What property of light allows a pencil in a glass of water to look bent?
The property of light that allows a pencil in a glass of water to look bent is called refraction. Refraction is the bending of light when it passes from one medium into another medium with a different density. In this case, the light from the pencil travels through the air and then enters the water.
To understand why the pencil appears bent, we need to consider the different speeds at which light travels through air and water. Light travels faster in air than in water because water is denser. When the light from the pencil enters the water, it slows down and changes direction, causing the perceived position of the pencil to change.
This bending of light is responsible for the visual distortion in the apparent position of the pencil. The light rays coming from the pencil are refracted as they pass from the air into the water, and then refracted again as they leave the water and enter the air before reaching our eyes. This causes the pencil to appear bent or displaced when viewed through the water.
So, in summary, refraction is the property of light that allows the pencil in a glass of water to look bent.