I need to get something straight.
In the acronym for the colors of the light spectrum, is it ROYGBIV or ROYGBV?
Is indigo supposed to be included in this acronym?
I really need to know, I have a wager riding on this.
Thanks!
I need to get something straight.
In the acronym for the colors of the light spectrum, is it ROYGBIV or ROYGBV?
Is indigo supposed to be included in this acronym?
I really need to know, I have a wager riding on this.
Thanks!
Red
Orange
Yellow
Green
Blue
Indigo
Violet
(Make sure you cut me in for half of your winnings.)
I’ve always heard it as “Roy G. Biv,” like a person’s name, including the i.
Hope this helps.
Me, I always suspected that we kept the “I” = “indigo” so that old Roy could have a pronounceable last name. Your average person wouldn’t know what “indigo” was. I’ve been told that it’s the color of blue jeans, but I’d tend to call that “blue”. There are some people who insist on Seven Colors, but there’s no fundamental reason for that. Colors, like musical sounds, actually form a pretty continuous spectrum with infinite gradations. People impose eight-note octaves ans seven-color spectra.
It’s a a mnemonic not an acronym. Mnemonics help you remember things. Acronyms are abbreviations for a longer name like RADAR.
The proper mnemonic is Roy G Biv. Indigo is supposed to be included. Run a google search on the spectrum of white light or prisms and refraction and this should be confirmed. If you look at a color plate of the visible spectrum of white light, there are distinct bands of color. Violet and indigo are the most difficult to distinguish because the wavelengths are much shorter at that end of the spectrum. The difference between red and blue is about 1700 A*. The difference between blue and violet is only about 700 A.
Again, it is a continuous spectrum, so you can define any color names you like. The 7-color range is what’s in common use. Blue-Violet, and Orange-Yellow are perfectly acceptable. If you do any kind of spectral line analysis, talk of Angrstroms can become tedious, instead of saying “4340 A”, it’s often easier to say “blue-violet”.
[sub]* Angstroms. (and these are gross approximations, because it’s late and I’m lazy) :)[/sub]
It’s ROYGBIV, easily remembered in two ways (that I know of), I’ll leave you to guess which one nearly got my physics teacher fired for telling us:
Richard
Of
York
Gave
Battle
In
Vain
or
Roll
Over
You
Great
Big
Innocent
Virgin
There are other useful color mnemonics. Here’s one that is probably familiar to anyone who ever worked in a color photo printing darkroom: Red Cadillac By General Motors.
RC BY GM is the set of CMY primaries and their opposites.
Red/Cyan Blue/Yellow Green/Magenta
I use this one all the time because I can never remember the complementary color for yellow or green, which is rather important when you’re working in RGB.
IIRC, I think someone once told me that indigo was a color made up expressly for the purpose of balancing the spectrum.
That is, the people wanted there two be seven colors for symmetry and numerological sake.
Anyone else remember this bit?
I’m not sure it was made up to bring the number to seven, as I noted above, I think that seven as a mystical number “worked” for the spectrum, so people expected it to be there, and wanted seven colors. I doubt if any one person is responsible. I think there’s a lot on this in Carl Boyer’s book The Rainbow from Myth to Mathematics. I gotta go dig out my copy.
Incidentally, the seven colors don’t take up equal space in the spectrum. Yellow is absurdly narrow compared to Green or (especially) Red, so when they named the colors they weren’t voting by population. I’m referring here to color widths by wavelength, which is the way you get them if you use a diffraction grating. As Minnaert (The Nature of Light and Color in the Open Air) points out, the relative widths of the colors in a rainbow depends on the size of the drops. But I don’t there is any drop size that makes the seven color bands equal.
As I have read it - Newton, who discovered the separation of light into its componant colours, was a religious Christian and since seven is the number of G-d in the Christian tradition, he wanted very much for there to be seven colours. There are people who can distinguish between two shades at the violet end of the spectrum - I am not one, perhaps Sir Isaac was…
Gp