Liberal Arts Blog — What Color Is the Sun? Who Cares? Who Should?
Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day
Today’s Topic — What Color Is the Sun? Who Cares? Who Should?
Think about it. Imagine being given a box of Crayola crayons. Imagine having to choose one crayon to draw the sun in the sky. What color do you pick? Why? What did you do as a child? What were you taught? What do you see in your mind when you think of the sun? Write down a description. Before reading the rest of this post. Does this story have a moral? It’s up to you. Experts — please chime in. Correct, elaborate, elucidate.
THE HISTORY OF MY DRAWING OF THE SUN (plus a little science)
1. I always thought of the sun as yellow. As a child, I definitely reached for the yellow crayon when drawing the sun.
2. Then, I learned that, no, the sun is really white.
3. But then I looked up fleetingly and saw the half-truth of the white story. The central circle is white, the spiky corona definitely has some yellow. Or so it seems to me. Now I would reach for the yellow crayon and draw faint lines creating the illusion of a central circle of white. In the lingo of art instructors this would be a “negative space” drawing.
NB: And that of course is during the day. At sunrise and sunset the sun can be many shades of yellow, orange, and red. “But that is only because its shorter wavelength light colors (green, blue, purple) are scattered out by the earth’s atmosphere, much like small waves are dispersed by big rocks along the shore. Only the long wavelengths of light from the sun (like red, orange, and yellow) are allowed through the Earth’s dense atmosphere at sunrise or sunset.” (Stanford Solar Center, first link below)
THREE EXPERIMENTS SUGGESTED BY THE STANFORD SOLAR CENTER (the midday sun, the moon, the clouds)
1.“Glance up at the Sun in the middle of the day when it’s slightly cloudy. Don’t stare of course — your eyes can be severely damaged by staring at the Sun! But it’s ok to glance up when you can easily see the Sun through whispy clouds. What color does it appear?”
2.“What color is the Moon when it’s high in the sky? Where does the Moon’s light come from? (Don’t be fooled by the golden glow of a rising or setting Moon. Its shortwavelength colors are being scattered out by the Earth’s. atmosphere, just as they are by a rising or a setting sun.)”
3. “What color are the clouds during the day (not at sunrise or sunset)? What lights up the clouds?
THREE MORE EXPERIMENTS — eclipse, photograph, reflections
1. “What color is the sun’s corona during an eclipse?”
2. “Find some photographs which include the Sun during the day. What color does it appear?” (Though note that the response of a film or electronic camera may not always be the same as the human eye.)
3. “Look at sunlight reflecting off the walls of a white building, or even a piece of white paper you hold up. Does the building, or the paper, look yellower in direct sunlight, or stay white?”
CONCLUSION — is there a powerful metaphor here? Candidates welcome.
FOOTNOTES — Three Pictures of the Sun from Wikipedia
1. Through a “solar filter”
2. During an eclipse
3. “As seen from the earth’s surface”
A LINK TO THE LAST FOUR YEARS OF POSTS ORGANIZED BY THEME:
ATTACHMENT BELOWS -
#2 “39 Songs, Prayers, and Poems: the Keys to the Hearts of Seven Billion People” — Adams House Senior Common Room Presentation, 11/17/20
Please share the coolest thing you learned this week related to science, engineering, or technology. Or, even better, the coolest or most important thing you learned in your life related to science and engineering.
This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.