A digital, 3D printed sundial whose precise holes cast a shadow displaying the current time
by Cory Doctorow from on (#13D6C)
https://www.youtube.com/watch?v=cCe7m7mhUxY
Julldozer created an amazingly clever digital sundial ("Cadran Solaire Numi(C)rique") that precomputes the angle of the sun throughout the day and uses those computations to make hundreds of precise holes calibrated to cast a shadow displaying the present time. (more")