https://www.youtube.com/watch?v=hwutHPYGgfU&list=FL9hgMHEAgpaOqfhbvB4aLpg&featur...


Here is a really cool retro video made by Westinghouse in 1943 about vacuum tubes that explains what they are and how they work and the various uses for them.

You'll probably be surprised that tubes are what made the industrial revolution possible, not to mention winning the war.

Enjoy,

Steve

BTW  the page I linked to also has some 96 of my favorites on youtube... which apparently auto play after the Westinghouse video.  Some of them are actually pretty good.