If you’ve ever wondered exactly what UHF, VHF, UV, LFO, gamma rays, cosmic rays and so on are and what exactly it is they do, this awesome old chart should do you right. Among other things, it has frequencies of quartz transparancy, FCC-allocated RF bands, the range of the human eye (distressingly small, top right), absorption rates by air, water, aluminum, copper, and lead, and about a billion other awesome things.
The amount of knowledge summarized by this chart is staggering to me. It’s like an entire electromagnetic almanac in a single illustration. These types of charts are common (XKCD parodied one) but this is particularly impressive. Commenters at Reddit pointed out a more complete, but less picturesque chart and a very utilitarian but informative allocations chart.
Very cool! Now you won’t have to make something up when your kid asks you why you can’t see microwaves.