10 Illuminating Facts About Light and Color

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Light is but a small part of a much, much bigger electromagnetic spectrum of radiation that we can’t see. The spectrum includes radio waves, microwaves, infrared light, visible light, ultraviolet, x-rays and gamma rays, but only visible light, which we interpret as colors, can be seen. Different colors are basically light at different frequencies, which travels through space in the form of waves. The closer together these waves are the higher the frequency. Radio waves have the smallest frequency and the biggest wavelength, while gamma rays are the reverse.

To experience color in all its beauty we need a source of light like a flashlight, your TV screen or the sun. We also need a hard surface for light to bounce off of and someone to see it. Without an observer to acknowledge it, color would not exist. And it’s hard to imagine how we would have survived without it, considering colors help us differentiate, say, blackberries in a thick bush from the bear sleeping in tall grass a couple feet away.

10. The Visible Light Spectrum

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Light is basically invisible energy traveling through space. For us to see it, light must go through dense particles of dust, smoke or water vapor in the form of clouds or mist. We can also observe it when it’s hitting something hard like a tree, a hand or the moon and reflects back into our eyes. Other than that it’s as if nothing’s there. Sir Isaac Newton discovered that when allowing a beam of light to travel through a prism it refracts into colors that always go in the same order: red, orange, yellow, green, blue, indigo and violet.

Our retinas contain two types of light sensitive cells, rods and cones. The rods are used to detect light intensity and brightness while the cones are responsible for color vision. We have three types of cones capable of recognizing red, green and blue. These are the primary colors, and combining any two will give us the secondary colors of green, cyan and magenta. All these hues in different combinations and intensities give us the many colors that we know and see every day.

Let’s say that the entire electromagnetic spectrum is the distance between New York and L.A., around 2500 miles. With that scale, the visible light spectrum would be about one inch long. That’s how much of the world we’re not seeing!

9. The Need for Darkness

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J.W. Goethe observed that by looking through a prism color forms around darker objects against a light background. This coloring always happens as a transition from white to black going through yellow and red, from black to blue violet or from turquoise to white. Overlapping these two boundaries are the secondary colors or inverted spectrum.

Color tends to form as a contrast between light and darkness. On one side we have warm colors such as red and yellow going from white to black, and on the other we have cold colors like blue and violet that go in reverse from black to white.

When you watch a perfect sunset do you notice what array of colors appear on the evening sky? The sun becomes reddish as it nears the horizon, engulfing the landscape in an orange haze, while shadows become longer and longer until they’re one and the same. Due to the angle of the sun, its light has to travel through more of the lower, denser atmosphere. The color red is actually a dimming of bright light traveling through much more stuff.

If we turn around from a sunset we’ll see the Earth’s shadow. The bright blue sky is gradually transforming into darker blue, indigo and violet as it meets the horizon. The more light there is in the air the brighter the blue. What we’re really seeing is the dark and emptiness of the cosmos as different shades of blue through the white light of the sun!

8. Colored Shadows

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If we look at a window for a couple of seconds and then close our eyes we’ll see its negative — a light frame with a dark exterior. This experiment can be done with colored objects as well. Each color has a complementary one. Red has cyan, green has magenta and blue has yellow.

If you illuminate a vase with two sources of light a short distance from one another, the vase will have two shadows. If one of those light sources shines a red light the opposite shadow will turn red because red light falls on it, but its own shadow will become cyan. If we could somehow isolate that shadow from its surroundings and look at it on its own we’ll see that it’s actually gray like a shadow should be, but in the context it’s an optical illusion.

7. What Color Do Objects Really Have?

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It all depends on light. Colored lights make up the visible spectrum but objects are not made of light. Let’s say you have a green shirt. You go outside and it’s still green. What happens if you go inside a room with red light? What color is it then? Normally red and green combine to create yellow but here we have a red light and a green pigment. Green pigment is made out of blue and yellow dyes which don’t reflect red, so the shirt is black. It’s also black if it’s in complete darkness, along with everything else that has no contact with light.

For another example, what makes a banana look yellow? When white light hits the banana all hues get absorbed except for yellow, which is reflected back into our eyes. In a sense bananas are every color except yellow, because we observe what’s reflected back at us. And what is everything but yellow? Its complementary color, blue! A banana is theoretically blue! We say theoretically because in order to have color we also need to have an observer. Color is not a property of an object; it’s merely an interpretation of the mind based on invisible waves at different frequencies.

6. Pink

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If we look at a light color wheel we see both the primary and secondary colors in alternative order. Each secondary color is produced by combining the neighboring primary colors. By combining red and green light we get yellow, green and blue equals cyan and if we combine red and blue we have pink.

Did you ever wonder why there’s no pink in a rainbow? The answer is simple — there’s no pink light! There’s yellow and cyan light, but no pink. That’s because red and blue are at opposite ends of the visible spectrum. By going full circle on this and combining these two colors we actually include the enormity of the entire electromagnetic spectrum into the visible one. Pink basically represents everything in the universe that’s invisible to us.

5. Vantablack

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We all know that black makes us look sophisticated and has the added bonus of slimming us down. But have you heard about the new black, Vantablack? It’s like looking into a black hole! As strange as it sounds, it’s almost impossible to see and we can only make it out because of its background. We see its edges but when looking straight at it it’s as if you are looking at nothing. Not black, not something very dark, nothing. It absorbs all but 0.035% of visible light — for comparison, dark coal almost never gets below 0.5%.

Vantablack was recently invented by English scientists and is going to be used in designing stealth aircraft and advanced weaponry. But its main use is in astronomy and space exploration, where sensitive telescopes need a very black surface to be able to detect with great clarity and precision distant stars and galaxies. We can see pictures of this material on the Internet because we’re looking through a light emitting monitor, but the scale of darkness is nowhere near to the kind of utter void that it truly is.

4. It’s My Red, Not Yours!

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If you and your friends are watching someone in a red dress, were you aware that they might be seeing something totally different from you?  What you see as red your friends might see as what you know to be blue or green. But all of you have come to know it as red, so you call it red! But how would you know? What questions would you ask your friends to find out if all of you see the same thing? Keep in mind that as you came to know your red, they came to know theirs in exactly the same way!

There are thousands of people who have different types of colorblindness that prevent them from seeing red, green or blue light, and we know that they see things differently from most of us. But what if we all see differently from one another? Ultimately we’re all alone in our minds. We all have our different realities, which may explain why one friend likes the red dress while the other thinks it’s hideous.

3. The Forbidden Colors

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By using red, yellow, green and blue in different combinations we can describe all the other colors in the visible spectrum. Purple, for example, can be described as reddish blue, lime as yellowish green, orange as reddish yellow and turquoise as bluish green. But how do you call something reddish green? What’s the name for bluish yellow? Don’t simply mix these two colors together like you’re a four year old scribbling in a coloring book — imagine a color that’s part green and part red, or one that’s both blue and yellow at the same time.

Not having any luck? That’s because those colors don’t theoretically exist, and thus are called forbidden. Everything comes down to how we perceive color. The cones in our eyes detect red, green and blue at different wavelengths. These wavelengths sometimes overlap. When green overlaps with red we usually see it as yellow, but if the frequency is not that of yellow light then it’s either green or red. It can’t, however, be both at the same time. The same principle applies for both blue and yellow colors.

This idea must have bugged Hewitt Crane and Thomas Piantanida, because in 1983 they made the unimaginable possible! By doing a set of experiments they managed to bring to life colors without a name. They created images of red and green (and yellow and blue) stripes next to each other. By making sure that light from each color only activated the same individual cones, over time the colors started blending together to form something never seen before! Even though volunteers were aware they were seeing totally different colors, they found it extremely hard to describe them. They were essentially the first people to witness something new.

2. What Do Animals See?

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We’ve all heard that dogs are colorblind and that bats are completely blind, but that’s not entirely true. Bats can see, just not well, while dogs are only colorblind from our perspective.

We have three color receptors, while dogs have only two. They can’t see red. Would a squid that can only see in blue consider a dog colorblind? Snakes can see very little “normal” color but can see in infrared, while bees can see in blue, yellow and ultraviolet.

Remember how infinitesimally small our visible light spectrum is compared to what’s really out there? Just try to imagine a brand new color — it’s impossible. Or imagine trying to explain to someone who’s been blind their whole life what red looks like.  You could say that it makes you feel warm and you associate it with passion, but what would they really understand or imagine red to be? They could know everything there is about light and color and it would still be as a foreign concept to them. There just aren’t words that allow someone to grasp the true meaning of something they haven’t experienced for themselves, which is known as an explanatory gap.

For example, some butterflies have our three color receptors and then an extra two: red, green, blue, ? and ?. We’d say just imagine the possibilities, but the whole point is that you can’t.

1. Light Is Personal

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You’ve probably heard people say things like “Oh, you have a beautiful purple aura!” or “You’re simply glowing!” It turns out there might be some truth to that. Scientists from Kyoto University have discovered that people actually emit visible light, but it’s 1000 times less powerful than what the naked eye can see. They’ve also discovered that we reach maximum “aura” brightness at about 4:00 pm because it’s a byproduct of our metabolism involving free radicals.

The greater the distance between a light source and an observer the dimmer the light is. That’s not because light gets lost on the way or gets absorbed by different objects, but rather because the energy of the light is spread out over a larger area of space. We see the sun equally as bright from all angles because light travels in all directions in equal amounts. Over time and at greater distances light gets more and more spread out until it becomes billions of single photons traveling in all directions.

Light also carries information. That’s how we know where other stars and galaxies are, what they’re made of, if they’re coming towards or moving away from us and what they were doing millions of years ago. The same rules apply to our own personal light — it will travel in all directions through the emptiness of space, possibly even going past the visible universe. It will never stop, and it will carry a tiny part of you with it.

Want to keep learning?
Isaac Newton loved studying light, and we loved writing our list of crazy facts about him. Or, if you’re looking to learn more about a very different kind of light, check out our list of paranormal spook lights.

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