Speed of Light in Various Mediums

In summary, the conversation discusses the concept of light and its speed in different mediums. It is noted that in a vacuum, all colors of light travel at the same speed, but when light enters the Earth's atmosphere or other mediums, its speed may slow down due to factors such as density. The question of what determines the speed of light in different mediums is raised.
  • #1
Sullivan Stockwell
8
0
This may be a rather ridiculous inquiry, but Google queries haven't helped much.

As I understand it, different colors (wavelengths) of light move at the same speed in a vacuum, which together make up what is often called "white light." However, when light enters the Earth's atmosphere, its speed slows slightly. It would seem to me that the speed of the light itself isn't really changing, but that the way various wavelengths react with different mediums could make it appear as such. Such as light traveling through a see-through gem might not really change the light's speed, but that the light simply has more to reflect around from inside the gem, and it makes it seem like the light slowed.

Exactly what factors go into various mediums and different wavelengths that affect light's speed? Thanks.
 
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  • #2
Sullivan Stockwell said:
It would seem to me that the speed of the light itself isn't really changing
'seem' ? Based on what, exactly ?

At the bottom of this paragraph you see what determines the speed of light. The 0 is for vacuum.
 
  • #3
Speed of light depends upon the density of the medium.
 

1. What is the speed of light in a vacuum?

The speed of light in a vacuum is approximately 299,792,458 meters per second, or about 670,616,629 miles per hour.

2. How does the speed of light change in different mediums?

The speed of light is affected by the density and composition of the medium it is traveling through. In general, light travels slower in denser mediums such as water or glass, but faster in less dense mediums such as air or a vacuum.

3. What is the index of refraction and how does it relate to the speed of light?

The index of refraction is a measure of how much a medium can slow down the speed of light. It is calculated by dividing the speed of light in a vacuum by the speed of light in the medium. The higher the index of refraction, the slower the speed of light in that medium.

4. Can the speed of light be exceeded in any medium?

No, according to Einstein's theory of relativity, the speed of light is the fastest possible speed in the universe. It cannot be exceeded, even in different mediums.

5. How does the speed of light in different mediums affect the appearance of objects?

The speed of light in a medium can cause refraction, which is the bending of light as it passes through different substances. This can affect the appearance of objects by making them appear closer or farther away, larger or smaller, or even distorted. This is why objects may look different when viewed through water or a glass lens.

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