David Bodanis is a futurist, business advisor and popular science writer, and when it comes to Einstein, he literally wrote the books – plural. His first was called E=mc2: A Biography of the World’s Most Famous Equation, which was translated into 26 languages and turned into a documentary and an award-winning ballet. Now Bodanis goes deeper into the genius’ world with the biography Einstein’s Greatest Mistake.

In the video above, Bodanis gives us a glimpse into Einstein’s mind and character. Einstein was one of the greatest scientists in history to date, but he was not above mistakes. His biggest one, according to Bodanis, was being burned by an experience in the 1920s and letting it affect the remainder of his career and work.

Einstein famously said that God does not play dice with the universe. He believed that the universe could not be chaotic and random – after all, he had composed an equation for general relativity so simple and concise that it was a thing of succinct, ordered beauty. That is until he looked at his formula and realized that, if it were true, it predicted that the universe was expanding. Einstein checked this with astronomers, but they said that no, the universe is definitely static – this was the dominant thought circa 1918. So Einstein ignored his prediction and had to add a symbol – a lambda – to his equation to account for the static nature of the universe.

About ten years later, in 1929, Edwin Hubble and other astronomers uncovered what was to most of the world’s experts a new twist: the universe was expanding. Einstein could have predicted this a decade earlier, and now faced the public embarrassment of retracting part of his equation. Einstein told a colleague that putting in the lambda was “the greatest blunder of my life.” But that’s where he was wrong; his mistake was not the retraction but, as Bodanis explains above, it was deciding that from that point forward he could ignore experiments that seemed to disprove what he was convinced was right.

David Bodanis’ most recent book is Einstein’s Greatest Mistake.

David Bodanis:  What Einstein did in 1905 his first theory of relativity that would be enough for most people. But he had another idea, a more powerful idea which came together in 1915 when he was in his mid-30s the middle of World War I and it's called General Relativity. And it's a magnificent idea, if he hadn't come up with it I doubt if anybody else would have in the more than century since then. And it's a notion of explaining how all of space and time and all of matter and everything is organized and what's amazing is instead of being a long complicated thing he got it down to two little symbols and this was extraordinary. He thought who had created a universe where all the complexity we see, the spinning of the earth around the sun, how the galaxy moves, if it moves at all, that all this could be explained in terms of two simple symbols. And he thought this was fabulous and then he looked at his symbols and he realized they predicted that the universe was expanding. He asked his astronomer friends in 1917/1918 is the universe in fact expanding? And they said no its static. They thought at that time the universe was just the Milky Way Galaxy a whole bunch of stars floating there in space and beyond there there was just an empty void. It was sort of like Donald Trump's brain there was just angry magnetic fields full of nothing.

And Einstein thought are you sure? And they said well that's kind of what the universe is like. So he had to change that beautiful simple equation and had to put in an extra term, which is symbolized by the lambda. And instead of thinking God or the old one or whatever force there is behind the universe had made something very simple for us to discover, there's this ugly equation, this additional term that sort of canceled the expansion. Anyways, about ten years later in 1929 Edwin Hubble in California and other people said oy were we wrong. They probably didn't say the word oy, were we wrong they said. The universe is expanding after all. And Einstein thought the good news is I get to take away the lambda, that extra term. I can go back to that beautiful simple clear thing I discovered back in 1915 in general relativity. And that's okay. That's an allowable mistake. I don't think that's his greatest mistake. The great mistake came after that.

He drew a psychological conclusion. He concluded that he was wrong to have listened to experimental evidence because he believed that the universe and should be crisp and clear an exact, from now on if he had those beliefs and experimental evidence came up that contradicted it he could ignore it. Remember, he would have been right, he would have been right to ignore all the evidence that the astronomers thought about the shape of the universe. They were wrong for ten years. Well, it turns out in the late 1920s when Einstein had this breakthrough or this idea that's when quantum mechanics was coming in, this idea of the ultra small, electrons, things like that. And they seemed to move around not in the clear beautiful ways that Einstein wanted but there was randomness and chance and probability and Einstein thought okay that's the limits of our technical abilities, our observations only see this fuzziness but if we have better tools we'll be able to see things more exactly.

Einstein thought that things like uncertainty were just a temporary stage in mankind's development, but the physicist said no the evidence is really clear. And Einstein said I was burnt once before with that lambda and the expansion of the universe, I'm not going to be burned again. So he dug in, he doubled up and as time went on the evidence for quantum mechanics, for this randomness and probability on the ultra small that evidence became stronger and stronger, but Einstein was stuck. He couldn't let it go. He just thought if I had held at my confidence for ten years before I would have been okay. Well, maybe it might be 20 years, maybe it might be beyond my lifetime but I'm sure Einstein thought I'm sure that the universe can't be disordered. That's why he said, "God does not play dice with the universe," and his good friend Niels Bohr said, " Einstein, stop telling God what to do."