Then get a grant and make one as wide as a city street

Love it, thank you for sharing and for being inspiring :-)

The video URL doesn't seem to be correct, through. ;)

nowadays when people don't want to go the rotating led bar way, which requires very high density led strips (hundreds of ~200-400 mil smd leds) and the accordingly complex control circuitry (basically an FPGA per bar + high speed bus, etc), they do nipkow disk but with individual leds instead of holes. this way you can get away with tens of leds while still having a reasonable sized picture and not that much bandwidth to drive it.

edit: another, less sophisticated take is for example

https://hackaday.io/project/191947-rotating-led-display/deta...