Does Glass Affect the Speed of Light's Travel from A to B?

[ralqs]

If a light travels from A to B and there's a plane of glass in between the two points, will the total time it takes to make the journey be different than if there was no glass? If light slows down in glass, then I guess the answer would be yes, but I've read that the index of refraction is more subtle than that.

 

[chrisbaird]

actual time taken between two static space points will be a product of the speed and distance traveled. The refraction of light by a dielectric material will effect both speed and distance. The light will slow down in higher-index materials, but it will also bend towards the normal which decrease the distance it travels through the layer. With the speed slower but the distance shorter, both effects could cancel out and you could end up with the same travel time. I think it will depend on the specifics of the material's index refraction, thickness, angle of incidence, etc. to determine which effect dominates.

 

[ralqs]

The light will slow down in higher-index materials..

Is that a fact? I've heard contradicting points on this. Someone quite knowledgeable about physics told me that the glass just affects the phase of the light in a way that makes it appear as if the light slowed down in glass.

 

[y33t]

Is that a fact? I've heard contradicting points on this. Someone quite knowledgeable about physics told me that the glass just affects the phase of the light in a way that makes it appear as if the light slowed down in glass.

Yes that's a fact. Actually refractive index is just comparison ratio between materials where n of vacuum is taken 1 as reference. Light doesn't just pass by from a medium, it interacts with it. Material having higher refractive index interacts with light more than lower index one. Each interaction is a delay thus affects the average velocity.

Light travels at different velocities in different mediums. Even more there are commercial IC's that offers features such as digitally controlling the speed of light in a chip. Refraction index is related to molecule's geometrical structure and dipole alignments.

 

[sardar]

Yes, the total time it takes for light to travel from A to B will be different if there is a plane of glass in between the two points. This is because the index of refraction of the glass affects the speed of light as it passes through the material. The index of refraction is a measure of how much a material slows down the speed of light compared to its speed in a vacuum.

In general, the higher the index of refraction of a material, the slower light will travel through it. This is due to the interactions between the light and the atoms or molecules in the material. When light enters a material with a higher index of refraction, it is forced to change direction and travel in a more circuitous path, which results in a longer total travel time.

While it is true that the index of refraction is more subtle than just the speed of light, it still plays a significant role in the overall journey of light. The index of refraction not only affects the speed of light, but also the direction and intensity of the light. This is why objects can appear distorted when viewed through certain materials, such as a glass of water.

In conclusion, the index of refraction does have a significant impact on the total time it takes for light to travel from A to B when there is a plane of glass in between. This is an important concept to consider when studying the behavior of light and its interactions with different materials.