Speed of electromagnetic waves

[Shadow_x007x]

Please don't just call me stupid or anything. Because I really don't know. So I came to ask in this thread.

We know that electromagnetic waves and radiation travel at the speed of light in a vacuum. But if they weren't moving in a vacuum, what would their speed be?

 

[Accelerated_Evolution]

It depends on which absorbing medium it is passing through

In air it travels at 99,97% the speed of light

 

[Nullflowerblush]

In air, the velocity factor is approx. 0.9997; i.e., electromagnetic radiation travels at 99.97% the speed of light in air.

 

[Shadow_x007x]

It depends on which absorbing medium it is passing through

In air it travels at 99,97% the speed of light

We use v =c/n in our calculations, right? Where

• v is the speed of electromagnetic waves in the medium.
• c is the speed of light in vacuum. which has a value of approximately 299,792,458 meters per second (m/s).
• n is the refractive index of the medium. (Index of refraction of air = 1.000293)

When electromagnetic waves travel through the air, they travel with speed.

• v = c/n
• v = 299,792,458/1.000293
• v = 299704644.539 m/s or 0.99c