Electricity and Magnetism: Two Sides of the Same Coin

Hans Christian Oerstred’s simple observation that electricElectrics current flowing along a wire generated a surrounding electromagnetic field whose strength was proportional to the amount of current was pivotal in the history of electricity. Based on the discovery Ampere made a quantitative electrometerElectrometers that he called a galvanometerGalvanometer and Ohm developed his famous eq. I=V/R relating current (I) to the voltage (V) and resistance (R) in an electrical circuit. Wired telegraphy soon revolutionized worldwide communication. Michael Faraday’s lines of force theory of electromagnetic waves marked the beginning of modern physics, and his induction coil provided a new and better way to stimulate nerves (faradizationFaradization). Faraday’s experiments on the electricElectrics eel inspired Michael Todd’s pioneering work on epilepsy and brain electrical stimulation.