Light travels in straight lines.
Light travels at 300 million metres a second in a vacuum, and about the same speed in air.
However, light travels at slower speeds in other media.
For example, the speed of light in water is only 230 million metres per second,
while in glass it is only 200 million metres per second.
When light travelling in one medium meets the boundary of another medium,
the following processes can occur
REFLECTION, REFRACTION, DEVIATION ,or DISPERSION .
These processes are simulated in the following programs.

Click on one of these.
Reflection of light..... Refraction of light..... Deviation of light
Dispersion of light....... Snell's Law....... Multiple reflections
Critical Angle..... More information..... Return to main menu