Last week Andrew Gelman picked up on a couple of graphs of extremely long time periods. Here they are again for your convenience (when one mentions a subject such as climate change, it’s like a magnet for time-wasters, so I’ll spare you from reading through the explosion of comments at Gelman’s blog)
What’s going on in that x-axis?!
Gelman liked the spirals within spirals; not everyone did. It put me in mind of two examples I saw recently when reading Isabel Meirelles’s book “Design For Information” (which is excellent!). The first is not good, in my humble opinion:
“10 years of Wikipedia” is a series of line graphs that are bent round into a spiral. You are supposed to compare the position of the line to the ideal spiral in grey. What this adds above and beyond the area chart on the left is questionable. I find it impossible to see the patterns, and I imagine that is something to do with how our brains perceive position radiating out from a central point.
The better use is when the spiralling is metaphorical. In this image from National Geographic, the number of space exploration missions that have flown by and visited different planets and moons are shown as concentric rings. One gets an immediate feel for the number of rings.