“Unlocking the Future: How a Simple Discovery Revolutionized Technology and Changed Our Lives Forever”
Ever pull out the relic of a flip phone from your pocket and think, “Wow, this ancient technology still trumps what sent humans to the moon!”? It’s wild to consider, right? The Apollo Guidance Computer boasted a mere 17,000 switches, while your lowly 2002 flip phone packs billions of ’em into a shell no bigger than a cupcake! This magical miniaturization came thanks to the marvelous invention of the transistor, that brilliant little invention that transformed not just our gadgets but the entire tech landscape! But here’s the twist—the saga of the transistor is riddled with twists, turns, and a whole lot of mishaps, all starting with Edison’s accidental spark back in the day. So buckle up as we delve into the electrifying tale of the transistor, a groundbreaking invention that literally changed our world! If you’re curious to learn how this began, just hit that link to LEARN MORE.
Reach into your pocket and pull out your cell phone. Even if you are rocking the most ancient, stripped-down flip phone from 2002, the object in your hands is still a marvel of modern electronics technology, packing billions of tiny switches into just a few cubic centimetres of space. By contrast, the Apollo Guidance Computer that sent humans to the moon contained only 17,000 switches, while the three-storey building-sized SAGE computer used for North American aerospace defence in the 1950s contained 50,000. This tremendous feat of miniaturization was made possible by advances in integrated circuit manufacturing, in which entire computers composed of parts just a few billionths of a meter across are etched into the surface of tiny silicon chips. But these developments would never have happened were it not for one key breakthrough made nearly 80 years ago – a discovery that forever changed the course of technology – and the world. This is the story of the transistor, one of the single most important inventions in modern history.
In the first half of the 20th Century, electronics design was dominated by one key piece of technology: the vacuum tube.
During Thomas Edison and his team’s thousands of experiments trying to create an economically viable incandescent lightbulb, there was a rather insanely revolutionary and far more unique device Edison accidentally invented in parallel with the lightbulb that was just one of his lightbulbs with a slight twist. But unfortunately for Edison, he did not realize the implication of what he’d just made in one of his thousands of tests, and how revolutionary it could be if refined a bit, and in the right applications. Because of his failure to realize any of this, nor be the one to perfect it for commercial use, despite his patent for the device, Edison is almost never given credit for his contribution on this world changing invention. Which is unsurprising as, as is a theme you’re probably picking up on, it’s the person who ultimately did the thing in its perfected commercial form, rather than was the first to come up with the thing, that usually gets credit in popular history.
On this one, enter English physicist John Ambrose Fleming, who was an advisor to Edison Electric Light. He would be inspired by Edison’s device to create his revolutionary Fleming valve vacuum tube in the early 20th century.
But going back to Edison’s original device, at one point during his experiments on the lightbulb, he and his staff were trying to figure out why carbon from the filament seemed to be jumping across the vacuum to the walls of the bulb. Clearly some current flow was involved. So in order to try to figure out what was going on here, Edison created a special bulb with a third electrode placed in between the legs of the filament, and then connected that to a galvanometer to measure the current. What he found was that if, relative to the filament, the plate was put at a negative potential, there would be no current between the plate and the filament. However, if the plate was at a positive potential, and the filament heated up enough, there would be a large current flow between the filament to the plate through the vacuum. Importantly in this, the electrons can only flow one way, from the hot element to the cold one, creating a rudimentary diode.
Edison ultimately patented the device for its potential use as a sort of voltage regulator, but seemingly did not understand the implications beyond that. Importantly, he did show it off at the International Electrical Exposition in Philadelphia in 1884, with one William Preece bringing several of these bulbs back to England and coining the term “Edison Effect,” also now known as “thermionic emission,” in a paper he published the following year on the phenomenon. And, of course, as noted, a couple decades later Fleming was inspired by all this and ultimately did his thing, as did others like Lee de Forest in the United States and the electronics age was born.
Vacuum tubes came in two basic varieties, which allowed electricity to be controlled in particular ways. The diode or thermionic valve, invented by Fleming in 1904, consisted of an evacuated glass bulb containing two basic components: a fine metal wire anode and a plate-shaped cathode. When current was run through the anode, as alluded to in the Edison test, the filament heated up red-hot and began giving off electrons via a process called thermionic emission. These electrons were then caught by the cathode, allowing the current to pass through the diode. If, however, the current was reversed, the lack of a filament on the cathode prevented it from heating up and emitting electrons – meaning the current could not flow in that direction. Diodes thus functioned like one-way valves – hence their alternative name – and were widely used as rectifiers for detecting radio signals, replacing the temperamental crystal detectors previously used in commercial radio sets.
