Lightning Control with Lasers; August 1997; Scientific American Magazine; by Diels, Bernstein, Stahlkopf, Zhao; 6 Page(s)

Despite centuries of scientific scrutiny--including Benjamin Franklin¿s famous experiment with a kite--lightning has remained a strangely mysterious phenomenon. Although scientists from Franklin¿s time onward have understood that electrical charges can slowly accumulate in clouds and then create brilliant flashes when the stored energy suddenly discharges, they puzzled for years over the exact physical mechanisms governing this process. How quickly do lightning strokes travel? What determines the path the energy takes? What happens to the bolt of electric current after it penetrates the ground? Such questions eventually yielded to scientific investigation. And this research has not only expanded the fundamental understanding of lightning, it has raised the prospect of exerting control over where lightning strikes--something traditionally considered a matter of divine whim.

Although lightning is inherently erratic, its aggregate effect is enormous. Every year in the U.S. (where about 20 million individual flashes hit the ground), lightning kills several hundred people and causes extensive property damage, including forest fires. Lightning is also responsible for about half the power failures in areas prone to thunderstorms, costing electric utility companies in this country perhaps as much as $1 billion annually in damaged equipment and lost revenue. Lightning can also disrupt the navigational devices on commercial airliners (or even on rockets bound for space), and it has caused one serious malfunction at a nuclear power plant.