It has been 40-years since research was published that led to the development of LCD flat-screens, which revolutionized computers and TV. Way back then, British chemist George Gray came up with a way to make liquid crystals that worked -- and here was the trick -- at room temperature.

Mark Lorch, a chemist at Britain's University of Hull who has been covering the history of LCD's in The Guardian, joins Marketplace Tech host David Brancaccio to discuss the origins of the LCD flat-screen, a hidden identity, and what the British military had to do with it.