Pyotr Kapitza

Kapitza's 1955 paper 'On the Nature of Ball Lightning' (Doklady Akad. Nauk SSSR 101, 245-248) proposed that ball lightning is a plasma fed by external radio wave resonance absorption. He derived the resonance condition λ ≈ 3.65d (wavelength ≈ 3.65 × ball diameter), predicting that natural ball lightning of 10-20 cm diameter corresponds to wavelengths of 35-70 cm (~430-860 MHz UHF). To test his theory, he developed the 'nigotron' — a continuous-wave high-power microwave generator producing up to 175 kW at 19.3-19.4 cm wavelength. By March 1958, he achieved free-floating gas discharge in a spherical resonator filled with helium at atmospheric pressure. Kapitza refused to work on the Soviet atomic bomb in 1945 and was under house arrest from 1946-1953. His ball lightning research was conducted after his reinstatement in 1953 and was published openly. The US Armour Research Foundation program (1958-1962) was explicitly 'based on speculation by Peter Kapitsa' according to a December 1960 Radio-Electronics article. Handel's maser-caviton theory (1975-1994) is described by Handel as 'the present-day version of the UHF discharge approach' that Kapitza pioneered. Ohtsuki and Ofuruton's 1991 Nature paper on microwave fireballs was explicitly 'based on Kapitza's [1955] theory.'