Light in Materials
Most recent answer: 01/30/2018
Q:
Hello, my queation is that when a light ray suffer refraction at any incident angle,how can the speed of light change when in einstein's theory of relativity, its stated that speed of light is constant
- Rupan n (age 15)
Kolkata, india
- Rupan n (age 15)
Kolkata, india
A:
Pure light in a vacuum travels at a constant speed. When light enters a material, it gets dressed by interactions with the particles in the material, especially electrons. What's traveling then is not simple light but a more complicated collective excitation. That packet travels at a slower speed.
Mike W.
(published on 01/30/2018)