"What color is the Sun?"

An example of science education pathology.

A 5-year-old comes up to you and asks "I'm told the Sun is a big hot ball! Awesome! What color is the ball?"

Take a moment, and say an answer.

Anecdotally, most astronomy graduate students will get this wrong. And at least some astronomy faculty. For correct crayon choice, it appears the 5-year-old should ask a spectroscopist.

Why? In textbooks, the question isn't a focus, and its treatment is usually ambiguous. The underlying problem I'll describe later. The issue is known, with years of folks pointing out confused students and colleagues. But awareness remains low, and little changes.

The intriguing question is, how much better might content become, if more and better experts were used. If a spectroscopist, rather than confused faculty, were asked "What color is the Sun?" If K picture books, and graduate astronomy texts, both got the crayon color right.

Asking the question

'A hypothetical 5-year-old asks "I'm told the Sun is a big hot ball. Awesome! What color is the ball?"' I've asked this, conversationally, for several years. Small n, some tens, mostly MIT and Harvard graduate students.

Getting it wrong

I see five common answers, plus a few outliers.

• yellow
• orange and yellow and red
• rainbow: "it doesn't have a color"; "it's lots of different colors"; "it's rainbow color"
• white
• 5700 K

The answer I expect depends on the person.

• From the public, I expect orange or yellow.
• From astronomy students, undergraduate and graduate, I expect yellow, with a small minority of white.
• From astronomy post-docs, I've seen white and yellow.
• From non-astronomy graduate students in physical sciences, I expect rainbow or yellow, but also see the others. I've seen rainbow from post-docs in several fields.

Yellow is the most common answer. A follow-up question of "what color is sunlight?" almost always results in recognition that something is wrong. White is an infrequent answer in all groups, except for astronomy post-docs, for whom I can't say.

White is unambiguously the correct answer.

So what is going on? "The Sun ball is white" is a concept accessible to 5-year-olds. So why do astronomy graduate students not know what color the Sun is? Why do physical-sciences graduate students not even know what color is? What implications might these have for science education content creation?

Implications

This failure mode is at least arguably atypical. But it's existence has implications.

A misconception can... persist into graduate school. While this is a single example, there is literature on ramshackle understanding persisting into professions. At least some of the perception that "misconceptions resolve" appears similar to the familiar "our teaching simply must be working" fallacy.

A misconception can... be an artifact of the field, not just of pedagogy. With a feedback loop between misconception and poor content, stable for decades. In the current case, the field is unable to bring its collective understanding to bear on creating content. Diffusion of knowledge within the field, and textbooks' "hundreds of collaborators", are here not sufficient. Even in this field with a singular emphasis on terminal introductory courses.

Creating content requires better experts. And more of them. Not merely random faculty, whose expertise outside of their specific research area, unsurprisingly looks much like a graduate student. For example. An MIT microbiology professor writes a nifty children's' picture book on photosynthesis. With such concern for correctness, that it has an errata page... which doesn't (yet) mention, the book's yellow Sun(s). This shouldn't surprise you now - an astronomy consult was needed for correct crayon paint choice.

Understanding can be poorly integrated and exercised. "Sunlight is white" and "the Sun is yellow", don't make sense together. Yet many astronomy graduate students believe both. This undetected conflict among conceptions, demonstrates the existence of poorly integrated knowledge. But they also instantly recognize them as inconsistent, when both are mentioned in these conversations. Suggesting a long-term failure to exercise knowledge - that in all their years of study, these two concepts haven't collided before.

Content could be better. Much. Consider integrated and transferable knowledge. Well shaped and chosen building blocks, exercised to knock off misconceptions, fit and fused together as foundation and scaffolding. If you believe "the Sun is yellow", that misshaped block interferes with others. Many related concepts don't make sense: blackbodies; star color; blue sky; how color works; and others. Making them in turn harder to learn. And discouraging exercise, over this broken pavement.

Get it right, get it insightful, get it understood without misconceptions. Even if failures to achieve these were rare, their impact could still be large. And instead of rare, they are pervasive. Suggesting the improvements in content over the coming decades, will not be a thing of refinement and decoration. But something much more profound.

Conclusion

How common is astronomy graduate students not knowing what color the Sun is? And astronomy professors? We don't know. These anecdotes don't stretch that far. I look forward to someone testing it.

What is clear, is that at least some graduate students are confused. In ways that surprise people. And which suggest content needs to be better. And can be.