Turns Out, Lightning Can Strike Twice, With a Little Help [Hackaday]

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Few things are more impressive than a lighting strike. Lightning can carry millions of volts and while it can be amazing to watch, it is somewhat less amazing to be hit by lightning. Rockets and antennas often have complex lightning protection systems to try to coax the electricity to avoid striking where you don’t want it. However, a European consortium has announced they’ve used a very strong laser to redirect lightning in Switzerland. You can see a video below, but you might want to turn on the English closed captions.

Lightning accounts for as many as 24,000 deaths a year worldwide and untold amounts of property and equipment damage. Traditionally, your best bet for protection was not to be the tallest thing around. If the tallest thing around is a pointy metal rod in the ground, that’s even better. But this new technique could guide lightning to a specific ground point to have it avoid causing problems. Since lightning rods protect a circular area roughly the radius of their height, having a laser that can redirect beams to the area of a lightning rod would allow shorter rods to protect larger areas.

The idea is simple. Electricity follows a path of least resistance. When electric charges are high enough to cause the air to ionize, that creates lightning. However, if a laser ionizes the air preemptively, the lightning will be prone to follow that path instead of creating a new one.

You won’t be able to replicate this with your favorite laser pointer. The laser used is a 1 kW laser that puts out a one picosecond pulse. A Swiss radio tower at a height of over 2.5 km was monitored for lightning strikes both with and without the laser system. The increased protection was modest, only 60 meters more than the lightning rod alone. However, the team wants to shoot for a 500-meter increase.

We don’t know if this will be super practical for most lightning protection jobs. We doubt that even [styropyro’s] laser is up to the task. If you want more background on the natural phenomena, [Maya Posch] took us through it last year.