Welcome to Interesting If True, the podcast that is kinda drunk right now, thanks mimosas! I'm your host this week, Shea, and with me is the indomitable Aaron: I'm Aaron, and I brought my amazing, technicolor, dream-mimosa. Imposi-Color! Better than the burger. So, this week I was sitting in a high school Space Science class this week with one of my students and we were learning about the electromagnetic spectrum, a cool fact only .0035% of the spectrum is visible light. We eventually got on the subject of human eyes and the photoreceptors we have, humans have rods and cones. Quick science lesson, rods are responsible for low light vision and don’t do color, whereas cones are in charge of the color with cones of red, blue, and green. If you remember, the rods and cones in my eyes are lazy as hell and don’t really work, hence my complete color blindness and inability to see at night. Regardless of my s****y vision, some of these facts got me thinking about color and wondering if we all see the same colors and how there is no real way to know, but what we do know is your eyes and brain like to invent a lot of colors you see. While falling down a rabbit hole filled with colors I can’t see I learned about Impossible Colors! These are colors our eyes simply cannot process because of the antagonistic way our cones work, for instance, “red-green” or “yellow-blue.” There is some pretty crazy stuff about color, my colorblind ass is going to attempt to teach you today. We take the way we see the world for granted. But our experience of the world is shaped in part by our visual system—which is both extremely complex and limited. Impossible colors, which are sometimes called non-physical colors, are a great reminder to not consider our perception of the visual world the only possible experience. I want you to try and imagine reddish-green — not the dull brown you get when you mix the two pigments, but rather a color that is somewhat like red and somewhat like green. Or, instead, try to picture yellowish blue — not green, but a hue similar to both yellow and blue. I can’t, but that could be because I forgot what those colors look like but I have a feeling most of you are having a hard time doing it too. Even though those colors exist, you've probably never seen them. Red-green and yellow-blue are the so-called "impossible colors." Composed of pairs of hues whose light frequencies automatically cancel each other out in the human eye, they're supposed to be impossible to see simultaneously. The human eye has three types of cone cells that register color and work in an antagonistic fashion: Blue versus yellow Red versus green Light versus dark There is overlap between the wavelengths of light covered by the cone cells, so you see more than just blue, yellow, red, and green. White, for example, is not a wavelength of light, yet the human eye perceives it as a mixture of different spectral colors. Because of the opponent process, you can't see both blue and yellow at the same time, nor red and green. I’d like to explain the opponent process but it is way above my paygrade and I’m a bit too dumb to figure it out on my own, what I stole from Healthline.com was “the opponent-process theory suggests that the way humans perceive colors is controlled by three opposing systems.” So, you're welcome. To wrap my head around this I need a bit more understanding of color itself. The colors we see are only reflections of light with different wavelengths. We see colors when the reflected light from an object is detected by millions of color-sensing cells in our retina known as ...