Here's why:
* Normal: The normal is an imaginary line perpendicular to the surface of the material at the point where the light ray enters.
* Refraction: When light travels from one medium to another (like air to water), it changes speed. This change in speed causes the light ray to bend.
* Denser Material: A denser material has a higher refractive index, meaning light travels slower through it.
* Bending: When light enters a denser material, it slows down and bends towards the normal. This is because the light ray is essentially trying to "catch up" with the part of the ray that entered the denser medium first.
Think of it like this: If you walk from a sidewalk onto a patch of soft sand, you slow down. Your body will naturally shift slightly towards the direction of the sidewalk to maintain balance – just like light bends towards the normal when it enters a denser material.
