I have a confession to make, and hope that it will help others. When faced with a graph like the one below about light pollution I panic, and look away befuddled. All those coloured sections of lines mean nothing to me.
Tonight though I really wanted to understand the graph above and asked my partner Deb if she could explain it to me. She has a far deeper understanding of maths than I do.
She pointed to the bottom line, Iceland, and to the key, and showed me that a tiny percentage of Iceland, maybe 1%, is polluted at the low level shown at the top of the key. Then another chunk, the blue, maybe 5%, is polluted at the blue level in the key. And so on, until 100% of Iceland has been accounted for.
In other words, instead of a pie graph where different chunks fill up a circle, these chunks have been reshaped to fill a line. It’s a flattened out pie graph.
Of course! It’s so obvious now I can’t even begin to understand how I could have been so befuddled by the things before. Except, that’s so often how things work: utter mystery, until you understand it, then absolute puzzlement that it could ever have been a mystery before.
And the benefit of this flattened form of the pie graph (I’m sure it has an official name) is that it’s easy to compare one instance with another. A page of 20 round pie graphs would make that very hard indeed.
Singapore’s night sky is very bright, very polluted. 100% of it is affected by the highest level of light pollution. In Iceland though, there’s only around 40% of extreme pollution.
So that’s something, I guess.
Oh, and New Zealand doesn’t show up in the list of most light polluted countries. That’s a big thing.