The second quantum revolution
For physicists trying to harness the power of electricity, no tool was more important than the vacuum tube. This lightbulb-like device controlled the flow of electricity and could amplify signals. In the early 20th century, vacuum tubes were used in radios, televisions and long-distance telephone networks.
But vacuum tubes had significant drawbacks: They generated heat; they were bulky; and they had a propensity to burn out. Physicists at Bell Labs, a spin-off of AT&T, were interested in finding a replacement.
