1940s experiment shows how cars are safe from lightning
Topics: Science, Technology
Kit Roberts
Featured Image Credit: u/amartyamishraaa/Reddit
Topics: Science, Technology
There are many things that we might wonder just how they work, or maybe we just accept that they do.
You may have heard that cars are apparently a safe place to be in during a thunderstorm, and one of the best places if you are unlucky enough to be struck by lightning.
To be fair, I'm going to tell you even if you haven't, and suffice to say it's not for the reason you think.
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When asked about why cars are safe (or at least, safer) to be in when struck by a giant spark of electricity, many people might default to the idea that the tires are made of rubber, which insulates the car.
It makes some sort of sense as the tires can be quite chunky.
Needless to say, this is not the scientific reason that cars are relatively safe to be in when struck by lightning.
That bolt of lightning has already travelled hundreds of meters in the air as it arcs down to the Earth.
Lightning strikes can leave even the mightiest of oak trees a smouldering stump.
With that in mind, it's safe to say that even the fanciest of tires are not going to pose any credible opposition to a bolt of lightning.
So, how exactly does a car become safe?
Well, it's an effect called a 'Faraday cage' which was shown in a 1940s experiment. In layperson's terms it means that an electrical current will take the path of least resistance, so if there's a conductive box around someone, it will just go through that.
After watching the experiment, a commenter on Reddit explained: "The car acts as a Faraday cage. It's a metal box. When an electrical charge hits it, the electrons move around the metal to equalise the charge.
"As a simple example, lighting is very positive at the top compared to the negative bottom.
"The electrons in the metal are attracted to the positive charge at the top and repelled by the negative charge at the base.
"They cancel out the charge, meaning no electrical charge within the car."
For a modern car or a plane this might mean that any electrical circuits in the vehicle get fried by the massive influx of energy, but the current wouldn't pass through into the interior.
So, the tires don't actually do anything, other than melt if the current is big enough, but the metal body will dissipate the current around you.
But just to be safe - don't try this at home.
And if you're in a plane that's hit by lighting, you'll probably be fine, though your underwear probably won't.