Against Dogma: On Superluminal Propagation in Classical Electromagnetism

摘要

It is deeply entrenched dogma that relativity theory prohibits superluminalpropagation. It is also experimentally well-established that under somecircumstances, classical electromagnetic fields propagate through a dielectricmedium with superluminal group velocities and superluminal phase velocities.But it is usually claimed that these superluminal velocities do not violate therelativistic prohibition. Here I analyze electromagnetic fields in a dielectricmedium within a framework for understanding superluminal propagation recentlydeveloped by Geroch(1996, 2011) and elaborated by Earman(2014). I will arguethat for some parameter values, electromagnetic fields do propagatesuperluminally in the Geroch-Earman sense.