Who has never felt that unpleasant little shock when shaking a metal handle, taking off a wool sweater, or brushing against someone in the dark? These tiny sparks are due to static electricity, a common but surprising phenomenon.
When electrons accumulate
Static electricity forms when certain materials exchange electrical charges. Rubbing a sweater, walking on a carpet, or sliding under a blanket are all actions that move electrons from one object to another. Result: our body can become electrically charged without us even realizing it.
Controlled production of a static discharge.
Image Wikimedia
As long as this charge remains "stored" on us, nothing happens. But as soon as we touch a conductive object, like a metal handle, the electrons suddenly move towards it. This abrupt transfer creates the little spark that we feel as a shock.
The phenomenon is particularly frequent in winter or in dry places, because humid air conducts electricity better and prevents this accumulation. When the air is dry, on the other hand, charges build up much more easily.
More of a nuisance than a danger
These little sparks can be surprising, but they are harmless in daily life. They release minimal energy, far too weak to harm the body. However, they can be problematic in certain sensitive locations, for example in factories handling flammable products or in operating rooms, where everything is designed to limit static electricity.
To avoid them, there are a few simple tricks: slightly humidify the air in a room, wear cotton clothes rather than synthetic materials, or regularly touch a metal surface. This allows the electricity to discharge gently, without the unpleasant spark.
Ultimately, these little "shocks" are a fun and harmless reminder of a fundamental principle of physics: electric charges love to flow, and they're just waiting for the opportunity to do so.