Long since before Ben Franklin tried to
electrocute himself in a thunderstorm, man has been curious about the
beauty and power of lightning. Post-Franklin, our
knowledge of the intricacies of atmospheric electrical discharge has
grown by leaps and bounds. One thing we haven't quite figured out is
how to reliably and safely trigger lightning
strikes. Shooting rockets trailing conductive wire into thunderclouds
has proved to be about fifty percent effective at producing a strike.
The idea of using lasers to provoke a
discharge has been kicked around for thirty years and recently
European researchers managed a small victory using high power pulsed
laser beams. Though much more powerful than the lasers of yore,
Teramobile's current laser lacks the power to bring a discharge to
The Teramobile project is an
international program dedicated to researching the nonlinear
propagation of high powered pulse lasers over great distances through
the atmosphere. One of the focuses of the research is triggering
lightning strikes using a mobile terawatt laser unit.
In this case, the lasers trigger
lightning by producing plasma filaments inside thunderclouds. The
filaments conduct electricity and can cause electrical discharge.
However, the filaments created by the Teramobile laser were too small
and dispersed too quickly to allow the discharge to carry for more
than a few meters inside the cloud.
The tests were conducted at Langmuir
Laboratory in New Mexico. The lab, perched upon the 10,500-foot South
Baldy Peak, is equipped with instruments to study atmospheric
electrical discharges. After firing the femtosecond-terawatt pulse
laser into passing thunderclouds, analysis showed that the electrical
activity in the target area was enhanced, alluding to small
discharges within the cloud itself.
The ability to trigger lightning
strikes could be beneficial in a number of industries. A better
understanding of the effects of lightning strikes on aircraft,
buildings, antennas, power lines, electrical systems and many other
man-made technology would be useful in designing systems and devices
that are better protected or more suited to use during them.
Lasers are also probably a lot safer than kite strings.