Three times a day, every day⁠—roughly 9am, 2pm, and 8pm Coordinated Universal Time⁠—an extremely low frequency electromagnetic pulse races around the Earth, reverberating between the lower edge of the ionosphere and the planetary surface. These pulses correspond to the peaks of daily lightning activity along the world’s three “lightning corridors” in Africa, South America, and Southeast Asia. The portion of the lightning-induced electromagnetic emissions whose frequencies match the Earth’s circumference, or a multiple of the Earth’s circumference, are magnified with each pass around the world when the peaks in amplitude align. These “resonances” were first predicted by a German physicist, Winfried Schumann, in 1952, and first measured reliably in the early 1960s.

This regular global pulsation has been likened, somewhat poetically, to the Earth’s “heartbeat” or its “breathing”. In a manner analogous to human cardiac activity or respiration, its rhythm and power are subject to various extraneous influences, such as the seasons, solar activity, or variations in lightning activity. In particular, the phenomenon of positive lightning can cause ectopic spikes or “extra beats” of Schumann resonance.