Quantum physics transports us into incredible universes where, through wormholes and quantum tunnelling, the line separating the possible from the impossible becomes porous. But nothing can radically be destroyed: nothing can ever become absolutely nothing. 

But physicists sometimes disappear without a trace, carried away by a craving for permanent wandering. 

This was the case of Ettore Majorana1, a brilliant theorist who evaporated one day in March 1938, at the age of thirty-one. Nobody knows what happened to him: suicide? flight to South America or a parallel universe? reclusion in a monastery? The young man orchestrated his disappearance so well that the mystery remains. It appears today as a quantum particle whose destiny superimposes a multitude of different trajectories. None of the possible hypotheses about his disappearance can be considered more substantiated than the others, the only thing that can be said today is that he disappeared on a certain date (which is known), that he died on another date (which is not known), and that between these two events the course of his life could have followed a thousand and one different scenarios, all equally plausible, all of which are impossible to distinguish (1).

A pale and frail man, Majorana lived for and by equations. In those days, the Macedonia that he smoked at a wipe speed rate were sold in 10 cigarette packs.  

Once empty, the young man used these small packages to write down an urgent idea or make a pressing (2) calculation, especially when travelling by tram:

Often a new idea came to mind, or the solution of a difficult problem, or the explanation of some experimental results that had previously seemed incomprehensible. He would then search his pockets, draw out a pencil and a pack of cigarettes on which he would scribble formulas. Once he got off the tramway, he went away, very absorbed, his head lowered, while a big strand of black hair fell on his eyes. As soon as he arrived at the Institute, he started looking for Fermi or Rasetti, and, with his pack of cigarettes in his hand, he explained his idea to them. * 

Majorana Let’s imagine now an individual, endowed with both superior intelligence and excellent memory, who would have stored in his mind all the equations and phrases written by Majorana on these cigarette packs, parallelepipedic and ephemeral material supports of his most abstract thoughts. It is no exaggeration to say that this unlikely individual would probably have more knowledge about the world of elementary particles than many encyclopaedias. But where could this now invisible past go? Is it nowhere, is it completely gone? (3) Or would he have retained the ability to project his evanescent reality into the present? 

Let’s take a closer and as penetrating as possible look at it. What do we see? When we focus on these cigarette packs, the mere fact of paying attention to them leads us to delve into their history, to move away from the surface of their present: we perceive then something that still seems to tie them to their distant provenance. Wasn’t Vladimir Nabokov right to evoke a “transparency of things, through which their past shines”? **

Moreover, if we consider them as relativity theory invites us to do so, we can see that they are not static things in space, but sequences of events in space-time; that they are not three-dimensional volumes, but four-dimensional hyper-volumes, which would have begun to take shape in the depths of the 1930s and would have never ceased since then to be translated in time, minute after minute.

In short, these cigarette packs have endured by repeating themselves in the same way, continuously, without ever missing themselves, without missing a moment of the moment. Fascinating perspective: the persistence of things that seem immobile to us hides in reality an invisible dynamic (4), incessant, that of the uninterrupted succession of moments that have carried their presence (5) since their first appearance. 

So, at the end of these cigarette packs deployed in space-time, what should we see after all? Ettore Majorana, the pleated forehead, writing a sublime formula, e. g. dedicated to the spin of hydrogen placed in a variable magnetic field (6)... 

Étienne Klein, Le philtre des macédonia, 2017

* Laura Fermi, Atomes en famille, mon existence avec Enrico Fermi, Paris, Gallimard, 1955, pp. 62-63.

** Vladimir Nabokov, La Transparence des choses, Fayard, Paris, 1979, p. 11.