Steve Mirsky: Welcome to Scientific American’s, Science Talk, posted on September 2, 2015. I'm Steve Mirsky. On this episode—

Lawrence Krauss: Einstein always approached deep problems. And therefore, when he made mistakes, they usually were about problems that were at the heart of physics.

Mirsky: That's Lawrence Krauss, he's the Director of the Origins Project at Arizona State University, where he's also a physicist and cosmologist. He's the author of nine books so far, the most recent being A Universe From Nothing: Why There is Something Rather Than Nothing. And, he's a contributor to Scientific American's September issue, devoted to the 100th anniversary of Einstein's publication of general relativity.Krauss's article is called "What Einstein Got Wrong". I called him at his office to talk about the errors of Albert. First, I wanna read your lead for the article because I really like it. "Like all people, Albert Einstein made mistakes, and like many physicists, he sometimes published them."

[Laughter]

That sounds like something that you can relate to?

Krauss: Yeah, I mean we all make mistakes. Hopefully we – if we know about the mistake, we don't publish it. Some people, I figure, may do that. But we all have that experience of – well, there are mistakes and there are mistakes and that's what I talk about in the article.

Mirsky: That's the great thing about the piece is when you discuss Einstein's mistakes, these are fertile mistakes of a mind – you know what I was thinking of, there's the famous biography of Newton called Never At Rest.

Krauss: Yes, I know that biography.

Mirsky: Right. And, I was thinking of Einstein with – these mistakes indicate a mind that's always working, it's always thinking about these issues that he found so compelling.

Krauss: Absolutely, and I think – what was surprising was how much he second guessed himself, I guess that surprised me when I was doing the research, thinking about the article. There are a variety of mistakes there – they're mistakes of not quite appreciating the nature of the universe and understanding that he'd actually made contact with it. And – but there are other mistakes where he really actually did do mathematical errors as well and I think there are both kinds. What's interesting is that they were both very significant. He was constantly trying to assess what he did and I guess what happened is that the kind of youthful confidence that he exuded when he published his first wonderful papers, with the wisdom of age or maybe the hesitation of age, he began to second guess himself a lot more and I think that was a surprise.

                           The fact – in one case, in the case of gravitational waves that he was saved by a referee – was one of the most amusing parts of the article for me to write and understand. That he was – I had no idea that in that time, journal articles weren't refereed as they are today. And the fact that he took such umbrage at the notion that physical review would somehow send one of his papers for someone else to look at before it was published was remarkable to me. But, he was quite lucky they did.

Mirsky: Yeah, you talk at length in the article about that particular case and how the reviewer actually figured out some things that Einstein had missed. And the reviewer then gets in touch with Einstein via Einstein's colleague and they actually fixed things.

Krauss:              [Laughs]. And Einstein claimed to have discovered the error independently and was guided either internally or by his correspondence with the referee, who was a very famous cosmologist, as it turned out, to fix it. But if it hadn't been for that – I mean, there are a number of cases where it's kind of interesting that he was saved in the nick of time. Something I also mention peripherally in the article, which wasn't really a mistake, was when he discovered the phenomena of gravitational lensing, which as I talk about, was an example of not an arithmetic mistake, because everything was fine, he just assumed it wasn't important and it turned out to be very important. That's the kind of mistakes most of us would like to have. I mean, most of us have the opposite experience with mistakes. Something we think is important and it turns out not to be.

[Laughter]

Mirsky: Right.

Krauss: And in his case, it was something it turned out – he thought was unimportant and it turned out to be very important. So that's the kind of mistakes that many of us don't mind having, where we do something, the work is correct and then we find out nature makes better use of it than we thought. And there have been articles like that for me, where I've published something I didn't think would be significant and then it turned out to be more significant. And it goes both ways, so those kind of mistakes happen. Those that we don't mind.

                           The ones where we actually make an arithmatic error or misunderstand something we're doing, is something that happens with all of us. It happened with Einstein, but interestingly, he was saved in the nick of time in the case of gravitational lensing not by having made a mistake, but rather the fact that the first time he calculated the amount by which light rays would bend around an object like the sun. He did that in 1912 when he had an earlier incorrect theory of general relativity – an earlier, one of his precursor theories. Had it not been for World War I, where several people were going to check his predictions by going out and looking at a solar eclipse – but had it not been for World War I, where they were delayed and then in that time he came up with the correct theory. And by the time the war was over, they were able to compare it with the right prediction, he would have made an incorrect prediction and perhaps people would have been less likely to have accepted general relativity in the first place.

Mirsky: Yeah, I found that fascinating, because the 1919 Eddington expedition where they take the measurements that confirm relativity, that's really pretty well known. But I didn't know about the fact that if this expedition had been able to go out in 1914, Einstein's earlier predictions wouldn't have looked so good and he wouldn't have looked so good.

Krauss: Yeah it was—he was—it would—greatness is a combination of talent and luck and he had both. [Laughs].

Mirsky: Well he certainly had the luck to be in the environment that he grew up in and the colleagues that he was surrounded with. I mean, that kind of environment has to play a role in the development of this thinking.

Krauss: Oh, absolutely, I mean—I think I wrote in the article, I can't remember if I did or not—but people have this illusion that science is done in this—by single individuals alone in the middle of the night in some kind of vacuum. But Einstein was in touch with what was going on and depended as much on, in some sense, on the results of others earlier. Standing on the shoulders of giants if you wish, and experimental results at the time. And he wasn't working in vacuum and that's important. And in fact, if you look at Einstein, the progress of his life as a physicist was one of, in some sense, slowly becoming more out of touch with what was going on and then his contributions became less and less significant.

                           The fact that, as I mention in the article, that he stubbornly in some sense, refused to accept quantum mechanics, kept him out the mainstream. And his stubborn insistence on looking for a unified field theory of electricity and magnetism and gravity at a time when other forces of nature had already been discovered meant that he was—his work was growing more and more out of touch. And that's why the latter part of his life is—none of those results are significant. And it's really important that the early work that he was vitally in touch with what was going on both experimentally and theoretically.

Mirsky: It almost seems like—you said he was stubborn I think. He really wanted the universe to behave in certain ways and when it didn't, it seemed like it really ticked him off.

Krauss: [Laughs].Yeah. I think at some point he—but, at the same time, the big difference of what happened with quantum mechanics and earlier, is he, like all of us, we kind of hope the universe behaves the way we think is beautiful. But he, like the rest of us when he discovered the universe didn't behave that way, to his credit, he was able to change his mind. And that's what makes a good scientist. Later on, he didn't and with quantum mechanics he was too stubborn and that's the difference. I guess he'd come to—he'd had so many successes that maybe he had such faith in his intuition that even when his intuition was wrong, he refused to give that up. That's an unfortunate thing that happens and maybe it kind of, not too surprising when you have the success that Einstein had in his intuition. But all of us hope that when we – when our intuition is wrong, we're able to change our minds. That's the difference between a scientist and a theologian.

Mirsky: [Laughs].Right. In the article you talk about areas that—major areas that wound up being built on ideas that he misjudged. And there's gravitational lensing, gravitational waves, the expansion of the universe and then the quantum mechanics situation. And the article is very readable so we don't need to get into every detail of it. But, I found it very interesting that in terms of gravitational lensing as you alluded to already, that he clearly had no trouble accepting or just acknowledging the fact that light was gonna bend around a star, but it never occurred to him that a forest is made out of trees, a galaxy is made out of stars.

Krauss: [Laughs]. Yeah, Einstein –

Mirsky: He couldn't see the galaxy for the stars.

Krauss: For the trees—yeah, exactly. In fact—well, you know, it's not—once again, it's not that surprising. External galaxies—this was in the 1930s. The existence of external galaxies other than our own had only been recognized a decade earlier by astronomers. Basically, Edwin Hubble was the first to really distinguish that there were other galaxies than our own in 1925. And so, Einstein wasn't a professional astronomer and, yeah, I think it's really remarkable that—for me, equally remarkable was not only that he missed the galaxy for the stars, but that so quickly, Fritz Zwicky, who was a remarkable astronomer, jumped on it and actually wrote an amazing paper that presaged 50 years of subsequent research by pointing out that Einstein had missed the boat a little. I mean, Zwicky loved pointing out other—that other people missed the boat, he wasn't a very pleasant fellow.

Mirsky: [Laughs].

Krauss: But Zwicky's paper was remarkable. And, but for me, the most amusing part was it—I mean, we don't know if Einstein was being honest, that he would have published the result anyway. But, the fact that he was induced to publish his result that later laid the groundwork for one of the more important areas of modern astronomical research, gravitational lensing, because someone said, you know, I'd like you to publish this result [laughs].I mean, if that's really true, it's kind of remarkable.

Mirsky: Yeah, you have the note from Einstein to the editor of the journal where he says, "this research here, it's of little value but it'll make the poor guy happy, so let's publish it." That's really amazing.

Krauss: Yeah, exactly. It's—I love that. It's one of my favourite lines, "yeah, but it makes the poor guy happy." So that's how great science is done.

Mirsky: Now, let's just talk for a moment about the expanding universe issue and it's really famous that Einstein said it was his biggest blunder. But you point out that – and what we're talking about is the cosmological constant to keep the universe static rather than expanding, because he wanted it that way, apparently.

Krauss: It wasn't him, I mean you've gotta remember he was living in a time when it was conventional wisdom that the universe was static and eternal. I mean, that was what – he was just living in that time. So it wasn't so much a personal incarnation as the fact that he was a product of his time.  

Mirsky: Mm-hmm.

Krauss: And, it was – it's unfortunate – you know, given how bold he was with special relativity and general relativity and quantum – and the origins of quantum mechanics. Given how bold he was to make bold predictions that flew in the face of common sense, it's unfortunate that he didn't realize his theory required the universe to expand or contract. Because, wouldn't it have been amazing if he could have predicted the result that Hubble later discovered in 1929, that the universe is expanding. As someone once said, and I don't think it was me – maybe I said it, but I think I heard it from someone else—it's a pity he didn't make that prediction, 'cause he could have been famous.

 [Laughter]

Mirsky: Oh, that's pretty good. So, the fact that he invoked this constant to keep the universe static, you point out in the article that it's—he kinda misses the boat there in two ways. Because, first of all that's not right, but he could have seen – well, you kind of just said this, but he could have seen that his own theory predicted more than he even gave it credit for.

Krauss: Yeah, absolutely. And again, as I—I can't remember if I wrote this, but it's easy for people to underestimate what their work can do. Because, it's really amazing when you're sitting there to think that nature actually [laughs]obeys something you're talking about. It's very intimidating. It's – some people might say it's pretentious too but it's intimidating, and so the fact that he somehow felt that that he had to modify his theory rather than the fact that nature had to obey him, demonstrates some humbleness on his part.

Mirsky: And, as we've said a number of times already, his mistakes are really good. They led other people in really interesting directions and sometimes they led him in interesting directions. They're fruitful errors and that's the difference between—I forget, there's a wonderful quote about, "a great man's errors are more valuable than a lesser man's successes" or—

Krauss: [Laughs]well—

Mirsky: The quote is much better than that but it's along those lines.

Krauss: [Laughs].For Einstein, as I say, his errors were significant and I mean, he was—you sort of said it, you hit the nail on the head at the beginning. Einstein always approached deep problems. For the most part. I mean, it's not 100% true, but he was focused on what were really, really deep problems. Not small little tidbits and therefore, when he made mistakes they were about—they usually were about problems that were at the heart of physics.

                           And so, it's not surprising the impact of it. And as I say, I think that's why he didn't publish the gravitational lensing paper till someone induced him to because he didn't think it was a deep enough problem. And it's – he really only wanted to work—many of us try and work on deep problems—what satisfied with getting result which is useful. Einstein was really focused on not just useful results but ones that really hit at the heart of nature.

Mirsky: This article's about what he got wrong. Let's remind everybody, [laughs]he got a lot right.

Krauss: Well, I mean he obviously was—if any of the one things he'd done had been all he'd done, he still would have been a great scientist and one of the greatest scientists of the 20th century. But the fact that in a few months when he was just a young man, he developed special relativity which changed our notions of space and time. He gave the first, really, calculation that demonstrated the existence of atoms. He laid the basis of quantum mechanics, all in three months. That was amazing, and all – had he just done that he would have been one of the greatest scientists of the 20th century.

                           But then producing for the first time since Newton a new theory of gravity is what vaulted him to be one of the greatest scientists of all time. I felt privileged and—to be able to follow it up a little bit and it was fun for me to learn some of the things I wrote about. And it's an amazing story, and the fact that he has amazing mistakes makes it even a more amazing story, so it was fun to contribute in that way.

Mirsky: There are – I'm sure you get letters from the same people that Scientific American gets notes from. There are a lot of people who spend a lot of their spare time coming up with—I was gonna say crackpot—

Krauss: Yeah, well, that's—they do.

Mirsky: Yeah.

Krauss: And you know what, they—and I often tell people that, you know—when I get these letters they say, they thought Einstein was crazy. And they think I'm crazy, therefore I must be Einstein. And the point is, no one really thought Einstein was crazy. More importantly, Einstein never threw out what went before him in order to do what he did. He built on the results of people before him.

                           I talk about it at great length in some of my books. And that's a really important distinction. These people say, "everything we know is wrong and I have this new theory." That's not how Einstein worked. General relativity built on what was done before him. Special relativity did, as did quantum mechanics and so Einstein's greatness in some sense was to bring together theories that didn't appear to be consistent with each other, until they were consistent. Unfortunately, I don't have time today to elaborate on that but actually, in my new book I will. You can wait for that.

Mirsky: [Laughs].When does that come out?

Krauss: Oh, I think it'll come out a year from now. I'm just trying to finish it now.

Mirsky: Okay. So, everybody remember—

Krauss: Which I'm—yeah, everyone remember.

Mirsky:               —Lawrence Krauss has a book coming out in a year—
Krauss: Yeah, and in fact, if you don't mind, I'm gonna have to go back and try and work on it now. It's been great talking.

Mirsky: No, that's fine. It's been great talking to you and when the book is ready, we'll talk again.

Krauss: Okay, that'll be great. I look forward to that.

Mirsky: The quote I could not remember was from Nietzsche and it translates to, in English, "great men's errors are to be venerated as more fruitful than little men's truths." Of course, today this thought is extended to great and little women as well. In 2009, Lawrence Krauss chaired a panel with cosmologists Alan Guth from MIT, John Carlstrom from the University of Chicago, and Fermilab's Scott Dodelson to talk about the state of their field at the annual meeting of the American Association for the Advancement of Science. I was there and put the conversation up as a two-part podcast. You can find it by Googling "Stars of Cosmology".

                           That's it for this episode. Get your science news at our Web site, www.scientificamerican.com. You can also check out the entire September issue devoted to Einstein and the 100th anniversary of general relativity. And follow us on Twitter where you'll get a tweet whenever a new item hits the Web site. Our Twitter name is @sciam. For Scientific American Science Talk, I'm Steve Mirsky. Thanks for clicking on us.

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