit together economically.

But you’re building on scientific truth in the sense of things that can be tested, so you have experiments, you have ideas, you see does it all fit together. So of course as human beings, when we’re doing science we can think about things however we like, but I think what’s great about science is there is ultimately a rigor.

Doesn’t mean that immediately we know which are the right answers, but over time, we get to test the ideas.

Tavis: When I saw this book come across my desk and we knew we were going to have you on the show, I just thought about this title for a few minutes and there are four or five different things that came to mind immediately for me for why you would name this book “Knocking on Heaven’s Door.” But now I get a chance, thankfully, to ask you why you named it “Knocking on Heaven’s Door.”

Randall: But alter you’ll have to tell me what yours were.

Tavis: Yeah.

Randall: Really, I wanted some way of expressing how I see science, which is we have this solid body of knowledge that’s evolving. We’re trying to go beyond it. We’re trying to reach beyond the edges, and it’s as technology advances, as our theoretical understanding advances, we include what we knew before.

A lot of people think, why (unintelligible) science? You’re just going to show everything you did before was wrong. But it doesn’t work like that. What we show is that what we knew before might have been an approximation, but a very good one that worked really well.

But meanwhile, we’re trying to go beyond it. I’m excited about the physics of elementary particles, what’s really in the internal structure of matter, I’m excited about knowing what’s out there in the universe, and I want to know how is that consistent with what I learned in school. We have theories of general relativity, we have theories of particle physics, so what are we going to learn more? What are the other forces?

What are the really underlying  – people sometimes think of matter like a Russian doll  – you just keep getting the same thing. But it’s not true. Every time we look at  – we looked inside matter, we found atoms.

Now, you may or may not be excited about that. I think a lot of people are. But we found quantum mechanics. That is a completely different way of thinking about the universe than classical physics, where we know everything.

The rules really changed. When we got inside a nucleus we found out about the strong nuclear force, so we’re really finding new ways that matter interacts, new forces, new  – and that to me is very exciting.

Tavis: I’m glad you said what you said a moment ago, because I’ve been, again, dying to ask you a number of things. This is another one on my list. So speaking of your point a moment ago of the things that we learn in school and the theory of relativity, I was not a  – let me be very clear with this  – I was not a great student in science. I barely got through, and I struggled with a lot of different parts of it.

But I thought I halfway understand Einstein’s Theory of Relativity  –

Randall: Wow.

Tavis: – halfway, and then I’m reading the other day these articles about whether or not Einstein was wrong, whether or not he made a mistake. So is it neutrinos, was that his argument?

Randall: Yeah, so the  –

Tavis: So you explain it. So neutrinos move faster than light, but you explain it, okay.

Randall: This is actually a really interesting example  –

Tavis: It is very interesting, exactly.

Randall: in this context. So first of all, what was measured was these physical particles called neutrinos. They interact really weakly, so they can go long distances without interacting. So they went 720 kilometers. These people wanted to measure properties of neutrinos, but in the process they measured how fast they went, and according to the measurements that they did, it looked like it went faster than the speed of light.

Now mind you, we don’t really think that it was correct, and neither do the experimenters. Some of the people on the experiment didn’t even want to sign it, because it’s not clear their result is right. What they don’t know is where the mistake is.

So one of the things that they did is they said let’s just put out the paper to the scientific community, see if they can figure out what’s wrong with it, or see if other people can reproduce it. But here’s the thing. Let’s suppose their result was right and it really  –

Tavis: Yeah, how does that change physics?

Randall: Exactly, let’s ask how that changes physics. Does that mean Einstein made a mistake? Absolutely not. Einstein’s theory works really well. It’s been tested. So what would it mean?

Well, it might mean that the assumptions he made were only approximations. The speed of light seems to be constant, but how do we know that unless we keep testing it? That’s what scientists do. We try to see are the assumptions we’re making absolutely true, or do they break down at some point? That’s perfectly legitimate.

It doesn’t mean Einstein was wrong, just like Newton wasn’t wrong. Newton’s laws still work, even though we know relativity is right and we know quantum mechanics is right, but he still gets where the ball lands completely right to the level we can make a measurement.

But when you can do things more precisely or measure them in different routines, you could find different answers. So even if this result turned out to be right, it wouldn’t mean Einstein made a mistake. It would just mean that the assumptions hadn’t been sufficiently well tested and at some level you can see something new emerge. My having said that, it’s probably not right.

Tavis: Yeah. (Laughs) Let me ask another broad question, then I’ll come back inside the book with more specificity. How concerned are you, to the extent you’re concerned at all, that we are losing ground in our country on science in that the data seem to suggest that our students are not being drawn like a magnet to math and science, and what do you make of all that?

Randall: I think it’s definitely an important issue and it’s particularly an issue with engineering, I believe. I still see some great students. But there’s something even more general that worries me, which is just I think we’re losing a respect for science and just rational thinking and numbers, and just the scientific method, and you see that not just in science, but you see that in policy debates.

The fact that people are almost embarrassed to talk about scientific measurements or scientific facts, and I think that’s a greater danger for our country. I think, of course, valuing science and scientific thinking is also important, and I’m glad you bring that up. It’s definitely true.

But I think that we still have many exceptional students in this country who will do great things in science. It is true not all of them will go into science, and probably at a lower rate than before, and that’s definitely something we want to pay attention to, and we want to pay attention to investing in science, investing in education, investing in infrastructure.

But just more generally, people should stop being afraid of thinking in a scientific, rational manner.

Tavis: I’m glad you raised that, because I was going to. The quote, there are a bunch of great quotes, a bunch of great blurbs on the back of the book, but on the front of the book is a politician extraordinaire named Bill Clinton, who endorses the book, and to your point now about the way that science is being treated, or maltreated, as it were, disregarded, disrespected in this present campaign for the White House, what’s the long-term danger of policymakers raising their nose or turning down their nose, as it were, at scientific data?

Randall: I don’t want to completely second-guess politicians, there’s a lot of issues at stake, but look, we have some serious problems at hand. The world is changing a lot, and we have some serious issues. Now, why in those circumstances you wouldn’t want to use all the powerful methods at your disposal and be proud of the fact that you are?

I think behind the scenes some politicians are doing those calculations, but why can’t we say this is the reason we want to do this policy, because this is the calculation we did. Over this time period, these will be the consequences if we don’t do this. It seems that given the kind of issues we’re facing, this is the only way out of it.

Tavis: What’s the abiding lesson that you want us to take from this book?

Randall: Well, I think there’s really two lessons. One is about the physics itself. I talk a lot about the physics, I do the physics of dark matter, the physics of what this amazing collider called the Large Hadron Collider is going to look for when it studies small distances and high energies.

But the other lesson is just the one we’re talking about  – that science isn’t a simple process, but if we understand science better, what it is, and I do try to explain what goes into it, what are the creative elements, what is the role of uncertainty, how science builds on itself, what is the role of risk, all of these things I think will help us just make better decisions, not just about science, but about the world.

Tavis: I got 30 seconds left. Since you mentioned it and we showed a picture of it, the LHC, which is in France, underground.

Randall: France and Switzerland.

Tavis: Exactly. Tell me more about that, for those who don’t know much about this, what the aim and end is of this project.

Randall: Well, we’re really trying to understand the fundamental nature of matter. We’re trying to understand properties of matter, we might even learn about the nature of space. By looking at these scales we can learn properties of matter forces, but also possibly even the nature of space-time. So there’s some pretty exciting things on the horizon.

Tavis: I halfway did my job tonight if you understood at least half of that.

Randall: You did a great job.

Tavis: Brian got like 10 percent of it.

Randall: That was a great job.

Tavis: So we got through it. The book is called “Knocking on Heaven’s Door,” written by best-selling author of “Warped Passages,” Lisa Randall, professor at Harvard, physicist there. Professor Randall, good to have you on the program, and thanks for the book.

Randall: Thank you so much.

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Last modified: November 14, 2011 at 1:45 pm