Tossing It All Into the Wash
In February the Explorers spent a couple of sessions doing exactly what your laundry says not to do—mixing all the colors together.
This activity built upon the discoveries of one of the most brilliant scientists of all time, Isaac Newton. In addition to a few other idle pastimes (such as developing the laws of motion that bear his name, providing the first comprehensive theory of gravity, and inventing the mathematics branch known as calculus while stuck at home during an unexpected school break caused by the Black Plague), Newton investigated the properties of light. He discovered that white light such as that from the sun is actually composed of a full “spectrum” of colors—essentially explaining where rainbows come from. He also demonstrated that just as a prism can split white light into these colors, the same prism can be used to recombine the individual colors back into white.
Rather than prisms, the Explorers used “color wheels” in their attempts to mix the colors. A color wheel is exactly what it sounds like—a wheel split into sections with the colors of the rainbow. The trick to getting this device to blend the colors together is to spin it—do it rapidly enough, the thinking goes, and human vision will be unable to distinguish the individual colors.
The Explorers started by making wheels with different designs on the two sides. On one side, the club members all made relatively uniform wheels, with pie-shaped wedges of each of the colors of the rainbow (red, orange, yellow, green, blue, and purple). When finished, these sides looked more or less like filled-in “pies” from the Trivial Pursuit game. On the other side, each Explorer created their own design—still using fairly equal portions of each color, they were free to use swirls or blobs or blocks or whatever tickled their fancies.
Once the coloring was done, each wheel still needed to spin. This was accomplished by poking a pair of holes near the center of the wheel and then passing a length of string back and forth through them. Tying off the end, this created a loop of string that held the wheel in the center. While one student held both ends of the string out tight, a partner turned and turned the wheel to twist the string. Once it was tightly twisted, the first person pulled both ends of the string loop apart and the wheel spun as the string unravels.
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Did we make the colors blend together? Most definitely. Did we get white? Eh, not so much—instead, as in previous years of doing this activity we mostly got a pinkish brown, at least on the side of the wheels colored in pie-shaped wedges. (The sides with the students’ own designs got all sorts of interesting effects, depending on where on the wheel—toward the middle or the outer edge—they placed each color.) As Mr. Ramsey told the club members, this might be in part due to the relative proportions of the colors (as the visible light spectrum peaks in the yellow/green part, maybe we need much more of those colors and far less of the “outer” colors of red and purple), but probably has much to do with the materials. Colored paper, after all, is not really the same thing as pure colored light, and this undoubtedly affects the result. In addition, there is a limit to how fast our technique can spin the wheels—perhaps even faster speeds would give a more whitish tint.
Regardless, we did indeed manage to mix the colors and prove the concept. To see photos of our sessions making and spinning the color wheels check out the gallery, and click on the links below to see information from previous years doing this activity.