Phrase guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
No pronunciation record was provided for this word.
noun
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.
Definition source: English Wiktionary via Wiktextract
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
History
Named after the physicist Winfried Otto Schumann, who predicted them mathematically in 1952.
