What is a Faraday Cage?
It’s very likely you woke up this morning in a Faraday cage, made your breakfast in another Faraday cage, and drove a Faraday cage to work. Depending on your particular job, you may have spent much of your day in front of yet another Faraday cage. The concept of a Faraday cage is logically attributed to Michael Faraday, an 19th Century pioneer in the field of electromagnetic energy. Faraday studied the work of earlier scientists such as Benjamin Franklin and theorized that electromagnetic waves naturally flowed around the surface of conductive materials, not through them. For example, if a metal box containing a mouse were placed directly in the path of an electrical current, the electricity would flow over the box but not into the compartment with the mouse. The mouse would not be electrocuted. Such a box would be considered a Faraday cage. The important concept to remember is that a Faraday cage acts as a shield against the effects of electromagnetic energy. When a car is struck by l
In Faradays studies and experiments regarding charge, magnetism and their interaction, he found that charge on a conductor only resided on the outer surface. Further, he discovered that nothing inside that conductor was affected by any change in charge on the outside. Later, field theory would be based on Faradays work, and he did believe, contrary to the accepted view at the time, that an electronic field extended into space beyond a charge. Having somewhat better understanding of things now, we know that the electrostatic repulsion of like charges will cause a redistribution of charge to the outside of a conductor resulting in a net electrostatic field within the conductor of zero. It should be noted that within the conductor means any space enclosed by a continuously conducting layer. This phenomenon produces a pretty neat result: any and all noise with an electronic component that exists outside the cage is completely cancelled within that space. This is the same mechanism we elect
