[fbcsafas] Heliostat

Create a device with a pointer that always points towards the sun without having to see the sun.  Fully automatic, utilizing GPS position, radio time, and magnetic compass would be neat.

Kind of an inverse sundial.

Also mark the circular path of the sun, so we know where it is going.  Mechanically probably similar to planetarium projectors or equatorial telescope mounts.

One alternative very simple version has three dials mounted orthogonally, e.g., on the faces of a cube.  Each dial hand points in the projection of the sun-pointing vector on the dial face.  You have to imagine the actual vector.  Perhaps an additional hand for moon.

A related simple device has an automatically spinning, automatically tilting globe illuminated by a static light source.