TABLE OF CONTENTS The invention of the transistor in 1948, by Nobel Prize winners Bardeen, Brattain, and Shockley of Bell Telephone Laboratories, has greatly changed the industrialized world. The transistor can increase the "amplitude" (voltage or current) of signals such as voice messages or machine-generated numbers, without wasting much energy as heat, or taking up much space, or costing much money. This means that a signal can be sent around the world, or through an extremely complex computer, without becoming weaker, because any decrease in amplitude can be made up for by a multitude of small, cheap transistors. If the signal becomes too strong, it can easily be "attenuated" (made weaker) by a resistor, which can bring it back to the original amplitude.
Another important factor, however, is the fairly new development of "digital" technology (which will be discussed in a later chapter). This prevents "noise" (random errors) from creeping into the signal. The two innovations, transistorization and digitization, have made it practical for us to make electronic systems of almost unlimited complexity. As an everyday example, the extremely complex little microprocessors in most new automobiles have improved gas mileage, lowered pollution, and improved the effectiveness of brakes. Of course, the reader knows of many other examples, such as cellular phones, etc.
An analog of the transistor is a water faucet, where a small amount of energy can open or close a valve, thus controlling a high pressure or flow rate. In the electrical case, a small voltage or current...
