Scientific advancement is more than a series of experiments: it is often a debate among scientists with fundamentally different points of view. Niels Bohr knew this firsthand thanks to Einstein. As science journalist George Musser explains, while Bohr may have tired of Einstein’s indefatigable questioning of quantum physics, the two maintained a healthy and competitive relationship throughout their careers. When Bohr came to work at Stanford University alongside Einstein, an intellectual debate began that shaped the future of modern physics.

George Musser: What is the purpose of science? It is to create a view of reality. It is to create a stable view of reality to understand why things happen in the world. A view that kind of transcends the everyday vagaries of life. The sun will rise. The rain will fall. I mean the ball will travel in an arc. At least in physics these are the things that occur despite all the other noise and joy and vagaries of living in the world and the experience that we have. There’s some rock solid kind of root to what’s going on in the world. And we expect physicists to find that.

So we usually think of the theoretical scientist, the theoretician sitting, working, pen and paper, blackboard – today a computer, mathematic or math lab and they produce equations and they change the world by the power of their individual thought. But science is a deeply collaborative enterprise and I’ve always been struck when I see physicists in action how much they are teaching one another. They’re at blackboards explaining an idea to a colleague. Then I see them at another blackboard an hour later explaining the very same idea to a different colleague in different ways. Then they give a presentation. Then they write a draft of a paper. This is a social enterprise. And they kind of go back and forth between the individual sitting, struggling against the brick wall, banging their head against it trying to make sense of the reality and the collaborative social side of things.

So one thing that’s crucial to that is that all scientists have to gather around them some kind of friend group. So science probably more than a lot of jobs really depends on strong personal friendships among people. And one reason for it is A, it just makes things a lot more fun that you work with people that you admire and who admire you. But also just at a practical mechanistic level these are the first line of people that you can try ideas out on. And they won’t say “God, that’s the dumbest idea I’ve ever heard!” They’re going to say “Oh, I’m not so sure about that idea. They’re more sympathetic to you. You feel easier broaching ill formed or dumb or just incomplete ideas with them before it kind of propagates into what could be a very vicious marketplace of ideas, a very unforgiving one that is beyond those immediate circle of people. Sometimes this idea isn’t located in either person’s head but it’s kind of floating in the space between them. And each person is kind of contributing to it. The idea is growing and growing and growing.

Einstein for one loved it. He reveled in this kind of intellectual play. So he had a series of very things he encounters with Niels Bohr at a series of meetings in the 20s and really in the 20s. In the 30s things kind of all fell apart for Europe in general and certainly for the German science community. So in the 20s and the teens he went to these conferences and would encounter these other scientists who just didn’t accept what he was saying. And they would go off and usually off the record - and these had to be reconstructed by historians - had these intense debates over breakfast, over wine, over just walking down the street. Einstein would engage in these kinds of intellectual games really with Niels Bohr and the other scientists. And there were some famous episodes where Einstein for instance tried to question the Heisenberg Uncertainty Principle. And he would come up with “Aha! Here’s a way to get around the Heisenberg Uncertainty Principle.” And Niels Bohr would stay up all night and come back the next day and say “Well nope, that won’t work.” “Ah, here’s another one!” said Einstein. And Niels Bohr would go back and figure out a way it didn’t work. And it would go back and forth.

And what’s funny about this in a way is that Einstein really never really doubted the Uncertainty Principle. He accepted it. He accepted it kind of at least maybe not from the very beginning but once the mathematics was worked out he accepted it. And yet he kind of poked and prodded at it because he thought such a strange feature of reality that it’s uncertain, it’s indeterministic should have some deeper meaning. And he tried to poke that principle and explore it from different sides to ascertain the meaning. So you need that kind of competitive idea building and I wouldn’t necessarily call it adversarial because Niels Bohr and Einstein considered themselves as close friends. When Bohr came to Princeton, Einstein gave Niels Bohr his office and said “Here, you work in my office. I’ll go sit in the assistant’s office. I’ll sit where the secretary sits.” I mean they were really close and Bohr reciprocated that. Bohr thought very highly of Einstein. He considered him a friend as frustrated as Bohr sometimes could get with Einstein’s ceaseless questioning. He loved it.

So physicists like every scientist is engaged in intense dialogue and interaction with their peers, with their colleagues and people further afield. That does not however mean they convince each other. Sometimes they don’t or sometimes they stake out positions and hold to those positions. And there’s actually a very interesting study done by a sociologist. I think it was in the early 70s of scientists involved in the Apollo program, the moon shots. And they actually did a lot of interviews and surveys of the different scientists who were studying the moon rocks and the geology of the moon. And one thing they found is that the most creative scientists were the most stubborn. They were the ones who were least likely to change their opinion and reaction to other people. You don’t want people just like caving in right away. People should stand their ground and let the idea sink or swim rather than fail to give it the due that it needs. It’s just amazing the kind of intellectual play that physicists engage in and that is essential to the progress that they make.