Suggested 20-30′ tall, though 100′ would be fantastic.
Fantastic proposed architectural monument to Isaac Newton by Etienne-Louis Boullee from 1784. Never built, I particularly like the glowing orb rotating within a large sphere in the second image.
An idea for a manually ray-traced, reflective sphere:
Step 1: A large sphere made of small facets – the pole to the right would have a laser-pointer attached at the top as the “light source”
Step 2: The laser traces four lines, one from the source to each of the corners – the points that they meet the floor are noted
Step 3: The resulting square is the shadow cast by that facet; the process is repeated for each facet
Step 4: A mirror is affixed to the facet and the laser is pointed at the center, reflecting out into the room
Step 5: The spot that the reflected laser beam hits is photographed, printed, and affixed to the facet on the sphere; this process is repeated for each facet
A lot of math today: if all the zeros and ones on my hard drive weighed 1 gram, they would form a pyramid running from the center of the Earth to a base of 6.2cm and 5.5cm respectively. If tipped on its side, that would mean the pyramid would run from NYC to Torino, Leipzig, Berlin, Senegal, or La Paz.
Map radius calculations via: Free Map Tools