During Ryland and Dr. Lokken’s conversation around the surprising realization that Astrophage store energy using neutrinos, the topic of pair production is also briefly discussed.

Dr. Lokken explains that “Sometimes gamma rays, when they pass close to an atomic nucleus, will spontaneously become an electron and a positron.” 13.184 Ryland responds that he’s never heard of this mechanism before, to which Dr. Lokken replies, “It’s a thing.” 13.186

Indeed pair production is a thing, with the usual example being the creation of an electron-positon pair resulting from a highly energetic photon in the presence of a nucleus. The resultant particle and antiparticle have the same mass but are opposite in other values, namely electric charge.

The 1948 Nobel Prize in Physics was awarded to Patrick Blackett for his work with cloud chambers which resulted in discoveries including the existence of electron-positron pair production.

The inverse process to pair production, in which a particle and antiparticle (such as the electron and positron) collide and convert their mass into energy (in this case, into high energy photons), bears the arguably flashier and more dramatic name of annihilation.