Imagine you are in an elevator and suddenly you decide to make a call. But when you try to dial a number, you realize there is no signal. Why is this happening? The answer is not only scientifically fascinating, but it may also have important implications for your safety.
In this article we explain the mystery of this phenomenon which, although frustrating, can even prove crucial in critical situations.
Why do elevators block phone signals?
Elevators are built with metallic materials that act like what is known in physics as a Faraday cage. This metal structure blocks electromagnetic wavesincluding mobile phone signals. When you try to make a call in an elevator, the metal walls interfere with the transmission of these waves, preventing signals from entering or exiting.
This is not just a simple curiosity about elevators. Other environments, such as planes and vehicles also exhibit similar effects. In a car, for example, the metal chassis can limit signal reception, although electromagnetic waves can still penetrate through the windows. THE planesHowever, they use this property to protect both passengers and the device’s electronics during thunderstorms, where lightning can pose a real threat.
What exactly is the Faraday cage? The reason you have no signal in an elevator
The Faraday cage, named after the British physicist Michael Faraday, is a device designed to block electric fields and electromagnetic waves. This invention is based on the principle that a conductor, when exposed to an electric field, redistributes its charges in such a way as to cancel out the field inside it. This means that No objects inside the cage will be exposed to external interference.
Faraday demonstrated this principle in 1836 by cover the walls of a room with metal sheets. By applying electricity from the outside, he found that there was no effect on the inside, confirming that charges are redistributed to neutralize the electric field.
The Faraday cage is not just limited to transportation. Her application in microwave ovens ensures that microwaves do not escape outside, thus protecting people from possible damage. Furthermore, in the area of cybersecurityDevices that block mobile signals are used to protect private meetings from possible unwanted interventions.
Losing signal in an elevator This can be frustrating, but it can sometimes help avoid misuse of technology in sensitive situations. So the next time you can’t make a call in an elevator, consider it a reminder of how science affects our lives, even in the most unexpected moments.
