❓ why
Why does light bend when it passes through glass or water?
PhysicsOptics
Quick Answer
Light slows down in a material because it interacts with the material’s atoms, so its path changes direction. This change in speed at a boundary is called refraction.
The Full Story
When light enters glass or water, it does not simply glide through unchanged. The electromagnetic wave interacts with the charged particles in the material, which delays its effective propagation compared with vacuum. If the light enters at an angle, the speed change makes the beam bend, a process described by refraction and Snell’s law. This is why a straw looks bent in a glass and why lenses can focus light. The index of refraction quantifies how much light slows in a given material.
Key Facts
1.Refraction is bending caused by a change in speed
2.Snell’s law describes the angle change
3.Lenses rely on refraction
YouTube Angle
Suggested video title for this topic:
"Why does a stick look bent in water?"