When light transitions from a faster medium to a slower medium, it bends in which direction?

When light travels from a faster medium, such as air, into a slower medium, such as glass or water, it experiences a change in speed that causes it to bend towards the normal line. The normal is an imaginary line that is perpendicular to the boundary surface between the two media.

This bending occurs due to the change in the speed of light as it enters the new medium. In a faster medium, light travels with a higher velocity, while in a slower medium, the speed decreases. According to Snell's law, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant, and this results in the bending of light towards the normal when entering a medium that slows it down.

In contrast, if light were to travel from a slower medium to a faster medium, it would bend away from the normal. Therefore, when light transitions from a faster medium to a slower one, the bending towards the normal is the expected behavior according to the principles of refraction.