“What color is the Sun?” An example of science education pathology (2012)

> So why do astronomy graduate students not know what color the Sun is?

Without any proof, I will offer a guess: Because it is the wrong question!

If you ask "What is the wavelengths of the light than the sun emits?", you are setting an expectation of an accurate answer. "What color is the sun?" seems a casual question that expects a casual answer.

> White is unambiguously the correct answer.

Obviously false without knowing at what relative speed and in which direction the Sun moves relative to the observer. There are always different degrees of accuracy and expectations need to be set to get the correct answer.

I just asked my 6 year-old this question.

— What color is the sun?

— White. (pauses...) But some people color it yellow.

— Why is that?

— I don't know, because it's a bright color. (shrugs and runs off to play)

It dawned on my that when drawing on a white piece of paper, it's not exactly easy to draw a white object without resorting to inverse video (coloring the blue sky in such a way as to leave a spot that represents the sun).

This subject isn't really related to physics or astronomy except in a kind of shallow sense.

It has way more to do with the biology and psychology of how we perceive and interpret color (which is an incredibly in-depth and complicated subject!)

Overall the post gives off huge crank vibes, and browsing around the rest of their site does nothing to disabuse me of this impression.

Or perhaps the best way of answering questions from five year olds isn’t causing these people who know about spectra and wavelength-response to go into pedantic and excessive detail?

If you answer “white” then the next question is “why does it look yellow”. This article seems to presuppose that there is a “correct” way to answer a five-year-old that will prevent further questions.

It definitely doesn’t help that astronomy students are taught that the sun and sun-like stars are called yellow dwarfs, and almost all visualizations of stellar types associate spectral class G with yellow as well…

The way I think of it is that our vision system has evolved to work in sunlight.

Therefore the sun looks "neutral" to us. Which is "white".

Or at least sunlight does. The sun itself looks like "pain" :)

The only pathology I see here is the claim that a vaguely specified question has a single unambiguous correct answer.

This seems like an ambiguous question deriving from the fact that "color" is a bad representation of light outside of a small window of power and frequency.

What color are x-rays?

It emits white light, but that's only one definition of color. Normally when we talk about color, we talk about reflection and absorption. If we shined a super sun on our sun and wore super sunglasses that block out all of out sun's relatively dim light, what would we see reflected back by the hydrogen-helium ball?

"White is unambiguously the correct answer."

Hmm, isn't sun wavelength actually closer to very very bright green?

The color of the Sun can be white, yellow or orange. Out in space, it will always be white. Down on Earth, Sun's light is scattered in the atmosphere. The short waves (blue) more so than the long waves [1]. The end result is that the sky looks blue and the Sun looks like the complement of the sky. At midday, the light from the Sun comes in the most direct way, so there is little scattering, and we perceive the sky as less blue and the Sun a very bright yellow. At sunset, the rays go through a much thicker layer of atmosphere, there's a lot of scattering going on, and you end up with a dark color of the sky (blue-purple) and an orange tending to red Sun.

Whoever says the color of the Sun is always white has no idea what they are talking about.

[1] https://en.wikipedia.org/wiki/Rayleigh_scattering

Well the other thing is that color is kind of a human concept, so we are also looking at the Sun with a specific set of equipment that is different from that of an insect, for example. Even questions like "what color is that flower" look very different in different wavelengths.

Even the lumen is calibrated to the receptivity of the human eye over various wavelengths.

https://en.wikipedia.org/wiki/Luminosity_function

I think a much better example of this idea is shown in one of my favorite 80s videos, "A Private Universe" which asks Stanford alumni (in their robes no less) why the moon has phases. Then they show how their misconceptions go all the way back to primary school and were never challenged.

https://vimeo.com/113349804

Go outside look at the non-sunset sun, it's white.

Look at photo's on the internet, it's clearly white.

Being clever about scattering blue is wrong. If it did change the color of the sun to yellow during the day, the clouds would be yellow around it like sunset clouds.

The only 'clever' answer why it's not white might be, that small part of the day when people see it without pain, it is yellow.

If you had never seen a sunset or sunrise or a NASA false color sun image or a crayon drawing as a kid, you'd be adamant it is white.

This is what the article is about, people here while trying to be smart still don't seem to get it is actually white most of they day. There is no trick, no optical illusion, it's just a simple question about a thing we are told not to look at.

http://solar-center.stanford.edu/SID/activities/GreenSun.htm...

What a strange article. I’m a physics grad student and I entirely disagree with his rather smug answer. From astronomy grad students, he seems to expect a plot of the black body spectrum when asking a casual question over lunch, yet he asks the same question to five year olds? If he wanted an “unambiguously correct” answer then he should ask an unambiguous question. The only pathology demonstrated here is his own.

I guess I'm that guy. My answer would be "principally Ultraviolet C." Only if you asked "What color is the sun after filtering through our atmosphere?" am I going to say "white."

Similarly the correct answer to "Why is the sky blue?" is: "It isn't - small particles reflect ultraviolet even better than blue. We just can't (consciously) see those colors."

ipRGCs do detect UV, and our brains do get this message, and we can report it under at least some conditions.

I looked directly at the Sun for 20 seconds without blinking. My brain could not settle on any particular color - it kept shifting hues.

In defense of the writer of this article notice that almost all pictures of the sun released by NASA are false colored in shades of yellow/orange. There is almost no sense in which this is close to correct.

Because it is a stupid question.

Somebody asks what colour is the sun, the follow up should be why? Are they going to draw the sun on a piece of paper? Then expect a traditional red sun. Or yellow. Nobody draws the the sun as white.

Note that the sun is red, at dusk.

https://en.m.wikipedia.org/wiki/Color_index Looks like 5700k white is pretty close, 5756.59 is more exact.

I love this line: "Ah, deadlines. So this is online, but still needs work. Hopefully before any viral attention."

If you’re a film student, the answer is obviously “blue.”

"What color is the sun?" "Bright."

The word everybody here is looking for is, "pedantry".

What a bad article.

Color is hard because of broad spectrum sources, atmospheric scattering effects, biology effects (2-4 wavelength receptors in human eyes), and human psychology ("auto white-balance"). This leads to ambiguous language.

The article does nothing to shed light on those issues.

> White is unambiguously the correct answer.

OMFG. It most certainly is not. "White" is a very good explanation for the sum of all visible light that reaches the environment on the ground.

But if you look at (or really towards) the actual bright thing in the sky, you see it as yellow. Preschool kids and amateurs aren't wrong on this. It's yellow. Go look.

I mean, even that's not correct. The disk of the sun itself is too bright for your retina to actually sense, saturates the cells, and leaves weird artifacts (and no small amount of permanent damage, of course) that look like all sorts of colors.

But the glare around the sun that you see before you look away is, for sure, yellow. The shorter wavelengths have been preferentially scattered away on the direct path to your eye. They are the "blue" that someone else sees when they look to that path in the "sky". What's left... is yellow (relative to the general color balance of the non-direct light, that is).

Sure sure, "solar irradiance" is as good a definition for "white" as you'll find. But "the sun" is yellow.