Schumann resonance

== English == === Etymology === Named after the physicist Winfried Otto Schumann, who predicted them mathematically in 1952. === Noun === Schumann resonance (plural Schumann resonances) Any of a set of spectrum peaks in the extremely low-frequency (ELF) portion of the Earth's electromagnetic field spectrum, generated and excited by lightning discharges in the cavity formed by the Earth's surface and the ionosphere.