Speed of light in refractive material

In summary, the speed of light slows down in a material with a refractive index greater than one due to "Dielectric Dispersion," where the atoms of the material absorb and re-emit the light wave, causing a net effect of a slower wave. This does not affect the actual speed of light, but rather the speed of the light wave traveling through the material. Time does not depend on the refractive index.
  • #1
benmww
8
0
i understand that the speed of light slows down in a nmaterial with a refractive index greater than one when compared to a vacuum, but is this merely the speed rather than the velocity decreasing, ie does time actually pass slower?
i suppose what i would really like to understand is the mechanism that casues the speed of light to be reduced
 
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  • #2
The propagation of light is determined by the wave equation.
The speed of the wave is c/n.
Time doesn't depend on n.
 
  • #3
benmww said:
i suppose what i would really like to understand is the mechanism that casues the speed of light to be reduced

The speed of light isn't reduced. The speed of a light wave going through it is reduced.

Its caused by "Dielectric Dispersion". This is when the atoms of the material react to the incoming wave (which is going at c). Their reaction causes the original wave to be absorbed by them but they re-emit a slightly delayed wave. As this happens over and over again along the direction of the the wave's motion, it has the *net effect* of a slower wave. The speed of light is not slowed down in the material.
 

FAQ: Speed of light in refractive material

What is the speed of light in a refractive material?

The speed of light in a refractive material is different from the speed of light in a vacuum. It is determined by the refractive index of the material and is typically slower than the speed of light in a vacuum.

How is the speed of light affected by different materials?

The speed of light is affected by the density and composition of the material it is passing through. Materials with a higher refractive index will slow down the speed of light more than materials with a lower refractive index.

Can the speed of light in a refractive material be faster than the speed of light in a vacuum?

No, according to the theory of relativity, the speed of light in a vacuum is the maximum speed at which energy, matter, and information can travel. Therefore, the speed of light in a refractive material can never be faster than the speed of light in a vacuum.

How does the speed of light in a refractive material affect the bending of light?

The speed of light in a refractive material determines how much the light will bend when passing through it. The greater the difference between the speed of light in the material and in a vacuum, the more the light will bend.

Is the speed of light in a refractive material constant?

Yes, the speed of light in a refractive material will remain constant as long as the material remains unchanged. However, the speed of light may vary depending on the wavelength of the light, as different wavelengths may have different refractive indices in the material.

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