Uranium glass is glass which has had uranium, usually in oxide diuranate form, added to a glass mix before melting for coloration. The proportion usually varies from trace levels to about 2% by weight uranium, although some 20th-century pieces were made with up to 25% uranium. This guy managed to get his hands on a uranium glass marble that is UV reactive, and the results are mind-boggling with the lights off. Click here to view the first image in today’s viral picture gallery. Continue reading for a viral video showing how to topple a giant domino with a tiny one.