For old-timers, CRTs — cathode ray tubes — were fixtures as kids sat ... We don’t miss that either. The basic idea is simple. An electron is fired at the phosphor behind the screen.

The glass envelopes of the cathode-ray tubes were carefully cut from the sockets, and the guts of the tubes were discarded to make room for the replacement circuit, which lives on two PCBs.

Between his 1874 discovery and his invention of cathode-ray tube in 1897, Braun moved from strength to strength in his teaching career. Having started out as a teacher at a Gymnasium (school ...