Brian Greene: Can the Rest of Us See the Beauty of Nature That Scientists See?

Brian Greene
I’m Alan Alda, and this is C+V, conversations about connecting and communicating.
When I see a young kid and I’m talking to him about black holes or the Big Bang and I see their eyes light up in a way that tells me that they’re so fired up about this cool idea. When they say to me, “I didn’t even know that was science.” At that point, you say, Wow, this is something that… it’s just tragic for kids and adults to not at least be given the opportunity to wander around some of the most wondrous ideas that the species has ever developed.
Brian Greene is not only a brilliant theoretical physicist but also a man dedicated to bringing the wonder of science to the rest of us. And that includes me. Brian and his wife Tracy Day asked me to join them a dozen years or so ago when they began the World Science Festival and it’s been a continuing education ever since. I’ve interviewed some of the world’s sharpest minds on dozens of stages in New York and Brisbane, happily contributing my ignorance and curiosity to the job of bringing their work to a wider audience.
The festival captures Brian’s extraordinary ability to bring a scientist’s understanding of nature at a very deep level up to the surface where we are so we can enjoy it, too. I’m always curious about how someone is able to do that, so I invited Brian in for a conversation at our studio in Manhattan.
Alan: 00:01 Brian, I’m so glad to be here with you today.
Brian: 00:05 My pleasure. Thank you for having me.
Alan: 00:05 You’re the first person to sit down at this table and look at something inscribed on the table. People write with the Sharpies on the table and what did you see?
Brian: 00:13 Well, right in front of me is the Einstein-Hilbert action. That is the prime way of deriving Einstein’s field equations of the general theory of relativity. Some erudite guest on some show has left that as a relic on the table here.
Alan: 00:29 See, you guys speak a secret language. This is not good for the rest of us. So, tell me about, Hilbert was a great mathematician.
Brian: 00:38 Yes, he was one of the greatest. Some will say he’s the greatest mathematician of the last few hundred years.
Alan: 00:45 When was he alive?
Brian: 00:46 Well, he was alive in the twentieth century and famously had an ongoing battle during the month of November of 1915 as he and Einstein-
Alan: 00:57 God, look how you know the dates.
Brian: 00:59 Yeah.
Alan: 00:59 I love this. He had a battle with Einstein?
Brian: 01:00 He and Einstein were both racing to the finish line trying to complete the equations of the general theory of relativity and the equation that you have on the table here, somebody wrote with a Sharpie, was Hilbert’s way of getting to the equations of gravity. Einstein had a different way of getting there and they both basically got to the finish line at the same time.
Alan: 01:21 Why do we know about Einstein with relation to this and not Hilbert? I mean, the general public?
Brian: 01:27 It’s a good question and it’s largely the fact that Einstein was working toward this solution for 10 years and he met with Hilbert in June of 1915 and told him everything he knew. Hilbert just started from June of 1915 and was only working for a few months. Nevertheless, he was such a brilliant mathematician that with the hints that Einstein gave him, he was able to finish it off on his own, but it was really Einstein’s idea that got the ball rolling. He kept the problem alive for all those years.
Alan: 02:03 This brings up the question of how poor was Einstein as a mathematician? He seemed to always be getting help on his math?
Brian: 02:12 Well, people like to-
Alan: 02:13 I mean, he was looking at the other guy’s homework a lot.
Brian: 02:16 It’s a romantic way of thinking about Einstein that he was a genius, but he couldn’t add two plus two. People love those kind of stories.
Alan: 02:24 You know, the story about playing violin.
Brian: 02:27 Yes, that he couldn’t count.
Alan: 02:30 Albert, one, two, three, four.
Brian: 02:33 Yeah, exactly, but he was a fantastically gifted mathematician and to work out the tensor calculus, which is the body of mathematics necessary to derive and develop the equations that now bear his name, was a fantastic achievement in an era when people weren’t teaching that subject to physicists. I mean, I like to tell people that now undergraduates routinely take classes of mine where we teach the methods that Einstein needed to work out his equations, but Einstein had no such teacher in those days.
Alan: 03:11 He worked it out on his own?
Brian: 03:11 He worked it out on his own and yes, he had conversations with various mathematicians to help him along, but how amazing to take a body of mathematics that nobody really thought would be relevant to the force of gravity and somehow be able to blend his intuitive ideas with the rigorous equations to come up with the final result. That’s an amazing achievement.
Alan: 03:31 This is really at the heart of what this program is about. You sat down at the table and you saw that equation and it spoke your language. I’ve looked at it a dozen times. I thought somebody had made a mistake with the Sharpie.
Brian: 03:47 Right, right.
Alan: 03:48 How do we get from your understanding of that equation to my understanding of it?
Brian: 03:55 Right.
Alan: 03:56 I know you’ve spent a lot of your life figuring out how to do that and we’ve worked together on that for a decade or two.
Brian: 04:03 Right.
Alan: 04:04 What do you think is the way to do it that’s most effective?
Brian: 04:08 Well, my feeling is that the actual mathematics itself is really a very specialized language that it’s not necessary for everybody to speak. Similarly, if there were things written on this table in Sanskrit, I’d have no idea what they are. They would just look like symbols to me and if someone could come along and translate the Sanskrit into a language that I understand, I’ll be satisfied that I get the gist of what those symbols mean. I think that’s what we need to do. We need to translate from the mathematical equations, into a more common vernacular using analogies, using plain old explanations, using visuals, and I think people can get pretty close to an understanding of what the mathematics is trying to tell us using that approach.
I mean, it’s an interesting question. I think you and I have kicked it around in the past from time to time. Are you always going to be missing something?
Alan: 05:04 That’s what I was going to ask you next.
Brian: 05:04 Yeah.
Alan: 05:07 It sounds like you have binoculars into the dark, unknown reaches of the universe that I’ll never have possession of. You can see things or at least are convinced you can see things, because I can’t check out your math, I don’t know how, but you seem to be able to see things in a way that I’ll never be able to see them if I don’t have the language of math.
Brian: 05:33 I’d like to say that you’re completely wrong and you can see everything, however, I think there’s some truth to what you’re saying. You do have a deeper, fuller way into the ideas if you understand the mathematics. Just as, I mean, with the analogy with Sanskrit, I’m sure there are nuances and subtleties of certain ideas that are expressed in say, a foreign language, Sanskrit or whatever.
Alan: 05:57 There are probably colorful insults in Sanskrit-
Brian: 06:00 There you go, exactly.
Alan: 06:01 … that all of you… You’ll take it literally [crosstalk 00:06:04]-
Brian: 06:01 Yeah.
Alan: 06:01 … they just have a basic understanding.
Brian: 06:05 Yeah, so you see that you are missing something in translation. There always is that case and it’s the case, too, with the mathematics. I mean, when I look at this equation on the table, and for those of you who are interested, it’s integral D four X root minus G, where G is the determinant of the metric, times R, which is the scale of curvature.
Alan: 06:26 I was just going to say that. I wish you hadn’t been so quick, so what?
Brian: 06:30 When I look at that equation, I do see a lot of things going on there. In my mind, I see curved surfaces and I see a mathematical gadget that measures distances on that curved surface and I see another mathematical gadget that uses those distance relations to determine whether the surface is curved or flat. All of that happens immediately when I look at this equation, just because I’m trained to recognize the symbols.
You definitely don’t get that if you don’t speak the language, but you can get the basic idea that Einstein was saying that warps and curves in space push things around, much like if you have a bowling ball and a rubber sheet is the canonical metaphor that we love to use.
Alan: 07:15 I know, I know.
Brian: 07:16 That’s what’s happening.
Alan: 07:17 My memory is that Einstein himself came up with that image and it’s a two-dimensional image, which always throws me.
Brian: 07:25 It is.
Alan: 07:25 It’s as if you had a rubber sheet and you put a bowling ball… stretched the sheet tight, you put a bowling ball in the middle, it dips down a little under the weight of the ball.
Brian: 07:35 Right.
Alan: 07:36 Which already is explaining gravity by using gravity to explain it, which already-
Brian: 07:40 I agree with you completely.
Alan: 07:41 It’s a little bit running in circles on its own.
Brian: 07:44 It is totally running in circles and the problem with most analogies and metaphors is if you push them too far, they break.
Alan: 07:49 Yeah, that’s true, but just to complete that for anybody who hasn’t heard it before, the idea, as I remember it, is the bowling ball makes the rubber sheet curve, dip, and if you, without the bowling ball, if you roll a, say a ping pong ball across the sheet, it will go in a straight line, but when you put the bowling ball on, it has to curve with the sheet and it takes a curved route to the other side.
Brian: 08:17 Exactly.
Alan: 08:18 Leaning toward dipping down towards the bowling ball.
Brian: 08:21 That’s right.
Alan: 08:22 Yeah, but my problem is in real life it’s three-dimensions. It’s pulling, it’s curved somehow in every way, all the way around let’s say, the earth.
Brian: 08:32 Yeah. Now, I have an analogy for that. I don’t know if it will help.
Alan: 08:34 Oh, come on. Tell me.
Brian: 08:35 Well, it kind of goes back to David Letterman in the 1980s.
Alan: 08:38 Of course.
Brian: 08:39 Yeah. When he used to sometimes have these big vats of Jell-O and he would challenge a guest to jump into the Jell-O. Imagine that the 3-D environment is like the Jell-O and when you have the bowling ball… or let’s call it the sun if we’re going to do a real 3-D example. When the sun is in space, it warps the Jell-O all around it, just like my body would warp and compress the Jell-O all around it if I was to jump into this big vat. It’s that kind of 3-D compression and curvature that ultimately is really responsible for [crosstalk 00:09:14].
Alan: 09:14 Okay, this sounds like a good analogy, except I can’t understand [crosstalk 00:09:17]. No, but that’s just me. What I’m trying to get is, if you have this big vat of Jell-O and you dump a bowling ball into the middle of it, in what way does it curve the Jell-O because the Jell-O’s still Jell-O. Is it thickening the Jell-O in some way?
Brian: 09:37 Yeah. It’s more like that. It’s as though the environment is now being compressed in certain directions, stretched in other directions. The value of the rubber sheet metaphor is it makes the curvature much more manifest. Our brains can see the curvature in the rubber sheet.
Alan: 09:37 Yeah.
Brian: 09:53 It’s much more difficult to fully take on the curvature of the Jell-O. That’s where you’re having trouble because the analogy is imperfect.
Alan: 10:02 Let me just keep everybody up to date who’s as slow as I am. We’re talking about Einstein’s idea, his new idea, that it’s not so much that gravity is a case of some object pulling other objects toward it. It’s that the space itself is curved in some way and that’s what we call gravity. Now, on the rubber sheet, the ping pong ball is actually curving toward the bowling ball. Right?
Brian: 10:38 Correct.
Alan: 10:40 Now, with the bowling ball and a bunch of Jell-O, nothing would curve toward it. It would slow down and stop. It would curve away from it. Wouldn’t it?
Brian: 10:51 That’s right. The only value of the Jell-O metaphor is to get a feel for the environment responding all round and [crosstalk 00:11:00].
Alan: 11:00 Okay.
Brian: 11:01 It’s not very good.

Alan: 11:02 This curve thing, this curve, the word curve, I really have a lot of trouble with that. What does it mean? Is it a mathematical term? Are you describing something in math?
Brian: 11:13 It is. In fact, it has a very concrete meaning that many of us know about from, if you’ll recall, in junior high school you learned the Pythagorean Theorem, which says that if you have a nice right triangle, that’s drawn a flat piece of paper, remember A squared plus B squared equals C squared.
Alan: 11:31 One of my favorite things. No, really. I did, I loved that. I loved the Pythagorean Theorem.
Brian: 11:37 Here’s the thing. If you took that triangle and you drew it, not on a flat surface, but for instance, on the surface of a basketball or the surface of a trumpet, where it would either curve inward or bloat outward, A squared plus B squared would not equal C squared. That’s one way of thinking about what curvature means. It’s an environment in which when you draw a triangle, A squared plus B squared does not equal C squared. The flat case, the one that we learn about in school, is the one with no curvature and you can intuitively understand that. The surface of the table is nice and flat, whereas the surface of a bowling ball or a basketball or a trumpet is not flat.
Alan: 12:14 The trumpet has many ups and downs and ins and outs.
Brian: 12:17 I should have been more precise. I meant the fluted part, whatever it’s called, right at the end.
Alan: 12:23 I see. Yeah. What have I just learned?
Brian: 12:29 Well, you’ve learned that the way we talk about curvature mathematically is by violations of that formula that you learned in junior high school. When that formula holds, then the surface, the environment is flat.
Alan: 12:43 Ah, this came from my saying, “What is this with the word curve?”
Brian: 12:46 Exactly.
Alan: 12:47 What’s another way to say curved that will help us visualize it? Is it possible to visualize this?
Brian: 12:52 It is. I mean, curved and warped are the two words that I am most fond of and a nice image to have in mind is take the Mona Lisa. We all know-
Alan: 13:02 You know I tried, they arrested me. That actually-
Brian: 13:06 Less aggressive taking.
Alan: 13:07 … the Mona Lisa was stolen, I think, in 1911.
Brian: 13:11 Maybe for this purpose, they tried to illustrate curvature.
Alan: 13:13 They’re not sure they got the real one back.
Brian: 13:15 Oh, you’re kidding.
Alan: 13:16 That’s what I read.
Brian: 13:17 Is that true?
Alan: 13:17 Isn’t that interesting?
Brian: 13:18 Oh, my God.
Alan: 13:19 Now, that has nothing to do with the curve.
Brian: 13:22 Yeah, but that’s much more interesting.
Alan: 13:24 I know, but it’s a little diversion to give everybody a break. Okay, so give me another word for curve.
Brian: 13:29 Warp, let’s use warped. Imagine you take the Mona Lisa and it gets wet and the canvas stretches and it becomes all motley with various bubbles and things in it. The Mona Lisa will look different and the reason it will look different is because the distance relations between various locations on her face will have changed because the canvas has stretched or compressed. It’s that warping of the image that is the diagnostic, which allows us to know that that surface is now curved, whereas it was previously flat.
Alan: 14:02 Somehow the canvas on the Mona Lisa is able to respond and distort the face, like an apple in our iPhone that makes us have a funny face when we pull the-
Brian: 14:13 Precisely.
Alan: 14:14 … the shape of the face around.
Brian: 14:15 Yeah, now that’s a case though where, obviously the surface of the iPhone stays flat and it’s done digitally, but in a real mechanical example-
Alan: 14:22 Mona Lisa, she’s distorted because she has ups and downs on the surface of the canvas?
Brian: 14:30 Precisely.
Alan: 14:31 I see. That’s different. What word is that associated with?
Brian: 14:36 Again, warps and curves. I’m sure there are other words, too, but those are the ones that I use.
Alan: 14:40 Why does that make… if the sun is Mona Lisa and if the space around the sun is Mona Lisa, that’s more like it.
Brian: 14:48 Sure.
Alan: 14:49 What makes me veer toward the sun when I go near it?
Brian: 14:53 Well, Einstein declared, and you could challenge it, but the data supports him. Einstein declared that objects always move on the shortest available trajectory. That’s not quite precise, it’s the extremal trajectory, but let me say shortest for now. And so if the Mona Lisa or space itself undergoes some kind of warping and curving, the trajectories that are the shortest ones, change. On a flat surface, we know the shortest trajectory. It’s the straight line from one dot on a table to another dot on the table, but in a warped environment, the shortest trajectory can be unusual.
Alan: 15:29 This is why when I flew from Copenhagen to Los Angeles, I didn’t fly in what I thought was a straight line, which would have taken me over New York. I flew over the North Pole.
Brian: 15:43 That’s right.
Alan: 15:44 That was the shortest route.
Brian: 15:45 That’s right because… exactly, the shortest routes on a sphere are so-called great circles, which are circles that pass through the diameter, so they are the largest possible circles on the surface. If you travel a trajectory along one of those circles, it gives you the most efficient path from one point to another.
Alan: 16:08 Bring me back again to curve… The space around the sun gets compressed in some way?
Brian: 16:18 That’s right.
Alan: 16:19 Therefore, it’s a shorter route-
Brian: 16:21 Yes.
Alan: 16:21 … to go closer to the sun as you’re passing by it.
Brian: 16:24 That’s right. The shorter route is a trajectory that we would normally call an orbital path, so the earth goes in orbit around the sun because that is the shortest trajectory that the earth can follow in that curved environment.
Alan: 16:39 Otherwise, the earth would just keep moving, find some other star.
Brian: 16:43 Exactly.
Alan: 16:46 Well, I’m exhausted.
Brian: 16:47 Hey, it’s you who put the equation on the table [crosstalk 00:16:51].
Alan: 16:51 [inaudible 00:16:51], believe me it wasn’t me.

Alan: This is really a good time to ask you a question that I get asked all the time and I wonder if you’re exhausted from being asked this too. Why do we have to help people understand science better than they do now?
Brian: 17:11 Well, you know-
Alan: 17:12 I mean, what difference does what we’ve just been saying make to anybody?
Brian: 17:16 Well, I think… I’ve sort of got two answers to that question. The first is, if you will, the more practical one, which is, look, you look out into the world and there’s enormous opportunity and fantastic challenges that we face on so many fronts. In alternative energy sources, in climate change, in the opportunities with personalized medicine and nanotechnology. There’s so much that we can do and there’s so much that we’re going to attempt to do. If you don’t understand any of the underlying ideas, you can’t participate in the decision making. You can’t participate in giving your representative some sense of how you want things to go, so you become a bystander and that, to me, infringes on the democratic process itself.
The health of democracy, I think, requires the populist to have some basic understanding of the key ideas that go into these decisions that would be made, but the answer that really touches me more deeply than that … that’s important, I’m not taking away from that, is when I see a young kid and I’m talking to him about black holes or the Big Bang and I see their eyes light up in a way that tells me that they’re so fired up about this cool idea. When they say to me, “I didn’t even know that was science.” At that point, you say, Wow, this is something that… it’s just tragic for kids and adults to not at least be given the opportunity to wander around some of the most wondrous ideas that the species has ever developed.
Alan: 18:53 I have a similar feeling, which is that it’s so beautiful, it’s so entertaining to find out stuff we didn’t know about the cosmos and about our own bodies, about biology and geology.
Brian: 19:10 Yeah.
Alan: 19:12 It’s so engrossing. To me, it’s as if you said, “Tomorrow, we’re going to start a new thing. They’ll never be any more music, they’ll be no more poetry, they’ll be no more essays written, they’ll be no more puzzles to solve, that’s where we are with science to a great extent right now and it doesn’t seem right.”
Brian: 19:32 Yeah. Right. I agree and I almost consider it a birthright that you need to be given the opportunity to engage with ideas that allow us to see further, deeper, and more fully what reality is all about.
Those are reasons for knowing more about science thatwe should all think about. I wondered what Brian’s own, personal reasons were. When we come back after this break, Brian explores the roots of his passion for both science… and for connecting with an audience.
This is Clear + Vivid, and now back to my conversation with Brian Greene.
Alan: 19:49 What started you? What was the beginning of your entry into this as something you loved rather than something you had to do?
Brian: 19:59 Well, it was [Young 00:20:00] and I think many theoretical physicists like me have similar stories, I suspect, but for me, it was all mathematics. At an early age, my dad taught me the basics of arithmetic, nothing deep. He was a high school dropout, but he loved these ideas. Once he taught me how to multiply, I just couldn’t stop multiplying.
Alan: 20:21 [inaudible 00:20:21]
Brian: 20:21 Yeah, exactly, right. He would get these big sheets of construction paper and tape them together and write down these 30 digit by 30 digit numbers and I would spend days and days doing these multiplications.
Alan: 20:32 Oh, great.
Brian: 20:33 It wasn’t for any purpose. Nobody cared about those numbers, but for me, it was to sit there and say to myself, “Nobody has ever done this multiplication problem before.”
Alan: 20:44 That seems to be a very important impetus to science.
Brian: 20:48 Yes.
Alan: 20:49 I’ve heard it said so many times by scientists who discovered something about nature. The phrase, “I’m seeing something no one’s ever seen before,” that comes up over and over again.
Brian: 20:49 Yeah.
Alan: 21:01 I guess, it’s the feeling of the guy who saw the Pacific Ocean for the first time, the guy from Europe who saw it for the first time-
Brian: 21:09 Right.
Alan: 21:09 … felt.
Brian: 21:10 Yeah, I mean there’s something in our evolutionary makeup that… I’m sure that the evolutionary psychologists can identify for us, that makes us enormously drawn to being the first person to recognize something. When I was multiplying 30 digit numbers, it didn’t really matter that it was something new, but later on, when you’re actually staring at a result in theoretical physics that you’ve come up with, there is this deep sense of connection to the universe when you’re sort of staring at something that you suspect nobody else has ever stared at before and you have this new secret of the universe that’s just yours for that moment. There’s a wondrous feeling with that.
Alan: 21:52 Didn’t you have an experience with a telescope when you were young?
Brian: 21:55 Not telescopes for me. No, I tried to build one when I was little and it didn’t really work out so well.
Alan: 22:02 Well, you tried to build a telescope?
Brian: 22:03 I tried to build a telescope, yeah. There was a class at the planetarium and I dropped out thinking that it was too easy. I could just do it on my own. There’s certain techniques that I didn’t quite master at that age of eight or nine.
Alan: 22:18 Were you able to see anything?
Brian: 22:20 It was just very distorted. Very distorted, so it was like the Hubble, the Hubble Telescope before they fixed it.
Alan: 22:26 Oh, well, that was quite an accomplishment.
Brian: 22:28 Yeah.
Alan: 22:30 Once you got this understanding of the excitement of seeing things for the first time and wanted to tell other people about it. How did you get from one of those to the other?
Brian: 22:43 Well, you know, I always felt that just doing the science wasn’t quite enough because it felt so isolated. Exciting, but isolated. A small community, you write a good paper, and if you’re lucky, a few hundred people will read it carefully. I mean, the numbers are so small and it just felt to me that these ideas should be out to a wider public. It just sort of happened by chance. I gave a lecture in the Aspen Center for Physics, for the general public, and it went well. Things just sort of went forward from there, but when I think back, it was my dad, I don’t know if we’ve ever discussed this. My dad was a performer, he was a singer, he was a Vaudevillian, he was a harmonica player, bass player, so in my house it was a very performance-oriented household even though I wasn’t doing any of that stuff.
Alan: 23:35 Can you play any instruments?
Brian: 23:36 No. In fact, it’s interesting because my dad found… he’s also a composer, it’s such a difficult life that he wanted to steer us kids away from the performing arts.
Alan: 23:47 What kind of music did he compose?
Brian: 23:49 It was more off Broadway musical type things, he had an off Broadway musical back in the 70s. Some popular tunes, that some did quite well. A song called Turn Around that as recorded by Harry Belafonte and various other pop stars. It limited success, but it’s such a hard life when it’s not, you know, when you’re not really at the top of the field.
Alan: 24:15 Oh, sure. He did want you to know… Oh, right. There was that background of performing that you-
Brian: 24:26 I mean, it was just there.
Alan: 24:28 … [crosstalk 00:24:28].
Brian: 24:27 I mean, look, Harry Belafonte was coming to our house sometimes every day for vocal coaching.
Alan: 24:32 Really.
Brian: 24:33 Yeah, so I’d be in my room and there’s like Day-O happening in the living room. It was like in the air-
Alan: 24:39 Yeah, yeah.
Brian: 24:39 … to be sort of out there, even those I wasn’t one, at least in high school, I wasn’t in the high school play and I wasn’t in high school sing, you know, that wasn’t really my thing at all, but later on, I sort of migrated more in that direction.
Alan: 24:54 How did you… wait, [Gramble 00:25:00], cut this part out where I stumble and stutter. What do you think you need to do to help people get from a general, sometimes misunderstood way of understanding science and get them on the right track? What do you have to do?
Brian: 25:19 Well, I think that you really need to speak about things that matter to you. I think that, to me, is the-
Alan: 25:27 [crosstalk 00:25:27] matter to the person listening?
Brian: 25:28 No, matter to the person speaking. In other words, I cannot just go out there and talk about anything, any science. It’s like I’m not, you know, I have my science research and I have my science for the public, but I would never be like a science correspondent because I’m not one who just is a vessel for taking scientific ideas and trying to translate them for the public. I need to really care about the scientific ideas.
Alan: 25:55 Well, you sound like you also need to have studied it deeply, so you don’t make a mistake.
Brian: 25:59 That to me makes a big difference and I have to tell you, when I look at folks who write for newspapers or do stories on television who are not scientists, I’ve tremendous respect for them because I wouldn’t have the courage to go out there and talk about these scientific ideas if I didn’t know them inside out.
Alan: 26:19 I have that same feeling. I’m in awe of people who take on that responsibility.
Brian: 26:23 Yeah. For the most part, they do a really good job, but for me, my process when I talk about these ideas for the public, is I look at it, some idea, relativity, whatever, and I say to myself, what really matters, what can I cut out without loss of integrity, what ideas are essential for sort of connecting the dots? I wouldn’t be able to do that if I didn’t really understand the full mathematical underpinnings of what I’m talking about. That, for me, is vital.

Alan: 26:54 How many years have we been doing the World Science Festival?
Brian: 26:54 12, 12 years. Yeah.
Alan: 26:57 12 years now. In that time, have you seen a change in the response of the public? Has it gone up in terms of their interest, has it gone down? I know we’re spreading around the world-
Brian: 27:10 Yeah.
Alan: 27:10 … but what’s the response like?
Brian: 27:13 It’s hard to say whether the individual response is up or down. It feels pretty constant, but what certainly is the case is I think that the general public is actually quite sophisticated about a whole host of ideas. We have programs that really go pretty far into the undergirding of black holes or cosmology and things of that sort. People are willing to go along and they’re hungry for it. In fact, I’ll tell you something with is curious. There’s a general rule that when you’re writing a book, you don’t want to have any equations in it or the rule is for each equation, you cut your audience in half, something like that. On the other hand, Roger Penrose wrote a book that was all chocked full of equations and did well and we find, at the World Science Festival, we create videos and sometimes we make them a little bit more mathematical. People really love it.
It’s not necessarily that they’re following all the equations, but they enjoy seeing the real stuff, the real ideas behind it and I think that that… that’s unexpected to me and it’s heartening that people really want to know what’s happening behind the scenes or at least go as far as they can to grasp it.
Alan: 28:32 Yeah. When I look at equations like the one on the table in front of us, I often think, “That funny symbol, I’ve seen it before many times. What is it?”
Brian: 28:32 Right.
Alan: 28:43 What does it do? Why is it there? There are things happening and the equation is in a way a kind of puzzle asking to be solved.
Brian: 28:52 Right, right, right.
Alan: 28:54 Do you find that the World Science Festival is appealing to people more in one aspect of science than another or is it equal?
Brian: 29:03 Yes, without a doubt.
Alan: 29:05 What’s most interesting?
Brian: 29:06 The public that we reach is most excited about physics, cosmology, astronomy, and also neuroscience, the brain, and sort of the future of thought in [crosstalk 00:29:19].
Alan: 29:18 This is so interesting. This is just like that study that I talk about a lot because it interests me so much. Somebody did a study on what were the most often emailed articles in the New York Times science section and they were not articles, as we might expect, about health or exercise or diet. They were articles about things that express the awe and wonder of nature.
Brian: 29:45 Yeah, I can even go in that direction, too. I mean, the World Science Festival has created programs on health and diet, programs on diabetes, programs on AIDS, programs on cancer research, and those are the ones that are the hardest sell. Although, you’d think they would be the ones that are the most practical, maybe even the most useful, but that’s not where the excitement is generated. The excitement is generated in the big ideas of-
Alan: 30:12 Now, in some of the big ideas are bound to include or be based on basic research.
Brian: 30:19 Yes.
Alan: 30:21 It seems to run counter to what you’re saying because people generally are not interested in funding research and helping fund research or pushing for funding for researching in things that don’t seem to have an immediate payoff.
Brian: 30:39 Yeah.
Alan: 30:40 They seem to want to learn about it and be entertained by exposure to these ideas, but they don’t seem to be taking them seriously with regard to their own lives. Do you experience it the way I do?
Brian: 30:50 Oh, I do. You could call it a paradox. I don’t actually think it is, but there’s definitely a disjuncture between what people would want to do with their time, in terms of ideas that they want to be exposed to and engaged with versus necessarily what they want to pay for. That’s sort of a funny thing, but I often wish that senators and congress folks would recognize that the public really has an excitement for understanding how the world is put together and it isn’t only a matter of investing in things that are going to have a practical payoff. The human mind is our most precious quality and having that mind journey across the cosmos, journey to the beginning of time. I mean, those are journeys that are deeply moving and in order that those journeys can be continued, you have to have the research that’s going to continue.
Alan: 32:00 I’ve heard smart people say that everything or almost everything that’s discovered in basic research, the way nature works at its most mysterious level, that that almost always leads to something practical. Einstein’s work took a hundred years to result in GPS, which we now carry around in our pockets.
Brian: 32:25 Yes.
Alan: 32:26 The idea that it takes a hundred years or sometimes more, maybe things that haven’t yet produced an application will take longer than we can imagine, but we don’t seem to think about the future as a real thing.
Brian: 32:41 Yeah. It is a funny thing. GPS and Einstein is a good example, but one that really comes to find even more forcefully is quantum mechanics. I mean, here’s a subject developed in the 1920s and 1930s that I’m sure seemed incredibly esoteric at the time. Particles and atoms and energy levels of electrons and Schrodinger equation.
Alan: 33:04 Gluons.
Brian: 33:04 Yeah. It was so abstract and yet, quantum mechanics is why we have integrated circuits, which is why we have cell phones. It’s why we have computers. It’s why we have effectively every piece of modern technology. It wouldn’t exist without the basic understanding provided by quantum physics. Here’s an example where if you were practically minded and were funding things in the 1920s and 1930s, you might have cut off funding for quantum mechanics.
Alan: 33:32 Right. Right. Fortunately, you didn’t need a big-
Brian: 33:36 You didn’t need a lot of money to do the kinds of [crosstalk 00:33:39] experiments in those days.
Alan: 33:36 Right.
Brian: 33:40 Yeah.
Alan: 33:40 Somebody sitting with a pencil could do a lot of the work.
Brian: 33:43 Precisely.
Alan: 33:46 To fund a huge accelerator that was already cut off once, which could have put us in the lead in that kind of work.
Brian: 33:54 Yeah. The Superconducting Super Collider down in Texas was meant to be three times the power of the large Hadron collider in Switzerland and it was canceled after a couple billion dollars was spent and tragic for science.
Alan: 34:11 I read that they now use the tunnels that were going to propel particles, for storing-
Brian: 34:17 Storage. Yes.
Alan: 34:18 … storing business records.
Brian: 34:19 That’s right. Yeah. How sad.
Alan: 34:22 There would have been more business records to store if we’d had that knowledge, at least at some point.
Brian: 34:26 Right.

Alan: 34:27 What about how you became focused on String Theory? How did that happen? What led you to String Theory because that’s your main serious professional work, right?
Brian: 34:38 Yeah, that’s right. It grew out of, I had a deep fondness and obsession perhaps with the force of gravity. Gravity, to me, was just this wondrous enigma. As I was in college, I bought my first textbook on general relativity when I was a sophomore. I had no idea what it was. I couldn’t understand it, but I kept it with me all the time, that book. I’d open it and I’d sort of sometimes caress the pages a little bit, because I knew I wanted to understand that stuff.
Alan: 35:10 You know, I tried reading that way, too. It didn’t work.
Brian: 35:12 It took a while, but certainly by junior/senior year, I understood the stuff and I just wanted to understand gravity. When I went to graduate school, that was my focus. It was really fortuitous at that time, right the very first year of graduate school, String Theory, the first major breakthrough happened. This was the promise of a gravitational theory that would also involve quantum mechanics, so I could not, not… I had to work on it because it was exactly where I wanted to be and it was also the ground floor of a new theory, which is always a wondrous time because you don’t have to know a lot to make progress.
Alan: 35:50 Yeah. I think I share your interest in gravity. I was waiting for somebody at a lunch table once in a restaurant, and for 15 minutes, while I was waiting, I would drop a fork or a spoon on the table and just watch it rush to the table. I kept thinking something’s happening that I can’t see. What is that that’s happening?
Brian: 36:17 Yeah. If you would have said that, whatever, 75 years earlier, you could have been Einstein.
Alan: 36:17 I know. I know.
Brian: 36:17 That’s what he was thinking.
Alan: 36:21 I could have been Einstein, but I turned it down.
Brian: 36:28 That’s a role that just didn’t fit in. Yeah, I know, that is the question and you’re right. Even right now, there’s something utterly amazing by the fact that you can take the Sharpie on the table in front of us and drop it, let go of it, and it knows what to do. It moves toward the earth and how does the earth do that? How does the Sharpie know to do that?
Alan: 36:50 Is the earth doing it in any way? I mean, the space around the earth is curved, we already figured that out earlier, so now, what role does the earth play in it? This is big, hunk of matter?
Brian: 37:02 It is what sets the curvature and then the pen is sliding down that indentation.
Alan: 37:07 All right, okay. You’ve got to solve this for me because I’m very anxious about this. What’s the difference between the earth causing the curvature in space and the earth just attracting stuff?
Brian: 37:19 Well, both are fine languages and both can be used to predict the motion of the Sharpie that I just dropped and both are accurate, but Einstein’s, which is the one that involves the curvature and not the earth pulling on the pen, gives predictions that in some situations are a little bit different than the predictions of the notion of the earth pulling on the pen.
Alan: 37:41 These predictions are useful in some way in the way that the other predictions aren’t?
Brian: 37:45 Well, the GPS stuff that you mentioned is one use of it and certainly, from the standpoint of fundamental understanding, Einstein’s predictions do better than Newtons. Therefore, that’s why we like Einstein’s language when we’re talking in the most precise way.
Alan: 38:02 I want to know more about this, the actual event of gravity. If I dig a hole a mile deep in the earth, and I go up a thousand feet above that hole and drop a bolt, the bolt is going to travel faster and faster as it goes toward the hole. When it hits the opening of the hole, is it going to continue to go faster and faster? In other words, is gravity more extreme the closer you get to the center of the earth-
Brian: 38:33 Yeah.
Alan: 38:34 … than it is on the surface.
Brian: 38:35 Yeah. What matters is the total amount of mass that separates the bolt from the center of the earth. There’s a-
Alan: 38:44 What’s such a big deal about the center? I thought the space around it was curved.
Brian: 38:48 Well, there’s a wonderful theorem that was proved by a guy named Birkhoff, which allows us to have a pneumonic in our minds for answering questions like the one that you asked. In a situation, we always want to know what will the gravitational pull be if I modify the mass in some way? In your case, you’re carving out a little cylinder-
Alan: 38:48 Well, I wanted to know the importance of the center of the earth.
Brian: 39:14 Well, the center is because in some sense you are able to replace the earth by a body that’s compressed right at the center and has the same mass. The theorem tells us that the gravitational pull of that little tiny nugget at the center is the same as the gravitational pull of the earth, which is a more complex body to have in mind.
Alan: 39:38 The curvature does affect the earth itself?
Brian: 39:44 It does. Now, when we solve Einstein’s math, we usually only use the solution outside the earth, but in principle, you could solve for the curvature of space inside the earth, too.
Alan: 39:57 Okay. Well, that makes it a lot clearer because I pictured this thing that was untouched by a curvature.
Brian: 40:02 Oh, I see. Now I understand your thinking on that. Yeah, no, so the curvature of the environment happens everywhere, even within the source of the gravity itself.
Alan: 40:13 Yeah, that just raises more questions, but I won’t bother you with them. That center part I don’t get. The center part… the center is nothing compared to everything around it. The earth, the earth is not-
Brian: 40:13 That’s right.
Alan: 40:23 It’s not like the earth has got some black hole in the center of it.
Brian: 40:27 That’s right, so in many ways, my move to thinking about the center was a mental pneumonic that I know of [inaudible 00:40:35].
Alan: 40:35 What’s that pneumonic?
Brian: 40:37 That you can always replace a spherical body by an object of the same mass that sits at the center of that body and the gravitational pull will be the same.
Alan: 40:46 That takes its own podcast [crosstalk 00:40:47].
Brian: 40:47 Yeah, right, exactly. The bottom line is, I think the better answer to, now that I understand the question that was puzzling you, is that when Einstein talks about the curvature of space and time, he doesn’t mean it just outside bodies, he means it everywhere, every nook and cranny of space, even within stars and planets, too. They are all subject to that curvature.

Alan: 41:09 I don’t know if anybody listening to this has had fun, but I sure have had fun. This is really… You know what I love about talking with you is I get the impression every time, and we never talk without getting into [crosstalk 00:41:22]-
Brian: 41:22 That’s true.
Alan: 41:24 … like this. I get the feeling that if I woke you up in the middle of the night and asked you the toughest question I could think of, you’d have this smile on your face and just start talking in a plain language. You seem to be able to do that without falling into the curse of knowledge problem, which is that when we know things in such detail that we forget what it’s like to hear it for the first time, we don’t talk in the language of the other person or with imagery or anything that helps them get it. Do you go through an experience when you do that, that is conscious? I know this, I understand it in these terms, is this person or this audience going to get it if I don’t translate it?
Brian: 42:07 On occasion, it’s a conscious thought. More often than not, it’s not. I’ll give you one example where it was conscious. When I was writing my first book, The Elegant Universe, I knew that I had to have chapter four on quantum mechanics, but I was intimidated to write that chapter because I thought this material is going to be so hard to get across in a way that the general person without technical training will understand, so I wrote every other chapter. Within those other chapters, I kept referring back to chapter four, so I put so much weight on chapter four.
Alan: 42:40 Oh, you guilt tripped yourself.
Brian: 42:41 Yeah. Then, when it came to writing chapter four, it was a real conscious thought. How am I going to do this? I would walk around Riverside Park, walking the dogs late at night, and just try to think of ways that I would get into the subject. Finally, throughout that deliberation, I came upon an approach that, to me, felt good and I wrote it up and it has been an effective way of describing the ideas of quantum physics.
There’s a sort of conscious version of it, but when I’m in conversation or just talking, I guess, I don’t know. Maybe one way of saying it is all ideas are difficult for me and I’m not trying to be all modest and everything. All ideas are difficult. I never forget how hard they are to understand and therefore, when I’m talking about them, I rely upon that intuitive sense that these ideas are tricky and need to be described in a manner that bridges from the known to the unknown.
Alan: 43:34 That’s so great. Well, I’ve really, really had fun. Before we end, though, I don’t know if you know, we ask seven quick questions.
Brian: 43:43 No, I do not know. Uh-oh, now I’m frightened.
Alan: 43:46 Don’t be frightened, they’re not intrusive, non-invasive questions and they’re generally and they’re roughly about communication and [crosstalk 00:43:53].
Brian: 43:46 Okay.
Alan: 43:53 Okay, first question, what do you wish you really understood? This is an interesting question to ask you because you understand so much, but what do you wish you really understood?
Brian: 44:04 I really wish I understood the inner workings of the human mind. I spent a whole career trying to understand the outer workings of the universe and I realized that all through that journey, it’s ultimately been taking in the outer world and trying to process it within our heads. My head and the heads of my colleagues. That inner world of conscious processing and unconscious processing is so deeply mysterious to me that I wish I just had a clearer sense of what happens inside the human mind.
Alan: 44:36 What do you wish other people understood about you?
Brian: 44:41 Oh. Goodness gracious. Whether it’s understood or not, I don’t know, but that I have sort of a deep and real organic interest in having everybody be able to enter into the world of these ideas because I deeply feel that it’s part of our human nature to explore and unfortunately, exploration has gone into languages that many people don’t speak and I consider that really tragic. I deeply care about trying to give everybody a way in to these ideas.
Alan: 45:20 What’s the strangest question anyone has ever asked you?
Brian: 45:26 Well, I get a lot of strange questions of people who think the ideas of physics can answer things like extraterrestrials or ESP and things of that sort, so I have a whole file cabinet full of the strangest questions that-
Alan: 45:43 Do you remember one?
Brian: 45:44 Oh, yeah. Some of them are distressing. I get emails from people and letters from people who read The Elegant Universe or one of my books and then, one guy in particular told me I spent the last 20 years trying to take the theory further. I just wanted to say to him, it’s just a translation. That’s not the theory in The Elegant Universe. There’s a whole body of mathematics that’s out there and without that you can’t push the theory further. It kind of almost was heartbreaking to imagine this individual who mistook, if you will, an attempt to explain the ideas for the actual rigorous ideas themselves.
Alan: 46:25 Yeah. How do you stop a compulsive talker?
Brian: 46:32 Well, you ask them to recite Einstein’s equations.
Alan: 46:37 If you can get a word in edgewise. Unless he’s already talking about Einstein’s equations.
Brian: 46:41 Then, you’re sunk. There’s nothing to do at that point.
Alan: 46:47 If we accept the idea of empathy as just, not compassion, but trying to figure out what the other person is going through, is there anyone for whom you can’t feel empathy? You don’t have to name names.
Brian: 47:00 Yes. I definitely can be sufficiently off put by someone that it’s very difficult to get over that hump. I think that’s part of our nature. We do our best to try to have a communal spirit, we are hunter/gatherers over the course of thousands of generations, so that’s part of how our DNA is constructed, but we also have out groups and that was clear even back in the Pleistocene. There are people in the out group and it’s very hard to feel empathy.
Alan: 47:34 How do you like to delivery bad news? In person, on the phone, or by carrier pigeon?
Brian: 47:41 The best way is, I ask my wife, Tracy, to do it.
Alan: 47:45 Oh, great. Oh, God. Is Tracy busy? I have some bad news for her to deliver.
Brian: 47:53 Right, exactly.
Alan: 47:55 Okay, last question. What, if anything, would make you end a friendship?
Brian: 48:01 If I felt that a person had been deeply unloyal in a way that couldn’t be justified through some other influence that I could wrap my head around. I think life is short and the number of friends that you have is small. If you’re going to have an investment in each other, there has to be a deep trust. If you violate that trust, it’s very hard to get it back.
Alan: 48:30 Well, I’m glad to be friends with you and I want you to know, I trust that what you’re telling me is the real McCoy.
Brian: 48:36 Thank you.
Alan: 48:38 Great to talk to you, Brian. Thank you.
Brian: 48:39 Great talking to you as well. Thank you.

Brian Greene is great friend of mine and I find his work at the intersection of science and theatre especially fascinating.
He and I share the same passion for improving the public’sappreciation of science, so I’m always supportive of his many projects – especially the World Science Festival, which takes place annually in New York City and Brisbane, Australia. To find out more about this fun event, please visit:
And for more details about Brian, including his lectures, books, film and TV appearances, and his work with theatre, go to: – that’s “Greene” with an E!

Next in our series of conversations I talk with another man with the passion and skills for explaining the mysterious. Robert Sapolsky tackles with verve and humor something more complex even than gravity – human behavior.
The danger is when people really do begin to think that, aha, this behavior, this societal problem, this whatever, is completely explained by this part of the brain, this hormone, this gene, this childhood experience, this neurotransmitter. What you’re doing there is, it’s like trying to judge how a movie got to its conclusion by watching only 30 seconds of it. You’re missing where all the influences came in.
Robert Sapolsky, next time on C+V.