Refraction of Light by 2E1 Bank

Refraction
The change in direction of light is called refraction. In an experiment where a straw in a glass of water appears bent, it is because of refraction, light changes direction when it passes from one transparent material into another, like from air to glass, from air to water, from water to glass and in the opposite direction, glass to air.

Light will bend first on passing from one material to another; it will first pass from air to glass and again on passing from the glass to the air again. When light moves from air to glass, it is refracted towards the normal. When the light moves from the glass to air, it is refracted away from the normal.

Light bends because its speed changes as it moves from one transparent material to another. Refraction can be seen when looking into a bowl of water. Air has a refractive index of about 1.0003, and water has a refractive index of about 1.33. If a person looks at a straight object, such as a pencil or straw, which is placed at a slant, partially in the water, the object appears to bend at the water's surface. This is due to the bending of light rays as they move from the water to the air.

We use refraction in mirrors, swimming pools, and many others. Refraction is also responsible for rainbows and for the splitting of white light into a rainbow-spectrum as it passes through a glass prism. Glass has a higher refractive index than air and the different frequencies of light travel at different speeds (dispersion), causing them to be refracted at different angles, so that you can see them. The different frequencies correspond to different colors observed.

Refraction is a topic that I have learnt this term. I never knew that when a straw looks bent in a glass of water, it is actually the cause of refraction. I find it interesting and something new to me.
Throughout the term, I have learnt how to draw the process of refraction and know the definition of refraction. I have learnt how refraction can happen like when light passes through from a less dense material to a denser material or the other way round.
Refraction is always all around me but I never realise it. I am glad to have learnt refraction this term.