Colours in rainbow... 6 not 7...?

Question

i had a science teacher (very respected) who told us that there were 6 colours in the rainbow and not 7. here was what he told us:

1. having both blue AND indigo in the 'rainbow', is the same as saying, dark green AND light green are in the rainbow

2. back when (whatever his name was) discovered the 'rainbow' he was living in a very religious society and so instead of concluding he found 6 colours in the rainbow (6 being the devils number), he said he found seven (a good religious number)

3. try looking at rainbow and finding the blue, violet AND indigo colours!!

am i the only one who'd heard of this...?

does anyone else agree/disagree...? why...?

Answer 1

The rainbow is a continuous spectrum of color.    The "numbers" of colors in the rainbow are somewhat arbitrary, chosen by human convention and the sensitivity of the human eye.  I don't know why science teachers are bothering to deal with that question.  In physics and the  science of light there is an infinite number of different wavelengths of light in the rainbow.  There are as many colors as you would like there to be or as many as you can distinguish and make up names for.  

It's like arguing about how many ages there are for people.  One person insists there are only 2: child and adult.  One insists there are 5: baby, toddler, child, teenager, adult.  One person insists there are more including infant, tween, young adult,, old person, and geezer.  You see?  It's kind of a meaningless discussion--there are infinite ages for a person and you can group or categorize them however you want.  It's not a scientific discussion; it's more of a philosophy question.

Answer 2

your teacher is probably right, it depends on your view it self. Cause Newton originally (1672) named only five primary colours: red, yellow, green, blue and violet. Only later did he introduce orange and indigo, giving seven colours by analogy to the number of notes in a musical scale. Some sources now omit indigo, because it is a tertiary color and partly due to the poor ability of humans to distinguish colours in the blue portion of the visual spectrum.

these article may help you:

http://eo.ucar.edu/rainbows/

and dear... i just can't believe there is somebody connecting rainbow with the devils number

(personally i also disagree with this kind of matter that there is a number used for a devil?? oh c'mon..??)

but if you still want to talk this issue in a religious context, you may found this article is interesting:

http://home.earthlink.net/%7Emflabar/Col...

even it doesn't explain much.

(here i think that you're a Christian.. sorry if i'm wrong)

everybody loves rainbow.. and remember that rainbow is one of the God creation..

Answer 3

Okay, I've heard of this and I dissagree because that is the way the rainbow is, because thats how the guy made it. I personally agree with them because why do you need blue, purple and indigo. So, yeah. I think they only need 6. Yellow, Orange, Red, Green, Purple, Blue. Thyere is no real need for "Indigo", cause its just a mix of bluye.

Answer 4

I disagree, you can very clearly see the dark and light blue in a rainbow.  The indigo is right between the dark blue and violet.  It's that brighter shade between the two darker ones.  With the other colors, they only (dominantly) show a single hue, whereas blue has two distinct hues.

Answer 5

there r 7 colors in rainbow  as   violet ,indigo ,blue, green ,yellow, orange, red.in science no religious matter.