No personality in the history of science has been pushed further into the realm of mythology than the Serbian-American electrical engineer Nikola Tesla. He is, without a doubt, one of the true giants in the history of electromagnetic theory. As an inventor he was as prolific as they come, with approximately 300 patents having been discovered in at least 26 countries, but many more inventions as well that stayed within his lab and were never patented. As remarkable as were his talents was his personality: private, eccentric, possessed of extraordinary memory and bizarre habits, and with a headlong descent into mental illness during his later years. Tesla's unparalleled combination of genius and aberrance have turned him into one of the seminal cult figures of the day. As such, at least as much fiction as fact have swirled around popular accounts of his life, and devotees of conspiracy theories and alternative science hypotheses have hijacked his name more than that of any other figure. Today we're going to try and separate that fiction from the fact.
First, a very brief outline of his life; but in order to put it in the proper perspective, we have to first clear up a popular misconception. Tesla did not invent alternating current, which is what he's best remembered for. AC had been around for a quarter century before he was born, which was in 1856 in what's now Croatia. While Tesla was a young man working as a telephone engineer, other men around Europe were already developing AC transformers and setting up experimental power transmission grids to send alternating current over long distances. Tesla's greatest early development was in his mind: a rotary magnetic field, which would make possible an electric induction motor that could run directly from AC, unlike all existing electric motors, which were DC. At the time, AC had to be converted to DC to run a motor, at a loss of efficiency. Induction motors had been conceived before his birth, but none had ever been built. Tesla built a working prototype, but only two years after another inventor, Galileo Ferraris, had also independently conceived the rotary magnetic field and built his own working prototype. Rightfully fearing that his own obscurity as a telephone engineer was hampering his efforts as an inventor, Tesla arranged to move to the United States. He did so in 1884, getting his famously ill-fated and short-lived job in Thomas Edison's laboratory.
The tycoon George Westinghouse, who understood the potential of AC and induction motors and was actively seeking them, gratefully purchased some of Tesla's patents as soon as he learned about them. Royalties from Westinghouse fattened Tesla's wallet, and a number of highly public projects on which they collaborated made him a celebrity, including the 1893 illumination of the World's Fair with alternating current, and the subsequent creation of the Niagara Falls power plant. It was as a result of this windfall that Tesla set up his own laboratories and created his most intriguing inventions. Let's run through a list of some of the seemingly magical feats attributed to Tesla, beginning with:
Did Tesla invent X-rays?
Tesla did in fact accidentally create the first X-ray photographs in 1895, although inadvertently, when taking a picture of his friend Mark Twain with an early form of fluorescent tube light called a Geissler tube that, unbeknownst to Tesla, also emitted X-radiation. Before he could investigate further, his lab burned down and he lost all that work. At nearly the same time, Wilhelm Röntgen announced his discovery of the X-ray. Later Tesla experimented with more powerful tubes to create stronger X-rays.
Did Tesla invent radio?
Generally, Tesla did beat Guglielmo Marconi to the demonstration of workable wireless communication and Tesla eventually won all the patent disputes (after his death), though Marconi is the one who shared a Nobel Prize for it. However, both men had been building upon theory and experimentation by dozens of other researchers going back nearly a full century. Patents for various types of wireless communication had begun to be filed by other inventors thirty years before either man. Tesla became famous for his radio controlled boat demonstration in 1896, but throughout 1895 and 1896, many inventors worldwide made all sorts of radio demonstrations, in Russia, India, the United States, and Europe. Tesla's contributions to radio were as good as anyone's, but they were hardly revolutionary in a field that was exploding at the time.
Did Tesla really sit in the middle of a room filled with lightning bolts?
Tesla spent two years in Colorado Springs where the El Paso Electric Company had agreed to give him free power. There he built the world's largest Tesla coil, the device most often associated with his name. A Tesla coil is a simple type of transformer, taking a low-voltage input and stepping it up to a very high voltage, even over several million volts. A large primary coil, into which the original low-voltage current is input, surrounds the base of a tightly-wound secondary coil sticking up in the air, like a big pole, and at the top is a metal torus. At full power, enough electrons are sent up that pole that they are forced to burst out into the atmosphere through the torus, creating the familiar lightning-like streamers that characterize Tesla coil demonstrations. Tesla posed for a famous publicity photograph, that you've seen many times, of himself sitting in a chair inside his lab taking notes while the air all around him is filled with such streamers from his giant coil. This picture was, unfortunately, a double exposure.
Among the actual cases of Tesla being ahead of his time was that his Colorado Springs coil had a third coil that increased the voltage through a process that we now call resonant rise. Resonant rise was not well understood until the 1970s.
Did Tesla cause a field of light bulbs 26 miles away to illuminate wirelessly?
He may or may not have; but it's almost certainly a myth. According to biographer John O'Neill, he did, but not quite as magically as is popularly depicted, and no supporting evidence has ever surfaced. Tesla's days at Colorado Springs were meticulously diaried, and no such experiment appears in them.
Tesla discovered that the function served by the long inner coil could also be served by a different type of conductor, including the Earth itself. He took a Tesla coil and stuck its inner secondary coil into the ground. He input electricity to the primary coil, and this setup caused his current to be sent into the Earth. That current could be received by an identical setup, some 26 miles away, by receiving current from the primary coil. Wired to that receiver coil, he had an array of some 200 conventional incandescent light bulbs set out in a field. So although the light bulbs themselves were conventionally wired to a normal power source, that power was transmitted wirelessly.
Whether this grand display ever happened or not (nobody has ever been able to duplicate it, despite many attempts), Tesla did record some of the calculations, and photographs do exist of very small scale experiments conducted locally at his lab — probably the closest he ever came. His idea for such a great distance as 26 miles relied on resonance to enhance the effect. He determined that the resonant frequency of the Earth's electromagnetic field was about 8 Hz. This frequency was rediscovered by science 50 years later when physicist Winfried Schumann predicted it while searching for ways to communicate with submarines. In the 1990s, the Schumann cavity was renamed the Schumann-Tesla cavity.
Did Tesla create ball lightning?
Ball lightning — the very existence of which is dubious at best — beautifully illustrates the type of mythology that has been built up around Tesla. Many sources say he routinely created ball lightning in Colorado Springs, and there are even carefully edited quotes of Tesla's purporting to describe it. In fact, Tesla is not known to have ever mentioned ball lightning in any of his writing or speaking, and no record from his time is known to exist stating that he created, demonstrated, or knew about anything that could reasonably be called ball lightning — despite intense rumormongering to the contrary, and despite a few mentions of "electric fireballs" in his writings which were about conventional matter burning normally. Tesla and ball lightning is pure mythology, consistent with cloaking a deified figure like Tesla with powers that seem almost magical.
Did Tesla plan to transmit power world-wide through the sky?
It was his ultimate plan, but the farthest he ever got was the partial construction of his famous tower at Wardenclyffe which was intended for wireless communication across the Atlantic. His worldwide wireless power system was theoretical only, employing the Schumann-Tesla resonance to charge the Earth's ionosphere such that a simple handheld coil could receive electrical power for free anywhere, and everywhere, in the world. Tesla's idea was innovative, but innovative idea it remained, as debts mounted and the tower was dismantled before it ever got to be used. Now that the nature of the ionosphere is much better understood, physicists now consider Tesla's concept unworkable, and no attempts to test it have ever worked.
All sorts of conspiracy theories exist, for example that the HAARP research facility in Alaska is secretly a test of Tesla's worldwide power grid, or some sort of superweapon based on it. The profound differences between these systems become clear upon doing even the most basic of research.
Did Tesla invent a Death Ray?
Investment in Tesla's projects stopped with the advent of the Great Depression in the 1930s. During the final decade of his life, Tesla was essentially penniless and living in a New York hotel, consumed by what we think today was probably obsessive compulsive disorder. It was during this period — and not earlier during his productive laboratory years — that he openly spoke of having built and tested a Death Ray. None of Tesla's lab assistants ever corroborated this, and no papers, prototypes, or evidence have ever surfaced. He gave vague descriptions with only inadequate hints of what type of technology such a weapon might use. Whether this was mere showmanship to attract new investment, was a legitimate but unknown concept, or was only the ramblings of a deteriorating mind, will probably never be known.
Did the government seize all his notes upon his death?
Yes, they did. Tesla died in January of 1943, during some of the darkest hours of World War II. The war was going badly, and the American government was more than a little willing to bend the rules. The year before, nearly all Japanese Americans were imprisoned in an effort to prevent spying. So it wasn't that big of a stretch for the government, having heard his claims of a Death Ray, to employ a statute enacted during World War I that enabled an Alien Property Custodian to seize all assets of any enemy during wartime — even though Tesla was an American citizen. They entered his New York hotel room and seized all his documents, which was all that remained of his life's work by that time. It wasn't very much, as Tesla's habit throughout his life was to keep plans in his head. It took the National Defense Research Committee's expert, Dr. John G. Trump, only three days to issue the following report:
[Tesla's] thoughts and efforts during at least the past 15 years were primarily of a speculative, philosophical, and somewhat promotional character often concerned with the production and wireless transmission of power; but did not include new, sound, workable principles or methods for realizing such results.
The hotel told them that Tesla had given them, as collateral in lieu of rent he could not afford, a piece of very dangerous equipment worth $10,000. Trump collected it and reported:
...A multidecade resistance box of the type used for a Wheatstone bridge resistance measurements — a common standard item found in every electric laboratory before the turn of the century.
Appreciate the man, not the myth.
Hardly anything written about Nikola Tesla fails to exaggerate his inventions and deify the man. Factually wrong descriptions of his accomplishments are found all over the place. His name is broadly smeared by association with virtually every crank conspiracy theory on the planet. They want magically easy answers to complicated problems, and when they hear that Tesla invented such answers and that the government and industry suppressed them, they trumpet his name to the world. This group has become little more than a cult, an insult to the man and his accomplishments.
However, Nikola Tesla was not to blame for any of that. Every reasonable textbook and history book on electromagnetic theory rightly confers upon him the enormous credit he fairly earned. Taking the trouble to learn about Tesla, about his unique personal history and about the reality of what his true contributions were, will always put you on firmer ground than accepting the untrue exaggerated or conspiratorial claims. Whenever you hear a good scientist's name co-opted and exploited by the promoters of crankery, you should always be skeptical.