A propos Derb and tinkering, several readers have written to remind me of Hedy Lamarr, who, aside from looking very fetching without her clothes on in Ekstase (1933) and almost as lovely if overly dressed in Algiers (1938), invented in her spare time a frequency-hopping system for torpedo guidance that was the forerunner of today’s spread-spectrum communications technology in WiFi and whatnot.