Back in the day, when the Mall of America had a Sharper Image store and I was about 7 years old or so, I remember always being fascinated by their fiber optic lamps. They looked like some kind of white, alien grass, or anemone, except for at the very top where the brightest colors emerged. It was like a merging of science and magic. The tops would dance with green and blue like the aurora borealis before then catching ablaze with oranges and reds, all the while taking on the colors of whatever shone from the lamp at their base. All this color, but in between? Nothing. Just thin white strands, like the seeds of a dandelion.
I wanted to know how it worked, but I also didn’t want the magic, the wall of illusion, to break down. I enjoyed the not knowing, the thrill, the wonder. But the truth is, the answers and their connections to nature are just as magical.
As it turns out, those lamps bear a striking similarity to the hair of the Polar Bear.
Most would agree that Polar Bears are white, but there’s more to the story than things may appear.
Each individual hair of the Polar Bear is actually a transparent follicle. Interestingly enough, a transparent follicle over black skin. This means that despite how they may often appear, they aren’t technically white. Rather, their color is determined by a combination of lighting, climate, and their environment.
Polar Bears can appear white, sugar cookie colored, stormy gray, grass-stained green, or even orange! Sure, sometimes they look less than white for the same reason your t-shirt that you accidentally tossed in with the wrong load of laundry looks less than white. White stuff is quite easy to get dirty, and bear hair is no exception. Dirt, mud, blood, and even their food can alter their look.
Yellowed fur is often related to the oils from their prey, like seals. Green fur in the wild is usually just grass stains, but a different cause in captivity (more on that in a second). Yet, most often, the color of their fur is not based on something on the fur, but a quality from within the fur.
Not only is each hair transparent, they’re hollow, too. This hollowness is part of what may lead some captive Polar Bears to develop a greenish tint. Rough surfaces in their enclosures can cause small holes and abrasions in their fur. Combine that with the moist and warmer-than-the-artic environment and their hairs become like miniature terrariums for algae.
None of this quite explains though how a Polar Bear, an 800-pound tank of a creature with black skin and transparent hair, looks snow white. If their fur really is transparent, then why don’t they appear black? Polar Bear fur looks white for the same reason snow does, and for the same reason oranges are orange, and many leaves are green, and rainbows exist. It’s all about light, what’s absorbed, what’s reflected, and the illusion of color.
What is color?
Color is light. Light, actually, is many things. Color is just one portion of it. What I mean is, without light, there is no color. At face value, that seems super obvious, right? If there’s no light, then that means it’s dark, and if it’s dark you can’t see, and if you can’t see then, well, you can’t see color. That’s all right, but it misses part of the story. Color isn’t something that you shine a light on to see. Color exists because the light shines.
What we call color is simply what we call the different parts of visible light that appear differently to us, and visible light is only a sliver of what light truly is.
Everything that is light is a part of something greater called the electromagnetic spectrum. In fact, visible ‘light’, and all the others, are technically a type of radiation, an energy that travels as a wave but comes from individual particles, or packets of energy, called photons.
Photons are tricky little buggers, but they can be summed up like this. When you drink coffee, you do it to get more energy, but at some point, you’re going to return to your baseline. In other words, that energy will get used somehow. Yet, the Law of Conservation of Energy states that energy cannot be created or destroyed, just transferred or transformed. In other words, it doesn’t just disappear. It has to go somewhere. When an electron gets a jolt of energy for whatever the reason may be, it eventually will have to release it to return back to its baseline, and it does so in the form of a photon.
Photons move in waves. The more energy they have, the shorter the wavelength, meaning the more waves there are in a certain period of time. The less energy they have, the longer the wavelength, meaning fewer waves in a certain period of time. It’s this amount of energy, the wavelength, that determines which portions of the electromagnetic spectrum are present.
Different portions of that spectrum have different properties. X-rays, microwaves, radio waves, infrared, ultraviolet, and others are all a part of this spectrum. The thing we call light is actually just one portion of that spectrum that we can see with our eyes. We call it visible light, and within that zone are all of the colors that exist.
The sun emits light from all across the range, but the visible portion is what we’re focused on today. That light, that white light, contains all of the colors of the rainbow within it as varying patterns of waves. When you look at something that appears black, it’s because all of those light waves were absorbed by that thing. If it looks white, it reflected all of the waves. But what about if it looks blue, or green, or red?
Let’s think about a leaf. You might say many leaves are green. Truthfully, they aren’t. The more correct way of thinking about it is that many leaves look green, to us and our eyes. Other organisms may see them completely differently. Either way, a leaf looks green because the green portion of visible light is what was reflected. An orange looks orange because everything but the orange was absorbed. What is reflected is what then enters our eyes, and what we then perceive to be the color of that thing.
The color of something is simply the frequency of light that is reflected from that thing. High frequencies look purple, while low look red. In between? Well, it’s just the order of the rainbow.
What determines what reflects can be a whole variety of things, like the structure of a pigment, or presence of a certain type of cell, but that’s a topic for another time.
Polar bears appear white because, like snow, their hair is excellent at reflecting light. Nearly all of it is reflected, and when all light is combined, it appears white.
Admittedly, when I first learned that, it didn’t make a whole lot of sense to me. I mean, when you mix all of the colors of paint, they don’t turn white. They turn brown or black. What’s the difference?
To make sense of this, you have to remember what exactly color is. Color is light. The color you perceive is what is being reflected, meaning all of the other colors are being absorbed. When you mix paints together, there are more colors of light being absorbed and less being reflected, and if color isn’t being reflected then we can’t see it.
Still, why then are all of the frequencies of visible light combined white? For that, we have to look at our own vision.
I hate to break this to you, but much of what you see is a lie.
To sum it up as briefly as I can, your eyes have three types of color receptors, that is, unless you’re colorblind or a tetrachromat. These receptors, called cones, are for red, green, and blue. If you zoom in on your phone screen or your tv screen, you’ll see a bunch of red, green, and blue lights, all combining in different ways to send the right signals to your eyes. No orange, no yellow, no purple, or beige. Yet, we see those other colors. How?
For example, where red and green overlap, we get yellow. But yellow is also its own frequency of light. This means we can see yellow in two ways. When you see yellow on your phone, what is actually happening is that red and green waves are both present and being picked up by the red and green receptors in your eye. Your brain knows, somehow, that when both are present, that thing is yellow. Your brain, essentially, made it up.
Of course, some things really are reflecting just yellow waves. Your eyes don’t have a receptor for that, but yellow is kind of close to green, and kind of close to yellow, so both of those receptors get activated, telling your brain that the thing you are seeing is yellow.
Here’s where everything takes a weird turn. It’s finally time to address the rainbow elephant in the room. All this time, I’ve referred to visible light as white light, and mentioned how combining the frequencies of light, or colors, make white light.
The truth is, there is no such thing as white light. White is a perception. White is what our brains make when our receptors are equally activated. White is a lie.
The truth of color is an illusion. It’s just one way that life perceives the universe around us. It’s our human experience, and it’s certainly not one shared by all. Different animals can see different frequencies of light. Some can see UV, some can see infrared, and some have entirely different sets or amounts of color receptors in their eyes. Of course, none of this is to mention any of the other abundances of senses and tools used by the natural world to perceive the universe around them.
In other words, color is in the eye of the beholder.
It’s one of those things in nature that seems so simple at first but extends so far beyond itself that it boggles the mind. Not just scientifically, but in its parallels to the overall human experience and the ways in which we interact with one another.
The human experience is an illusion. No one human moves through this life in the same way, facing the same challenges, the same joys, or the same losses. Beyond that, there’s truth. There’s your truth, there’s my truth, and there’s the truth. Rarely do they align, but if there’s one thing for certain, nothing is ever as it seems.
And to think, all of this started with Polar Bears.
Seeing Polar Bears, Polar Bears Seeing
As I worked on this blog post and episode, I asked followers on Twitter and members of the Facebook group if they had anything they wanted me to address. Consistently, Polar Bear vision was brought up as a must-know.
As it turns out, polar bears see quite well. In fact, their vision is nearly the same as that of a human. Where they have us beat is low-light or night vision.
Speaking of which, Polar Bears are practically invisible through night vision goggles. That’s because their thick blubber is such a good insulator that hardly any infrared radiates from their bodies.
Thank you for taking the time to read this today. I hope you feel you’ve learned something new and walk away feeling curious about taking on new perspectives and in learning more about the natural world.
Peace out, Rainbow Trouts.
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The Wild Life was created in January of 2017 by, me, Devon Bowker (He/They) after finishing my degree in wildlife biology. It’s been amazing to see how things have changed over the past 5 years, both personally and here. I have tons of ideas and projects in the works and cannot wait to share them with you. Whether you’re a long-time follower or new to The Wild Life, thank you for being here.