Scientists in Switzerland have used lasers (激光器) to change the path of lightning (闪电). The experiment was carried out on Santis mountain in Switzerland, near a TV tower that's hit by lightning about 100 times a year.
Lightning can cause serious problems on the ground. It can cause fires, destroy buildings, and kill people. The damage from lightning costs billions of dollars every year. Scientists have been trying to find a way to protect buildings from lightning for a long time.
Now, the best way is by putting metal rods (杆) on the buildings. They are connected to the ground and can safely guide the electricity into the ground. ____ If a building is very large, it needs a lot of lightning rods. Some buildings—such as airports —are so large that it's difficult to protect the whole building using lightning rods.
Another idea is to use lasers to guide lightning. It isn't new. Scientists have been working on the idea for over 20 years. They have successfully guided lightning with lasers inside a laboratory. But scientists haven't been able to make it outside until recently. Scientist Matteo Clerici wasn't part of the experiment, but he also studies guiding electricity. He said, "The fact that they managed to do it in an outdoor environment is really a very big step."
Although they have made great progress, the laser still didn't guide the lightning as far as the scientists would like. To protect buildings from most lightning, lasers will have to guide the lightning for a much longer distance (距离). The laser is also very dear. The scientists say it costs about $2 billion. It will probably take 10 or more years before a laser is truly able to protect large buildings.
