Dutch sand writing artist Gijs van Bon wants his work to be ephemeral, so he designed a machine that he calls Skryf that writes on the sidewalk using sand.
Skryf started life as a CNC milling machine used for woodworking, but Van Bon hacked it so that instead of cutting wood, it lays down a thin line of fine white sand as it goes. The computer controlled cutting head now holds the sand dispenser, and moves so that the letters are laid down as neatly as any typewriter.
Skyrf can write about 525 feet a day, so it can get a good long piece of text down if needed. Still, you’ll have to read fast, because Skryf’s writing tends to disappear almost as fast as it’s written. Anything from pedestrians to the wind simply brushes the letters away.