Scientists take first picture of thunder
Acoustic wave maps give insight into physics of lightning
BOOM CLAP Scientists captured the first acoustic image of thunder (right) emanating from an artificially triggered lightning strike (left). Warmer colors indicate louder measured sound waves.
Univ. of Florida, Florida Institute of Technology, SRI
MONTREAL — For the first time, scientists have precisely captured a map of the boisterous bang radiating from a lightning strike. The work could reveal the energies involved in powering some of nature’s flashiest light shows.
As electric current rapidly flows from a negatively charged cloud to the ground below, the lightning rapidly heats and expands the surrounding air, generating sonic shock waves. While scientists have a basic understanding of thunder’s origins, they lack a detailed picture of the physics powering the crashes and rumbles.
Heliophysicist Maher Dayeh of the Southwest Research Institute in San Antonio and colleagues sparked their own lightning by firing a long, Kevlar-coated copper wire into an electrically charged cloud using a small rocket. The resulting lightning followed the conductive wire to the ground. Using 15 sensitive microphones laid out 95 meters from the strike
