Light travels at around 300,000 km per second. Why not faster? Why not slower? A new theory inches us closer to an answer
Electromagnetic theory gave a first crucial insight 150 years ago. The Scottish physicist James Clerk Maxwell showed that when electric and magnetic fields change in time, they interact to produce a travelling electromagnetic wave. Maxwell calculated the speed of the wave from his equations and found it to be exactly the known speed of light. This strongly suggested that light was an electromagnetic wave – as was soon definitively confirmed.
A further breakthrough came in 1905, when Albert Einstein showed that c, the speed of light through a vacuum, is the universal speed limit. According to his special theory of relativity, nothing can move faster. So, thanks to Maxwell and Einstein, we know that the speed of light is connected with a number of other (on the face of it, quite distinct) phenomena in surprising ways.
But neither theory fully explains what determines that speed.
The new theory, involving virtual pairs in the quantum vacuum, is considered encouraging but not definitive.
Whether it was the ‘hand of God’ or some truly fundamental physical process that formed the constants, it is their apparent arbitrariness that drives physicists mad. Why these numbers? Couldn’t they have been different? More.
Unfortunately, from here on, the article trails off into any number of alternative universes at once, where everything could be different. (The multiverse does that to people.) But we do learn some interesting things Follow UD News at Twitter!