Bludman, S. A. and M. A. Ruderman.
Text: "Possibility of the speed of sound exceeding the speed of light in ultradense matter." Physical Review. 170(5), June 25, 1968. p. 1176-1184.
See Also: tachyons, electromagnetics, superluminal velocity, electrodynamics, relativity, quantum mechanics, sound, sound waves, longitudinal waves.
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