Summary

Nikola Tesla (Serbian Cyrillic: Никола Тесла), born July 10, 1856 in Smiljan in the Empire of Austria (present-day Croatia) and died January 7, 1943 in New York City, was a Serbian-born American inventor and engineer. He is known for his leading role in the development and adoption of alternating current for the transmission and distribution of electricity.

Tesla first worked in telephony and electrical engineering before emigrating to the United States in 1884 to work with Thomas Edison and later with George Westinghouse, who registered many of his patents. Considered one of the greatest scientists in the history of technology, having filed some 300 patents covering a total of 125 inventions (many of which were wrongly attributed to Edison) and having described new methods of achieving "energy conversion," Tesla is recognized as one of the most creative engineers of the late 19th and early 20th centuries. He preferred to describe himself as a discoverer.

His best-known and most widely distributed work concerns electrical energy. He developed the first alternators that allowed the birth of alternating current electrical distribution networks, of which he was one of the pioneers. Tesla was very interested in modern technologies focusing on electricity which was the core of his inventions. He is known for having put into practice the discovery of the wave character of electromagnetism (theorized by James Clerk Maxwell in 1864), using the natural frequencies of the components of electrical circuits to maximize their efficiency.

During his lifetime, Tesla was renowned for his inventions as well as for his sense of showmanship, making him an archetypal "mad scientist. A great humanist who set himself the goal of bringing free electricity into homes and carrying it wirelessly, he remained relatively anonymous until several decades after his death. His work has found renewed interest in popular culture since the 1990s. In 1960, the name tesla (T) was given to the international unit of magnetic induction. In 2003, the innovative electric car manufacturer Tesla Inc. was established, with the name chosen for the brand referring to Nikola Tesla.

His burial place is in Belgrade, Serbia, in the Nikola-Tesla Museum.

Nationality and origins

Nikola Tesla was born into a Serbian Orthodox family in Lika, in the Croatian Krajina, from western Serbia, near Montenegro. Proud of his origins, Tesla always claimed both his Serbian ancestry and his Croatian heritage, identifying himself as a Serb from Croatia. However, born in the Austrian Empire, Tesla declared himself an Austrian citizen when he applied for American naturalization in 1891.

The Tesla family is said to have descended from the Draganić family, one branch of which is said to have adopted the nickname "Tesla" meaning adze in Serbian, given because of a particular physical characteristic of its members. Another legend links them to the Herzegovinian noble family of Pavle Orlović, a semi-mythological Serbian knight.

However, because he was born in the Croatian part of the military confines (a Habsburg-controlled buffer zone along the Ottoman border), some Croats claim Tesla as a Croatian national. Thus, since his death in 1943, many controversies have erupted about his nationality, with Serbian and Croatian nationalists engaging in numerous debates to claim his origin.

Youth

Nikola Tesla was born on the night of July 9-10, 1856, in Smiljan, in the military confines of the Austrian Empire. He was born during a very violent stormy night. His grandmother interpreted this as the "child of the night", while his mother said that he was the "child of the light". His father, Milutin Tesla, is the Serbian Orthodox priest of Smiljan. His mother, Đuka Mandić, is the daughter of a Serbian Orthodox priest from Lika and Banija and previously from Kosovo. She has a gift for making handicrafts and, although illiterate, is able to memorize texts of Serbian epic poetry and passages from the Bible. Nikola is the fourth of five children. He has three sisters, Milka, Angelina and Marica, and an older brother, Dane, who died after a horseback riding accident when Nikola was seven.

Dane's death has a negative impact on Nikola's relationship with his parents, especially his father. Indeed, Dane is seen as "extraordinarily gifted" and is Milutin's favorite son. His death is thus very difficult to accept, and Nikola feels rejected by his parents: "Everything I did worthwhile only accentuated my parents' sense of loss. So I grew up with little self-confidence. Dane was supposed to follow his father in becoming a priest, so Milutin placed his hopes on Nikola. He gives Nikola exercises, such as mental arithmetic, repeating long sentences or trying to guess his thoughts, all in an effort to improve his critical thinking. His complicated relationship with his father causes Nikola to have strange obsessions: he can't stand the sight of earrings and pearls on women, refuses to touch other people's hair, is disturbed by the smell of camphor, is forced to count his steps, and forces himself to do a number of acts divisible by three or else he will restart any action.

From childhood, Tesla showed great intellectual ability, with an uncommon eidetic memory and an inventive genius that he later attributed to his mother's genes and influence. However, Tesla was troubled by visions and had difficulty controlling his emotions. He became fascinated with archery and used his imagination to "ride those arrows he shot out of sight into the blue vaults of heaven. He then tried to imagine a device that would allow him to fly and designed a flying object using the properties of vacuum and pressure to make a cylinder turn. His first experiments were conclusive, but the rotation speed of the cylinder was not sufficient to make the machine take off. Another project of flying machine, supposed to "put the energies of nature at the service of the man", consists in moving four propellers by attaching to it of hannetons. However, this project was abandoned after another child caught and ate one of the insects. Disgusted by the event, Tesla promised never to touch insects again in his life.

Shortly after his brother's death, Tesla begins reading in his father's library, which his father does not approve of. Milutin hides the candles to prevent Nikola from "ruining his eyes", but Tesla eventually creates his own candles and continues to read. At the age of 12, he discovered the book Abafi by Miklós Jósika, which tells the story of "a young man absorbed in debauchery and love of pleasure, who, by the firmness of his will and the energy of his resolution, exalts himself to become one of the most respected and exemplary heroes of his country, whom the inflexibility of purpose can overcome in everything". The book was a revelation to Tesla, and it allowed him to finally take control of his emotions: "In a short time I overcame my weakness and felt a pleasure I had never known before, that of doing what I wanted to do.

In 1861, Tesla attended the elementary school in Smiljan, where he studied German, arithmetic and religion. In 1862, the Tesla family moved to the nearby town of Gospić, where Tesla's father worked as a parish priest. Tesla finished elementary school there, and then college. In 1870, Tesla moved to Karlovac to attend high school at the Karlovac Gymnasium, where classes were taught in German, as was customary in schools located within the Austro-Hungarian military border. Tesla was able to do integral calculus in his head, which made his teachers think he was cheating. He completed a four-year course of study in three years, graduating in 1873.

Tesla's interest in electricity began at an early age. While playing with his family's cat Macak, he discovered static electricity, "a miracle that renders one speechless with astonishment." He later said, "Macak's back was a sheet of light and my hand produced a shower of sparks loud enough to be heard throughout the house. Curious, he asked his father, who told him it was electricity, "the same thing you see through the trees in a storm. These early questions became an obsession for Tesla: "I cannot exaggerate the effect of that wonderful night on my childish imagination. Day after day I asked myself, 'What is electricity?' and I could not find an answer.

At the Karlovac Gymnasium, Tesla was impressed by the demonstrations of his physics teacher. They motivated him more than ever to study electricity, this "marvelous force". Tesla read everything he could find on the phenomenon, became fascinated with Crookes' radiometer and experimented with batteries, coils and electric generators.

While studying in Karlovac, Tesla lived with his father's sister in a very swampy area. Mosquitoes were numerous, and he contracted malaria, which he treated by taking a lot of quinine. However, the disease did not leave him for several years.

After graduating from the Karlovac Gymnasium, Tesla returned to Smiljan. Shortly after his arrival, he contracted cholera, was bedridden for nine months and almost died several times. Nikola's father, in a moment of despair, and although he wanted his son to enter the priesthood, promised to send him to the best engineering school if he recovered from the illness. While ill, he reads the works of Mark Twain, which he credits with helping him miraculously recover from his illness.

High School

In 1874, Tesla escaped compulsory military service in the Austro-Hungarian army in Smiljan by fleeing southeast of Lika to Tomingaj, near Gračac. There, he explored the mountains in hunter's clothing, read many books, and conceived inventions that he himself considered "delirious." According to Tesla, this contact with nature made him stronger, both physically and mentally.

In 1875, Tesla enrolled at the Technical University of Graz on a scholarship from the Military Frontier. He enrolled in the physics and mathematics departments with the idea of later becoming a teacher, probably to satisfy his father who would have found it difficult to imagine Nikola as an engineer. During his first year, Tesla never missed a class, got the best grades possible, passed nine exams (almost twice the required number) and founded a Serbian cultural club. The dean of the technical faculty wrote a letter to his father saying, "Your son is a first-class star. When Tesla returned to Smiljan at the end of the school year, he expected to impress his parents with his results, but found them unenthusiastic and worried about his health. During the school year, Tesla's life is hectic; he wakes up at 3 a.m. and usually reads until 11 p.m., leaving himself no time for leisure activities, even on Sundays and holidays. One of his teachers, fearing for Tesla's health, sent several letters throughout the school year to Nikola's father begging him to withdraw his son from school.

In 1876 or 1877, Tesla disagreed with his physics professor Jakob Pöschl when demonstrating a Gramme machine. Pöschl connected the machine to a battery for use as a DC motor, but the poorly adjusted brushes created sparks. Tesla observed the machine and concluded that it could work in the same way without brushes. Pöschl, who believed that it was the brushes that converted electrical energy into mechanical energy, contradicted Tesla, saying that this would be equivalent to trying to create perpetual motion. Convinced that he was right, Tesla abandoned his plans to become a professor and joined the engineering faculty.

Although his position as an engineering student would have allowed him to build a working model of a brushless motor, Tesla chose to simply explore the idea in his imagination, in two stages: "I began by imagining a direct current machine, running it and following the changing flow of currents in the armature. Then I imagined an alternator and studied the processes that took place in the same way. The images I saw were very real and tangible to me. Tesla thought that the solution lay in alternating current, an innovation since, at that time, direct current was used for almost all applications of electricity. Tesla also had the idea of coupling a motor to a generator, not a battery, which was also an innovation probably inspired by Hippolyte Fontaine's presentation in Vienna, which Pöschl explained to Tesla, in which Fontaine connected a motor to a dynamo. Despite a well-established basic concept, Tesla was unable to physically realize his idea.

After an altercation with a German classmate, during which the latter mocked Tesla for his diligence in school work, Tesla began to hang out with other students until late at night. There he learned dominoes, chess, became a very good pool player, and developed an addiction to card and money games. During the first semester of his third year, Tesla stopped attending classes and was not registered for any classes in the spring of 1878. Tesla lost his military scholarship, and tried unsuccessfully to get a new one from a pro-Serbian newspaper in Novi Sad.

According to some sources, Tesla received his undergraduate degree from the University of Graz. However, according to the university, he did not continue his studies beyond the first semester of his third year, and thus did not receive a degree.

First jobs

In December 1878, Tesla left Graz, did not contact his family and moved to Maribor where he was employed as an assistant engineer. He spent his evenings in a pub, the Happy Peasant, playing cards. In January 1879, his former roommate Kosta Kulišić stayed in Maribor and met Tesla by chance at the Happy Countryman. Kulišić then contacted Tesla's family, telling them that he was in Maribor. Two months later, Milutin Tesla went to Maribor to convince Nikola to resume his studies at Charles University in Prague. Tesla refused to return to his parents' home and stood up to his father, who became ill. Tesla is, however, sent back to Gospić a few weeks later after being arrested for vagrancy. Milutin, shocked to see his son brought back by the police, died on April 17, 1879.

After his father's death, Tesla stayed in Gospić, continued to participate in gambling and taught at his old school. With his mother's help, he manages to put aside his addiction and finally agrees to resume his studies in Prague, his maternal uncles providing the necessary funds. There he was influenced by Ernst Mach and took a course from Carl Stumpf entitled "David Hume and the Investigation of the Human Intellect" in which Tesla learned the concept of tabula rasa. Tesla continued to work on his idea for an alternating current motor in Prague, although he was only registered for courses in mathematics, experimental physics and philosophy: "The atmosphere of this old and interesting city was favorable to invention. He made experiments there, such as "detaching the collector from the machine and studying the operation under this new aspect", without really reaching conclusive results. Despite this, these tests were important to Tesla because they gave him a better understanding of how an engine worked, and he felt that he was "getting closer to a solution.

In January 1881, after his uncles stopped sending him money, Tesla left Prague for Budapest. Tesla chose Budapest because he had recently learned that Tivadar Puskás, a collaborator of Thomas Edison, was about to build telephone exchanges there. The work is to be supervised by Ferenc Puskás, Tivadar's brother, who served in the army in the same unit as Tesla's uncle, Pavle Mandić. Tesla asked his uncle to recommend him to help build Budapest's telephone network, but, unable to finance their project immediately, the Puskás brothers found Tesla a job as a draftsman for the Hungarian government's Central Telegraph Office. He was quickly spotted by the chief inspector and eventually transferred to a position that saw him making calculations and estimates, and helping to design a new telephone system. Tesla then made his first real invention, an ancestor of the loudspeaker, which he never patented or exhibited publicly.

Although he was initially happy to be in direct contact with electrical devices, Tesla soon tired of a job he considered too limited. Tesla eventually resigned and concentrated on his inventions. During 1881, Tesla was affected by a strange illness that doctors were unable to diagnose. He suffered from acute sensitivity of all the senses - John Joseph O'Neill described his experience as "a beam of light shining on him produces the effect of an internal explosion" - and was confined to bed for several months, with doctors giving him little chance of recovery. It is possible that this illness was a nervous breakdown due to the lack of interest people had in his new inventions. Tesla owes his remission to Anthony Szigeti, a man he met in Budapest and befriended: "was an athlete of extraordinary physical power - one of the strongest men in Hungary. He dragged me out of my room and forced me to do physical exercises... he saved my life.

To help Tesla recover from his illness, Szigeti invited him to walk with him at Városliget. Tesla accepted and spent most evenings with Szigeti discussing his ideas for an alternating current motor. One day, while Tesla was reciting a poem by Johann Wolfgang von Goethe, he had a "eureka moment" during which an idea came to him "like a bolt of lightning. He then began to draw the plans for a new invention in the sand while explaining it to Szigeti. The images would have appeared so clearly to Tesla that he would have asked his friend if he "saw the engine turning". It was the images of "the sun retreating and rushing forward" and "invisible wings that lift the spirit but not the body" from Goethe's poem that inspired Tesla to use a rotating magnetic field for his engine design.

The episode in the park in Budapest not only helped Tesla to advance his research on the first alternating current motor, it also confirmed that he was capable of becoming an inventor, and he became fully aware of his creative power. Tesla saw himself becoming "rich and famous". In 1882, he took advantage of his work at the Ganz Companies to learn more about alternating current - Károly Zipernowsky, Ottó Bláthy and Miksa Déri, who also worked at Ganz, later created the first alternating current electrical network. It was while working at Ganz that Tesla, while experimenting with a defective ring-shaped electrical transformer, confirmed his theory that it was possible to use alternating current to create a rotating magnetic field.

In 1882, Tesla was finally hired by Ferenc Puskás to help develop the telephone network in Budapest. It was then that Tesla invented new telephone repeaters and amplifiers. After the work was completed, Tivadar Puskás, who was in Paris to help Thomas Edison introduce his incandescent street lighting system in France, invited Tesla and Szigeti to join him to work for the Edison General Electric Company.

Engineer at Edison

In Paris, Tesla distinguished himself to the director of Continental Edison, Charles Batchelor (en), probably thanks to his higher education in physics and mathematics which made him as good in theory as in practice. He tried on several occasions to explain his ideas of the alternating current motor to his colleagues, but to no avail. They were not interested in his ideas, because the Edison Company was busy marketing electric lighting solutions and did not see the need to develop motorized systems. Another reason for the disinterest of Edison employees may be that Tesla's ideas seem to be too copper-intensive. Indeed, one of Thomas Edison's policies is to use as little copper as possible in his systems, and Tesla plans to power his motor with six copper wires, so as to create three out-of-phase alternating currents.

Tesla was then employed by Edison's company in France and Germany at several lighting stations. He impressed the director of one of Edison's branches, Louis Rau, and was sent to Strasbourg, which was then part of the German Empire. There, he was assigned to repair the damage caused by a short circuit at the Strasbourg-City station, which was being built as part of the Neustadt. The Strasbourg station had a lighting system of 1,200 lamps powered by four generators and a Siemens & Halske installation of five direct current generators for arc lamps. During the work, Tesla found a Siemens AC generator and began building a prototype AC motor in his spare time. After several trials, he managed to turn his motor for the first time: "I finally had the satisfaction of seeing the rotation carried out by alternating currents of different phases, and without slipping contacts or commutators, as I had designed a year before. It was an exquisite pleasure, but incomparable to the delirium of joy that followed the first revelation.

In Strasbourg and Paris, Tesla tried several times to find investors, but no one seemed to be really interested in his projects. In the spring of 1884, Charles Batchelor was called back to the United States by Edison to manage the Edison Machine Works (en) in New York. Batchelor then asked Tesla to follow him to work on his motor.

Tesla emigrated in June 1884 and began working almost immediately at the Machine Works on Manhattan's Lower East Side, alongside a score of "field engineers" who were struggling to set up the city's electric plant. As in Paris, Tesla works on troubleshooting installations and upgrading generators. The workshop where he worked was overcrowded: several hundred machinists, workers and executives were employed there. Historian W. Bernard Carlson notes that Tesla may have met Thomas Edison only a few times. One such meeting is described in Tesla's autobiography: after spending the night repairing damaged dynamos on the SS Oregon, he met Batchelor and Edison, who called him "our Parisian." After Tesla told them that he had stayed up all night repairing the Oregon, Edison remarked to Batchelor that "he's a damn good man. One of the projects Tesla was assigned was to develop a street lighting system based on arc lights. Arc lighting is the most popular type of street lighting, but it requires high voltages and is incompatible with Edison's low-voltage incandescent system, and the company is losing contracts in cities that want street lighting. Tesla's designs never went into production, perhaps because of technical improvements to incandescent street lighting or an installation contract Edison had with an arc lighting company.

After six months of working at Machine Works, in 1885, Tesla resigned. The event that precipitated his departure is not certain. It may have been a bonus he did not receive, either for designing new generators or for the arc lighting system that had been shelved. Tesla has had previous run-ins with the Edison company over unpaid bonuses he thought he deserved. In his autobiography, Tesla states that the head of Edison Machine Works promised him a $50,000 bonus for designing "twenty-four different types of standard machines," "but it turned out to be a joke." In later versions of this story, Thomas Edison reportedly offered a bonus himself and then went back on his word, saying "Tesla, you don't understand our American humor." Tesla then resigned, and Edison tried to get him to stay by offering him a raise. Tesla's diary contains only one comment on his resignation, a note he scribbled on the two pages covering the period from December 7, 1884 to January 4, 1885, saying "Good by to the Edison Machine Works."

Beginning as an independent inventor

Soon after leaving Edison, Tesla set about the task of patenting an arc lighting system, perhaps the same one he had developed at Edison. In March 1885, he met with attorney Lemuel W. Serrell, who worked for Edison, among others, to get help in submitting the patents. Serrell introduced Tesla to two businessmen, Robert Lane and Benjamin Vail, who agreed to finance an arc light manufacturing and utility company in his name, Tesla Electric Light & Manufacturing (en). Tesla works for the rest of the year on an improved DC generator and system construction and installation in Rahway, New Jersey, and obtains his first U.S. patents. Tesla's new system is noticed by Electrical Review, a New York technical journal, which publishes a front-page article on the Rahway installation.

Investors, however, showed little interest in Tesla's ideas for new types of alternating current motors and electrical transmission equipment. After the company began operations in 1886, they decided that the manufacture of arc lamps was too competitive a market. They opted to simply operate an electrical business, which they established, abandoning Tesla's company. Tesla even lost control of his patents, having previously sold them to Tesla Electric & Manufacturing in exchange for stock. Penniless, the inventor could no longer find work as an engineer and took on many odd jobs, such as repairing electrical circuits or working for a company that dug ditches for $2 a day ($57 in 2022). Tesla himself considered this period to be very difficult, writing, "I lived through a year of terrible heartache and bitter tears, my suffering being intensified by material need. My higher education in various branches of science, mechanics, and literature seemed to me .

In late 1886, Tesla met Alfred S. Brown, a Western Union superintendent, and Charles Fletcher Peck, a New York attorney. Both men had experience in starting businesses and promoting inventions and knew how to make a profit. Based on Tesla's new ideas, including an idea for a thermo-magnetic motor, they agreed to support the inventor financially and take care of his patents. Together they formed the Tesla Electric Company in April 1887 and agreed that Tesla would receive one-third of the profits, while Brown and Peck would share one-third; the remaining third was reinvested in future inventions. They rented a laboratory for Tesla in Manhattan, where he worked on improving and developing new types of electric motors, generators, and other devices, with Sziget as his assistant.

In 1887, Tesla developed an induction motor that operated on alternating current. In addition to patenting the motor, Peck and Brown arranged for independent tests to verify that it worked and promoted it through press releases sent to technical publications for articles to appear in conjunction with the patent grant. Physicist William Arnold Anthony, who tested the motor, and Electrical World magazine editor Thomas Commerford Martin organized a demonstration of Tesla's motor on May 16, 1888 at the American Institute of Electrical Engineers. Westinghouse Electric engineers then reported to George Westinghouse that Tesla had a viable AC motor, which Westinghouse needed for an AC system it had already begun marketing. Although Westinghouse had sought a patent on a similar motor developed in 1885 by Italian physicist Galileo Ferraris, he settled on Tesla's design, believing it was likely to dominate the market.

In July 1888, Brown and Peck negotiate a license agreement with George Westinghouse to design Tesla's motors and transformers for $60,000 in cash and stock and a royalty of $2.50 per horsepower produced by each motor ($1,707,333 and $71 in 2022, respectively). Westinghouse also hires Tesla for one year for $2,000 per month ($56,911 in 2022) to be a consultant at Westinghouse Electric's Pittsburgh laboratories.

During this year, Tesla works in Pittsburgh, helping to create an alternating current system to power the city's streetcars. He found this period frustrating because of conflicts with other Westinghouse engineers over how best to implement AC power. Among themselves, they agree on a 60-cycle AC system that Tesla proposed (to match the frequency of Tesla's motor operation), but they soon realize that this will not work for streetcars, since Tesla's induction motor can only operate at a constant speed. They end up using a DC traction motor instead.

Tesla's demonstration of his induction motor and Westinghouse's subsequent licensing of the patent, both in 1888, occurred at a time of intense competition among the electric companies. The three major companies, Westinghouse, Edison, and Thomson-Houston, were trying to expand in a capital-intensive industry and underestimated each other. Edison Electric goes so far as to propagandize and try to make the case that its DC system is better and safer than Westinghouse's AC system. The competition means that Westinghouse ultimately does not have the financial and technical resources to develop Tesla's motor immediately.

Two years after signing the contract with Tesla, Westinghouse Electric found itself in trouble. The near-collapse of the Barings Bank in London triggered the Panic of 1890, causing investors to demand repayment of their loans to Westinghouse Electric in return. The sudden lack of cash forced the company to bail out its debts. New lenders then demanded that Westinghouse cut back on what appeared to be excessive spending on acquisitions of other companies, research, and patents, including the per-motor royalty in the Tesla contract. By this time, the Tesla induction motor is struggling to get off the ground and is stuck in the development phase. Westinghouse then pays a guaranteed royalty of $15,000 per year even though working models of Tesla's motor are rare and the polyphase power systems needed to operate it are even rarer.

In early 1891, George Westinghouse made his financial difficulties clear to Tesla, saying that if he did not meet the demands of his lenders, he would no longer control Westinghouse Electric and Tesla would have to deal with the bankers himself in an attempt to collect his future royalties. Tesla was convinced by Westinghouse's continued advocacy for the engine, and agreed to release the company from its contracted royalties. Six years later, Westinghouse bought Tesla's patent for $216,000 ($6,638,112 in 2022) as part of a patent-sharing agreement with General Electric (a company formed from the 1892 merger between Edison and Thomson-Houston).

The money Tesla earned from his patents made him financially independent and gave him the time and funds to pursue his own interests. In 1889, Tesla moved out of the Liberty Street store that Peck and Brown rented for him. He then worked for the next twelve years in several shops and laboratories in Manhattan: a laboratory at 175 Grand Street (1889-1892), the fourth floor of 33-35 South Fifth Avenue (1892-1895), and the sixth and seventh floors of 46 & 48 East Houston Street (1895-1902).

As Tesla leaves Westinghouse, Szigeti, his friend and partner of more than nine years, tells him that he would like to leave to develop his own ideas. His departure was particularly difficult for Tesla to accept and hurt him deeply.

In the summer of 1889, Tesla went to the World's Fair in Paris and learned of Heinrich Hertz's experiments proving the existence of electromagnetic radiation. Tesla found this new discovery "refreshing" and decided to explore it further. By repeating and then developing these experiments, Tesla invented the Tesla coil, which was used to produce high-voltage, low-current, high-frequency alternating current electricity.

Tesla's work then focused on high frequency, particularly the conversion of electricity to light, while Guglielmo Marconi, another inventor, developed Hertz's theories for use in telecommunications. To promote his discoveries, Tesla used what he had learned from Peck and Brown: he published several articles in specialized journals, patented his inventions and gave a series of lectures at universities and engineering schools. In public demonstrations for a lighting system, he lit Geissler tubes and incandescent bulbs without using wires. In 1893, Tesla told audiences at several conferences that he was confident that a system like his could eventually conduct "intelligible signals or perhaps even energy to any distance without the use of wires" by conducting it through the earth. Tesla also came into conflict with Elihu Thomson, who was working on high frequency and did not always observe the same results as he did; Tesla and Thomson responded to each other with a series of articles in specialized journals between March and April 1891.

On July 30, 1891, at the age of 35, Tesla became a naturalized citizen of the United States. In 1892, and until 1894, Tesla became vice-president of the American Institute of Electrical Engineers, the precursor of the Institute of Electrical and Electronics Engineers.

In early 1893, Westinghouse engineers Charles F. Scott and then Benjamin G. Lamme made progress on a working version of Tesla's induction motor. Lamme found a way to make polyphase power compatible with the older single-phase AC and DC systems by developing a commutator. Westinghouse Electric now had a way to supply electricity to all potential customers and began to call their polyphase AC system the Tesla Polyphase System. They believed that Tesla's patents gave them priority over other polyphase AC systems, and sent out brochures to their customers warning them that if they bought an AC system elsewhere, they could be sued.

Westinghouse Electric asked Tesla to participate in the 1893 World's Fair in Chicago, where the company had a large space devoted to electrical exhibits. Although the company came very close to bankruptcy, Westinghouse Electric also won the bid to light the exhibition with alternating current; Westinghouse won the contract by offering much lower prices than its competitors, forcing its engineers to use larger alternators and higher electrical voltage. Nevertheless, it was a key moment in the history of AC power, as the company demonstrated to the American public the safety, reliability, and efficiency of a multiphase AC system that could supply both AC and DC power to other booths at the fair.

A special exhibit area is set up to showcase various models of Tesla's induction motor. The rotating magnetic field that drives them is explained through a series of demonstrations, including a Columbus egg that uses the two-phase coil of an induction motor to spin a copper egg and make it stand upright. One of the reasons Tesla visits the fair is to attend the International Congress on Electricity and give a series of demonstrations at the Westinghouse booth. A specially darkened room was set up where Tesla demonstrated his wireless lighting system, using a demonstration he had already made across America and Europe; this included using high voltage, high frequency alternating current to light wireless discharge lamps.

At his presentation at the International Electrical Congress in the Agricultural Hall of the World's Fair, Tesla introduced a steam-powered alternating electrical generator that he patented that year, which he thought was a better way to generate alternating current. Steam is forced into an oscillator and escapes through a series of orifices, pushing a piston attached to an armature up and down. The magnetic armature then vibrates up and down at high speed, producing an alternating magnetic field. This induces an alternating electric current in nearby wire coils. This eliminates the need for complicated motor parts

In 1893, Edward Dean Adams, who ran the Niagara Falls Hydraulic Power and Manufacturing Company, sought Tesla's advice for a system to transmit the electricity generated at Niagara Falls. For several years, Adams received a series of proposals and opened several competitions to determine the best way to use the power generated at the site. Among the systems proposed by several U.S. and European companies were two-phase and three-phase AC, high-voltage DC and compressed air systems. Adams asked Tesla for information on all the competing systems. The inventor recommended a two-phase system to Adams, which Tesla considered more reliable, and explained that Westinghouse had proposed a system compatible with incandescent lighting using two-phase AC. Adams' company then awarded a contract to Westinghouse Electric to build a two-phase AC system at Niagara Falls, based on Tesla's advice and Westinghouse's demonstration at the World's Fair that they could build a complete AC system. However, another contract is made with General Electric to build the distribution system.

Nikola Tesla Company

In 1895, Edward Dean Adams, impressed by what he saw on his visit to Tesla's laboratory, agreed to help found the Nikola Tesla Company, which was created to finance, develop and market a variety of old and new patents. Alfred Brown becomes involved with Tesla, bringing with him the patents developed under Peck and Brown. William Birch Rankine and Charles F. Coaney are also on the company's board of directors. Tesla found few investors; the mid-1890s were a difficult time financially, and the wireless lighting and oscillator patents he brought to market never came to fruition.

At dawn on March 13, 1895, the Fifth Avenue building that housed Tesla's laboratory caught fire. The fire began in the basement of the building and was so intense that Tesla's fourth-floor laboratory collapsed on the second floor. The fire not only sets back Tesla's ongoing projects, but also destroys a collection of research notes and materials, models and demonstration pieces, many of which were displayed at the 1893 World's Columbian Exposition. The losses amount to nearly $100,000 ($3,073,200 in 2022.

The destruction of his laboratory affected Tesla greatly. He spent several days in bed and, according to the New York Herald, appeared "dejected and despondent. A few days later, Tesla returned to the scene of the fire with workers to salvage what could be salvaged. To overcome this ordeal, Tesla tried electrotherapy; he gave himself several shocks a day, probably with one of his coils, in order to "avoid sinking into a deep state of melancholy".

Once his depression subsided, Tesla moved to 46 & 48 East Houston Street and rebuilt his laboratory on the 6th and 7th floors. With much of his equipment destroyed in the fire, Tesla began working on new subjects: X-rays and radio control.

Tesla had already been studying X-rays since 1894; he referred to the phenomenon as "invisible radiant energy", which he had observed in previous experiments. He conducted experiments with Crookes tubes, and was perhaps the first man to capture, by accident, an X-ray image: in December 1895, when he tried to photograph Mark Twain illuminated by a Geissler tube, the only thing apparent in the image was the metal locking screw of the camera lens. A few months later, after learning of Wilhelm Röntgen's discovery of X-rays, Tesla realized that he had missed a major scientific discovery: "too late, I realized that my guiding mind had steered me again and that I had not understood its mysterious clues."

Tesla then proceeded with his own x-ray experiments and developed a high-energy vacuum tube that emitted continuous braking radiation and was powered by a Tesla coil. As part of his research, Tesla designed several experimental devices to produce X-rays. He then claims that, with his inventions, "the instrument will enable the generation of Roentgen rays of much greater power than can be obtained with an ordinary apparatus."

Tesla himself noticed the dangers of working with x-ray machines. In his numerous notes on the early investigations of this phenomenon, he attributes skin damage to various causes. Early in his research, he believed that skin damage was caused by ozone generated on contact with the skin. Tesla finally realized that the rays were dangerous after one of his assistants, who was exposed for five minutes at thirty centimeters from the tube, suffered severe burns to his abdomen. Tesla abandoned his x-ray research during 1896, probably when he realized that he would not be able to compete in the market with General Electrics or even with small scientific instrument manufacturers. It is also possible that the only reason Tesla conducted his X-ray research was to advance his work on wireless power transmission. Thus, when Tesla realized that X-rays would not help him in this task, he would have moved on.

As a child, recurring nightmares led Tesla to the realization that the human being was merely a "self-propelled machine whose movements are governed by impressions received by the eye. He became fascinated with automation and, in 1897, after abandoning his work on X-rays, his new project was to develop radio-controlled automata - he called this discipline "teleautomatics".

The naval arms race between Britain and its rivals led Tesla to try his hand at a prototype remote-controlled torpedo in the shape of a boat. The boat is controlled by means of a transmitter, which emits a signal at a certain frequency, which is received by a coheater on the machine. The rotation of the control lever activates one of the four contacts, which in turn deactivate the signal for a given moment. When the signal is turned off, a disc with contacts in the boat rotates, activating a predefined maneuver depending on the position of the disc. Later, to ensure that spurious frequencies do not activate the boat, Tesla adds a second signal with a different frequency in parallel to the first.

Tesla patented his invention and gave private demonstrations in his laboratory; John Pierpont Morgan, William Kissam Vanderbilt, John Hays Hammond, and Charles A. Cheever (en) would have attended these presentations. Tesla's radio-controlled boat arrived on the market a few months after the beginning of the Spanish-American War, and Tesla took the opportunity to announce that his invention would end the war. Several countries requested the rights to Tesla's invention; within a year, thirteen countries owned Tesla's boat. The device caused a sensation, some considering that it was driven by Tesla's spirit, or piloted by a clever monkey hidden inside the boat, and was well received by the magazine Electrical Review, but it was highly criticized by others. It was seen by Cyrus Fogg Brackett, a professor at Princeton University, as impractical for deployment in wartime, and Electrical Engineer, a trade journal run by Thomas Commerford Martin, a friend of Tesla's, found the invention "uninnovative" and accused him of copying William Clarke's torpedo.

Wireless electric power

From 1890 to 1906, Tesla devoted much of his time and fortune to a series of projects aimed at developing wireless electrical power transmission. This was an extension of his idea of using coils to transmit energy, which he had already demonstrated with wireless lighting. At the time Tesla formulated his ideas, there was no way to wirelessly transmit communication signals over long distances, let alone large amounts of energy. Tesla studied radio waves and concluded that some of Hertz's existing study of them was incorrect. Furthermore, Tesla notes that even if the theories of radio waves are true, they do not help him in his goals, since this form of "invisible light" decreases with increasing distance, like any other radiation, and travels in a straight line through space, becoming "irretrievably lost."

To further study the conductive nature of low-pressure air, Tesla set up an experimental station at high altitude in Colorado Springs in 1899. There he could safely operate much larger coils than those confined to his New York laboratory, and an associate made an agreement with the El Paso County Electric Company to supply him with free alternating current. To finance his experiments, he persuaded John Jacob Astor IV to invest $100,000 ($3,073,200 in 2022) to become a majority shareholder in the Nikola Tesla Company. Astor thinks he is investing mostly in the new wireless lighting system. Instead, Tesla is using the money to fund his experiments in Colorado Springs. After his arrival, he tells the media that he plans to conduct wireless telegraphy experiments, transmitting signals from Pikes Peak to Paris.

There, he conducted experiments with a large coil operating in the megavolt range, which produced artificial lightning (during one experiment, he inadvertently burned the El Paso generator, causing a power outage. His observations of the electronic noise of lightning led him to conclude, incorrectly, that he could use the entire globe to conduct electricity.

During his stay in 1899, Tesla observed unusual signals coming from his receiver, which he assumed were communications from another planet. He took advantage of the beginning of the new century in January 1901 to report his discovery. Although Tesla was very careful in his statement, the signals were quickly interpreted by journalists as coming from Mars, and the story made the rounds of the tabloid press. A hypothesis by Marc Seifer, a biographer of Nikola Tesla, suggests that he detected an experiment by Guglielmo Marconi, but Marconi was in Italy at the time, and his system was probably not powerful enough to send signals to Colorado Springs. In 1996, the Corum brothers recreated Tesla's test conditions, and came up with the hypothesis that he would have picked up a signal from Io, one of Jupiter's moons, which emits a 10 kHz signal when it passes through a torus of charged plasma particles.

Tesla also makes an agreement with the publisher of Century Magazine to produce an article about his discoveries. The magazine sent a photographer to Colorado to photograph Tesla's work. The article, entitled The Problem of Increasing Human Energy, appeared in the June 1900 issue of the magazine. He explained the superiority of the wireless system he had devised, but the article was more of a philosophical treatise than a comprehensible scientific description of his work, illustrated with what later became iconic images of Tesla and his experiments in Colorado Springs.

In July 1901, Tesla expanded his plans to build a more powerful transmitter to outpace Marconi's radio system, which Tesla thought was a copy of his own. He approached Morgan to ask for more money to build a larger system, but Morgan refused. In December 1901, Marconi succeeded in transmitting the letter S from England to Newfoundland, beating Tesla in the race to be the first to achieve transatlantic transmission. A month after Marconi's success, Tesla tried to convince Morgan to support an even larger project to transmit messages and energy by controlling "vibrations throughout the world. Over the next five years, Tesla wrote more than 50 letters to Morgan, requesting and demanding additional funds to complete the construction of Wardenclyffe. Tesla continued the project for another nine months in 1902. The tower was erected to a height of 57 meters. In June 1902, Tesla moves his laboratory operations from Houston Street to Wardenclyffe.

With his success, Marconi began to attract more and more investors, while some of the press began to talk about Tesla's project as a sham. Tesla was desperately short of money, which prevented him, in 1903, from covering the top of the tower with copper, preventing it from functioning as planned. Morgan thus withdrew, and with him other investors. The project was a failure, and Tesla ended up mortgaging the Wardenclyffe property to cover his debts to the Waldorf-Astoria.

New inventions and research

After Wardenclyffe closed, Tesla continued to write to Morgan; after the death of the "great man," Tesla wrote to Morgan's son, Jack, to try to obtain additional funds for the project. In 1906, Tesla opened offices at 165 Broadway in Manhattan, trying to raise additional funds by developing and marketing his patents. He then had offices in the Metropolitan Life Tower from 1910 to 1914. He rented the Woolworth Building for a few months, but moved because he could not afford the rent to 8 West 40th Street from 1915 to 1925. After moving to 8 West 40th Street, he went bankrupt: most of his patents had expired and he had difficulties with the new inventions he was trying to develop.

On his 50th birthday in 1906, Tesla demonstrated a 200 horsepower (150 kilowatt) paddleless turbine at 16,000 rpm.

When World War I broke out, the British cut the transatlantic telegraph cable connecting the United States and Germany in order to control the flow of information between the two countries. They also attempted to cut off German wireless communications to and from the United States by having the American company Marconi sue the German radio company Telefunken for patent infringement. Telefunken called physicists Jonathan Zenneck and Karl Ferdinand Braun to defend itself, and hired Tesla as a witness for two years for $1,000 a month. The case stalled and became moot when the United States entered the war against Germany in 1917.

In 1915, Tesla attempted to sue the Marconi Company for infringement of its wireless tuning patents. Marconi's first radio patent was granted in the United States in 1897, but his 1900 patent application covering improvements in radio transmission was rejected several times before finally being approved in 1904 on the grounds that it infringed other existing patents, including two of Tesla's 1897 patents on wireless tuning. The 1915 Tesla case was unsuccessful, but in a related case, in which the Marconi Company attempted to sue the U.S. government for infringement of World War I patents, a 1943 U.S. Supreme Court decision reinstated the earlier patents of Oliver Lodge, John Stone Stone and Tesla. The court states that its decision has no bearing on Marconi's claim as the first to achieve radio transmission, simply that since Marconi's claim to certain patented improvements is questionable, the company cannot claim infringement of those same patents.

Last years

Nikola Tesla's rival won the Nobel Prize in Physics in 1909 and the Wardenclyffe Tower was destroyed in 1917. Nikola Tesla now lives in a room in the New Yorker Hotel, refusing any charity, but receiving a monthly salary of $125 from the Westinghouse Electric & Manufacturing Company to continue his various research projects.

In 1928, Tesla filed his last patent, a biplane with vertical takeoff and landing.

In the fall of 1937, trying to avoid a cab, Tesla suffered a bad fall while on his regular route to the cathedral and Central Park where he used to feed the pigeons and collect them in his hotel. Refusing to see a doctor or be taken to the hospital, he was escorted back to his hotel room where he never fully recovered.

Plagued by OCD and a chronic insomniac, he died on January 7, 1943 in his New York hotel room, alone, penniless and in debt, leaving behind him more than 300 patents and the reputation of a genius, visionary and half-mad scientist. On January 17, he was given a state funeral in the Cathedral of St. John the Theologian in New York, attended by 2,000 people. His body was then taken to Ferncliff Cemetery where he was later cremated.

After Nikola Tesla's death, his family engaged in a lengthy legal process with the U.S. administration to acquire his working papers and personal effects. In 1952, his nephew Sava Kosanović obtained that his entire estate (original manuscripts, thousands of letters, photographs and most of his inventions) be shipped to Belgrade. After a long trial, this same nephew succeeded, in 1957, in recovering his uncle's funeral urn. The urn and the documents are today in the Nikola-Tesla Museum in Belgrade, Serbia.

Tesla is the author of about 300 patents, many of which are wrongly attributed to Thomas Edison, dealing with new methods of approaching energy conversion.

Other major ideas

Tesla's theories on the possibility of wireless transmission date back to lectures and demonstrations he gave in 1893 in St. Louis, Missouri, at the Franklin Institute in Pennsylvania, and at the National Electric Light Association. He developed the Tesla coil around 1891, and between 1895 and 1898 an amplifying transmitter.

In August 1917, Tesla proposed the frequencies and energy required for a remote obstacle tracking system in the periodical The Electrical Experimenter. He proposes the use of a continuous wave to locate objects, this wave forming a standing wave with the reflection by the target when the frequency is adjusted appropriately (Continuous wave radar). The frequency used can then determine the distance of the object or its variation in time can deduce the radial speed of movement. He proposed as an alternative the use of pulses to obtain the same result. Tesla envisaged the display of the resulting echoes on a fluorescent screen, an idea taken up by the radar.

Awards

Nikola Tesla was 1.88 m tall and weighed 64 kg between 1888 and 1926, his weight varying very little during this period. His appearance is described by newspaper editor Arthur Brisbane as "almost the tallest, almost the thinnest, and certainly the most serious man who regularly visits Delmonico's." While living in New York, he is elegant and stylish, meticulous in his grooming, clothing and daily activities, an appearance he maintains to further his business dealings. He is a self-proclaimed "most elegant man on Fifth Avenue". He is also described as having light eyes, "very large hands" and "remarkably large thumbs".

Eidetic memory

During his life, Tesla read extensively, memorizing entire books, and supposedly had a photographic memory. He was multilingual, speaking eight languages: Serbo-Croatian, Czech, English, French, German, Hungarian, Italian and Latin. Tesla recounts in his autobiography that he experienced detailed moments of inspiration. On several occasions he saw blinding flashes of light, often accompanied by visions. Often the visions are related to a word or idea he might have encountered; at other times they provide the solution to a particular problem he is facing. When he hears the name of an object, he can imagine it in great detail. Tesla can visualize an invention in his mind with extreme accuracy, including all dimensions, before moving on to the construction stage, a technique sometimes called "visual thinking." He does not usually draw by hand, but works from memory. Even as a child, Tesla has frequent flashbacks to earlier events in his life.

Relationships

Tesla is antisocial and tends to isolate himself in his work. However, when he finally engages in social activities, many people speak very positively and admiringly of Tesla. Robert Underwood Johnson described him as having achieved "remarkable gentleness, sincerity, modesty, refinement, generosity and strength." His secretary, Dorothy Skerrit, wrote, "his genial smile and noble bearing always denoted the gentlemanly characteristics that were so deeply rooted in his soul." Tesla's friend Julian Hawthorne wrote, "One seldom met a scientist or engineer who was also a poet, philosopher, music lover, linguist, and connoisseur of food and drink.

Tesla never married, explaining his chastity as very useful for his scientific abilities. Margaret Cheney, author of Nikola Tesla: The Man Who Enlightened the World, also explains that his multiple phobias made Tesla "an unlikely candidate for intimate relationships." Tesla did, however, reportedly have a significant number of women interested in him, and, while living in New York City, he rented two hotel rooms at the same time in two different parts of the city to "meet special friends."

Tesla was good friends with Francis Marion Crawford, Stanford White, Fritz Lowenstein, George Scherff, and Kenneth Swezey. In mid-life, Tesla became a close friend of Mark Twain; they spent much time together in his laboratory and elsewhere. Twain notably described Tesla's invention of the induction motor as "the most valuable patent since the telephone." At a party hosted by actress Sarah Bernhardt in 1896, Tesla met the Indian Hindu monk Vivekananda, and the two discussed how the inventor's ideas about energy seemed to fit with Vedantic cosmology. In the late 1920s, Tesla befriended George Sylvester Viereck, a poet, writer, mystic, and later Nazi propagandist. Tesla occasionally attended dinner parties hosted by Viereck and his wife.

Tesla can sometimes be harsh and openly express his disgust for overweight people. He was quick to criticize clothing; on several occasions Tesla ordered a female employee to go home and change her dress. Upon Thomas Edison's death in 1931, Tesla provided the only negative opinion in extensive coverage of Edison's life for The New York Times :

Habits

Tesla said he never slept more than two hours a night, but he admitted to "dozing off" from time to time "to recharge his batteries." During his sophomore year at Graz, Tesla developed a passionate skill for billiards, chess, and card playing, sometimes spending more than 48 hours at a time at a gaming table. On one occasion, in his laboratory, Tesla worked for 84 hours without rest. Kenneth Swezey, a journalist with whom Tesla had befriended, confirmed that Tesla rarely slept. Swezey recalled one time Tesla called him at 3 a.m.: "I was sleeping in my room like a dead man...Suddenly the ringing of the telephone woke me up...was talking animatedly, with pauses, ...working on a problem, comparing one theory with another, commenting; and when he felt he had arrived at the solution, he suddenly hung up the telephone.

Tesla worked every day from 9:00 a.m. to 6:00 p.m. or later, with dinner at exactly 8:10 p.m. at Delmonico's Restaurant, or later in his life at the Waldorf-Astoria Hotel. Tesla would then order his dinner by phone from the maitre d', who was the only one who could serve it. "The meal had to be ready by eight o'clock... He dined alone, except on the rare occasions when he gave a dinner party to fulfill his social obligations. Tesla would then return to his work, often until 3 a.m." Tesla became a vegetarian in his later years, living on milk, bread, honey and vegetable juice.

Experimental and theoretical physics

Tesla disagreed with the theory that atoms are composed of smaller subatomic particles, claiming that there are no electrons creating an electric charge. He thought that if electrons existed, they were a fourth state of matter or "subatom" that could only exist in an experimental vacuum and had nothing to do with electricity. Tesla believes that atoms are immutable - they cannot change state or be divided in any way. He believed in the 19th century concept of an omnipresent ether that transmits electrical energy.

Tesla generally disagreed with the theories on the conversion of matter into energy. He is also critical of Albert Einstein's theory of relativity, saying:

"I argue that space cannot be curved, for the simple reason that it cannot have any properties. One might as well say that God has properties. He has no properties, only attributes, and these are of our own making. We can only speak of properties when it comes to the matter that fills space. To say that in the presence of large bodies, space becomes curved is equivalent to saying that something can act on nothing. For my part, I refuse to subscribe to such an opinion."

Tesla claimed to have developed his own physical principle concerning matter and energy, which he began working on in 1892, and in 1937, at the age of 81, he claimed in a letter to have completed a "dynamic theory of gravity" that would "put an end to idle speculations and misconceptions, such as that of curved space." He states that the theory is "worked out in all its details" and that he hopes to give it to the world soon. His writings have never elucidated his theory further.

Company

Tesla is widely considered by his biographers to be a humanist in his philosophical outlook in addition to his gifts as a technological scientist. This did not prevent him, like many of his time, from becoming a proponent of a version of eugenics, based on imposed artificial selection. Although his argument did not depend on the concept of a "master race" or the inherent superiority of one person over another, he argued for eugenics in a 1937 interview, stating, "Man's new sense of mercy has begun to interfere with the ruthless workings of nature. The only method compatible with our notions of civilization and race is to prevent the breeding of unfit people by sterilization and the deliberate direction of the mating instinct... The trend of opinion among eugenicists is that we must make marriage more difficult. Certainly no one who is not a desirable parent should be allowed to produce offspring. In a century it will not occur to a normal person to mate with a eugenically unfit person."

As a young man, Tesla did not consider himself worthy of a woman, seeing women as superior in every way. His opinion begins to waver later, when he begins to think that women are trying to outdo men and make themselves more dominant. This "new woman" is met with great indignation by Tesla, who feels that women are losing their femininity by trying to be in power. In an interview with the Galveston Daily News on August 10, 1924, he said, "In place of the gentle, soft-spoken woman I revere, has come the woman who thinks her chief achievement in life is to make herself as much the equal of the man as possible - in dress, voice and action, in sports and achievement of all kinds... The tendency of women to push man aside, to supplant the old spirit of cooperation with him in all the affairs of life, disappoints me greatly."

In the 21st century, the Galveston Daily News interview made Tesla popular with the MGTOW movement, an anti-marriage masculinist community that considers the inventor one of the pioneers of their movement. According to Massimo Teodorani, author of the biography Tesla, The Flash of Genius, the connection between Tesla and this movement is a matter of political instrumentalization. According to Teodorani, the interview shows Tesla's strange personality rather than a sexist mentality. In another interview dated 1926, Tesla states: "The struggle of women for equality of the sexes will give rise to a new sexual order, with women as superior. It is not in the superficial physical imitation of men that women will first assert their equality and then their superiority, but in the awakening of their intelligence. Through countless generations, the social subjugation of women has naturally led to the partial atrophy or at least the hereditary suspension of the mental qualities of which we now know that the female sex is no less endowed than the male sex.

Religion

Tesla was raised as an Orthodox Christian but did not consider himself a "believer in the Orthodox sense." He states that he opposes religious fanaticism, and that "Buddhism and Christianity are the greatest religions, both in number of followers and in importance." He also said: "For me, the universe is simply a great machine that has never seen the light of day and will never end" and "what we call 'soul' or 'spirit' is nothing more than the sum of the functioning of the body. When this functioning ceases, the "soul" or the "spirit" also ceases".

He is also interested in Hindu mythology and Sanskrit.

Most of Nikola Tesla's family members were killed by the Ustasha during the genocide against the Serbs in the independent state of Croatia; William Terbo, grandson of Angelina Tesla - Nikola's older sister - and who died in 2018 in New Jersey, claimed to be the last known member of Nikola Tesla's family. Tesla's legacy lives on, however, in many books, movies, television series, plays, comic books, video games and also in the world of music. The impact of the technologies invented or imagined by Tesla is a recurring theme in various types of science fiction.

Several places, objects and companies have been named after Tesla, such as the Tesla Coil, the Tesla Oscillator, the Tesla Tower, the Tesla Turbine, the Electromagnetic Induction Unit, the Tesla Company, Inc. and the Nikola Tesla Airport in Belgrade. A crater on the Moon and the asteroid (2244) Tesla are also named after the inventor.

The scientist has also been celebrated with national and regional commemorative dates around the world, such as in Serbia, Canada; Niagara Falls, New York and Palo Alto, United States; Niagara Falls, Ontario and Hamilton, Canada; and Baku, Azerbaijan.

Sources

1. Nikola Tesla
2. Nikola Tesla