Inducted 2019

Michael Faraday observed that the excess charge on a charged conductor resides only on its exterior and has no influence on anything enclosed within it. To demonstrate this fact, he built a room coated with metal foil and allowed high-voltage discharges from an electrostatic generator to strike the outside of the room. He used an electroscope to show that there was no electric charge present on the inside of the room's walls. That application, known today as a Faraday cage, is commonly used in printed circuit board design to block electromagnetic fields.