This colorful diagram depicts the allocations of frequencies of the electromagnetic spectrum in the US. It's stunning to see how revealing the comparison between different media/communication system and the spectrum range they "inhabit". For instance, blue is “tv broadcasting". Navigation is very present too.
Why do I blog this? Lots of stuff to analyze with these inscription, it's intriguing to see what you can draw in terms of social organization (as well as assumptions about society) from technical diagrams like this. A nice exercise for the bored reader, try to find 3 hidden patterns about human activities in this representation.
On a more user-centric angle, see also “the bubbles of radio”.