Final answer:
Consequences of light's varying speed in different media include internal reflection, the formation of rainbows, and the appearance of mirages. These effects occur due to refraction and the change of light's speed across boundaries between different materials.
Step-by-step explanation:
The question pertains to the consequences of light traveling at different speeds in different media, which manifest in phenomena such as refraction and dispersion. The consequences of light's varying speed in different media include internal reflection, the formation of rainbows, and the appearance of mirages.
For instance, internal reflection occurs when light reflects entirely within a medium, because it hits the boundary at an angle greater than the critical angle, relative to the medium's index of refraction. Rainbows result from the dispersion of light as it refracts through raindrops, with different wavelengths bending at slightly different angles due to varying speeds in water. Mirages are formed due to the refraction of light in layers of air with different temperatures, and hence different indices of refraction, which cause the light paths to bend and create the illusion of water or distant objects.