Laser pulses travel faster than light without breaking laws of physics

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No laws of physics were broken but light seems to have moved faster than its speed limit


The speed of light may not necessarily be constant. Light travelling through a plasma can appear to move at speeds both slower and faster than what we refer to as “the speed of light” 299,792,458 metres per second without breaking any laws of physics.

Clément Goyon at Lawrence Livermore National Laboratory in California and his colleagues accomplished this using a pair of lasers fired into a jet of hydrogen and helium plasma. One laser beam, called …