Almanac: The vacuum tube
And now a page from our "Sunday Morning" Almanac: November 16th, 1904, 110 years ago today . . . the birthday of an invention heard 'round the world.
For that was the day the British inventor John Ambrose Fleming patented the Thermionic Valve, otherwise known as the Vacuum Tube.
The 1943 film, "Electronics at Work" (which explored how these inventions were applied "to the service of Man"), showed how the vacuum tube worked . . . a flow of electrons from a fixture called a cathode, through a vacuum, to a receiver known as an anode.
And the way vacuum tubes served most Americans for many years was inside their radios.
The radio back then was frequently like a piece of furniture, in the center of the room, and filled with vacuum tubes.
After World War II came an even bigger vacuum tube: the cathode ray tube that provided the picture for generations of television sets.
Today, of course, transistor, chips and wafer-thin flat-screens have largely replaced old-fashioned tubes, but the vacuum tube still glows warmly in many a memory.