DISCO BALL MOON INFORMATION: The large mirror-tiles are 150km squared, and the small ones are 100km squared. They are all 10 km thick with glass (with an IOR of 1.56) There are 3012 mirrored tiles When as near as the ISS, the Earth surface to disco-ball-moon surface distance is 420 km or so The orbital period in relation to the earth is realistic, about a 2.1 hour period. When the disco moon is in low orbit, each reflection of the sun as a caustic is effectively a tiny sun, although you can never reflect enough light to get above the temperature of the surface of the sun (about 6000 degrees). Since the sunlight is going through glass first, glass will in general filter out a lot of the UV, so your caustics shouldn't reflect too much UV. The projection of a mirror-tile is larger than the projection of the sun when seen from low altitude. . when seen from far away the tile is smaller than the sun, and hence the caustic isn't as bright . Basically the disco tiles are glass with a silvered backing. Some of the light will not penetrate the glass, and will be simply reflected off the first surface of the glass, This reflection strength increases as the angle of incidence approaches 90, generally referred to as a Fresnel reflection.. or rather the strength follows that equation. This reflected light will generally be full spectrum The center of the giant flat mirror is orbiting at a distance of 2157.4 Km above the Surface of the earth, It's diameter is 3474.8 km (same as the moon), It's orbital period would be longer than the disco moon simply because it has less mass. But in this video it has the same orbital period as in the moon. The actual mass of the giant mirror is absurd.. it's way over­-engineered.. if a real one were to be built it wouldn't have huge thick rims, it would more likely resemble a girder work, with Mylar films. Not huge death star like mirror with towers, and strobe lights (and a strange lack of solar panels) Follow me on twitter! https://twitter.com/tweetsauce or instagram: http://instagram.com/electricpants and subscribe to Vsauce for more: http://www.youtube.com/user/vsauce?sub_confirmation=1 visuals by YETI DYNAMICS: https://www.youtube.com/yetidynamics music by JAKE CHUDNOW: http://www.youtube.com/JakeChudnow