> Some, even when given the answer (in micrometers), didn't believe it. :/
Why not? Did they thing the actual answer was smaller or larger?
> And of the few students who get it right, about half (but small N) learned it in a seminar on common misconceptions in astronomy education, rather than from their own atypically successful and extensive education in astronomy.
No. The atmosphere gives the yellowish tinge by scattering blue. The sun looks white from outside it, emitting strongly all the colors we can see. The strongest emissions are near green.
See this is not "no", this is "yes, but I didn't mean the perceived colour by humans".
The question then is "when you said colour what did you mean?". If you want the colour as viewed by a person, but from space without Earth's atmosphere, then that's a very specific request.
If someone says "yellow", you should ask, "why?" (as I did to one of my kids very recently). If they mention Rayleigh scattering then I'd say they answered an ill-defined question quite well.
If you think about it "the sun is white" is one of those weird physicisty things we do when we mean in an idealised situation that's not normally true. Like saying water is a liquid at RTP and not accounting for evaporation.
TL;DR "the sun is white" is incorrect perceptually. Physically -- not bound by human perception -- it's not just white as there is infrared and x-ray radiation too.
Ouch, my bad. There are differing views on misconceptions. Some view them as no big deal: create 'em now, maybe clean them up later. Incremental lying and clarification. Another is that they're more problematic: hard to undo, creating thought "friction" that discourages knowledge integration and application, and more.
My own atypical view, is that they are extremely toxic mutagenic agents of corrupting cognitive death. ;) In part because the corruption spreads. Have one bogus bit of story, try to reconcile it with valid bits, and soon one has a creative flurry of additional bogus stories attempting to patch them together. Recurse.
I once saw an introduction to the solar system page, with a big graphic at the top. It was a work of art. It reinforced so many common misconceptions about the solar system. My thought then was, there's no way the rest of this page can dig out from the hole of damage done by this first graphic. Net-negative learning. In general, it seems so very easy for content to cause severe collateral damage.
I use a remark like "from space" or "outside the atmosphere", to prune a conversation space. But it does reinforce the idea, to the best of my knowledge incorrect, that seen from the surface, the Sun is not often white. Sorry. I'll have to think about how to mitigate that. Thanks.
This was the method used to teach me in school. Maybe it worked well but I recall at two stages having conversations like (me) "that's not true" and (teacher) "this is how we have to learn it for now".
Perhaps it would sit better with me if it was explicitly acknowledged that the model was flawed. "We're going to learn about how a ball flies, and bounces; but that's a surprisingly complex thing to make a physics picture of. So, we'll be simplifying it a lot just so we can kick-start our understanding by focussing on some basic concepts that are mathematically easier to model."
If you go down this line of questioning, then there's another reason "white" probably doesn't fit as an answer. The sun doesn't emit "white photons", we simply perceive the combination of photons of the visible light spectrums as white.
Hmm, I'd like to follow up more on the education aspect than on the Sun bit...
Imagine a conversation with a five-year old. "What are you doing? Making this Arduino blink an LED light. What color is the light?"... Now imagine responding to that five-year old with a discourse on spectra and photons.
Yes, the misconceptions in such discourse can be fun and amazing. A recurring response from non-astronomy physical-sciences graduate students is something like "The Sun doesn't have a color; it's lots of different colors; it's rainbow colored". But maybe I've long missed the interesting question.
Why is stuff like this even a candidate to be said? Does the Sun seem so alien or aphysical that normal experience of objects doesn't apply? Are concepts of color fragilely situational? ("Bananas are yellow, but wow, mangoes? Do mangoes even have a color? Photons mumble spectra mumble."?) Are answers just associational mind dumps? (Before the "five-year old" was emphasized, a recurring response was a brain dump of random ideas about color and about the Sun, followed by "Did I get it right?".) Just what is going on here?
There's seems an opportunity to think less superficially about this than I have done. Yay. Thanks!
Oh yes absolutely, and it's not the current sun, it's the 8 minutes ago sun, and the photons may have spent a lot longer getting to you maybe 10-100 thousands years bouncing around in the sun before it escapes, shoots through Space, maybe bounces again and ends it's journey flexing a molecule in your eye.
:) When people watch this[1], and I'm standing next to them, they'll often ask about the ripples. But if they were watching it alone, there isn't an easy way to do that.
Someone did an art project, where you sit and watch an interesting drama video. But why was it interesting? There's an eye tracker, and the video is a graph of scenes, like an old "choose your own adventure" story. So if you're interested in character A... the video explores/emphasizes character A.
AR/VR is coming. With eye tracking (eventually... patents). So...
Imagine science education that's consistently mind blowing, rather than boring. What might that be like?
Though a cautionary note: there's apparently a problem of students, who have consistently had excellent teachers, clearly and motivationally presenting material, reaching college without the skills or inclination to themselves wrestle with a body of knowledge and distill understanding. Another opportunity for improvement. :)
Incoming light spectra are convolved with the frequency responses of the eye's photoreceptor cells (basically R, B, and G for color). The Sun, and your computer screen, achieve white using quite different spectra. They just have to poke the cells to similar extents. Forgetting that the eye matters is common. "Spectra peak in green, so Sun is green" is one (not so common) resulting misconception.
Years ago I saw paper go by, a NATO long-term "sky survey" - a color-calibrated camera watching the full hemisphere of the daytime sky somewhere in Spain(?) for year or so. As I recall it, the chromaticity of the Sun, when more than a couple of tens of degrees above the horizon, regardless of cloud cover, was nothing but white.
> Why not? Did they thing the actual answer was smaller or larger?
Good question - I don't know. I didn't pursue it, but where it was obvious, smaller. Thinking back now, years later, my impression of one student, is that of a feeling of great smallness, contrasted with a concrete length, maybe yielding a "no, that doesn't feel small enough".
Why not? Did they thing the actual answer was smaller or larger?
> And of the few students who get it right, about half (but small N) learned it in a seminar on common misconceptions in astronomy education, rather than from their own atypically successful and extensive education in astronomy.
Is the answer not yellowish-white?