Dear List Subscribers, I propose a challenge to the tinkering gang:
Devise and BUILD a dialists' (i.e., shadow-observation- based) method to measure the apparent angular diameter of the sun, and to compare its values at the two solstices. No glass, or specular-reflective, image-forming elements are allowed. "Pinholes," opaque or transluscent screens, shadow-sharpeners, camera obscuras, and opaque-walled sighting-tubes are permitted. Clocks and watches may be employed. No prize is on offer. The only reward will be the fun of trying, and perhaps, "bragging rights" for elegance, precision, etc.. Bill Maddux
