robert oppenheimer He was a great admirer and friend of Neils Bohr. In Christopher Nolan’s latest film We see how, when he was still a student, he attended one of Bohr’s lectures, asking him, according to the Danish physicist, the only interesting question in the audience. Later, Oppenheimer would tell him everything that happened in the manhattan project. Her trust in him was such that she attracted the attention of Leslie Groves, who in the film questions why he is such an important scientist. To that, Oppenheimer confesses that he had been the only physicist capable of prove Einstein wrong. And it is true, because that conversation between the physicist and the military man may never have existed, but it is true that there was an intense debate between Einstein and Bohr in which the second proved to the first that he was wrong.
At that time, for many Einstein was the most important physicist in the world. Therefore, that Bohr managed to catch him in a resignation, was something of the most shocking. But in reality it was not a simple moment of weakness. During the Solvay Congress of 1927Einstein and Bohr started a debate that is still valid today.
With him practically two teams of physicists and philosophers. On the one hand, there were those known as realists, who were positioned in favor of Einstein. Among them there are names as important as Erwin Schrödinger, Louis de Broglie or Hugh Everett. And, on the other hand, the anti-realists. These were in favor of Bohr’s theories and included physicists such as Wolfgang Pauli, Max Born or Werner Heisenberg. It should be noted that there was no clear winner. That both theories, each in their own way, had their share of truth, and that Einstein and Bohr were colleagues who respected each other throughout their lives. This was a simple professional dispute, like so many others, but led by two of the greatest minds of all time.
Realism vs anti-realism, a battle prior to the history of oppenheimer
Although the concept of realism and anti-realism in the history of science is much older, it reached its peak when quantum physics began to be discussed.
On the one hand, and in very broad terms, Einstein considered that the parameters associated with quantum physics could be measured straight through math, taking concrete values. Instead, Bohr, along with Born and Heisenberg, postulated something known as Copenhagen interpretationwhere he spoke rather of odds. That is, no definite values can be attributed to properties of the quantum system, such as the position or velocity of the electron, until they have been observed. This means that, in the absence of an observer, there is a complementarity, in which they can have two values at the same time. At most, the probability of obtaining one value or another could be calculated.
It was in a debate on this last aspect that Einstein uttered his famous phrase “God does not play dice”. This, in fact, also appears in oppenheimerin a conversation between the director of the Manhattan Project and Lewis Strauss.
Many misinterpretations have been given to this phrase. Some suggest that Einstein was a fervent believer in God and that he opposed Darwin’s evolutionary theories. But he is nothing further from the truth. He simply wanted to argue that quantum physics cannot be based on probabilities.
When Schrödinger took the wrong side between Einstein and Bohr
Schrödinger developed his famous cat in the box thought experiment to try to show the inconsistency of complementarity and the uncertainty principle enunciated by Heisenberg.
In this experiment, an opaque box is described in which there is a cat and a vial of poison. He has a hammer on him, associated with an electron detector. It all starts when the box is bombarded with electrons. If they hit the detector, it activates the hammer, which breaks the vial, releasing the poison and killing the cat. Instead, if the electron takes another path, the cat remains alive.
Basically, quantum physics would be taking to the macroscopic world so that it is better understood. If physics worked as described by Heisenberg and Bohr, until the box is opened, the cat would be alive and dead at the same time. This is so because you cannot know what the electron is doing until you observe it.
It is apparently ridiculous. However, over time it has been possible to reproduce this experiment under quantum conditions. The calculations did not fail, so Schrödinger had no choice but to admit that, perhaps, Bohr and Heisenberg were right.
Battle of puzzles between Einstein and Bohr
both in the Solvay Congress of 1927as in the later, celebrated in 1930, Einstein dedicated himself to attending meetings outside of conferences, held in restaurants and cafeterias, with problems that were intended to demonstrate that quantum parameters can be calculated accurately, using mathematics. However, Bohr always found some loophole that confirmed his interpretation of quantum physics. He normally didn’t do it at the time, but if he read the problem in the food, had the answer for dinner time.
There was only one in which it took a little more than a day. However, when Einstein already felt victorious, Bohr showed that, in reality, the German’s problem did not hold because he had not taken into account his own theory of relativity.
So yes, Bohr pointed out on several occasions that Einstein was wrong. But he never stopped admiring him. Like Einstein, despite the stubbornness in contradicting him, he never stopped feeling respect and admiration for Bohr. Since this is a subject that has been put on the table again in a film about the war, it is inevitable to think that, hopefully, the discrepancies that lead to the wars were solved as Einstein and Bohr did. Having seen the film, surely Oppenheimer would have preferred it too.