1. Refraction:
* Bending: The light ray bends *away* from the normal (an imaginary line perpendicular to the surface). This is called refraction.
* Speed: Light travels *faster* in the medium with the lower refractive index.
* Wavelength: The wavelength of the light *increases* in the medium with the lower refractive index.
2. Snell's Law:
This law mathematically describes the relationship between the angle of incidence (angle at which the light hits the surface), the angle of refraction (angle at which the light bends), and the refractive indices of the two mediums:
* n₁ sin θ₁ = n₂ sin θ₂
Where:
* n₁ = refractive index of the first medium
* θ₁ = angle of incidence
* n₂ = refractive index of the second medium
* θ₂ = angle of refraction
3. Total Internal Reflection:
* If the angle of incidence is large enough, the light ray will not be able to refract into the second medium. Instead, it will be completely reflected back into the first medium. This phenomenon is called total internal reflection.
Example:
Imagine a beam of light traveling from water (higher refractive index) into air (lower refractive index). The light will bend away from the normal as it enters the air, causing it to appear "bent" at the surface. If the angle of incidence is large enough, the light will be completely reflected back into the water, creating the effect of a "mirror" at the water-air interface.
In summary:
When light travels from a medium with a higher refractive index to a medium with a lower refractive index, it bends away from the normal, travels faster, and its wavelength increases. This is a fundamental principle of light behavior and plays a crucial role in many optical phenomena.
