Spectral serendipity
01/06/12
This morning we had a serendipitous moment that I wanted to record for posterity.
I love answering Lily’s questions about things, about anything. It makes me realise that by teaching we also learn.
As I’m answering it gets me thinking, both about the subject and about a good way to demonstrate or illustrate the answer. Often I’ll try and use some nearby thing to help.
The school is closed for a PA day today but Harry’s daycare is open, so we headed to drop him off just before 10. It’s rainy & grey out so we had raincoats on. Just as we arrived Lily asked why raincoats are often yellow. I told her it probably came from fishermen’s bright yellow sou’westers, and as I told her I thought about why that might be.
“Maybe it’s because yellow stands out well against blue, so if a fisherman fell in the sea he’d be easier to spot. The same way lifejackets are often yellow,” I said.
Lily thought for a moment and added “yeah, because yellow and blue are opposites.”
“Yes they’re opposites, they’re opposite each other on the colour wheel,” I said, opening the school building door. And right inside, on the floor, was an open umbrella which was basically a giant colour wheel! So we were able to check that, yep, yellow and blue are opposite each other.
We dropped Harry off and he got upset because I’d forgotten to bring indoor shoes for him, so we left him in Andrea’s arms and headed back home in the rain.
Postscript
I carried on thinking about colour wheels and the electromagnetic spectrum and it occurred to me for, I think, the first time, how curious it is that red and violet are quite similar colours.
They blend into each other even though they’re at opposite ends of the particular chunk of spectrum that our eyes and brain can perceive.
It’s amazing enough that visible light is part of the same physical mechanism as heat, radiowaves, microwaves, x-rays etc.
But also amazing that our brains have mapped this particular chunk of the spectrum so neatly to the colours that it can “display” that our visible colours appear to smoothly cycle.
Natural science is… just… wow!