Thomas Edison. Thomas Alva Edison (February 11, 1847 â October 18, 1931) was an American inventor and businessman, who has been described as America's greatest inventor. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and the long-lasting, practical electric light bulb.
Pipe dope, or pipe joint compound, is a gooey compound used to seal the connection between threaded pipes and fittings. Because the threads in pipes and fittings still leave an air gap between the two surfaces, the gap must be filled to make it water tight (or gas tight for gas lines).
The tape helps lubricate the threads and improves the seal. Threaded joints where the pipe is not tapered (parallel threads) employ a gasket or washer to make the seal (such as on a union joint), in those cases, the tape serves no purpose, as the seal is made with the gasket, not the threads.o quote wikipedia.com: Commonly known as  Teflon tape, PTFE tape, tape dope, or  plumber's tape â is a polytetrafluoroethylene (PTFE) film cut to specified widths for use in sealing pipe threads. The tape is wrapped around the exposed threads of a pipe before it is screwed into place.