That’s why you get an electric shock – Dagsavisen

Electric shock is a little annoying, but by no means dangerous. Maybe you’ll be a little careful next time you touch a doorknob? In fact, you should do the opposite.

– If you touch a relatively sharp object, you will feel an electric shock. That’s because a lot of current is coming out of a small area. The great trick is to touch the doorknob with the entire palm of your hand, rather than tapping it with your finger first, says physics professor Are Raklev of the University of Oslo.

That’s why you get shocks

Electric shocks happen because you carry an excess of positive or negative electric charge. Rakliffe explains that when you touch something with a lesser positive or negative electrical charge, you get an electric shock.

What happens when you touch a doorknob is that the atoms in the doorknob attract electrons, and when the electrons move you feel an electric shock.

Another trick to avoid bumps is to touch a doorknob, for example, with a set of keys first.

But what makes us attract more electrons?

Static electricity can occur when materials rub against each other, says Wall.

More effect with wool

The more you rub a substance, such as a wool sweater, the more electrons it collects, and the greater the chance of an electric shock.

Substances have different abilities to accumulate electrons. Wool and hair on the head both attract electrons more easily than, for example, cotton.

– Substances farther apart on the so-called electro-friction scale increase the effect. At one end of the scale we find materials that easily give up electrons, and at the other end materials that accept electrons easily. This is how sparks fly, says Wahl.

– The traditional way is to rub a balloon on the hair on your head, if you have hair. Then the hair becomes electric and erect, says Rakliffe.

Wahl shows that the balloon is negatively charged, that is, with an excess of electrons.

– While your hair becomes positively charged with a lack of electrons. The hair stands in the air and stretches toward the charged balloon, Wahl says.

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Miniature lightning bolt

Another place where a lot of people get electric shock is on trampolines.

– If you want to avoid electric shock on a trampoline, you can jump in rubber shoes, but it might not be as fun, says Rakliffe.

What happens on a trampoline is that friction from the materials gives you more or less electrons, and they become electrically charged.

– We like to say that we are “still”. When we touch a doorknob or someone else, a whole bunch of electrons jump together one way or another. We are shocked, says Wahl.

If it is dark, it is already possible to see the electrons.

– Then we can see that the electrons heat the air in a small flash of light, a spark. Wahl says the spark is a miniature version of lightning from the sky.

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More often in the winter

How often you get an electric shock depends on how dry the air is. In Norway, the air is dry in spring, but also in winter and summer. In the fall, there is usually moisture in the air.

When the air is moist, it becomes more difficult for the charge to move back and forth, says Rakliffe.

– Does it mean there is a little less chance of electric shock if you live near the coast because of the humidity?

– Yes, probably. If you live in a tropical rainforest, you’re less likely to get an electric shock, he says.

Andreas Wahl explains that dry air is a poor conductor of electricity.

Then the static charges have the opportunity to accumulate to a greater extent. Hair stands up easier in the dry winter air. Our traumas are lighter, he says.

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