Many people in history used light for communication
heliographs, flags („semaphore“), ...
150 BC smoke signals for communication;(Polybius, Greece)
1794, optical telegraph, Claude Chappe
Sailor – codes represented by flags
Here electromagnetic waves are of special importance:
1831 Faraday demonstrates electromagnetic induction
J. Maxwell (1831-79): theory of electromagnetic Fields, wave equations (1864)
H. Hertz (1857-94): demonstrateswith an experiment the wave character of electrical transmission through space(1888, in Karlsruhe, Germany, at the location of today’s University of Karlsruhe)
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