Because my brain is still stuck back on the whole eye/color/spectrum thingie. And I don't have much to blog about; I'm still knitting. In the next week or so I hope to drag out the Mystery Knit (remember it?) do some photography and pattern writing, and get it up for sale. 'Tis the season for warm knits.
Meet the Electro-Magnetic spectrum.
(Image from here.)
Called the EM spectrum for short. You should have encountered this in middle school science, but if it was presented to you like it was presented to me, you rolled your eyes, thought "I'll never need to know this in a million years" and promptly forgot it. But there's all kinds of cool information to be had from it. Seriously. Take a good look.
What was never sufficiently explained to me in school was, it's a continuation of wavelengths. Meaning that the visible light part, in the middle, is just PART of all the 'light' that's out there bouncing around. All that other stuff is there, too. We just can't see it. By that standard, X-ray machines are nothing but cameras that take photos using a kind of light our eyes can't see. Cool, no? (From a technical standpoint, everything on that chart is 'radiation', which can be fun when you warn people about the copy machine putting off radiation. It does put off radiation - VISIBLE LIGHT. Haha. I'm such a bitch.)
The reason I'm putting this up there is because, with the tetrachromate issue of this past week in mind, I'd have SWORN that when the human eye started evolving or mutating, we'd have oozed off the 'visible light' scale into infrared or ultraviolet. And we'd start having humans who could see those extra few wavelengths. Once you're looking at the chart, it doesn't sound that insane; it'd be a simple matter of extra sensitivity in the retina. (There are critters on the planet who can see both ends of the spectrum we can't; mostly reptiles with the infrared, and mostly insects with the ultraviolet.) But instead, imagine my surprise, when it turns out that people are mutating to see MORE COLORS within the spectrum we already see. (And I might be one of them. Go figure.)
Anyway. Since I'm putting up more babbling info about this stuff, I thought I'd include something that was actually useful to knitters and crafters. Namely, why different light is such a big deal, when trying to see color. Here, take a look at the wavelengths put off by the sun, first:
As you can see, the sun puts off wavelengths of light all through the EM spectrum, not just in the visible light band. But MOST of the light put off is visible. (I doubt that's a coincidence. Mother nature's pretty smart about this kind of thing.) As you see from the chart, the sun puts off a fairly well-balanced amount of light in the visible spectrum. Thanks to us spending most of the history of the human race seeing by sunlight, this spectrum of light is what our eyes consider 'normal', and what it's most used to using.
With sun light, THAT MEANS THE LIGHT IS THERE, to bounce off whatever you're looking at, and get soaked up by your eyes. Compare that to the 'spectra' (specific wavelengths) put off by street lights (which are the worst in the world, for color vision).
See that top chart? That's the spectra put off by a low-pressure sodium light (also known as 'those really cheap street lights'). Now you know why everything looks orange under those lights; that's the only light it puts off, so that's all that can bounce off things to get soaked up by your eyes. Get the idea? (Cops hate these lights, by the way, because they're so notrious for fucking up color vision. They can find witnesses who saw a crime happen right in front of them, but can't say what color the getaway car was, or what color clothing the criminals were wearing, or even what color their skin was. You're reduced entirely to 'light' and 'dark'.)
Here are some more spectra for different types of light:
If you can't tell from the picture (it's pretty small), from top to bottom the artificial lights shown are: compact fluorescent, fluorescent, metal hallide, mercury vapor, high pressure sodium, and again, the low pressure sodium. You can see how unholy awful the low pressure sodium is, with the comparisons. You can also see how the old-school fluorescent will lead to some seriously funky color vision.
Unfortunately that chart doesn't have incandescent light, which is still the main at-home lighting used for most of the world. So after digging around some more, I found this:
Which isn't terribly helpful, but you can see how, even though it's better than most other types of artificial light, it still puts off more red than it should, particularly when compared to sunlight.
So there you go. More than you ever wanted to know about color.
And instead of no wisdom teeth, or super color vision, I really wanted the Power of Laundry. Damn. Maybe next time. I wonder if this would be good enough to get me into Xavier's School for Gifted Youngsters?