Fewer things have made a greater contribution to the general welfare of man than development of the electronic valve, or vacuum tube as it is commonly known. The vacuum tube heralded the birth of modern electronics.
Invented in 1905 by John Ambrose Fleming, the vacuum tube worked very similarly to the light bulb invention credited to Thomas Edison, via a flow of electric current through a vacuum. Its purpose was to act as an amplifier and a switch. Vacuum tubes could make weak signals stronger and and even more importantly, stop and start the flow of electricity instantly. Our modern computers are based on this very principle.
The Tube was standard equipment in radio receivers, radar sets, early television sets and other forms of electronic communications for half a century. People of a certain age can recall that at one time, every hardware store had a machine that could be used to test vacuum tubes. Eventually, the vacuum tube was replaced by the transistor. One transistor replaced the equivalent of 40 vacuum tubes!
The vacuum tube was an extremely important step in the advancement of computers. The massive ENIAC electronic computer, launched in 1947, was a thousand times faster than any previous electro-mechanical computers. It used 17,468 vacuum tubes instead of the earlier mechanical switches. Such a large number of vacuum tubes created other problems though, with massive power consumption, high heat generation, and the necessity for a huge machine footprint. Entire rooms were filled with the components to run a single machine.
Although transistors have largely replaced vacuum tubes, today the tubes are still popular with audiophiles who prefer them in stereo amplifiers because they produce less distortion. They are also still used in some electric guitar amplifiers. Just think: what could Leo Fender have done—along with a whole generation or two of electirc guitarists—without the invention of the vacuum tube? Not to mention the fact that computers in so many different forms and sizes today have become a huge part of our everyday life.