Exam 20: Light, Color and Atmospheric Optics

When the bright light beams appear to converge toward the part of the horizon opposite from the Sun, the beams of light are called ____________________ rays.

The Sun radiates almost half of its energy as visible light.

Atmospheric mirages are created by light passing through and being ____________________ by air layers of different densities.

Which type of particle causes a whitish haze, and a glare in clouds near the Sun?

What atmospheric conditions are necessary for an inferior mirage? A superior mirage?

What can make a setting (or rising)Sun appear red?

What is a tangent arc in relation to a halo?

Because of atmospheric refraction, a star seen near Earth's horizon is actually ____.

Volcanic eruptions rich in sulfur produce yellow sunsets.

Why does the Sun usually appear white to the human eye? How do stars that are cooler, hotter, and about the same temperature compare to the Sun?

Occasionally, when the size of the suspended particles is similar to the primary wavelengths of visible light, the Sun can appear blue, even at noon.

A star that is cooler than our Sun appears ____.

Light that passes through a substance is said to be refracted.

Why do stars "twinkle"?

Twilight is the name given to the time ____, when the sky remains illuminated and allows outdoor activities without artificial lighting.

When a star appears to twinkle or flicker, it is a condition called ____________________.

The green flash is largely an example of the ____ of light by Earth's atmosphere.

Explain what causes secondary rainbows to form.

The blue color of the sky is a result of ____.

Explain the difference between crepuscular and anticrepuscular rays.