Bouncing Putty

Looking for a synthetic rubber during the Second World War, James Wright at General Electric heated silicone oil with boric acid. The result was no rubber: it bounced, shattered under a hammer, stretched like toffee when pulled slowly and slumped into a puddle overnight. Nobody found an industrial use; in 1950 it was sold as a toy. **US 2,541,851**, "Process for making puttylike elastic plastic, siloxane derivative composition containing zinc hydroxide", Wright, assigned to General Electric, filed 23. December 1944, granted 13. February 1951: liquid dimethylsiloxane heated with 5 to 25 % by weight of a boron compound such as boric acid or borax. **You measure both of its lives**: how high it bounces, how fast it flows, and where one turns into the other.