The First Law of Refraction states that:
The incident ray, the refracted ray, and the normal to the interface are at the point of incidence. They all lie in the same plane.
Here’s a simple breakdown:
- Incident Ray: The ray of light that strikes the surface between two media.
- Refracted Ray: The ray of light that bends as it passes through the interface between the two media.
- Normal: An imaginary line perpendicular to the surface at the point where the incident ray strikes.
This law essentially means that the bending of light takes place within a single plane. This occurs when it passes from one medium to another. It does not happen in a random three-dimensional direction.