Whitney Clay: Welcome to the West Valley College TEACH Center podcast.
Michelle Francis: TEACH stands for training educators advocating change.
Whitney Clay: I'm Whitney Clay, Instructional Designer.
Michelle Francis: And I'm Michelle Francis, Professional Development Coordinator and Instructor in Child Studies.
Whitney Clay: At the TEACH Center, we support faculty as they cultivate excellence in teaching and learning and welcome their students with engaging pedagogies.
Michelle Francis: In this podcast, we discuss hot topics in teaching and learning. We interview educators about what they are doing in their fields, and we talk to learners about what inspires them.
Whitney Clay: Today in the studio, we have Professor Mel Vaughn from the physics department. Welcome.
Mel Vaughn: Hi Whitney, how's it going?
Whitney Clay: Great. I really appreciate having you here, and the topic for this series is color. And so I wanted to ask you about how does color show up in physics?
Mel Vaughn: That is a very fascinating question, and color shows up all over the place, but it's a really interesting topic. It's a really interesting concept because what goes into color, what we call color is really a very, very tiny portion of something called electromagnetic waves. Physicists often just call that light. And electromagnetic waves – That's a phenomenon in which you have electric fields in magnetic fields vibrating and encompasses everything from radio waves to infrared waves to ultraviolet waves to x-rays and gamma rays. This is a huge spectrum in which visible light, and that would be the colors that we see, visible light is a very, very tiny portion of that spectrum. If to give you a sense for how tiny a portion of that spectrum is, if the width of visible light was the width of a dollar bill. If you circle the Earth with dollar bills, it would be circled three hundred and eighty million times for the entire spectrum. And light is only one dollar of that 380 million times, so it's a very tiny portion of this huge range. And if we could see the other ranges like radio waves or infrared waves or x-rays, it would probably be mind-boggling.
Whitney Clay: So I think we go insane. I don't think we could handle it.
Mel Vaughn: Yeah, or it might be like a jazz symphony. I think of light. I think of color in a way is kind of like music that the eyes can hear.
Whitney Clay: I love it.
Mel Vaughn: The mechanism is similar. It has to do with oscillations and vibration. So how it appears in my physics class is we talk about light and when I and again, when I say light, I mean, the entire electromagnetic spectrum in which visible light is just a small portion. And we talk about how that mechanism works, how our eyes are able to actually perceive this thing called color. How I share it with my students is that the colors of the rainbow in the visible light spectrum has to do with the number of oscillations, the frequency of electromagnetic wave that you're perceiving. So for example, red, the color red vibrates so many times per second, it has an electromagnetic wave. It's the slowest vibration of the visible light spectrum. And then if you've heard of ROYGBIV you go to orange and yellow and green blue indigo violet, as you go higher up to violet, the oscillations get faster and faster. And so each color corresponds to a different frequency of this oscillation, where red is the lowest, followed by orange ending up with violet. And then we can't really see below red. So we would call that infrared – infra meaning below. We can't really see with our eyes above red, so that would be ultra violet. So our eyes are just like these little tiny radio antennas. Maybe I could liken it to hearing, to an eardrum. You know, we hear different pitches of sound based off of our eardrums vibrating. Similarly, we see different pitches of light, and those pitches of light is color and based off of these things in our eyes called cones that are receptive to three primary frequency ranges in like red, green and blue. But what allows us to see the various combinations is how our eyes combine these different intensities of red, green and blue. And so our eyes are actually serving like radio antennas. They are. The cones in our eyes can resonate to these particular frequencies. So, so it's a very, you know, so getting into the theory of electromagnetic waves, you certainly don't have time for that now. But that's usually how I kind of like to introduce the idea of of color.
Whitney Clay: You know, what's so interesting is the similarity between color and sound. And I'm just imagining if someone could write a song that has no sound, that's all color. I wonder what that song would look like.
Mel Vaughn: That would be amazing.
Whitney Clay: Especially for a jazz song. Would it be all on top of each other, or would it be like a patchwork? Or I mean, how would you express that I? I don't know. I'm just thinking out loud here.
Mel Vaughn: Kaleidoscope. Or, you know, it's... I can't imagine it either. And to think that we can only really see a tiny portion of the electromagnetic spectrum. Many birds are sensitive to the violet region of light. Many of them have a fourth cone from what I understand. And so they could see millions of colors that you and I can't even imagine. I know, at least with spiders, I learned this a while ago, that spiders will design their web to look like a flower under ultraviolet light.
Whitney Clay: Wow.
Mel Vaughn: So you and I can see that with our eyes like butterflies can and other other pollinating insects can so they can strike webs in a range of light with color that we can't see to attract their prey.
Whitney Clay: You know, I will look at spider webs very differently now. I will. I mean, they're already beautiful but beautiful in a very different way.
Mel Vaughn: Yes. Yes.
Whitney Clay: Hmm. Wow. So when you're talking about you're talking about light and color with your students, what is it that surprises or changes their perception of how they are in the world?
Mel Vaughn: One of the questions I like to ask my students is why is the sky so or what causes wrinkles? And I asked these questions. One, because it's to make up for my graduate school comprehensive exam in which I made the difference in me getting a master's, or we're progressing to a PhD. They asked a couple of general questions. One question was why is the sky blue? And the other question was was what causes rainbows? And at the time, I really didn't know the answer. I had all this mathematical formulation that I tried to apply to answer the question. And really, I just didn't know the answer. I didn't have the conceptual understanding of what color was and what causes these things until I taught my first physics class. It was a conceptual physics class physics without the mathematics, and in the textbook was Why is the sky blue? You know what causes rainbows? And and that's something that I think connects us all that question, because if we can agree as to something being blue, which you know, we have different perspectives, but when we look up at the sky on a clear day, we might say what a blue sky that is. That's something that connects us. And so when I talk about the physics behind that,how the molecules in our atmosphere love to vibrate at a frequency that allows them to emit blue light like our atmosphere is really emitting some light. And not only that, how our atmosphere scatters sunlight in such a way that, you know, based off of the position of the sun in the sky, for example when the sun straight overhead and you were to look at it, which I don't advise, it might see largely white or very, very light yellow. And as the day goes on, it gets more and more orange-y to the sun. Sets might be near red because it has to do with how the atmosphere absorbs and scatters the different frequencies of light. So I start talking to my students about this and about the mechanisms, and they're just fascinated by that. And and I've had students just really start saying they now see physics everywhere because these mathematical equations, which I thought it was when I was taking that. But really, the math is just really a formalism for the concepts, the idea and and other aspects, you know, like like the ability of using color to really understand the world, to understand the universe we live in. For example, we knew the universe was expanding out of, you know, about 100 years ago or so when we took observations of distant galaxies and saw that their color was shifting in a certain direction. Now that's a huge thing because we learned a while ago that you can identify materials based off of the colors they emit and the colors they absorb. It's like a unique fingerprint. So if if we were to look at the colors emitted and absorbed by the Sun, we would put up something called the diffraction grating, or if we were to look at the color is emitted and absorbed by the Sun. It would be a unique fingerprint of the elements Sun contains, so we could see that the Sun contains a certain percentage of hydrogen, a certain percentage of helium or percentage of the other elements, because each one of those elements has a unique fingerprint. And that fingerprint is a pattern and that pattern we can use to uniquely identify various substances. So this is important because once we have that understanding of this fingerprint and we look at the night sky, not only can we tell what certain stars are made of and maybe how old they are and and maybe what certain galaxies are primarily composed of. Not only that. But because color emitted and absorbed by these elements in these stars have a unique fingerprint based off of whether that galaxy, for example, is moving away from us or towards us. That's going to shift the fingerprint a certain amount. So a be like shifting the fingerprint, maybe over a couple lines or two in one direction or another. If it shifts to the left, that might be something that looks more red. If it shifts to the right, it will look more blue. But the pattern is unique. So when we see a pattern that we know should look green, for example, because that's what the pattern is if we were standing right next to it, but it's shifted towards the red. We know it's moving away from us or if it's shifted towards the blue. We know it's moving towards us. So because these distant galaxies and specifically certain supernovas, I believe I should talk to Benjamin R Astronomy person because I might be confusing the type of stellar object we're looking at. I believe it's called type 1A supernovas. As we look at the light emitted from these things, we see that the more distant ones are all moving away from us. And it also, the more distant it is, the faster it's moving away from us. And so being able to know that our universe is expanding is huge. And it's not this hypothetical thing that can't that isn't well understood or can't really be tested. There is no controversy that the universe is expanding. And to me, that's a powerful thing of being able to use color, having an understanding of color and having an understanding of how different elements have a unique color. Fingerprint allows us to understand that our universe is expanding and allows us to know what stars are made of. And to me, and I think too many of my students, that's just mind blowing it. It connects us.
Whitney Clay: I love the fact that you said that your students are seeing physics everywhere. It gives me goosebumps.
Mel Vaughn: Me too. Every time.
Whitney Clay: Well, thank you so much. This has been fantastic, wonderful conversation. I really appreciate it.
Mel Vaughn: Yeah, me too. I really enjoy speaking with you, Whitney.