The letter that Enrico Fermi 's wrote to Paul Dirac

Fermi’s article on the statistical properties of a gas of particles obeying to the Pauli’s Exclusion Principle immediately became very popular, since by applying Fermi’s statistics, several physicists were able to calculate the behaviour of electrons in metals, obtaining predictions that coincided with experimental data. The article’s fame reached as far as England, and Paul Dirac also read it, but he soon forgot about it because the problem it dealt with was not in his interests at the time. A few months later, however, he took an interest in the problem, studied it from scratch and devised a slightly different method that still reached the same analytical conclusions as Fermi.

Fermi wrote to Dirac to claim priority for the discovery, and Dirac immediately sent Fermi a message of apology and from then on always referred to the discovery as the Fermi-Dirac statistic, generously attributing much of the authorship to Fermi. If we now call particles that obey the exclusion principle “fermions” it is precisely because Dirac recognised Fermi’s precedence in the discovery. The Fermi-Dirac statistic describes the behaviour of particles that have a half-integer spin value and is used extensively in the study of electrons in solids, and is the basis of electronics and semiconductor physics that made discoveries such as the transistor possible.