Bell Labs Point-Contact Transistor

In December 1947, three Bell Labs scientists—including William Shockley—were trying to improve on the bulky, slow, heat-producing vacuum tubes used in the telephone system when they demonstrated an amplifier made of a tiny germanium chip that generated almost no heat. The invention marked the birth of the transistor, which paved the way for modern semiconductors by amplifying signals with a small, reliable, and mass-producible device.