Question

1.The greenish blue of water is evidence for the
A) interaction between green and blue frequencies of light.
B) reflection of red light.
C) reflection of greenish-blue light.
D) absorption of greenish-blue light.
E) absorption of red light.

2.Atmospheric refraction tends to make daytimes
A) longer. B) shorter. C) no change in day length

Answer 1

1. It is usually E). Blue light is less absorbed than red in ocean and clear lake water, and it is blue light that is mainly reflected back.

However in glacial lakes, which are often a cloudy green, the main reason is C)

2. A) When the sun looks like it is just setting or rising, the REAL sun position is about a degree below the horizon, as a result of refraction.

Dawn and twilight extend the day also, but for a different reason. (upper atmosphere scattering)