or do indigo and violet just confuse matters?

[HoratiaWinwood]

A rainbow is a spectrum of visible light, right? So there aren't distinct stripes of colour.

What the fuck is with distinguishing between indigo and violet? What do we lose by saying purple?

Fuck. That. Shit.

From now on I'm saying purple. Physics Life is complicated enough already.

Eh, really a rainbow is red green and blue and the other colours are mixtures thereof.

I agree it's subjective and cultural, but it is helpful as it is because you have infrared red to the left of red and ultraviolet (UV) to the right of violet.
painless physics lesson

Purple doesn't help as much.

Oh and you do get pink and a bright cyan blue in the reflection rainbows of soap films and CDs. I believe that's because lots of rainbows cross and mix in these situations.

CDs
Pretty picture

The science bit

light isn't like paint

And here endeth the lesson I have daughters to feed

Richard - red
Of - orange
York's - yellow
Got - green
Big - blue
Pants - purple

Hell I'm still sulking cos they took Pluto out of the Solar System and it messed up My Very Elegant Mother Just Sat Upon Nine Puppies.

I saw a program about a tribe of people who didn't distinguish between blue and green, it was a cultural construct that meant they simply had no grasp of there being a difference

Bugger turquoise then! Apparently the Welsh have a different concept of this anyway.

I'm with you Beat - My Very Easy Method Just Set Up Nine Planets. It was the perfect nemonic now defunct in two ways. So sad.

Newton was a genius, probably the greatest mind this country has ever seen, but that doesn't mean he wasn't also a bit of a loony alchemist. Seven is nice magical number, hence everything comes in sevens even if that means you have to make stuff up.

Camila is right about there being six colours - it was on QI, so it must be true.

(Though haven't read Startail's links yet, so expect to be proved wrong.)

The guy who decided on 7 colours in a rainbow was into numerology and didn't like the number 6 so had to come up with a new colour.

ROY G BIV that's how I learnt it at school

Ah yes, Roy G Biv! But it always struck me as an odd way to try to remember anything. Who is/was Mr Biv anyway?

Following on from Horatio's post, I suppose what this illustrates - along with the demotion of Pluto from planetary status - is that while we believe that science describes an objective reality, in fact it can depend on our definitions and cultural perceptions.

DD is very cross about Pluto as she has a mnemonic that is now defunct too!

Startail - your link doesn't work for me, what is the the light isn't like paint thing? I was trying to remember it the other day and couldn't work it out.

This really made me laugh OP! DS is 2.10 and I was convinced he was colourblind for ages. Now he has been able to explain that the big standard blues and reds just don't cut the mustard in his world. He is all about the purples vs indigo vs mauve vs violet!! Yesterday I heard DH have to use taupe as a colour before he was satisfied!! I think I'm going to get him a job at Dulux as he would love to have to distinguish between Crushed Gooseberry 5 and 6!!

I meant bog standard!!

Ginandtonic My DS also decided that the standard primaru colours were not enough and kept asking me for the names of all the various shades in between. So I took him to B&Q. He was very impressed with the booklets 'of every colour in the whole world.' .....and even more impressed he was allowed to take them home for free!

Oh great idea! I'm glad he's not the only one - I was starting to wonder at his sanity. He is so pernickety about certain things!!!

Virgins In Bed Give You Odd Results! Courtesy of my old physics teacher - no-one forgot that one!