PURPOSE: Show that electromagnetic theory obeys a relativity principle.
DESCRIPTION: Measure the current (qualitatively) in a coil when the coil and a bar magnet are in relative motion. Einstein (1905) complained that the standard conceptualization (electric forces if the magnet moves, magnetic forces if the coil moves) seems more convoluted than the phenomenon which appears the same whichever component is "at rest."
REFERENCES: (PIRA unknown.) See Demonstration Reference File for articles on this topic, including the first section of Einstein's paper on special relativity.
EQUIPMENT: Magnet, earth inductor coil, and overhead projector microammeter.
SETUP TIME: None.
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