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  • If you get caught in the middle of a big, open field during a lightning storm, which

  • of the following uniforms would be most likely to keep you safe? A thick wetsuit; a superman

  • costume; a medieval coat of armor; or a birthday suit?

  • If you answered "medieval coat of armor," you might be a little crazy--but you'd also

  • be right. You'd be crazy, of course, because lightning is much more likely to strike metal

  • than to strike rubber, fabric, or bare skin. The reason is that lightning bolts are just

  • long streams of fast-flowing electrons looking for the easiest path from point A to point

  • B, and no everyday material provides an easier path than metal.

  • So why would a material that lures lightning bolts keep you safe during a thunderstorm?

  • Ironically, for the exact same reason it attracts the the lightning in the first place: metal

  • is a great conductor of electricity. Electrons glide so easily over metals that they barely

  • penetrate into the surface. And if an electrical current happens to be moving over a hollow

  • metal container, like a can or a box or even a welded coat of armor, the current won't

  • reach the inside of the container.

  • Physicists call this kind of container a Faraday cage . Or, in the case of the steel-woven

  • clothing worn by linemen working on high-voltage wires, a Faraday suit.  In fact, your car

  • is an everyday example of a Faraday cage, which is why--despite what you may have heard

  • about rubber tires--it's actually the closed metal body surrounding you that keeps you

  • safe. It channels lightning around, rather than through you.

  • Of course, if you're away from your car and get caught in an open field during a storm,

  • chances are slim that you'll have a medieval coat of armor or high voltage line-suit handy.

  • In that case, whether you're naked or in costume, your body unfortunately happens to be a better

  • electrical conductor than both air and soil, so it provides a great shortcut for traveling

  • current. Stand upright, and you're the fastest route for a descending lightning bolt. Lie

  • down, and you're the best path for current racing along the ground from a nearby strike.

  • So the best thing to do is crouch low and keep your feet close together. Crouching low

  • is obvious. But similarly important, when your feet are right next to each other, your

  • legs don't make for much of a shortcut for the current to get from A to B. And even if

  • they are the best path for the lightning, when your feet are the only thing touching

  • the ground, then the current will most likely travel up one leg and down the other, missing

  • critical organs like your heart--something these cows couldn't avoid.

  • But, actually, the real best thing to do is avoid lightning altogether--armor or no armor--and

  • head indoors when you spot a storm on the horizon.

If you get caught in the middle of a big, open field during a lightning storm, which

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B1 中級 美國腔

如何在雷擊中生存 (How to Survive a Lightning Strike)

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    李顯章 發佈於 2021 年 01 月 14 日
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