Lightning can cause fires and explosions if it strikes chemical works or
nuclear power plants, so the French Atomic Energy Commission has come up with a
way of avoiding direct hits (WO 98/1929).
When the build-up of charge in the clouds above passes the danger threshold,
a laser is switched on. The beam shoots up into the atmosphere, ionising the air
and creating a conductive path. The lightning follows the path down to a
conventional lightning arrester, a device that safely leaks the charge directly
to earth, preventing lightning running to earth through a nuclear reactor.
