The Speed Of light (1 Viewer)

[rumour]

If the speed of light is only constant in a vacuum, then why is it constant on Earth?

 

[Rorix]

The speed of light is constant in any medium, but it's a different constant for different mediums.

The speed of light on Earth isn't actually = c, but in physics when something is close enough, it's good enough for approximation purposes.

 

[rumour]

So what is it?
Do you know?

How can you find out?

 

[Rorix]

You can find out with Snell's Law, for one.

Speed of light in vacuum is 299 792 458 m/s
Speed of light in Earth's air is 299 702 547 m/s

if you put speed in air/c you should get 1.003 (refractive index of air)/1 (of vacuum)

 

[Rorix]

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here's the answer to all the what is the speed of light in X? questions you could possibly have