Questioning Color

26 September 2023
By Paul Schmelzer
A blue jay rendered in purple hues

What color is a blue jay? Unlike, say, goldfinches or cardinals, male and female blue jays look essentially the same. But ask the three professors behind Carleton’s interdisciplinary class Color! (IDSC 250) and the answer might not be resoundingly: blue.

While males and females look nearly identical to us, they don’t to fellow blue jays, Associate Professor of Psychology Julia Strand explains. Each sex has plumage that reflects ultraviolet light differently, and while the UV spectrum is invisible to humans, it isn’t to birds. So answering the question depends on what you mean by color.

“Do you mean it as something about a perceiver? To humans, they’re the same color, but if you put a spectrometer over them, they’re reflecting different wavelengths of light,” she says. “Then consider that X-rays and radio waves are also forms of light. Do we want to talk about color as being about how objects interact differently with radio waves and X-rays? That sounds like a different definition.”

Joining Strand and her psychological vantage point of color are physics professor Marty Baylor and philosophy professor Jason Decker. While Baylor’s interest might be in how light interacts with matter, Strand says, Decker might consider whether color is a property of objects or whether it’s defined by how it is experienced.

The class’s students have approached these kinds of questions from all sides. They used ChatGPT to learn about misperceptions and misinformation about color. They addressed the 2015 viral buzz about #TheDress, which appeared black and blue to some and white and gold to others. They heard from art professor David Lefkowitz ’85 on the historical symbolism of colors. And they covered topics as diverse as optical cloaking, spectrometry, the metaphysical concept of haecceity, and pigment mixing.

For students, the class means three distinct and nuanced perspectives on color, plus a chance to experience three unique teaching styles. But it also models a method of inquiry where—to our question about blue jays—there really is no one right answer. “In order to really understand the problem that we’re trying to solve, you need that diversity of perspective that only looking at this through one lens gives you an incomplete picture,” says Strand. By the end of term, she adds, the most satisfying thing is seeing the class embrace this ambiguity: “It’s really fun to see students get wide-eyed and look around the room and say, ‘Wow, do I even know what I’m seeing?’”

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