Hail cannons, yes — you heard that right. They resemble a long bull horn and generate shock waves that travel at the speed of sound. These shockwaves are supposed to disrupt the formation of hailstones in their growing phase.

Hailstones are formed by layers of water attaching and freezing in a large cloud. A frozen droplet begins to fall from a cloud during a storm but is pushed back up into the cloud by a strong updraft of wind. When the hailstone is lifted, it hits water droplets. Those droplets then freeze to the hailstone. The stone eventually falls from the cloud when it becomes too heavy, or when the updraft stops or slows down.

Apparently, these hail cannons have been around since the late 18th century — who knew? There’s no scientific evidence to indicate that these actually work, we imagine if they did work that they would be everywhere. Scientists believe that hail cannons do not work, however, disproving them is hard because the weather is unpredictable. In part, scientists harbor their disbelief due to the fact that thunder is a much more powerful shock wave than anything a long bullhorn can create, and yet — where there is hail there is almost always thunder.

Farmers who use these cannons swear by them, and use them when storms are predicted. As you might imagine, a shock wave generator that’s literally called a cannon gets a bit noisy. The cannon is supposed to emit a shock wave every four-seconds as the storm approaches until it passes. Some companies such as VW and Nissan have used these machines in certain locations in an attempt to protect their new vehicles from hail damage. As you can imagine, the loud whistling sound every 4 seconds any time a sizable storm cloud passes can get annoying to those who live within earshot. Because of this, farmers surrounding certain factories have complained and even sued, claiming that the sound is disrupting their crops as well as staving off the rain. VW in Mexico has stopped using the hail cannons, and opted for hail nets instead, while Nissan in Germany is still firing the cannons anytime a storm approaches.

Would you try out a hail cannon to protect your property? Tell us why or why not.

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