Elements of Physics: The Speed of Light
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Light travels at a finite speed, 3.0 x 108 m/s. Einstein said that the speed of light in a vacuum was a universal constant and the speed limit in the universe. A light year is the distance light... (more info)

Light travels at a finite speed, 3.0 x 108 m/s. Einstein said that the speed of light in a vacuum was a universal constant and the speed limit in the universe. A light year is the distance light travels in one year.

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