* Refraction: The phenomenon of light bending as it passes from one medium to another is called refraction. This occurs because light travels at different speeds in different media.
* Speed of Light in Different Media: Light travels fastest in a vacuum (approximately 299,792,458 meters per second). In other media, like air or water, the speed is slightly slower. This is because light interacts with the molecules of the medium, which slows it down.
* Snell's Law: The relationship between the angles of incidence and refraction and the speeds of light in the two media is described by Snell's Law:
* n₁sinθ₁ = n₂sinθ₂
where:
* n₁ and n₂ are the refractive indices of the two media (air and water)
* θ₁ is the angle of incidence
* θ₂ is the angle of refraction
Key Points:
* Slower Speed: The speed of light in water is about 75% of its speed in air.
* Bending Towards the Normal: When light enters a denser medium like water, it bends towards the normal (the line perpendicular to the surface).
* Angle of Incidence and Refraction: The angle of incidence (the angle at which light strikes the surface) and the angle of refraction (the angle at which light travels in the new medium) are related by Snell's Law.
In summary: When light passes from air to water at an angle, its speed decreases, and its direction changes due to refraction. The amount of bending depends on the angle of incidence and the refractive indices of the two media.
