LIGHT REFRACTION Meaning and
Definition
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Light refraction refers to the change in direction and speed of a light wave as it passes from one medium (such as air or vacuum) to another (such as water or glass) at an angle. It occurs due to the variation in the speed of light in different mediums.
When light enters a new medium, it can either speed up or slow down depending on the refractive index of the second medium compared to the first. The refractive index is a measure of how much a medium can slow down the speed of light. This change in speed causes the light wave to bend or change its direction.
The bending of light is explained by Snell's law, which states that the angle of incidence (the angle between the incident light ray and the normal to the surface) is related to the angle of refraction (the angle between the refracted light ray and the normal) and the refractive indices of the two media.
Light refraction is responsible for various optical phenomena that we observe in everyday life, such as the apparent bending of a straw in a glass of water or the formation of rainbows. It also plays a vital role in the functioning of lenses and other optical devices.
Understanding light refraction has been crucial in fields like optics, ophthalmology, and photography, where it is used to correct vision impairments, capture and manipulate images, and design optical instruments.
Etymology of LIGHT REFRACTION
The term "light refraction" is composed of two main components: "light" and "refraction".
The word "light" comes from the Old English word "lēoht" which means "brightness" or "radiance". It can be traced back to the Proto-Germanic word "*leuhtam" and the Proto-Indo-European root "*leuk-" which means "light" or "bright".
The word "refraction" originates from the Latin word "refractio", which derives from the verb "refringere", meaning "to break" or "to bend back". In this context, "refraction" refers to the bending or changing direction of light when it passes from one transparent medium to another with a different density.
Overall, the term "light refraction" combines these two components to describe the bending of light as it passes from one medium to another.
