Back in 1925, scientists speculated, “Energized, radioactive particles might zip through the booms and flashes of a thunderstorm.” From a mere conjecture, this idea was confirmed by Teruaki Enoto, a physicist at The University of Tokyo. During a lightning storm, electrons collide with atmospheric gases along the way and create blackbody radiation; the flash of bright light that is typically associated with lightning can be attributed to this radiation, but some of the radiation occurs at frequencies undetectable by human eye.
Enoto showed that the undetectable beams of energy lead to nuclear fission by exciting nitrogen and oxygen in the atmosphere. As the unstable radioactive isotopes of nitrogen and oxygen decay, additional neutrinos and positrons are released. As the positrons come in contact with electrons in the atmosphere, the collision of matter and antimatter results in a “signature flash of energy”. The detection of gamma rays of 0.511 MeV thus showed that lightning bolts can act as natural particle accelerators. This novel understanding of lightning opens up potential for new observations that were not possible with human-made accelerators.