In the early days of aviation, airports would paint their name in big letters on the roof of the terminal. Incoming aircraft had few navigational aids at the time, so turning the territory into something resembling a map was a clever expedient.
I like the fact that nobody on the ground ever saw the sign. It was a well-targeted sign, visible only to the eyes that needed to see it.
Now we all have eyes in the sky. We travel by air more these days, but beyond this, Google and other mapping services have given us a permanent seat in the sky. Deskbound archaeologists can discover previously obscure ruins. But what about signage for the Google Earth set?
It’s arrived in the form of rooftop QR codes. Want to know what company is based in that building? Just scan the code. You’ve heard of cornfield mazes. Now meet the QR cornfield. We should carve a giant QR code onto the moon so that approaching spaceships could scan it. But what to link to? Assuming visiting aliens could decipher the message (and why not? they’ve got a freakin’ spaceship already), it would be good to link them to a video of earth music. Perhaps something by Rick Astley.