ELF Electromagnetic Radiation from Small Explosive Charges in Air and Water

Two short series of tests involving measuring low-frequency electromagnetic radiation from ten-gram explosive charges in air and water have revealed signals lower than 1 cps, of duration occasionally greater than fifteen seconds. Care was used to insure that the signals were not of microphonic or other spurious origin. While radiation from explosions is well known, it is believed that the extremely low frequencies and long persistence as well as their occurrence in water are novel. No theory appears to fit all aspects of the phenomenon. Possibly related natural signals are discussed and an experimental program to yield information to formulate a hypothesis is described briefly.