For millennia, people have looked to the sky with a sense of wonder and fear to witness lightning striking through the atmosphere. Lightning was something so powerful and unpredictable that, throughout history, it was thought to be a weapon of the gods; Zeus, Thor, and Jupiter wielded its unruly power to smite their enemies. This year, scientists have taken the power of the deities, as they have managed to control this natural phenomenon.
No, they are not mad scientists, hungry for power, in search of a superweapon. The scientists, who published their paper in Nature, had one goal in mind: to be able to direct lightning away from people and buildings in order to save lives and money. This innovation could become the modern alternative for the centuries-old lightning rod.
To understand how this new technology works, we must first understand how lightning forms, and why a lightning rod works. Lighting is almost like the static electricity discharges you are all familiar with, and caused by the same phenomenon. During storms, turbulence in the air and rain causes the particles in the air to rub together, creating a negative electric charge in the air. Since now there is a difference in charges between the air and the ground, electricity wants to flow, to equalize this difference. Once enough difference in charge builds up, a bolt of electricity travels through the air, balancing out the charges. This lightning bolt travels in a seemingly random path, however, this path is the path of least electrical resistance. A lightning rod works because the rod itself provides the lightning with a lower resistance path than whatever it is protecting.
This new lightning rod system, published in Nature, uses a laser to complement the traditional lightning rod. The mechanism with which they accomplished this is relatively simple: they fired a powerful laser into the sky, and the lightning followed. This works with the same principle as the simple lightning rod. The infrared laser strips the electrons of atoms in its path and pushes other atoms out of the way, creating a low resistance tunnel for lightning to follow in the otherwise chaotic atmosphere. Before the lightning is able to strike the laser itself, the system detects that lightning is inbound, and switches the laser off. At this point the lightning jumps to the lightning rod placed close to the base of the laser. This extends the lightning rod’s range up into the air, significantly increasing the area that a single lightning rod can cover.
The results yielded were impressive: during the six hours of thunderstorm that the system was active, it was able to direct four lightning strikes toward the lightning rod. One of these lightning strikes was measured to follow the laser's path for more than 50 meters — more than four school buses long.
The system is intended to protect large structures or areas from lightning where it simply would not be possible to install lightning rods everywhere, such as airports or other sizable infrastructure. That goal, however, is still a long way away, as this is just the first field test of such a laser lightning protection system; scaling beyond 50 meters to hundreds or thousands of meters will most likely be quite a challenge. So don’t worry — scientists using the power of lasers to shoot lightning at you won’t be something you’ll have to worry about for some time.