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The Science of Color (Part 2): Why Objects Have “Color”

Why do we see color? Does color truly exist? It’s more complex than you might think.

This article is the second in the series called The Science of Color. If you haven’t already read the first article, it is highly suggested that you do so since it is an introduction to some topics covered in this article. You can read the article here.

This article is sprinkled with pictures taken for your visual enjoyment; photos owned by me unless otherwise credited. Vary your vision from soft to sharp focus and take in all of the colors you see.


Like many people, I went to sleep on July 3rd in anticipation of seeing fireworks the next day. I woke up on July 4th to the sound of profound, incessant rain. Houston was flooding while the rest of the United States was celebrating the Fourth of July.

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Fireworks exploding over Tybee Island, Georgia. Image from Wikipedia.

I looked outside the window while eating my pancakes with strawberries and blueberries and saw the rain slam down on the monochromatic scene; hues of cool-toned gray bombarded my eyes.

I had enough of the lack of visual stimulation, so I went to my room, whipped out my markers, and got to drawing. Fireworks were my inspiration.

When you see fireworks, you gaze in awe at the brilliant colors. You might think: “Wow, that firework had amazing color!” A firework may be red, green, blue, etc.

Think of a banana…it’s yellow, right? Or is it? Nope— a banana isn’t really yellow. That’s just how we perceive it to look. No object can have a true color. What may be yellow for us might be very different for another organism.

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Houston Zoo Lights. How do we perceive the lights?

All objects interact with light; they can absorb and/or reflect light. The specific chemicals, elements, or molecules that reflect/absorb vary from object to object. For example, chlorophyll, a natural pigment found in jalapeños, gives them their characteristic green color.

When visible light (white light, like that from the sun) strikes a jalapeño pepper, chlorophyll absorbs each distinct frequency of EM radiation to a different degree. We see green because chlorophyll reflects the frequencies of EM radiation that we perceive as “green”. The other frequencies of EM radiation are absorbed by the pigment (some more than others, see absorption spectrum.

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Jalapeño peppers at a grocery store.
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An emperor scorpion looks black under white light, but fluoresces under ultraviolet light. Picture by Rosa Pineda from Wikipedia.

This applies to all objects that are shone with white light. When objects are shone with other frequencies of EM radiation besides visible light, the same principles of absorption and reflection apply except the object might respond differently, such as this scorpion.


Takeaway

Our bodies are constantly absorbing and reflecting light. Melanin, a pigment found in our bodies, absorbs and reflects visible light, giving our eyes, hair, and skin different colors.

Someone might describe someone else’s skin tone as “olive”. But colors don’t really exist in the objective world. Creatures that see in infrared light might have a hard time characterizing my skin tone. And that is the takeaway — color is subjective. This can be hard to understand because we live in a very constructed and objective world, a world that is easier for humans to understand. For example, our desire to live in an objective world has led to the standardization of colors, such as the RGB color model. What people might call purple, violet, eggplant etc. is purely defined as rgb(128,0,128) under the RGB color model.

It’s very convenient to bring objectivity to our lives—it makes many processes more convenient and practical and in a way, it gives us peace of mind (less chaos, more order). But the fact that we are all unique in what and how we experience life makes subjectivity inescapable. Humans have constructed a system of colors so intricate that other concepts such as shadow and form might be often overlooked, and these concepts help us reveal more intrinsic characteristics of objects we see, such as texture and shape. Our obsession with labels shrouds our eyes from appreciating the truly objective characteristics of objects. When we start seeing past color, beautiful things can happen. These sentiments are unique to every person and are hardly quantifiable.


Photo Gallery

Please enjoy the color of these pictures below. Try to see past the colors and look at shadows, form, etc.

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Citations

(1) “Light Absorption, Reflection, and Transmission.” The Physics Classroomhttp://www.physicsclassroom.com/class/light/Lesson-2/Light-Absorption,-Reflection,-and-Transmission.

 

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