Helgoland

by Carlo Rovelli

Perhaps rather than explaining how to understand quantum mechanics, I explain why it is so difficult to understand.

Nothing is like the emotion of seeing a mathematical law behind the disorder of appearances.

Except for Born, who is in his forties, Heisenberg, Jordan, Dirac and Pauli are all twentysomethings. In Göttingen they call their physics Knabenphysik, or ‘boys’ physics’.

Today we live with tens of thousands of nuclear warheads aimed at our cities. If anyone were to lose their head, or make a mistake, there is ample capacity to destroy life on our planet. The devastating power of the ‘boys’ physics’ is evident for all to see.

Once again, we are back with what can be ‘observed’. And once again, this raises the question: what does Nature know or care about whether we are observing it or not?

Does this mean that the quantum mechanics of Heisenberg and Schrödinger fails to take all the relevant givens of the problem into account? Is this why we have probability? Or is it that Nature actually leaps about here and there by chance? Einstein put the question colourfully: Does God play dice?

Hence: ‘Does God play dice?’ means literally: ‘Are the laws of Nature really not deterministic?’ As we shall see, a hundred years after Heisenberg and Schrödinger’s bickering, this question is still open.

The only one to be overlooked is Pascual Jordan, despite the fact that Einstein had (correctly) nominated Heisenberg, Born and Jordan as the true originators of the theory. But Jordan had shown too much loyalty to Nazi Germany, and those defeated in war do not receive recognition.

Cubism and quantum theory both moved away from the idea that the world is representable in a figurative manner. In the first decades of the twentieth century, it is the whole of European culture that no longer thinks we can represent the world in a simple and complete way.

Everyone has the right to seek to cure themselves as they see fit. But no one has the right to cheat their fellow citizens with the kind of quackery that can cost lives.

It is true that we have the ‘intuition’ of an independent entity that is the ‘I’. But we also once had the ‘intuition’ that behind a storm there was Jove … And that the Earth was flat.

The interconnectedness of things, the reflection of one in another, shines with a clear light that the coldness of eighteenth-century mechanics could not capture. Even if it leaves us astonished. Even if it leaves us with a profound sense of mystery.