Asked by: Jack Stecher, Dallas, Texas

Light is a manifestation of the laws of electromagnetism, which show that whenever sources of electric charge – such as electrons – are accelerated, the resulting energy is converted into waves of electromagnetic energy that travel outward from the source at the speed of light.

In other words, it’s impossible for light to stand still – the laws of physics decree that it’s always on the move.

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Authors

Robert is a science writer and visiting professor of science at Aston University.