Thomas Edison was involved in the invention of revolutionary devices like the camera, the microphone and the phonograph.But none are as famous as his improvement to the light bulb that brought light to homes around the world.A leaky receptacle causing a chemical leak.A fire in a train carriage.The list of reasons why Thomas Alva Edison was fired from the various jobs he held in his youth seems almost as long as that of the patents he filed.If Edison the inventor had revolutionary ideas which were to influence the destiny of the various sectors in which he had worked before he was fired, Edison the young man had for his part, and in the words of his published obituary in 1931 by the New York Times, "earned a reputation as a [telegraph] operator unable to hold a post".As history would show, Thomas Edison would eventually become famous for his legendary ability to apply himself (and for his oft-repeated mantra that genius is "one percent inspiration and 99 percent perspiration." ).He was to develop devices that would define the world as we know it today as well as a number of groundbreaking innovations.His work to improve the incandescent light bulb, for example, allowed as many people as possible to use electricity for lighting at home.This is how the man who was sometimes nicknamed the "wizard of Menlo Park" carved out a reputation commensurate with his excess and why he is still considered today as the greatest inventor of all time.Born in Ohio in 1847, Thomas Alva Edison grew up in Port Huron, Michigan, where he received only a brief formal education.His mother, a former teacher, educated him at home from the age of seven and made him a great reader.His youthful adventures were notably marked by ambitious chemical experiments in his parents' basement which resulted, in the words of one of his biographers, in "near-explosions and near-disasters".Pictured here at the age of 14, young Thomas Alva Edison had ideas that changed the world, and which often distracted him from the mundane tasks he was made to do in the all-too-common jobs he had busy in his youth.From the age of 12, driven by curiosity and his entrepreneurial spirit, Thomas Edison became a traveling merchant (news butcher) for a railway line.He sells snacks, newspapers and products of all kinds on board the trains.Not content with selling the news of the day, he also decides to print them.He then founded and published the first newspaper written and printed on board a moving train: the Grand Trunk Herald.He will continue his chemical experiments on board the train.At the age of 15, thanks to his unique propensity to get fired for thinking about his experiments and inventions instead of working, Thomas Edison became a traveling telegrapher for Western Union before settling in New York to open his own studio.The telegraph inspired many of his first patented inventions.In 1874, at the age of 27, he invented the quadruplex telegraph, which allowed telegraphers to transmit four messages simultaneously and increase the performance of this sector of activity without having to build new telegraph lines.Sketch of an electric light bulb drawn by Thomas Edison on February 13, 1880. The previous year, the inventor had demonstrated the durability of his light bulb in front of a hundred people in his Menlo Park laboratory.In the meantime, Thomas Edison married one of his employees, Mary Stilwell.Together, they moved to Menlo Park, New Jersey, in 1876. This rural setting was the perfect place to set up a new laboratory in the image of his inventive and entrepreneurial spirit: a research and development infrastructure where Edison and his muckers, as he called them, can build anything they can think of.Thomas Edison continued to perfect the telegraph, and while working on a machine capable of recording telegrams, he had the idea of ​​making it record sound as well.He therefore creates a machine translating the vibrations produced by the voice into marks on a piece of paper.In 1877, aged 30, Thomas Edison recited the first two lines of the nursery rhyme "Mary had a little lamb" in his device and played them back using a crank.He had just invented the phonograph (Edison Speaking Phonograph).In the same year, he developed an improved microphone transmitter that would improve the telephone.This four-meter-tall replica of an incandescent light bulb sits atop the Thomas Edison Memorial Tower in Menlo Park, New Jersey.It took more than 2,700 kilos of glass, a three-tonne steel skeleton and eight months to build.Edison's phonograph is a revolution but it is considered above all a bauble.Anyway, the brilliant inventor has already moved on to another idea that will change the world: the incandescent lamp.Light bulbs have been around since the early 19th century but are fragile and short-lived because of their filament (the light-emitting part).An early form of electric lamp, the arc lamp, was powered by steam generated by carbon rods heated by a battery.But you had to turn it on by hand and the bulb flickered, hissed and burned out easily.Other models were indeed imagined but they were too expensive and too impractical for their use to become widespread.Thomas Edison's filaments, on the other hand, were cheap, practical, and durable.In 1879, after years of obsessively perfecting his idea, he created a light bulb capable of lasting 14.5 hours, a record.“My light is finally a perfect light,” he prides himself on a journalist from the New York Times.When news of his invention spreads, the public flocks to Menlo Park and hundreds of people have the chance to visit his laboratory (illuminated by electricity) during a public demonstration which takes place on December 31 1879.“The opinion of [scientists] as well as the opinion unanimously expressed by non-scientists was that Edison had actually produced the light of the future,” wrote the New York Herald at the time.Then, a black inventor by the name of Lewis Latimer improves upon Edison's advance by making filaments that are more durable and having them made efficiently.Meanwhile, Thomas Edison creates a service to provide electricity and works on innovations that should make electric light more accessible.Drawing by Lewis Latimer showing him working as a consultant for engineer Edwin Hammer in 1912. Lewis Latimer collaborated with the luminaries of his time: Thomas Edison, Alexander Graham Bell and Hiram Maxim, among others.Thomas Edison's inventions earned him international fame and generated ruthless competition around electric currents.Edison's systems run on direct current, which can only deliver electricity to a large number of buildings in a densely populated area.However, Thomas Edison's competitors (including famous Serbian-American inventor Nikole Tesla and George Westinghouse) used alternating current systems.These are less expensive and allow electricity to be delivered to customers over long distances.Helpless, Thomas Edison sees alternating current systems spreading.He then uses the press to fight Westinghouse and Tesla.According to him, the fatal electrocutions are due to alternating current.He launches an advertising campaign showing the deadly potential of alternating current.The competition reached a certain level when Thomas Edison decided to finance experiments in public during which animals were killed by electrocuting them with alternating current.But a macabre climax is reached when Thomas Edison, desperate for his technology to prevail, secretly finances the invention and construction of the first electric chair by having it run on alternating current.Despite the shock caused by his campaign to smear alternating current, Thomas Edison ended up losing the power war because of market realities and the waning influence of the electricity supplier he created.In 1884, tragedy struck when Mary died of what appeared to be a morphine overdose.Two years later, aged 39, Thomas Edison married Mina Miller, who was then 20 years old.While spending the winter in Fort Myers, Florida, the couple met a man who would become one of Edison's scientific collaborators: Henry Ford, automotive pioneer and founder of the Ford Motor Company.During World War I, both Henry Ford and Thomas Edison worried the United States depended on the United Kingdom for rubber supplies.It is indeed an essential material for the war effort.Together with Henry Firestone, who made his fortune selling rubber tires, the duo founded a research organization and a laboratory to discover potential domestic sources of rubber.Edison will consider for a time that solidago could act as a substitute, but the project will never prove viable enough to produce rubber locally.Thomas Edison will continue to make a name for himself thanks to the inexhaustible energy that drives him to innovate and experiment.His inventions will benefit many areas ranging from cinema (we owe him the opening of the world's first film production studio, the Black Maria, created in 1893) to talking dolls.According to him, he sleeps only four hours a night, does not believe in the benefits of physical exercise and, according to rumour, lived only on milk and cigars for years.He succumbed to complications from diabetes in 1931, at the age of 84.Lewis Latimer, one of the earliest known African-American inventors, played a crucial role in the development of many modern innovations such as the incandescent lamp.He made the carbon filament of Edison's light bulb even stronger by sheathing it with cardboard.The hand of the "Wizard of Menlo Park" is still felt in the myriad of areas he influenced.From cinema to fluoroscopy to electric batteries, there seems to be not a single corner of technological innovation that he hasn't touched.During his lifetime, he will have accumulated no less than 1,093 patents to his name in the United States alone.Throughout its existence, it will have been criticized for what some took for a botched approach to innovation.But Thomas Edison's creative genius and willingness to try everything possible and imaginable along the way made him one of the greatest minds in American history.“Each incandescent lamp is his memory,” wrote the New York Times after his death.“Each power station is its monument.Wherever there is a phonograph or a radio, wherever there is a film, silent or talking, EDISON lives.»This article originally appeared on nationalgeographic.com in English.