Question

Why does light take the quickest path?

Answer 1

This question is based on the concept of Fermat’s principle. To answer this question, first we need to understand the basic definition of light. Light, also known as visible light, is defined as the electromagnetic radiation which falls within the area of the electromagnetic spectrum that can be perceived by the human eye.

Complete answer:
Light can also be defined as the form of energy that helps us to see various things. Light starts from a particular source and then bounces off objects which are perceived by our eyes and our brain further processes this signal and eventually we are able to see the object.It is important to keep in mind that the shortest path need not be the quickest path. Since light is always in a hurry while travelling, it tends to bend when it enters from one medium to another medium as it is still following the quickest path.

Fermat's principle of the least time travelled by the light is used to understand how light rays travel. According to this particular principle, the path taken by the light between any two points is the path that can be taken in the shortest time period, but it is not necessary to be the shortest path. The principle of least time states that the light ray always takes the quickest path between any two arbitrary points which may not necessarily be the shortest path.

Thus, from Fermat's principle, we can say that light takes the quickest path which may not be the shortest path.

Note: In order to predict the path that waves will take, they are frequently approximated as rays. The ray model of light takes an assumption that the light ray moves in a straight line in a vacuum or in any of the uniform medium. A ray can be defined as the straight line that is used to depict the path of a light beam.