Another episode, another "Cutting Room Floor" blog post! Today's CRF topic concerns Newton's discovery of the light spectrum and how Aristotle influenced Newton's presentation of it as a circle.
This blog post is somewhat of a transition between this week's episode 02 and next week's episode 03, because what we now call Newton's "color wheel" had a lasting impact on how color theory was developed after Newton. But we'll get into that ironic relationship more in next week's CRF post!
If you remember from the podcast, though, I did hint how Newton became so influential in art. For millennia, philosophers and scientists believed that objects physically changed the color of light as it passed through or reflected off of them. And since color was simply how an object changed light, it stood to reason that any paint or dye color could be made by mixing the right amount of brighter and darker pigments. We can thank the Greek philosopher, Aristotle, for that idea—which was so close to the actual truth that it took almost 2,000 years for someone (Sir Issac Newton) to test the ancient theory and find out that it was wrong. Newton did this by using a prism to separate the colors of light and then used another prism to put them back together into a beam of white light. At the time of the discovery, and for the next hundred years or so, Newton's new theory would be divisive.
While you would think that Newton's biggest contribution to the world of art would be discovering that white light already contained all the colors we see, for artists though, Newton's legacy mostly lives on in the form of the color wheel.
But let's talk for a minute about that color wheel, and why it is the shape of a wheel at all. Right off the bat, it needs to be said that there is no scientific reason for Newton to have arranged the colors in a circle. This isn't at all how light waves work: Light (or electro-magnetism) is a linear spectrum. Red and violet don't ever meet up at any point. When you go past red on the spectrum, light becomes invisible microwaves and radio waves. When you go beyond violet, light becomes X-Rays and Gamma radiation.
But Newton probably knew that his newly found spectrum wasn't circular, because his reasoning for putting the color spectrum in a circle had absolutely nothing to do with scientific accuracy. Newton was showing a relationship between color and music. If you look at his color wheel, you can see that the circle is divided into seven segments and each segment is correlated to a letter. These letters aren't meaningless, though; they're the letter notation of the diatonic scale. (You know, the notes you first learn on a piano—A, B, C, D, E, F, & G.)
Having this bit of trivia tucked away in your brain actually makes Newton's color wheel a bit easier to understand and number of things about it start to make sense.
1) No one listed seven basic colors. Philosophers and artists almost exclusively describe anywhere from two, four, or six basic colors, but no one mentioned seven. This is partly because two of the colors Newton described—orange and indigo—are nearly impossible to isolate in nature. But orange really isn't the biggest problem here. The problem really lies with indigo. In Newton's day, violet didn't mean "a shade of purple" it meant "deep blue". (As in "roses are red, violets are blue".) So in essence, Newton's color scheme—which had blue, indigo, and violet—had three blues of varying intensity in a row! He might as well have called them "light blue, darker blue, and the most blue."
(Today's usage of "violet" as a synonym for "purple" is actually a direct result of Newton not including the color purple on his color wheel. But this isn't Newton's fault. The color spectrum doesn't include a true purple, but we'll get to that next week.)
2) The "pie slices" are all different colors, but orange and indigo are half the size of the other colors. This is because once Newton tried to force diatonic musical notation onto a color spectrum, he had to account for the tonal differences between five whole steps and two half steps that make up an octave. Orange and indigo, being the made-up colors, fit nicely into the idea of a half step between their neighboring colors that actual do exist in the spectrum.
3) The chart is the shape of a circle because once you have gone through the entire set of notes in an octave, (A-G) you have reached a higher tone of the note you began with and start over. Even though you never move from violet back to red in the spectrum, you do always move from G back to A or vice-versa.
Back to Aristotle
So why would Newton even make such a forced relationship between color and music? Well, because Newton was reaching all the way back to 2000 years before his time and making a reference to Aristotle—the man whose theory of color he had just disproved.
Remember, Aristotle believed that objects gave light color. While I discussed this in the podcast, what I did not have time to discuss was how Aristotle illustrated this idea to his students. To better understand his color theory, Aristotle described light as the string of a lyre. When the string wasn't plucked, there was no sound. This corresponded to dark or black. When the string was plucked, the vibrations made a sound and this sound was bright or white. But every string could be made to make a different note by cutting that string into different lengths and plucking it again.
If you cut the string into equal parts, the two halves create the same sound, but it is still different than the sound they made as a whole string. If you cut the strings into different lengths, you get get two different notes per cut. The longer string is closer in tone to the full string while the smaller string—in Aristotle's understanding—was closer to silence. (Less string is closer to no string, and no string can make no noise.)
In this way, Aristotle argued that if white is the fullness of light and black is the absence of that fullness, then color is simply light changing it's "tone" when it hits an object. And just like you can make any note from any string just by changing its length, Aristotle concluded that by mixing certain amounts of white and black, you can get any other color.
You can perhaps begin to see why this theory of light and color stuck around for so long! It is surprisingly close to the truth.
By the time of the middle ages, the correlation between music and color was well established. Visual depictions of Aristotle's color theory usually had a line divided into equal parts showing the progression from dark to bright and assigning musical notations to the colors in between.
The only problem of course was that no one could really agree on which color mixtures made which colors and which proportions of white to mix with black. This rendered most of the visuals useless, especially the musical notations. Newton's color wheel was simply taking the new discovery of a light spectrum and placing it within the context of Western thought about color, even though the discovery he had illustrated slowly tore color theory apart.
The most interesting thing about this story, is not that Newton made a mistake, but that Newton most likely knew his depiction was pointless.
If you look at a spectrum from a prism, you cannot easily identify orange or two different blues, much less three. Newton's notes indicate that he projected the spectrum onto a white wall and had a friend mark where he saw different colors, but given that orange and indigo—the colors "hardest to see"—were given the designation of half-step notes, it becomes clear that Newton was forcing his theory of light onto his favored musical scale.
Newton also noted a couple of decades later while studying Newton rings that the frequency of change between red and violet was more akin to a major sixth than an octave. Instead of admitting defeat though and changing his theory, Newton instead argued that a major sixth was actually the same thing as an octave.
Issac Newton never recanted his color wheel of musical notation, but it did inspire many others to use the same basic diagram as they formed their rebuttals about the nature of color. And so, as Aristotle once suggested, there really is a connection between color and music after all.
It just all began with a mistake.