Faraday Cages for EMPs and Solar Flares

A Faraday Cage could be explained as a cage created by conducting materials that stops external electric fields (both static and non-static).

These shields— cages can be used to secure several kinds of digital devices from electrostatic discharges. They can’t block magnetic fields like Earth’s magnetic field, but they can guard the interior from electromagnetic radiation coming from the outside.

The Invention of Faraday Cage

Michael Faraday invented the “cages” in 1836, and they were named after him, but Benjamin Franklin even made a great addition to “Faraday Cage” development and application.

Faraday noticed that the conductor charge (on a charged conductor) did not influence anything that was wrapped within; the charge stayed only on the exterior. Faraday constructed a room, coated the whole room with metal foil, and used an electrostatic generator to create high-voltage discharges that stroke the outside of his metallic foil-coated room. He found no electricity charge on the inside walls. Faraday used an electroscope to validate this.

In 1755, Benjamin Franklin uncovered what we now refer to as “A Faraday Cage“, in his own experiment. He utilized a cork ball and a metal can. The cork was suspended on a string and put into the can via a little hole. Franklin discovered that the cork wasn’t attracted to the inside, although it did touch the base; when drawn out, the cork was not electrified. If it touched the outside, it would have been energized.

How Does It Work?

An external electrical field results in rearrangement of the charges, and this removes the filed inside. Electric fields (applied on the surface) create forces on electrons in the conductor, making a current, which will further result in charge reformation. The current will end when the charges rearrange and the applied field inside is canceled.

Applications of the Faraday Cage

Safety against lightening: The cage shields the interior of the vehicle from the powerful electrical fields. Automobiles and airplanes act as Faraday cages/ guards to protect people when the motor vehicle is struck by lightening.

Microwave: the microwaves inside the oven are entrapped and used for food preparation. The metallic cover of the microwave works as a Faraday cage.

Protections for electronic products: Computerized equipment can be covered and safeguarded from stray electro-magnetic fields by using coaxial cords that contain a conducting cover that serves as a Faraday cage.

Protective suits for linemen: electricians typically put on preventive suits which serve as Faraday cages while working with very high voltage power lines. These suits guard them from getting fried.

MRI (Magnetic resonance imaging) scan rooms are actually great examples of a Faraday cage. Outside radio frequency signals are prevented from interfering with the information coming from the individual.