How did the transistor change the world?

The transistor made electronics small, cheap, durable and efficient. It could amplify a signal and switch current on and off, which let it replace vacuum tubes. That change opened the way to integrated circuits, personal computers, portable radios and the digital devices of today. Some historians of technology call it the most important invention in human history, though that is a judgment and not a settled fact. [1] [2]

Before the transistor, electronics relied on vacuum tubes, glass bulbs with charged plates inside an airless space. According to Popular Science, tubes could generate more power, but they were bulky and delicate, burned out quickly and needed time to warm up. The American Physical Society notes that AT&T found tubes unreliable, power-hungry and hot, and that they could not handle the ultrahigh frequencies needed for transcontinental telephone service. [1] [2]

The Computer History Museum summarizes the transistor's advantages as smaller size, higher reliability, lower power use and lower cost. Popular Mechanics gives a comparison: the ENIAC computer needed about 150 kilowatts, while a smartphone uses less electricity in a year than ENIAC used in one minute, and performs billions more calculations per second. [3] [4]

The first transistor, built by William Shockley, John Bardeen and Walter Brattain, was about the size of a human palm and made of germanium. They won the 1956 Nobel Prize in Physics. By the mid-1960s most transistors were silicon, and engineers were packing them into integrated circuits, the basis of computer chips. Moore's law, the observation that the number of transistors on a leading-edge circuit doubles roughly every two years, has guided the industry for decades. Modern transistors are a few nanometers across, and a typical processor holds billions of them. [1]

Science magazine estimates that at least 3 sextillion transistors have been made and shipped since 1947, a year in which the count started at zero. It also stresses that development into modern integrated circuits was the work of huge teams of researchers and engineers, not only the original inventors. [5]

The first transistor product on the market was a hearing aid in 1953, followed by the transistor radio. Portable tube radios existed, but Popular Science says handheld radios likely would not have become so common without the transistor. The inventors themselves expected uses mainly in special instruments and possibly military radios, according to IEEE's Ravi Todi. [1]

Computers changed too. ENIAC used 18,000 vacuum tubes and filled a space the size of a ballroom, and 1951's UNIVAC I cost over a million dollars and was bought by large businesses and agencies. Transistor-powered personal computers reached middle-class homes in the 1970s and 1980s. The Apollo guidance computer was also transistor-based, and Science notes that transistors supported tools such as DNA sequencing through computing and high-power electronics. The Computer History Museum traces today's chips, phones, cars and appliances back to the transistor. [1] [5] [6]