From youtube – on how it works:
LowerCO2-
The board respects celestial mechanics (Kepler Rocks!). It’s perpendicular to the equator, with an unobstructed exposure to the west. The “waves” start at about 12:00 when the sun crosses the threshold above the board. The challenge was not the sun’s azimuth, but altitude, which due to the Earth’s tilt requires the scalloped awning’s shape to be distorted so the shadow appears correct. Thanks to CBS Outdoor…