In 1959, Bell Labs researchers Dawon Kahng and Mohammed Atalla developed the world's first truly compact semiconductor, the MOSFET transistor. Their transistor wasn't the first, but it was the first that could be miniaturized and mass-produced practically.
And when I say "mass-produced," I really mean it...
Analyst Jim Handy, talking to the Computer History Museum, estimated that some 13 sextillion (13, followed by 21 zeros) transistors have been manufactured since the very first prototype in 1947. By his estimate, that makes the transistor the most numerous manmade item in all of human history by a comfortable margin.
In fact, as of 2018, there are probably more transistors on Earth than there are grains of sand.
Good thing, then, they've been growing smaller by the year.
Back in 1954, colorful Regency TR-1 "pocket" radios sold for the equivalent of $476 in today's dollars. The TR-1's four pricey transistors meant a little less than 20% in profits for Regency.
The Sony TR-63 hit shelves in 1957. It sported six transistors and sold for roughly $354 of today's dollars.
Smaller, more powerful, cheaper - with fatter profit margins, to boot.
By 1959, there were 6 million personal radios in America that brought in $1.3 billion (in 2020 terms) in profits for the three Japanese companies - Sony, Sharp, and Toshiba - that made them.
In 2020, every single iPhone 11 Apple makes sports 8.5 billion transistors, more than 171 million per square millimeter of chip. Estimates vary, but Apple may make 40% in profits on every unit sold.
You could easily argue the transistor belongs up there with the wheel, the nail, and the brick among the inventions that "changed everything." It has certainly generated incalculable wealth.
Today, the semiconductor industry is worth around $430 billion and counting.