Overview

In 1895, using principles of electricity worked out in the earlier part of the century, the Italian engineer Guglielmo Marconi (1874-1937) sent a radio signal more than a mile (1.6 km). The work of Marconi, and of those before him, laid the groundwork for investigations into the electrical properties of solids that opened ways of manipulating electrons to do useful work. The result of these endeavors was a humble device called the transistor, which formed the basis for the revolution in microelectronics that is now reshaping the world. It won for its inventors the 1956 Nobel Prize in physics.

Background

Radio waves are easy to send, but they are difficult to detect. They are difficult to detect because the current in an antenna oscillates back and forth, or alternates, and earphones require one-way bursts...