Reflection and Refraction
1. Reflection
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. This phenomenon is governed by the Law of Reflection, which states that the angle of incidence is equal to the angle of reflection.
Example: When you look at yourself in a mirror, the light rays from your face hit the mirror surface and bounce back to your eyes. The angle at which the light rays hit the mirror (angle of incidence) is the same as the angle at which they bounce back (angle of reflection).
2. Refraction
Refraction is the change in direction of a wave due to a change in its speed as it passes from one medium to another. This phenomenon is described by Snell's Law, which relates the angles of incidence and refraction to the refractive indices of the two media.
Example: When you place a straw in a glass of water, it appears bent. This is because the light rays traveling through the water slow down and change direction as they enter the air, causing the straw to appear distorted.
Understanding the Differences
While reflection involves the bouncing back of light rays at the interface of two media, refraction involves the bending of light rays as they pass from one medium to another. Both phenomena are crucial in understanding how light behaves in different environments.
Example: Imagine a pool of water. When you look at the surface from above, you see the reflection of the sky and surroundings. When you look at the bottom of the pool, you see the refracted image of the pool floor, which appears closer than it actually is due to the bending of light rays.