The Physics
Hypertextbook
Opus in profectus

# Color

## Problems

### practice

1. Write something.
2. Write something else.
3. Write something different.
4. Write something completely different.

### conceptual

1. Imagine that our sun was a red star instead of a yellow star, but that everything else about the solar system was unchanged.
1. What would clouds look like?
2. What would a rainbow look like?
3. What would the midday sky look like?
4. What would a sunset look like?
5. What would a full moon look like?

### numerical

1. The Deep Space Climate Observatory (DSCOVR) is a spacecraft in a halo orbit at Lagrange point 1 (L1). This special orbital configuration keeps DSCOVR between the Earth and the Sun at all times. DSCOVR has two primary missions:
• Monitoring the side of the Sun facing the Earth to provide advanced warning of solar storms that might affect power grids, communications systems, and satellites.
• Monitoring the side of the Earth facing the Sun to provide measurements of the radiation reflected and emitted by Earth for atmospheric, environmental, Earth, and ocean scientists.
One of the instruments responsible for the second of these two missions is the Earth Polychromatic Imaging Camera (EPIC). EPIC takes 2048×2048 pixel (4 megapixel) images of the whole sunlit side of the Earth every two hours or so. Your typical digital camera works with three color channels that divide the visual spectrum up into three broad bands (red, green, and blue). EPIC is a digital camera with ten narrowband channels in the visible, ultraviolet, and infrared. For each of these channels, determine the color (if the radiation is visible) or the type of electromagnetic wave (if the radiation is not visible). Compile your result in a table like the one on the right.