ROBERTS What did you think of The Black Swan on the same topic?

MLODINOW It’s on the topic of how little things can cause big changes, you mean, and . . .

ROBERTS And how poorly we understand what really matters.

MLODINOWÂ I haven’t read the book from beginning to end so it’s hard to comment on that.

ROBERTS What about his previous book? There are similar ideas in the two books.

MLODINOW I didn’t really notice that book when I started writing Drunkard’s Walk; I wasn’t aware of the book. I had looked–in the library–gone through tons of books that seemed somehow related to randomness and somehow that one didn’t stand out to me. Sometime later it came out in paperback and it got very popular. Then I rediscovered it, and yes, I agree with a lot of what he says in that first book, but I still never read it from cover to cover. I’m not the type who feels compulsive about reading everything that’s been written on the subject that I’m writing on.

ROBERTS Yes. I always think of his book as being about these very long-tailed distributions–not only about that, but they play a large role–whereas you didn’t mention long-tailed distributions in your book.

MLODINOW Not explicitly, but I did talk about that idea and certainly the idea that not everything follows a normal distribution and how important it is to note that, for instance in Hollywood–Hollywood box office receipts. But I think The Black Swan was exclusively about that, so in that sense it was a different topic.

[For readers who don’t know what that is, if you’re talking about the probability of events occurring–let’s say you’re talking about the probability of a movie making a certain amount of money–there may be a mean amount of money that a movie makes or that a movie of that type makes. Then there will be fluctuations around it; some movies will make more, some movies will make less. The normal distribution is a distribution of the revenues that would follow a bell curve and the long-tailed distribution differs. One of the important respects that it differs in is that it has a lot more results that are far from the average that you would expect in a normal distribution. So if the average movie makes $1,000,000 or to be more realistic let’s say the average movie makes $50,000,000 and if it was normally distributed you would have, depending on the variance, but let’s just say you would have a certain number that make 40 or would make 60 and another small number would make 30 or 70 and you have a very small number indeed–probably practically zero–that would make $500,000,000. In Hollywood the way it really works is there are more that differ that far from the median than you would have if it were a normal distribution. That’s what they call a long-tailed distribution–the number of occurrences that are far from the average is much higher than you would expect with the normal distribution. — LM]

So that applies in many areas of life as well. I think that translated into what we were just talking about, it means that these little minor incidents can have major effects on you. It’s not all kind of pushed toward the mean effect, which is just going into my office and doing more physics.

ROBERTS Yes, I think that if you take the different things that have happened to you and you measured their effect, the effects will have a power-law distribution. A tiny number will have a huge effect and . . .

MLODINOW Yes.

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ROBERTS I see. The smaller the event, the bigger the outcome, the better the story. The more famous the person happens to be . . .

MLODINOW The idea that Bruce Willis decides to visit his girlfriend in Los Angeles leads to the Diehard series is interesting. It’s a more interesting idea than the fact that I’m on my way to the mailbox to mail a letter turning down a fellowship to Germany when I bump in–literally cross paths at the mailbox, when I was in school–with the lady from the fellowship office who’s appalled that I’m not taking this fellowship that is so hard to get and makes me go talk to my advisor about it. I literally had the envelope in hand turning it down and it was the last day for deciding. I go to my advisor whom I’m sure will agree with me that it’s a stupid thing to leave Berkeley and go to Germany for a year on this fellowship and he convinced me to do it. That completely changed my life. Had I not bumped into this lady, had I not had an extra sip or had I had two extra sips instead of one of my coffee, we would not have crossed paths, literally, at the mailbox. It’s a really bizarre thing and . . .

ROBERTS You mean your advisor convinced you to take the fellowship?

MLODINOW He convinced me to take the fellowship and go and I hadn’t even considered it, I just thought, ’Well here I am in graduate school, I have to get through and to go on something that could be just a lark in Germany . . .’ But I ended up meeting a woman I fell in love with, learning the language, loving Europe, staying there for years. Many, many things in my life changed; it was really a life changing experience and I think it broadened my horizons quite a bit also, living abroad. It just changes your whole view of the world. All that wouldn’t have happened if I hadn’t literally crossed paths on campus with this lady. To make the story weirder, I had heard about the fellowship a month earlier or six weeks earlier, I don’t remember, but just ignored it and by chance the night before had come across the letter and thought, ’Oh I shouldn’t be impolite, I should tell them whether I’m taking it or not; someone else might be waiting for this.’ That’s why I wrote the letter and was walking to the mailbox that next day. If anything, had I found the letter a day earlier and sent it out or not found the letter on my desk or not bumped into her or any of those things wouldn’t have happened, I would not have had these experiences.

ROBERTS I think different events have different potentials for change–you could say they have different life-changing potency. If you spend an hour doing the events with the big life-changing potencies you’re going to be in a lot better position than if you spend an hour doing the dead events, the events that are unlikely to change your life. I think your example plays into what I think because I think traveling is one of the events that has high life-changing potency.

MLODINOW Yes, that’s true.

ROBERTS And why that is, I think, is sort of interesting. You refer to something you call the Normal Accident Theory of life–what is that?

MLODINOW The Normal Accident Theory of accidents. The Theory of Normal Accidents is the theory that in a complex system you can’t prevent accidents; they will happen and you need to account for them, you need to plan for them and you should stop–well, I shouldn’t say stop–but you should give up the idea of zero tolerance and certainly try to minimize them. You also have to look at implications of when they occur because they will occur and in a very complex system there are always going to be events that on their own–or even in certain other combinations–are unremarkable and yet together in certain combinations can cause huge catastrophes.

One example is the story that I just told, meeting the lady at the mailbox. If you want to consider that–I don’t want to say that it was a catastrophe–but it was on a big event which is the life-changing event of going and the little things that caused it that are normally totally unremarkable such as straightening out my desk, which caused me to find the letter. Taking the letter to the mailbox on my way to work and a number of other things that were minor and on their own not noteworthy conspired to have me collide with this lady at that time and end up in Germany. The nuclear reactor on Three Mile Island or the space shuttle or Chernobyl, these are complex systems that are so complicated that little events can conspire to cause a big event which can be a big tragic event. After those big events–after 9/11, after Pearl Harbor–we go back and we find the little events that made the big event happen and we blame people for not having avoided them. The question in the Normal Accident Theory is whether that’s really wise because you can’t know ahead of time what those un-noteworthy events will mean what or will cause what. Finding the actual events and tracing the path of tragedy doesn’t really tell you a lot because there are a million possible paths which could have happened. You couldn’t have worried about all of them. And only one of them, which is really not distinguishable from the others, a priori, is the one that led to the catastrophe. It’s all about trying to understand that–that’s the Normal Accident Theory.

I think in life, as I just said, I think that a lot of unremarkable, un-noteworthy events happen to push you this way or that, give you different opportunities or cause things to happen in your life that have the potential to cause major changes in life. It’s as much that sort of thing than your actual planning and conniving on how to get ahead causes you to get where you are.

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MLODINOW How happy I would be in Kentucky or Georgia or Minnesota, maybe, though you don’t know. One thing I learned from Gilbert’s book is you don’t necessarily know really what would make you happy. My German girlfriend at the time was telling me that, too: “Right now you think you need to be in a big city, but you may find other things in life later, your family, that you focus on.” Certainly I’m here and I’m very focused on my kids but still what do we like to do? We like to into the Chinese parts of town and explore restaurants or the Mexican neighborhoods and look around or Vietnamese Town. We’ve got a lot of it here in Los Angeles and we like to go and find a new noodle shop.

ROBERTS Yes, I’m exactly like you. I love doing that sort of thing.

MLODINOW Yes, that’s why we’re friends.

ROBERTS I admire you; I’m glad that you’re willing to be friends with me. What were you doing at the World Trade Center on 9/11? Speaking of living in cities.

MLODINOW My kids went to school at the schools that were a block or two away from the World Trade Center and I would take the subway right at the World Trade Center back to Uptown, a few minutes Uptown to where I work, which was just on the border of the Village on Broadway and I happened to be standing under the building and saw the first plane come in, fly over me and fly into the building. It’s a long story what happened after that. I was hit with debris and injured. It’s a long story because my ex-wife was living two blocks below the Trade Center and just had surgery, my son was at the school there and I was trying to find them, get together, and I got caught in the collapse and trapped and it’s a long story, but that’s a book in itself.

ROBERTS It led to your leaving New York, right?

MLODINOW It did, because, in the end, without going into the details, my son–who was in kindergarten–saw the whole thing, saw people jumping off the building, had to actually flee for his life when the Trade Center collapsed and went for about five or six hours thinking that I was dead because the last place I was seen was standing under the World Trade Center building and we didn’t find each other until about 2:00 in the afternoon. That just caused psychological difficulties for him to live in the City as we were. I had shared custody with my ex-wife and I wanted to move into the suburbs and she didn’t want to do that and our compromise, since we continued to share custody, was to move back out here to California just to get him away from the City. And it was a great move because his problems diminished dramatically in just a week after we got here, or two weeks, I don’t remember, but just very shortly. Maybe it was a month.

ROBERTS How old was he?

MLODINOW I think 9/11 was his third day of kindergarten, something like that.

ROBERTS By then you’d already written Euclid’s Window?

MLODINOW I had written Euclid’s Window, so it wasn’t just, ’Oh, I’m going to go out and write, it’s pie in the sky,’ I had written Euclid’s Window and I think had written Feynman’s Rainbow but it wasn’t out yet, if I remember. The first book I wrote when I came here was the book with Hawking, A Briefer History of Time. I had stuff I knew I could do and it’s all worked out very well and I’m much happier so that shows you that if you are a high paid executive somewhere maybe you’ll have an even happier life if you would be not a high paid executive somewhere else and you just don’t realize it.

ROBERTS Well, it’s kind of amazing that this happened to you–this 9/11 thing happened to you–and in your book at the end, the last chapter is about the effects of random events on people’s life stories. But you don’t tell the story about yourself.

MLODINOW I had many stories I could have told about myself in the book, about how random events impact you, how things that you think are going to be good turn out later in hindsight not to have been so good or things that you think are going to be bad turn out in hindsight to have been good. How things that you think make a big effect on you have very little effect and how things that you hardly imagine would have an effect on you, like having an extra sip of a cup of coffee in the morning, can have a big effect on you, because, let’s say you’re three seconds past where the big crash was–the car crash on your way to work–or something like that, that you could have been hit if you hadn’t had that coffee, or whatever. I have many ironic situations I can pinpoint in my life that I could have told them about but what I decided instead to do–I don’t think I’m that interesting–was to find very famous people, Bruce Willis, Bill Gates and people everyone knows and a lot of people care about, and talk about how these events changed their lives. I thought that would be more interesting.. I tried to minimize the stories from my life although I picked a few dramatic events, I think maybe three or four that I do talk about–I’m not afraid to talk about it, it’s just that in many cases unless the event itself is very interesting. If it’s a mundane, small thing that happened that caused a big change in my life, I think it’s more interesting. If it’s a mundane, small thing that happened to Bruce Willis that caused a big change in his life, it made him a star, so that’s why I chose those examples.

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