Here's why:
* Speed of light changes: Light travels slower in denser mediums like glass than in air. When light enters the glass, its speed changes.
* Change in direction: The change in speed causes the light ray to change direction. The angle of refraction (the angle between the refracted ray and the normal to the surface) depends on the angle of incidence (the angle between the incident ray and the normal) and the refractive indices of the two mediums.
Here's a more detailed explanation:
1. Angle of Incidence: Imagine a light ray traveling from air (less dense) to glass (more dense) at an angle. The angle of incidence is the angle between the incident ray and the normal (an imaginary line perpendicular to the surface of the glass).
2. Refraction: As the light ray enters the glass, it slows down. This change in speed causes the light ray to bend towards the normal.
3. Angle of Refraction: The angle between the refracted ray (the light ray inside the glass) and the normal is called the angle of refraction.
Key Points:
* The angle of refraction is always smaller than the angle of incidence when light enters a denser medium.
* The amount of bending depends on the refractive indices of the two mediums. Glass has a higher refractive index than air, so light bends more when entering glass.
* This principle is why we see objects submerged in water appear to be in a different position than they actually are.
Let me know if you'd like me to explain any of these concepts in more detail!
