When light passes at an angle to the normal from one material into another material in which its speed is higher, it is bent away from the normal to the surface. When light passes at an angle to the normal from one material into another material in which its speed is lower, it is bent toward the normal to the surface.

Refractive index is also equal to the velocity of light c of a given wavelength in empty space divided by its velocity v in a substance, or n = c/v.

Therefore, when light goes from one material into another material having a HIGHER index of refraction , its speed will decrease. As we know that : Speed of light is directly proportional to the wavelength of light. If the speed of light decreases , then wavelength of light will also decrease.

Case 1: When light rays travel from optically rarer medium to denser medium then they bend towards normal. In this case angle of refraction is smaller than angel of incidence. When light rays travel from air into glass or from air into water, it bends towards normal.

Light is refracted when it crosses the interface from air into glass in which it moves more slowly. Since the light speed changes at the interface, the wavelength of the light must change, too. The wavelength decreases as the light enters the medium and the light wave changes direction.

What are two ways that you could direct a light wave around a corner? interacting with other objects and internal diffraction.

Any physics student knows that light travels in a straight line. But now researchers have shown that light can also travel in a curve, without any external influence. Out in space, light rays passing near very massive objects such as stars are seen to travel in curves.

Materials like air, water, and clear glass are called transparent. When light encounters transparent materials, almost all of it passes directly through them. Glass, for example, is transparent to all visible light. Translucent objects allow some light to travel through them.

Light passes through transparent objects, so you can see through them. Some objects are translucent meaning they only let some light through. For example, most paper is translucent. You will see that the paper allows some light to pass through.

Translucent objects allow light to pass through them partially. We cannot see through opaque objects. Examples: Glass, air, water, etc. Examples: Wax paper, greased paper, etc.

Snow is white because it reflects and scatters all the different colors of light equally. Light does not have to pass from paper back to the eye. The paper is transparent, or, to be more technically correct, translucent.

Butter paper is paper made to have low opacity, allowing light to pass through. So it is considered as a translucent material. It pases light partially through it that is why it is called transclusant .

Baking paper – also known as bakery paper or parchment paper, as it is often called especially in the US – is grease proof paper that is used in baking and cooking as it provides a heat-resistant, non-stick surface to bake on.

“It only has to pass from air through the grease. Light does not have to pass from paper back to the eye. The paper is transparent, or, to be more technically correct, translucent.