Enrico Fermi. The obedient genius. Translated from the Italian by Ugo Bruzzo
The most puzzling feature of this -- otherwise admirable -- book is its subtitle: ``The obedient genius.'' Why on earth the ``genius'' of Enrico Fermi should be dubbed as ``obedient'' is a bit of a mystery because the author never again seems to use this word in this sense in the subsequent chapters, but for a few lines in the \textit{Epilogue}: ``My story with Enrico Fermi started three years ago [in fact three years before 2007, the date of the first Italian edition], and that with the physics of his time, 25 years ago. Now I think to know many aspects of his person, perhaps difficult to document, but very clear in my perception: his style, the different nuances of his scientific `prudence' the young researcher's \textit{obedience} [reviewer's emphasis] to the academic rules, and the wisdom of the great master.'' The words ``obedient, obedience'' are nowhere else to be found with the same meaning along the more than 300 pages of this study, while from the previous quotation they seem to point to some sort of ``prudence'' and even ``obedience to academic rules,'' so that the reader could almost expect the utterance of the profane epithet ``conformist,'' if it were not to be related to such an outstanding scientific personality as Enrico Fermi was. Could all that possibly make reference to the well known fact that in 1934 (as it is duly recalled in the Sections 4.7 and 5.3) Fermi and his coworkers discovered the neutron-induced artificial radioactivity, but failed to see the fission reactions later recognized (1938--9) by Hahn, Strassmann, Meitner and Frisch? Should this blunder be attributed to some sort of lack of non-conformist imagination? Did they not dare to think new enough, despite Ida Noddack's hints? This mesmerizing point is discussed in some detail in the Section 5.3 without however reaching -- naturally enough -- a definitive conclusion, but without explicitly articulating the word ``obedient'' either (was this finally a suitable lexical choice?): ``One thing that can be safely said is that Fermi and his group were unable to get rid of the basic principle that at the time regulated the investigations in radiochemistry, namely, the axiom that all radioactive transformations, including the artificial ones, created elements that in the periodic table were close to the original element.'' May that be the suggested \textit{obedience}? But here suddenly, in the same paragraph of the said \textit{Epilogue}, Bruzzaniti changes course and hints that ``According to a received view, the philosophical label to be attached to Fermi is pragmatism. But I always had a feeling, reading about his 'pragmatic attitude,' that this is a polite way of saying that he had no philosophy at all.'' Here too we are then left figuring out whether his \textit{obedient} could finally mean \textit{pragmatic} in a sense strongly resembling to \textit{non-philosophical} or even \textit{anti-ideological}. It is true that -- at variance with other founding fathers, as for instance Bohr and Heisenberg -- Fermi never indulged in the philosophical speculations so characteristic of the debate about quantum mechanics from its beginning until today. This could also have been passed to his school in Italy where scientists asking too irksome questions about quantum mechanical paradoxes have often been kept at arms length by the academic establishment. And even if the author concedes to be ``sure that Fermi had a philosophy,'' he also underlines that all its innovative charge was ``the importance it assigned to the quantitative aspects of knowledge,'' as it is for instance witnessed by a subsequent quotation (quite prophetic indeed, being articulated in 1923) stressing the practical relevance of ``the relationship that ties the mass of a body to its energy'' which however received much less attention of ``the relationships between space and time'' because the former looks ``less sensational and, let us say, even less paradoxical.'' Whether or not these hints (about conformism and/or anti-ideologism) scattered in the \textit{Epilogue} may constitute the real meaning of the word ``obedient'' -- displayed in such a prominent position as a subtitle is -- it is not quite clear, and certainly a more detailed elaboration would have been welcome. It is consequently even more striking that Bruzzaniti -- instead of the usual departure for the US in 1938 -- rightly takes as the watershed of his narrative (separating the two main parts of his book) the scientific result that Fermi himself considered ``his masterpiece, that will be remembered by posterity'' (p. 146): the 1933 theory of the \(\beta\) decay that is in fact a remarkable example of scientific non-conformism. In this paper (which was non-conformistic enough to be rejected by \textit{Nature} with the infamous motivation that it ``contained abstract conjectures that are too far from physical reality to be of some interest to the reader'' p. 14) Fermi finally abandons the idea that neutrons consist of a proton plus an electron, and consequently he jettisons the then accepted ``principle of pre-existence of the emitted particles'' (p. 152) postulated to justify the emission of protons and electrons in the \(\beta\) decay: a big conceptual step forward with a few ideological overtones, since it proposes a model where a particle (neutron) \textit{decays} into three other different particles (proton, electron and neutrino) which did not exist before. It is then a pity in this context that Bruzzaniti did not update his book with the outcomes of historical researches that, while not available for the first Italian edition (2007), were already published at the time of the present English translation (2016): in a paper published in 2009 [``Enrico Fermi's discovery of neutron-induced artificial radioactivity: the influence of his theory of beta decay'', Phys. Perspect. 11, 379--404 (2009; \url{doi:10.1007/s00016-008-0415-1})], and based on newly recovered archival evidence, \textit{F. Guerra} and \textit{N. Robotti} stress indeed the influence that Fermi's theory of the \(\beta\) decay (December 1933) had also on his experimental discovery of the neutron-induced artificial radioactivity just four months later (March 1934): the very result that earned him the Nobel Prize. In particular, they discuss how Fermi was influenced by his own theory in planning his neutron-bombardment experiments, in his decision to use a radon-beryllium (Rn-Be) neutron source, and in his choice of the elements he bombarded with Rn-Be neutrons. The paper of Decembre 1933 must then be considered as a real game changer, rightly deserving the role of turning point assigned in the book. Around this 1933 divide the book is organized in five chapters and several appendices: apart from the first chapter with a biographical outline, the following four chapters are divided into two blocks, before and after 1933. In every block there is a first couple of chapters briefly summarizing the evolution of the 20\(^{th}\) century physics from 1900 to 1954 (with the help of documents and short digressions collected in the Appendices \(B\) and \(C\)) by making use of what is here called \textit{global maps}, namely ``those networks of connections among the various elements of a certain discipline which the scientific community regards as well established'' (\textit{Preface}). The subsequent pair of chapters describes instead in some detail the evolution of Fermi's own ideas and results along the so-called \textit{research itineraries}, but always in connection to the said global maps. As stated indeed by the author himself (\textit{Preface}), the ``work of establishing the causal connections underlying a scientist's research itinerary raises subtle interpretative questions. The links indeed are not always explicit, and to unveil them one needs to examine other sources, such as personal reminiscences, letters, popular and review papers, and also completely external elements, such as the political and cultural events that took place in the relevant historical period. Sometimes one does not find direct connections to other documents, but rather links with elements that belong to what we could call the `global maps''' The book is finally enriched with a chronology (Appendix \(A\)) and a bibliography (Appendix \(D\)) listing more than 270 papers and a dozen of books by Fermi himself.
scientific article; zbMATH DE number 6559660