Scientists have noticed that all cultures developed names for colors in a certain order: black, white, red, green, yellow, and blue. Basically this means that the colors later in this list weren't identified with names until the colors at the beginning of the list were named. For instance, if a community has a name for green, it will have names for black, white, and red.
This trend is interesting and all, but is there a scientific reason for it?
In a recent study, a team of researchers presented a possible explanation for this color hierarchy. By creating a community of virtual people imposed with the limits of human vision, the researchers were able to watch color naming in action. Based on their observations, the team posited that the color hierarchy is caused by the properties of human vision.
You might have noticed that blue is last on the hierarchy. This doesn't mean that blue is the least significant color--it just means that humans eyes probably weren't able to detect it as easily as other colors.
In fact, blue light is unique because it has one of the shortest wavelengths of visible light. This property grants blue light some very useful applications.
1) Blue light goes the farthest
you may know, white light is all colors of light mashed together. When
white light shines on an object, the object absorbs every color besides
one. This color is reflected into our eyes, so we perceive the object as
being that color.
As you also know, the ocean is blue. This is because water (along with salt, plankton, and other gunk) absorbs all the other colors in sunlight besides blue. The deeper you go, the more light is absorbed by the water, which makes most colors appear very faint--except blue.
Because blue light has a very short wavelength, it resists being sucked up by the water and penetrates farther down into the ocean than any other color of light.
Check out the difference between these pictures of the same coral that I took on a scuba diving trip. The one on the left was taken with a flash (which provides a source of white light under the ocean).
2) Blue light may help with depression
However, other studies have shown that light, and specifically blue light, may help to relieve Seasonal Affective Disorder (SAD). People with this disorder develop depression in the winter months due to the short days. Light therapy may help patients by decreasing their melatonin levels and by allowing their circadian melatonin rhythms to re-sync. In one study, blue light was better than red light at relieving symptoms of SAD, but further research is needed to determine optimal wavelengths.
3) Blue light makes better movies
I know it's a pain to have to re-build your movie library, but you have to admit that Blu-ray technology is pretty nifty. Quite possibly, the coolest thing about it is that it uses blue light.
Boring old DVDs are read with boring old red lasers, but Blu-ray discs are read with blue lasers. Because blue light has a shorter wavelength than red light, blue lasers can read bumps on a disc that are very small and spaced closely together. This means that a whole ton of data can be packed onto a Blu-ray disc and the machine can still read it accurately.
4) Blue light helps plants grow
Both red and blue light are essential for plant growth. No only do plants absorb light in these wavelength ranges in order to perform photosynthesis, but these specific colors trigger certain chain reactions in plants that regulate growth and life-cycles.
Blue light triggers mechanisms involved in leaf growth and phototropism, while red light tells a plant when to germinate. But these colors are not in competition. In fact, they work together quite nicely.
In a 2011 study, scientists showed how red and blue light need to work in tandem in order to promote growth and development in plants. However, it seems that blue light starts the molecular signaling necessary for plant growth while red light simply keeps it going.
5) Blue light treats acne
Though blue light probably won't remove your braces or get you a date to prom, it may help you out with another plague of puberty. Several studies have shown that blue light might be a gentle way to treat moderate acne.
The blue light works by zapping some compounds found in zit-causing bacteria. Chemical changes occur within the compound, causing it to kill the bacteria from the inside.
One recent study saw a change in some subjects' pimple size after just two treatments with a hand-held blue light.
6) Blue light is everyone's favorite
I probably don't even have to impress upon you the immensity of blue's awesomeness because blue is probably your favorite color already. In fact, most people in the world prefer the sight of blue light over any other color.
If you prefer a different color, maybe you want to reconsider. Because when in comes to wavelength, smaller is definitely better.