As on other occasions, I cannot deny a certain degree of surprise at the winners of the Nobel Prize in Physics 2020. In this case, I believe that the Academy itself lets us glimpse some of that same surprise. You will agree with me that it arouses some astonishment to read that someone is awarded for "the discovery that the formation of black holes is a robust prediction of the general theory of relativity". Surely it must be a robust prediction when it merits half the prize, instead of the quarter that corresponds to his peers.  

The latter have been awarded for discovering that a "supermassive object" conditions us from the center of our galaxy. The quotation marks are important. The Academy has been careful to assert that the center of our galaxy is inhabited by a supermassive object, which all the compelling evidence we have points to as a black hole of the kind that Penrose studied in the mid-1960's. However, if we know anything about these objects, it is how little we know about them. The reason is subtle and leads us to the "robust predictions" found by R. Penrose. In these objects, from which not even light is able to escape, the laws of physics become singular and the way in which nature behaves beyond them is a mystery, and where the very equations from which they are derived could be meaningless.

There are many elements that give rise to my surprise. I have no objection to the degree of refinement achieved by astronomy in interpreting the data from the center of our galaxy, much less to Penrose's singularity theorem which has triggered a huge amount of work in the world of cosmology. However, both facts are still fraught with a significant degree of uncertainty and open questions. We certainly make a lot of progress in finding that the mathematics are robust solutions to Einstein's equations, and that these are compatible with our observations of the Cosmos. Nevertheless, it never ceases to amaze me that the Academy must resort to the term "robust prediction" to justify its award. At least in recent years, I do not remember this Swedish institution using such an expression.

In any case, this year's prize will almost certainly have a beneficial effect: many people will discover R. Penrose's popular works, some of which are written with masterly finesse. Those who engage with them will travel almost unknowingly into the subtle - and often puzzling - predictions of mathematical formalism. Let us hope this is the case, for they are worthwhile.