Why speed of light is different in different medium?
Beside this, what is the speed of light in different mediums?
Light travels at approximately 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows down to 225,000 kilometers per second in water (refractive index = 1.3; see Figure 1) and 200,000 kilometers per second in glass (refractive index of 1.5).
Secondly, is velocity of light same in all media? No, the velocity of the light will not be same in all media. The denser the medium, the slower light travels. It travels the maximum velocity in air or vacuum.
Likewise, people ask, does the speed of light vary?
It is a basic postulate of the theory of relativity that the speed of light is constant. This can be broken down into two parts: The speed of light is independent of the motion of the observer. The speed of light does not vary with time or place.
What affects light speed?
As far as I am aware, there are two things that effect the speed of light, and that is gravity and medium. Gravity can slow down light considerably, to the point where it doesn't even move, i.e. a black hole. For the most part however, this effect is almost too small to measure.