Exam 20: Light, Color and Atmospheric Optics

Cloud iridescence is most often seen within 20 degrees of the Sun, and it is often associated with clouds such as ____.

To see a rainbow, people must face the falling rain with the Sun at their backs.

When we look at a cloud, it appears white because countless cloud droplets ____.

____________________ scattering is most noticeable when particles of dust, salt, or smoke are about the same size as the wavelengths of visible light (or between about 0.1 and 1 µm).

How can volcanic eruptions cause red sunsets?

At high latitudes during the summer, morning and evening twilight may converge, producing a(n)____, or a nightlong twilight.

The sky will begin to turn milky white ____.

We perceive light because radiant energy from the Sun travels outward in the form of ____________________ waves.

When electromagnetic waves from the Sun reach the human eye, they stimulate antenna-like nerve endings in the ____.

In polar regions, when air next to a snow surface is much colder and denser than the air immediately above it, light from distant objects entering it bends toward the normal in a way that shifts the appearance of objects upward, known as a ____________________ mirage.

A whitish halo around the Sun, or a bright sheen visible in a nearby layer of thin clouds, is often the result of Mie scattering.

A ____ can occur during a full moon, usually when rain is falling in one area of the sky and the Moon is visible in another.

Haze can scatter light from the rising or setting Sun in a way that produces bright light beams, or ____________________ rays, radiating across the sky.

Halos are caused by ____.

What color would the sky be if air molecules selectively scattered only the longest wavelengths of visible light?

Some people will remark that the "Sun appears to be drawing up water" when they are actually observing ____.

A corona is due to diffraction of light.

Imagine that a piece of paper is illuminated with white light and appears red. You see red light because the paper ____.

At sunset in the middle latitudes, look for a rainbow toward the ____.

Describe how, when, and where sun pillars are formed.