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# Physics/Light speed

Question
Hello,
there is a particular physical-mathematical reason because the speed of light has the value of 299,792 km/s,ie the -nature- could do so that this speed was different (type 350,000 km/s or 250,000 km/s), or was it a choice- forced -?
And if this rate had been different, what consequences would have resulted in the physical world as we know it today?

The speed of light in empty space is due to the fact that electromagnetic fields obey Maxwell's equations.  When solved for an electromagnetic wave, the velocity of the wave is equal to the speed of light.  The shocking part of this solution is that it's always the same speed, no matter how you're moving, but you should study Relativity a little to understand why/how that works.  We can't speed up light.  We can slow it down, the solution is different if the electromagnetic field gets to interact with materials.  Light traveling through water travels slower (about 75% of the speed in empty space).  Inside certain very special materials, scientists have almost gotten it to stop.  But that's all due to the fact that the light is interacting with the material.  You can't get light to go faster than it does in empty space.  The consequences would be extreme, since you could create causality violations.  There's no known way to manipulate empty space in a way that would substantially affect light aside from gravity (which can bend it or change its frequency).   If the physical constants of empty space could be altered, then you could change the wave solution...but there's no way to change empty space like that.  I'm not sure what you mean by choice-forced, no one chose the speed of light...it's a property of spacetime itself.

Physics

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#### Dr. Stephen O. Nelson

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