Nikola Tesla
Overview
Nikola Tesla was a Serbian-American
Serbian American
Serbian Americans are citizens of the United States who are of Serbian ancestry. For the 2000 US Census, 140,337 Americans indicated Serbian as their first ancestry, while 170,312 persons declared to have Serbian ancestry...

 inventor, mechanical engineer
Mechanical engineering
Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the...

, and electrical engineer. He was an important contributor to the birth of commercial electricity
Mains electricity
Mains is the general-purpose alternating current electric power supply. In the US, electric power is referred to by several names including household power, household electricity, powerline, domestic power, wall power, line power, AC power, city power, street power, and grid power...

, and is best known for his many revolutionary developments in the field of electromagnetism
Electromagnetism
Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...

 in the late 19th and early 20th centuries building on the theories of electromagnetic technology discovered by Michael Faraday
Michael Faraday
Michael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....

 and used in direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

 (DC) applications. Tesla's patents and theoretical work formed the basis of modern alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....

 (AC) electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

 systems, including the polyphase system
Polyphase system
A polyphase system is a means of distributing alternating current electrical power. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each conductor. Polyphase systems are particularly useful...

 of electrical distribution and the AC motor
AC motor
An AC motor is an electric motor driven by an alternating current.It commonly consists of two basic parts, an outside stationary stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft that is given a torque by the...

.

Born an ethnic Serb
Serbs
The Serbs are a South Slavic ethnic group of the Balkans and southern Central Europe. Serbs are located mainly in Serbia, Montenegro and Bosnia and Herzegovina, and form a sizable minority in Croatia, the Republic of Macedonia and Slovenia. Likewise, Serbs are an officially recognized minority in...

 in the village of Smiljan
Smiljan
Smiljan is a village in the mountainous region of Lika in Croatia. It is located northwest of Gospić, and fifteen kilometers from the Zagreb-Split highway; its population is 417 .-Tesla:...

 (now part of Gospić
Gospic
Gospić is a town in the mountainous and sparsely populated region of Lika, Croatia. It is the administrative centre of Lika-Senj county. Gospić is located near the Lika River in the middle of a karst field....

), in the Croatian Military Frontier of the Austrian Empire
Austrian Empire
The Austrian Empire was a modern era successor empire, which was centered on what is today's Austria and which officially lasted from 1804 to 1867. It was followed by the Empire of Austria-Hungary, whose proclamation was a diplomatic move that elevated Hungary's status within the Austrian Empire...

 (modern-day Croatia
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

), Tesla was a subject of the Austrian Empire by birth and later became an American citizen.
Quotations

There is something within me that might be illusion as it is often case with young delighted people, but if I would be fortunate to achieve some of my ideals, it would be on the behalf of the whole of humanity. If those hopes would become fulfilled, the most exciting thought would be that it is a deed of a Serb.

Address at the Belgrade train station (1 June 1892)

Money does not represent such a value as men have placed upon it. All my money has been invested into experiments with which I have made new discoveries enabling mankind to have a little easier life.

As quoted in "A Visit to Nikola Tesla" by Dragislav L. Petković in Politika (April 1927); also in Tesla, Master of Lightning (1999) by Margaret Cheney, Robert Uth, and Jim Glenn, p. 82

I have harnessed the cosmic rays and caused them to operate a motive device.

Brooklyn Eagle (10 July 1931)

If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search. ... I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor.

New York Times (19 October 1931)

Encyclopedia
Nikola Tesla was a Serbian-American
Serbian American
Serbian Americans are citizens of the United States who are of Serbian ancestry. For the 2000 US Census, 140,337 Americans indicated Serbian as their first ancestry, while 170,312 persons declared to have Serbian ancestry...

 inventor, mechanical engineer
Mechanical engineering
Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the...

, and electrical engineer. He was an important contributor to the birth of commercial electricity
Mains electricity
Mains is the general-purpose alternating current electric power supply. In the US, electric power is referred to by several names including household power, household electricity, powerline, domestic power, wall power, line power, AC power, city power, street power, and grid power...

, and is best known for his many revolutionary developments in the field of electromagnetism
Electromagnetism
Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...

 in the late 19th and early 20th centuries building on the theories of electromagnetic technology discovered by Michael Faraday
Michael Faraday
Michael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....

 and used in direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

 (DC) applications. Tesla's patents and theoretical work formed the basis of modern alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....

 (AC) electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

 systems, including the polyphase system
Polyphase system
A polyphase system is a means of distributing alternating current electrical power. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each conductor. Polyphase systems are particularly useful...

 of electrical distribution and the AC motor
AC motor
An AC motor is an electric motor driven by an alternating current.It commonly consists of two basic parts, an outside stationary stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft that is given a torque by the...

.

Born an ethnic Serb
Serbs
The Serbs are a South Slavic ethnic group of the Balkans and southern Central Europe. Serbs are located mainly in Serbia, Montenegro and Bosnia and Herzegovina, and form a sizable minority in Croatia, the Republic of Macedonia and Slovenia. Likewise, Serbs are an officially recognized minority in...

 in the village of Smiljan
Smiljan
Smiljan is a village in the mountainous region of Lika in Croatia. It is located northwest of Gospić, and fifteen kilometers from the Zagreb-Split highway; its population is 417 .-Tesla:...

 (now part of Gospić
Gospic
Gospić is a town in the mountainous and sparsely populated region of Lika, Croatia. It is the administrative centre of Lika-Senj county. Gospić is located near the Lika River in the middle of a karst field....

), in the Croatian Military Frontier of the Austrian Empire
Austrian Empire
The Austrian Empire was a modern era successor empire, which was centered on what is today's Austria and which officially lasted from 1804 to 1867. It was followed by the Empire of Austria-Hungary, whose proclamation was a diplomatic move that elevated Hungary's status within the Austrian Empire...

 (modern-day Croatia
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

), Tesla was a subject of the Austrian Empire by birth and later became an American citizen. Because of his 1894 demonstration of wireless communication through radio and as the eventual victor in the "War of Currents
War of Currents
In the "War of Currents" era in the late 1880s, George Westinghouse and Thomas Edison became adversaries due to Edison's promotion of direct current for electric power distribution over alternating current advocated by several European companies and Westinghouse Electric based out of Pittsburgh,...

", he was widely respected as one of the greatest electrical engineers who worked in America. He pioneered modern electrical engineering and many of his discoveries were of groundbreaking importance. In the United States during this time, Tesla's fame rivaled that of any other inventor or scientist in history or popular culture. Tesla demonstrated wireless energy transfer
Wireless energy transfer
Wireless energy transfer or wireless power is the transmission of electrical energy from a power source to an electrical load without artificial interconnecting conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible...

 to power electronic devices in 1891, and aspired to intercontinental wireless transmission of industrial power in his unfinished Wardenclyffe Tower
Wardenclyffe Tower
Wardenclyffe Tower also known as the Tesla Tower, was an early wireless telecommunications tower designed by Nikola Tesla and intended for commercial trans-Atlantic wireless telephony, broadcasting, and to demonstrate the transmission of power without interconnecting wires...

 project.

Because of his eccentric personality and his seemingly unbelievable and sometimes bizarre claims about possible scientific and technological developments, Tesla was ultimately ostracized and regarded as a mad scientist
Mad scientist
A mad scientist is a stock character of popular fiction, specifically science fiction. The mad scientist may be villainous or antagonistic, benign or neutral, and whether insane, eccentric, or simply bumbling, mad scientists often work with fictional technology in order to forward their schemes, if...

 by many late in his life. He died without much money to his name.

The SI
International System of Units
The International System of Units is the modern form of the metric system and is generally a system of units of measurement devised around seven base units and the convenience of the number ten. The older metric system included several groups of units...

 unit measuring magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...

 B (also referred to as the magnetic flux density and magnetic induction), the tesla
Tesla (unit)
The tesla is the SI derived unit of magnetic field B . One tesla is equal to one weber per square meter, and it was defined in 1960 in honour of the inventor, physicist, and electrical engineer Nikola Tesla...

, was named in his honor (at the CGPM
General Conference on Weights and Measures
The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures . It is one of the three organizations established to maintain the International System of Units under the terms of the Convention du Mètre of 1875...

, Paris, 1960).

Early years

Nikola Tesla was born to Serbian parents in the village of Smiljan, Austrian Empire
Austrian Empire
The Austrian Empire was a modern era successor empire, which was centered on what is today's Austria and which officially lasted from 1804 to 1867. It was followed by the Empire of Austria-Hungary, whose proclamation was a diplomatic move that elevated Hungary's status within the Austrian Empire...

 near the town of Gospić
Gospic
Gospić is a town in the mountainous and sparsely populated region of Lika, Croatia. It is the administrative centre of Lika-Senj county. Gospić is located near the Lika River in the middle of a karst field....

, in the territory of modern-day Croatia. His baptismal certificate reports that he was born on 28 June (N.S.
Old Style and New Style dates
Old Style and New Style are used in English language historical studies either to indicate that the start of the Julian year has been adjusted to start on 1 January even though documents written at the time use a different start of year ; or to indicate that a date conforms to the Julian...

 10 July)
1856 to father Milutin Tesla, a priest in the Serbian Orthodox Church
Serbian Orthodox Church
The Serbian Orthodox Church is one of the autocephalous Orthodox Christian churches, ranking sixth in order of seniority after Constantinople, Alexandria, Antioch, Jerusalem, and Russia...

. His mother was Đuka Tesla, née Mandić, whose father was also a Serbian Orthodox priest. She was talented in making home craft tools and memorized many Serbian epic poems
Serbian epic poetry
Serb epic poetry is a form of epic poetry written by Serbs originating in today's Serbia, Bosnia and Herzegovina, Croatia, Macedonia and Montenegro. The main cycles were composed by unknown Serb authors between the 14th and 19th centuries...

, but never learned to read. Tesla's biographer John O'Neill relates that "the Tesla and Mandić families originally came from the western part of Serbia near Montenegro."

Nikola was the fourth of five children, having one older brother (Dane, who was killed in a horse-riding accident when Nikola was five) and three sisters (Milka, Angelina and Marica). His family moved to Gospić in 1862. Tesla attended school at Higher Real Gymnasium
Gymnasium Karlovac
Gymnasium Karlovac , sometimes historically referred to as Higher Real Gymnasium, is a gymnasium in the city of Karlovac in Croatia. Housed in a dedicated building constructed in 1863, the school considers itself to have been founded as early as 1766. At that time, Karlovac was part of the Croatian...

 in Karlovac
Karlovac
Karlovac is a city and municipality in central Croatia. The city proper has a population of 49,082, while the municipality has a population of 59,395 inhabitants .Karlovac is the administrative centre of Karlovac County...

. He finished a four-year term in the span of three years.

Tesla went on to study electrical engineering at the Austrian Polytechnic
Graz University of Technology
The Graz University of Technology is the second largest university in Styria, Austria, after the University of Graz. Austria has three universities of technology – in Graz, in Leoben, and in Vienna. The Graz University of Technology was founded in 1811 by Archduke John of Austria. TUG, as the...

 in Graz
Graz
The more recent population figures do not give the whole picture as only people with principal residence status are counted and people with secondary residence status are not. Most of the people with secondary residence status in Graz are students...

 (1875). While there, he studied the uses of alternating current. Some sources say he received Baccalaureate degrees from the university at Graz. However, the university says that he did not receive a degree and did not continue beyond the first semester of his third year, during which he stopped attending lectures. In December 1878, Tesla left Graz and broke all relations with his family. His friends thought that he had drowned in the Mur River. He went to Marburg
Maribor
Maribor is the second largest city in Slovenia with 157,947 inhabitants . Maribor is also the largest and the capital city of Slovenian region Lower Styria and the seat of the Municipality of Maribor....

, (today's Maribor, in Slovenia
Slovenia
Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...

), where he was first employed as an assistant engineer for a year. He suffered a nervous breakdown
Nervous breakdown
Mental breakdown is a non-medical term used to describe an acute, time-limited phase of a specific disorder that presents primarily with features of depression or anxiety.-Definition:...

 during this time. Tesla was later persuaded by his father to attend the Charles-Ferdinand University
Charles University in Prague
Charles University in Prague is the oldest and largest university in the Czech Republic. Founded in 1348, it was the first university in Central Europe and is also considered the earliest German university...

 in Prague, which he attended for the summer term of 1880. Here, he was influenced by Ernst Mach
Ernst Mach
Ernst Mach was an Austrian physicist and philosopher, noted for his contributions to physics such as the Mach number and the study of shock waves...

. However, after his father died, he left the university, having completed only one term.

Tesla engaged in reading many works, memorizing complete books, supposedly having a photographic memory. Tesla related in his autobiography that he experienced detailed moments of inspiration. During his early life, Tesla was stricken with illness time and time again. He suffered a peculiar affliction in which blinding flashes of light would appear before his eyes, often accompanied by visions. Much of the time the visions were linked to a word or idea he might have come across, at other times they would provide the solution to a particular problem he had been encountering; just by hearing the name of an item, he would be able to envision it in realistic detail. Modern-day synesthetes
Synesthesia
Synesthesia , from the ancient Greek , "together," and , "sensation," is a neurologically based condition in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway...

 report similar symptoms. Tesla would visualize an invention in his mind with extreme precision, including all dimensions, before moving to the construction stage; a technique sometimes known as picture thinking. He typically did not make drawings by hand, instead just conceiving all ideas with his mind. Tesla also often had flashbacks to events that had happened previously in his life; these began during his childhood.

In 1880, he moved to Budapest
Budapest
Budapest is the capital of Hungary. As the largest city of Hungary, it is the country's principal political, cultural, commercial, industrial, and transportation centre. In 2011, Budapest had 1,733,685 inhabitants, down from its 1989 peak of 2,113,645 due to suburbanization. The Budapest Commuter...

 to work under Tivadar Puskás
Tivadar Puskás
Tivadar Puskás was a Hungarian inventor, telephone pioneer, and inventor of the telephone exchange He was also the founder of Telefon Hírmondó.-Biography:...

 in a telegraph
Telegraphy
Telegraphy is the long-distance transmission of messages via some form of signalling technology. Telegraphy requires messages to be converted to a code which is known to both sender and receiver...

 company,
the National Telephone Company
Telephone company
A telephone company is a service provider of telecommunications services such as telephony and data communications access. Many were at one time nationalized or state-regulated monopolies...

. There, he met Nebojša Petrović, a young, Serbian inventor who lived in Austria. Although their encounter was brief, they did work on a project together using twin turbines to create continual power. On the opening of the telephone exchange
Telephone exchange
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...

 in Budapest, 1881, Tesla became the chief electrician to the company, and was later engineer for the country's first telephone system. He also developed a device that, according to some, was a telephone repeater
Repeater
A repeater is an electronic device that receives asignal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.-Description:...

 or amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...

, but according to others could have been the first loudspeaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...

.

France and the United States

In 1882 he moved to Paris, to work as an engineer for the Continental Edison Company, designing improvements to electric equipment brought overseas from Edison's ideas. According to his autobiography, in the same year he conceived the induction motor
Induction motor
An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are robust and have no brushes...

 and began developing various devices that use rotating magnetic field
Rotating magnetic field
A rotating magnetic field is a magnetic field which changes direction at a constant angular rate. This is a key principle in the operation of the alternating-current motor. Nikola Tesla claimed in his autobiography that he identified the concept of the rotating magnetic field in 1882. In 1885,...

s for which he received patents in 1888.

On 6 June 1884, Tesla first arrived in the United States, in New York City with little besides a letter of recommendation from Charles Batchelor
Charles Batchelor
Charles W. Batchelor was an inventor and close associate of American inventor Thomas Alva Edison during much of Edison’s career. He was involved in some of the greatest inventions and technological developments in history....

, a former employer. In the letter of recommendation to Thomas Edison
Thomas Edison
Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

, it is claimed that Batchelor wrote, 'I know two great men and you are one of them; the other is this young man', but the exact contents of the letter is disputed in McNichol's book. Edison hired Tesla to work for his Edison Machine Works. Tesla's work for Edison began with simple electrical engineering and quickly progressed to solving some of the company's most difficult problems. Tesla was even offered the task of completely redesigning the Edison company's direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

 generators
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...

.

Tesla claimed he was offered US$50,000 (~ US$1.1 million in 2007, adjusted for inflation) if he redesigned Edison's inefficient motor and generators, making an improvement in both service and economy. In 1885 when Tesla inquired about the payment for his work, Edison replied, "Tesla, you don't understand our American humor
American humor
American humor refers collectively to the conventions and common threads that tie together humor in the United States. It is often defined in comparison to the humor of another country - for example, how it is different from British humor and Canadian humor...

", thus breaking his word.
Earning US$18 per week, Tesla would have had to work for 53 years to earn the amount he was promised. The offer was equal to the initial capital of the company. Tesla immediately resigned when he was refused a raise to US$25 per week.

Tesla, in need of work, eventually found himself digging ditches for a short period of time for the Edison company. He used this time to focus on his AC polyphase system.

Middle years

Electromechanical devices and principles developed by Nikola Tesla:
----
  • Various devices that use rotating magnetic field
    Rotating magnetic field
    A rotating magnetic field is a magnetic field which changes direction at a constant angular rate. This is a key principle in the operation of the alternating-current motor. Nikola Tesla claimed in his autobiography that he identified the concept of the rotating magnetic field in 1882. In 1885,...

    s (1882)
  • The Induction motor
    Induction motor
    An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are robust and have no brushes...

    , rotary transformers, and "high" frequency alternator
    Alternator
    An alternator is an electromechanical device that converts mechanical energy to electrical energy in the form of alternating current.Most alternators use a rotating magnetic field but linear alternators are occasionally used...

    s
  • The Tesla coil
    Tesla coil
    A Tesla coil is a type of resonant transformer circuit invented by Nikola Tesla around 1891. It is used to produce high voltage, low current, high frequency alternating current electricity. Tesla coils produce higher current than the other source of high voltage discharges, electrostatic machines...

    , his magnifying transmitter
    Magnifying transmitter
    The magnifying transmitter is an advanced version of Tesla coil transmitter. It is a high power harmonic oscillator that Nikola Tesla intended for the wireless transmission of electrical energy...

    , and other means for increasing the intensity of electrical oscillation
    Oscillation
    Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...

    s (including condenser discharge transformations and the Tesla oscillators)
  • Alternating current
    Alternating current
    In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....

     long-distance electrical transmission system
    Electric power transmission
    Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...

     (1888) and other methods and devices for power transmission
    Power transmission
    Power transmission is the movement of energy from its place of generation to a location where it is applied to performing useful work.Power is defined formally as units of energy per unit time...

  • System
    System
    System is a set of interacting or interdependent components forming an integrated whole....

    s for wireless
    Wireless
    Wireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications...

     communication
    Telecommunication
    Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

     (prior art
    Prior art
    Prior art , in most systems of patent law, constitutes all information that has been made available to the public in any form before a given date that might be relevant to a patent's claims of originality...

     for the invention of radio
    Invention Of Radio
    Within the history of radio, several people were involved in the invention of radio and there were many key inventions in what became the modern systems of wireless. Radio development began as "wireless telegraphy"...

    ) and radio frequency oscillators
    Electronic oscillator
    An electronic oscillator is an electronic circuit that produces a repetitive electronic signal, often a sine wave or a square wave. They are widely used in innumerable electronic devices...

  • Robot
    Robot
    A robot is a mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control. In practice a robot is usually an electro-mechanical machine that is guided by computer and electronic programming. Robots can be autonomous, semi-autonomous or...

    ics and the electronic logic gate
    Logic gate
    A logic gate is an idealized or physical device implementing a Boolean function, that is, it performs a logical operation on one or more logic inputs and produces a single logic output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and...

  • Electrotherapy
    Electrotherapy
    Electrotherapy is the use of electrical energy as a medical treatment In medicine, the term electrotherapy can apply to a variety of treatments, including the use of electrical devices such as deep brain stimulators for neurological disease. The term has also been applied specifically to the use of...

     Tesla currents
  • Wireless transfer of electricity
    Wireless energy transfer
    Wireless energy transfer or wireless power is the transmission of electrical energy from a power source to an electrical load without artificial interconnecting conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible...

     and the Tesla effect
  • Tesla impedance phenonomena
  • Tesla electro-static field
  • Tesla principle
    Tesla principle
    Historically, the term Tesla principle was used to describe certain reversible processes invented by Nikola Tesla. However, this phrase is no longer in conventional use...

  • Bifilar coil
    Bifilar coil
    A bifilar coil is an electromagnetic coil that contains two closely spaced, parallel windings. In engineering, the word bifilar describes wire which is made of two filaments or strands. It is commonly used to denote special types of winding wire for transformers. Wire can be purchased in bifilar...

  • Telegeodynamics
    Telegeodynamics
    Telegeodynamics is an electromechanical earth-resonance concept for underground seismic exploration proposed by Nikola Tesla.-Description:Tesla designed this system for use in prospecting and discerning the location of underground mineral structures through the transmission of mechanical energy...

  • Tesla insulation
  • Tesla impulses
  • Tesla frequencies
  • Tesla discharge
  • Forms of commutators
    Commutator (electric)
    A commutator is a rotary electrical switch in certain types of electric motors or electrical generators that periodically reverses the current direction between the rotor and the external circuit. In a motor, it applies power to the best location on the rotor, and in a generator, picks off power...

     and methods of regulating third brushes
  • Tesla turbine
    Tesla turbine
    The Tesla turbine is a bladeless centripetal flow turbine patented by Nikola Tesla in 1913. It is referred to as a bladeless turbine because it uses the boundary layer effect and not a fluid impinging upon the blades as in a conventional turbine...

    s (e.g., bladeless turbines) for water, steam and gas and the Tesla pumps
  • Tesla igniter
  • Corona discharge ozone generator
  • Tesla compressor
  • X-ray
    X-ray
    X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

    s Tubes using the Bremsstrahlung
    Bremsstrahlung
    Bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus. The moving particle loses kinetic energy, which is converted into a photon because energy is conserved. The term is...

     process
  • Devices for ionized gases
    Plasma (physics)
    In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...

     and "Hot Saint Elmo's Fire".
  • Devices for high field emission
    Electric field gradient
    In atomic, molecular, and solid-state physics, the electric field gradient measures the rate of change of the electric field at an atomic nucleus generated by the electronic charge distribution and the other nuclei...

  • Devices for charged particle beam
    Charged particle beam
    A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same velocity . The kinetic energies of the particles are typically measured in keV or MeV, much larger than the energies of particles at ambient temperature...

    s
  • Phantom streaming devices
  • Arc light
    Arc Light
    Arc Light is the debut novel by Eric L. Harry, a techno-thriller about limited nuclear war published in 1994 and written in 1991-2.As China and Russia clash in Siberia in June 1999, nuclear missiles strike the United States. The U.S. retaliates against Russia, and World War III begins...

     systems
  • Methods for providing extremely low level of resistance to the passage of electric current (predecessor to superconductivity
    Superconductivity
    Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...

    )
  • Voltage
    Voltage
    Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...

     multiplication circuitry
    Electronic circuit
    An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow...

  • Devices for high voltage
    Voltage
    Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...

     discharges
  • Devices for lightning
    Lightning
    Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...

     protection
  • VTOL
    VTOL
    A vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...

     aircraft
  • Dynamic theory of gravity
  • Concepts for electric vehicles
  • Polyphase system
    Polyphase system
    A polyphase system is a means of distributing alternating current electrical power. Polyphase systems have three or more energized electrical conductors carrying alternating currents with a definite time offset between the voltage waves in each conductor. Polyphase systems are particularly useful...

    s

In 1886, Tesla formed his own company, Tesla Electric Light & Manufacturing
Tesla Electric Light & Manufacturing
The Tesla Electric Light & Manufacturing was a company formed by Nikola Tesla in 1886. Located in Rahway, New Jersey, Irving street, the company started after Tesla left Thomas Edison's employment following a payment disagreement. Tesla planned to sell and license his patent and innovations...

. The initial financial investors disagreed with Tesla on his plan for an alternating current motor and eventually relieved him of his duties at the company. Tesla worked in New York as a laborer from 1886 to 1887 to feed himself and raise capital for his next project. In 1887, he constructed the initial brushless
Brush (electric)
A brush is a device which conducts current between stationary wires and moving parts, most commonly in a rotating shaft. Typical applications include electric motors, alternators and electric generators.-Etymology:...

 alternating current induction motor
Induction motor
An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are robust and have no brushes...

, which he demonstrated to the American Institute of Electrical Engineers (now IEEE
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...

) in 1888. In the same year, he developed the principles of his Tesla coil
Tesla coil
A Tesla coil is a type of resonant transformer circuit invented by Nikola Tesla around 1891. It is used to produce high voltage, low current, high frequency alternating current electricity. Tesla coils produce higher current than the other source of high voltage discharges, electrostatic machines...

, and began working with George Westinghouse
George Westinghouse
George Westinghouse, Jr was an American entrepreneur and engineer who invented the railway air brake and was a pioneer of the electrical industry. Westinghouse was one of Thomas Edison's main rivals in the early implementation of the American electricity system...

 at Westinghouse Electric & Manufacturing Company's Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...

 labs. Westinghouse listened to his ideas for polyphase systems which would allow transmission of alternating current electricity over long distances.

In April 1887, Tesla began investigating what would later be called X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

s using his own single terminal vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...

s (similar to his patent ). This device differed from other early X-ray tubes in that it had no target electrode. The modern term for the phenomenon produced by this device is bremsstrahlung
Bremsstrahlung
Bremsstrahlung is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus. The moving particle loses kinetic energy, which is converted into a photon because energy is conserved. The term is...

 (or braking radiation). We now know that this device operated by emitting electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...

s from the single electrode through a combination of field electron emission and thermionic emission
Thermionic emission
Thermionic emission is the heat-induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the binding potential, also known as work function of the metal. The charge carriers can be electrons or ions, and...

. Once liberated, electrons are strongly repelled by the high electric field
Electric field
In physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...

 near the electrode during negative voltage peaks from the oscillating HV output of the Tesla Coil, generating X rays as they collide with the glass envelope. He also used Geissler tube
Geissler tube
A Geissler tube is an early gas discharge tube used to demonstrate the principles of electrical glow discharge. The tube was invented by the German physicist and glassblower Heinrich Geissler in 1857...

s. By 1892, Tesla became aware of the skin damage that Wilhelm Röntgen later identified as an effect of X rays.

In the early research, Tesla devised several experimental setups to produce X-rays. Tesla held that, with his circuits, the "instrument will [... enable one to] generate Roentgen rays of much greater power than obtainable with ordinary apparatus".

He also commented on the hazards of working with his circuit and single-node X-ray-producing devices. Of his many notes in the early investigation of this phenomenon, he attributed the skin damage to various causes. He believed early on that damage to the skin was not caused by the Roentgen rays, but the ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...

 generated in contact with the skin, and to a lesser extent, nitrous acid
Nitrous acid
Nitrous acid is a weak and monobasic acid known only in solution and in the form of nitrite salts.Nitrous acid is used to make diazides from amines; this occurs by nucleophilic attack of the amine onto the nitrite, reprotonation by the surrounding solvent, and double-elimination of water...

. Tesla incorrectly held that x-rays were longitudinal wave
Longitudinal wave
Longitudinal waves, as known as "l-waves", are waves that have the same direction of vibration as their direction of travel, which means that the movement of the medium is in the same direction as or the opposite direction to the motion of the wave. Mechanical longitudinal waves have been also...

s, such as those produced in waves in plasma. There are known examples of this and these plasma waves can occur in the situation of force-free magnetic field
Force-free magnetic field
A force-free magnetic field is a type of field which arises as a special case from the magnetostatic equation in plasmas. This special case arises when the plasma pressure is so small, relative to the magnetic pressure, that the plasma pressure may be ignored, and so only the magnetic pressure is...

s. His hypotheses and experiments were confirmed by others.

Tesla continued research in the field. He performed several experiments prior to Roentgen's discovery (including photographing the bones of his hand; later, he sent these images to Roentgen) but did not make his findings widely known; much of his research was lost in the 5th Avenue laboratory fire of March 1895.

Tesla demonstrated wireless energy transmission as early as 1891. The Tesla effect is a term for an application of this type of electrical conduction (that is, the movement of energy through space and matter, not just the production of voltage across a conductor).

American citizenship

On 30 July 1891, at the age of 35, he became a naturalized citizen
Naturalization
Naturalization is the acquisition of citizenship and nationality by somebody who was not a citizen of that country at the time of birth....

 of the United States. Tesla established his South Fifth Avenue
Fifth Avenue (Manhattan)
Fifth Avenue is a major thoroughfare in the center of the borough of Manhattan in New York City, New York, United States. The section of Fifth Avenue that crosses Midtown Manhattan, especially that between 49th Street and 60th Street, is lined with prestigious shops and is consistently ranked among...

 laboratory in New York in the same year. Later, Tesla established his Houston Street laboratory in New York at 46 E. Houston Street. He lit electric lamps wirelessly at both of the New York locations, providing evidence for the potential of wireless power transmission.

Soon thereafter, in 1892, Tesla was awakened from a dream in which his mother had died. He returned to Europe for her funeral. After her death, Tesla fell ill. He spent two to three weeks recuperating in Gospić and the village of Tomingaj near Gračac
Gracac
Gračac is a village and a municipality in the southern part of Lika, Croatia. It is located south of Udbina, northeast of Obrovac, northwest of Knin and southeast of Gospić...

, his mother's birthplace.

Some of Tesla's closest friends were artists. He befriended Century Magazine
The Century Magazine
The Century Magazine was first published in the United States in 1881 by The Century Company of New York City as a successor to Scribner's Monthly Magazine...

 editor Robert Underwood Johnson
Robert Underwood Johnson
Robert Underwood Johnson was a U.S. writer and diplomat. His wife was Katharine Johnson.-Biography:A native of Washington, D.C., Johnson joined the staff of The Century Magazine in 1873...

, who adapted several Serbian poems of Jovan Jovanović Zmaj
Jovan Jovanovic Zmaj
Jovan Jovanović Zmaj was one of the best-known Serbian poets. He was a physician by profession, like his literary predecessor writer Jovan Stejić ....

 (which Tesla translated). Also during this time, Tesla was influenced by the Vedic philosophy
Vedanta
Vedānta was originally a word used in Hindu philosophy as a synonym for that part of the Veda texts known also as the Upanishads. The name is a morphophonological form of Veda-anta = "Veda-end" = "the appendix to the Vedic hymns." It is also speculated that "Vedānta" means "the purpose or goal...

 (i.e., Hinduism
Hinduism
Hinduism is the predominant and indigenous religious tradition of the Indian Subcontinent. Hinduism is known to its followers as , amongst many other expressions...

) teachings of the Swami Vivekananda
Swami Vivekananda
Swami Vivekananda , born Narendranath Dutta , was the chief disciple of the 19th century mystic Ramakrishna Paramahansa and the founder of the Ramakrishna Math and the Ramakrishna Mission...

; so much so that, after his exposure to Hindu-Vedic thought, Tesla started using Sanskrit
Sanskrit
Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...

 words to name some of his fundamental concepts regarding matter and energy.

When Tesla was 36 years old, the first patents concerning the polyphase power system were granted. He continued research of the system and rotating magnetic field principles. Tesla served, from 1892 to 1894, as the vice president of the American Institute of Electrical Engineers
American Institute of Electrical Engineers
The American Institute of Electrical Engineers was a United States based organization of electrical engineers that existed between 1884 and 1963, when it merged with the Institute of Radio Engineers to form the Institute of Electrical and Electronics Engineers .- History :The 1884 founders of the...

, the forerunner (along with the Institute of Radio Engineers
Institute of Radio Engineers
The Institute of Radio Engineers was a professional organization which existed from 1912 until January 1, 1963, when it merged with the American Institute of Electrical Engineers to form the Institute of Electrical and Electronics Engineers .-Founding:Following several attempts to form a...

) of the modern-day IEEE
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...

. From 1893 to 1895, he investigated high frequency
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...

 alternating currents. He generated AC of one million volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

s using a conical Tesla coil and investigated the skin effect
Skin effect
Skin effect is the tendency of an alternating electric current to distribute itself within a conductor with the current density being largest near the surface of the conductor, decreasing at greater depths. In other words, the electric current flows mainly at the "skin" of the conductor, at an...

 in conductors
Electrical conductor
In physics and electrical engineering, a conductor is a material which contains movable electric charges. In metallic conductors such as copper or aluminum, the movable charged particles are electrons...

, designed tuned circuits, invented a machine for inducing sleep, cordless gas discharge lamps, and transmitted electromagnetic energy without wires, building the first radio transmitter
Transmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...

. In St. Louis
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

, Missouri, Tesla made a demonstration related to radio communication in 1893. Addressing the Franklin Institute
Franklin Institute
The Franklin Institute is a museum in Philadelphia, Pennsylvania, and one of the oldest centers of science education and development in the United States, dating to 1824. The Institute also houses the Benjamin Franklin National Memorial.-History:On February 5, 1824, Samuel Vaughn Merrick and...

 in Philadelphia, Pennsylvania and the National Electric Light Association
National Electric Light Association
The National Electric Light Association was a national United States trade association including the operators of central power generation stations and interested individuals. Founded in 1885 by G. S. Bowen Terry and Charles A. Brown, it represented the interests of various private companies...

, he described and demonstrated in detail its principles. Tesla's demonstrations were written about widely through various media outlets. Tesla also investigated harvesting energy that is present throughout space. He believed that it was merely a question of time when men would succeed in attaching their machinery to the very wheelwork of nature, stating: "Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe."

At the 1893 World's Fair
World's Fair
World's fair, World fair, Universal Exposition, and World Expo are various large public exhibitions held in different parts of the world. The first Expo was held in The Crystal Palace in Hyde Park, London, United Kingdom, in 1851, under the title "Great Exhibition of the Works of Industry of All...

, the World's Columbian Exposition
World's Columbian Exposition
The World's Columbian Exposition was a World's Fair held in Chicago in 1893 to celebrate the 400th anniversary of Christopher Columbus's arrival in the New World in 1492. Chicago bested New York City; Washington, D.C.; and St...

 in Chicago, an international exposition was held which, for the first time, devoted a building to electrical exhibits. It was a historic event as Tesla and George Westinghouse introduced visitors to AC power
AC power
Power in an electric circuit is the rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductance and capacitance may result in periodic reversals of the direction of energy flow...

 by using it to illuminate the Exposition. On display were fluorescent lamp
Fluorescent lamp
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...

s developed by Westinghouse and single node bulbs. An observer noted:
Tesla also explained the principles of the rotating magnetic field and induction motor
Induction motor
An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are robust and have no brushes...

 by demonstrating how to make an egg made of copper stand on end in his demonstration of the device he constructed known as the "Egg of Columbus
Tesla's Egg of Columbus
Nikola Tesla, at the 1893 World's Columbian Exposition, demonstrated a device he constructed known as the "Egg of Columbus." It was used to demonstrate and explain the principles of the rotating magnetic field model and the induction motor. Tesla's Egg of Columbus performed the feat of Columbus...

".

The Tesla generator was developed by Tesla in 1895, in conjunction with his developments concerning the liquefaction
Liquefaction
Liquefaction may refer to:* Liquefaction, the general process of becoming liquid* Soil liquefaction, the process by which sediments become suspended* Liquefaction of gases in physics, chemistry, and thermal engineering* Liquefactive necrosis in pathology...

 of air. Tesla knew, from Lord Kelvin's discoveries, that more heat is absorbed by liquefied air when it is re-gasified and used to drive something, than is required by theory; in other words, that the liquefaction process is somewhat anomalous or 'over unity'. Just prior to Tesla's completion of his work and the filing of a patent application, Tesla's laboratory burned down, destroying all his equipment, models and inventions. Immediately after the fire, Carl von Linde
Carl von Linde
Professor Doctor Carl Paul Gottfried von Linde was a German engineer who developed refrigeration and gas separation technologies...

, in Germany, filed a patent application for the same process.

A "world system" for "the transmission of electrical energy without wires" that depends upon the electrical conductivity of the earth was proposed, in which transmission in various natural media with current that passes between the two points are used to power devices. In a practical wireless energy transmission system using this principle, a high-power ultraviolet beam might be used to form a vertical ionized channel in the air directly above the transmitter-receiver stations. The same concept is used in virtual lightning rod
Lightning rod
A lightning rod or lightning conductor is a metal rod or conductor mounted on top of a building and electrically connected to the ground through a wire, to protect the building in the event of lightning...

s, the electrolaser
Electrolaser
An electrolaser is a type of electroshock weapon which is also a directed-energy weapon. It uses lasers to form an electrically conductive laser-induced plasma channel...

 electroshock weapon,
and has been proposed for disabling vehicles.

Edison

Also in the late 1880s, Tesla and Thomas Edison
Thomas Edison
Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

 became adversaries in part because of Edison's promotion of direct current (DC) for electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

 distribution over the more efficient alternating current advocated by Tesla and Westinghouse. Until Tesla invented the induction motor, AC's advantages for long distance high voltage
High voltage
The term high voltage characterizes electrical circuits in which the voltage used is the cause of particular safety concerns and insulation requirements...

 transmission were counterbalanced by the inability to operate motors on AC. As a result of the "War of Currents
War of Currents
In the "War of Currents" era in the late 1880s, George Westinghouse and Thomas Edison became adversaries due to Edison's promotion of direct current for electric power distribution over alternating current advocated by several European companies and Westinghouse Electric based out of Pittsburgh,...

", Edison and Westinghouse went nearly bankrupt, so in 1897, Tesla released Westinghouse from contract, providing Westinghouse a break from Tesla's patent royalties. Also in 1897, Tesla researched radiation
Particle radiation
Particle radiation is the radiation of energy by means of fast-moving subatomic particles. Particle radiation is referred to as a particle beam if the particles are all moving in the same direction, similar to a light beam....

, which led to setting up the basic formulation of cosmic ray
Cosmic ray
Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...

s.

In 1897, at age 41, Tesla filed the first radio patent . A year later, he demonstrated a radio-controlled
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...

 boat to the US military, believing that the military would want things such as radio-controlled torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

es. Tesla claimed to have developed the "Art of Telautomatics", a form of robotics
Robotics
Robotics is the branch of technology that deals with the design, construction, operation, structural disposition, manufacture and application of robots...

, as well as the technology of remote control. In 1898, he demonstrated a radio-controlled boat to the public during an electrical exhibition at Madison Square Garden
Madison Square Garden (1890)
Madison Square Garden was an indoor arena in New York City, the second by that name, and the second to be located at 26th Street and Madison Avenue in Manhattan...

. Tesla called his boat a "teleautomaton". In the same year, Tesla devised an "electric igniter" or spark plug
Spark plug
A spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed fuels such as aerosol, gasoline, ethanol, and liquefied petroleum gas by means of an electric spark.Spark plugs have an insulated central electrode which is connected by...

 for Internal combustion
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

 gasoline engines. He gained , "Electrical Igniter for Gas Engines", on this mechanical ignition system
Ignition system
An ignition system is a system for igniting a fuel-air mixture. Ignition systems are well known in the field of internal combustion engines such as those used in petrol engines used to power the majority of motor vehicles, but they are also used in many other applications such as in oil-fired and...

. Tesla lived in the former Gerlach Hotel, renamed The Radio Wave building, at 49 W 27th St. (between Broadway and Sixth Avenue), Lower Manhattan
Lower Manhattan
Lower Manhattan is the southernmost part of the island of Manhattan, the main island and center of business and government of the City of New York...

, before the end of the century where he conducted the radio wave experiments. A commemorative plaque
Commemorative plaque
A commemorative plaque, or simply plaque, is a plate of metal, ceramic, stone, wood, or other material, typically attached to a wall, stone, or other vertical surface, and bearing text in memory of an important figure or event...

 was placed on the building in 1977 to honor his work. Remote radio control
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...

 remained a novelty until World War I and afterward, when a number of countries used it in military programs.

Colorado Springs

In 1899, Tesla decided to move and began research in Colorado Springs
Colorado Springs, Colorado
Colorado Springs is a Home Rule Municipality that is the county seat and most populous city of El Paso County, Colorado, United States. Colorado Springs is located in South-Central Colorado, in the southern portion of the state. It is situated on Fountain Creek and is located south of the Colorado...

, Colorado in a lab located near Foote Ave. and Kiowa St., where he would have room for his high-voltage, high-frequency experiments. Upon his arrival he told reporters that he was conducting wireless telegraphy
Wireless telegraphy
Wireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio before the term radio came into use....

 experiments transmitting signals from Pikes Peak
Pikes Peak
Pikes Peak is a mountain in the Front Range of the Rocky Mountains, west of Colorado Springs, Colorado, in El Paso County in the United States of America....

 to Paris. Tesla's diary contains explanations of his experiments concerning the ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...

 and the ground's telluric current
Telluric current
A telluric current , or Earth current, is an electric current which moves underground or through the sea. Telluric currents result from both natural causes and human activity, and the discrete currents interact in a complex pattern...

s via transverse wave
Transverse wave
A transverse wave is a moving wave that consists of oscillations occurring perpendicular to the direction of energy transfer...

s and longitudinal wave
Longitudinal wave
Longitudinal waves, as known as "l-waves", are waves that have the same direction of vibration as their direction of travel, which means that the movement of the medium is in the same direction as or the opposite direction to the motion of the wave. Mechanical longitudinal waves have been also...

s.
At his lab, Tesla proved that the earth was a conductor, and he produced artificial lightning
Lightning
Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...

 (with discharges consisting of millions of volts, and up to 135 feet long).
Tesla also investigated atmospheric electricity
Atmospheric electricity
Atmospheric electricity is the regular diurnal variations of the Earth's atmospheric electromagnetic network . The Earth's surface, the ionosphere, and the atmosphere is known as the global atmospheric electrical circuit...

, observing lightning signals via his receivers. Reproductions of Tesla's receivers and coherer circuits show an unpredicted level of complexity (e.g., distributed
Distributed element model
In electrical engineering, the distributed element model or transmission line model of electrical circuits assumes that the attributes of the circuit are distributed continuously throughout the material of the circuit...

 high-Q
Q factor
In physics and engineering the quality factor or Q factor is a dimensionless parameter that describes how under-damped an oscillator or resonator is, or equivalently, characterizes a resonator's bandwidth relative to its center frequency....

 helical
Helix
A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...

 resonators, radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

 feedback
Feedback
Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...

, crude heterodyne
Heterodyne
Heterodyning is a radio signal processing technique invented in 1901 by Canadian inventor-engineer Reginald Fessenden where high frequency signals are converted to lower frequencies by combining two frequencies. Heterodyning is useful for frequency shifting information of interest into a useful...

 effects, and regeneration techniques
Regenerative circuit
The regenerative circuit or "autodyne" allows an electronic signal to be amplified many times by the same vacuum tube or other active component such as a field effect transistor. It consists of an amplifying vacuum tube or transistor with its output connected to its input through a feedback...

).
Tesla stated that he observed stationary waves during this time.

Tesla researched ways to transmit power and energy wirelessly over long distances (via transverse waves, to a lesser extent, and, more readily, longitudinal waves). He transmitted extremely low frequencies
Extremely low frequency
Extremely low frequency is a term used to describe radiation frequencies from 3 to 300 Hz. In atmosphere science, an alternative definition is usually given, from 3 Hz to 3 kHz...

 through the ground as well as between the Earth's surface and the Kennelly–Heaviside layer. He received patents on wireless transceivers that developed standing waves by this method. In his experiments, he made mathematical calculations and computations based on his experiments and discovered that the resonant frequency of the Earth was approximately 8 hertz (Hz). In the 1950s, researchers confirmed that the resonant frequency of the Earth's ionospheric cavity was in this range (later named the Schumann resonance
Schumann resonance
The Schumann resonances are a set of spectrum peaks in the extremely low frequency portion of the Earth's electromagnetic field spectrum...

).

In Colorado Springs Tesla carried out various long distance wireless transmission-reception experiments. Tesla effect is the application of a type of electrical conduction (that is, the movement of energy through space and matter; not just the production of voltage across a conductor). Through longitudinal wave
Longitudinal wave
Longitudinal waves, as known as "l-waves", are waves that have the same direction of vibration as their direction of travel, which means that the movement of the medium is in the same direction as or the opposite direction to the motion of the wave. Mechanical longitudinal waves have been also...

s, Tesla transferred energy to receiving devices. He sent electrostatic forces through natural media across a conductor situated in the changing magnetic flux
Magnetic flux
Magnetic flux , is a measure of the amount of magnetic B field passing through a given surface . The SI unit of magnetic flux is the weber...

 and transferred electrical energy to a wireless receiver.

In the Colorado Springs lab, Tesla observed unusual signals that he later thought may have been evidence of extraterrestrial
Extraterrestrial life
Extraterrestrial life is defined as life that does not originate from Earth...

 radio wave communications coming from Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

 or Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

. He noticed repetitive signals from his receiver which were substantially different from the signals he had noted from storms and earth noise. Specifically, he later recalled that the signals appeared in groups of one, two, three, and four clicks together. Tesla had mentioned that he thought his inventions could be used to talk with other planets. There have even been claims that he invented a "Teslascope
Teslascope
A Teslascope is a radio transceiver that was alleged to have been invented by Nikola Tesla for the purpose of communicating with life on other planets...

" for just such a purpose. It is debatable what type of signals Tesla received or whether he picked up anything at all. Research has suggested that Tesla may have had a misunderstanding of the new technology he was working with, or that the signals Tesla observed may have been non-terrestrial natural radio source such as the Jovian
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

 plasma torus
Jupiter's magnetosphere
The magnetosphere of Jupiter is the cavity created in the solar wind by the planet's magnetic field. Extending up to seven million kilometers in the Sun's direction and almost to the orbit of Saturn in the opposite direction, Jupiter's magnetosphere is the largest and most powerful of any planetary...

 signals.

Tesla left Colorado Springs on 7 January 1900. The lab was torn down ca. 1905 and its contents sold to pay debts. The Colorado experiments prepared Tesla for the establishment of the trans-Atlantic wireless telecommunications facility known as Wardenclyffe.

Wardenclyffe years

In 1900, with US$150,000 (51% from J. Pierpont Morgan), Tesla began planning the Wardenclyffe Tower
Wardenclyffe Tower
Wardenclyffe Tower also known as the Tesla Tower, was an early wireless telecommunications tower designed by Nikola Tesla and intended for commercial trans-Atlantic wireless telephony, broadcasting, and to demonstrate the transmission of power without interconnecting wires...

 facility. In June 1902, Tesla's lab operations were moved to Wardenclyffe from Houston Street. The tower was dismantled for scrap during World War I. Newspapers of the time labeled Wardenclyffe "Tesla's million-dollar folly". In 1904, the US Patent Office
Patent office
A patent office is a governmental or intergovernmental organization which controls the issue of patents. In other words, "patent offices are government bodies that may grant a patent or reject the patent application based on whether or not the application fulfils the requirements for...

 reversed its decision and awarded Guglielmo Marconi
Guglielmo Marconi
Guglielmo Marconi was an Italian inventor, known as the father of long distance radio transmission and for his development of Marconi's law and a radio telegraph system. Marconi is often credited as the inventor of radio, and indeed he shared the 1909 Nobel Prize in Physics with Karl Ferdinand...

 the patent for radio, and Tesla began his fight to re-acquire the radio patent. He finally won, albeit rather late: in 1943, the Supreme Court of the United States
Supreme Court of the United States
The Supreme Court of the United States is the highest court in the United States. It has ultimate appellate jurisdiction over all state and federal courts, and original jurisdiction over a small range of cases...

 reversed this decision and granted Tesla the main patents, thus proclaiming him to be the true inventor of radio.

On his 50th birthday in 1906, Tesla demonstrated his 200 hp
Horsepower
Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...

 (150 kW) 16,000 rpm bladeless turbine
Tesla turbine
The Tesla turbine is a bladeless centripetal flow turbine patented by Nikola Tesla in 1913. It is referred to as a bladeless turbine because it uses the boundary layer effect and not a fluid impinging upon the blades as in a conventional turbine...

. During 1910–1911 at the Waterside Power Station in New York, several of his bladeless turbine engines were tested at 100–5000 hp.

Nobel prize and Tesla

Since the Nobel Prize in Physics
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...

 was awarded to Marconi for radio in 1909, Thomas Edison
Thomas Edison
Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

 and Tesla were mentioned in a press dispatch as potential laureates to share the Nobel Prize of 1915
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...

, leading to one of several Nobel Prize controversies
Nobel Prize controversies
Subsequent to his death in 1896, the will of Swedish industrialist Alfred Nobel established the Nobel Prizes. Annual prizes were to be awarded for service to humanity in the fields of physics, chemistry, physiology or medicine, literature, and peace. Similarly, the Bank of Sweden Prize in Economic...

. Some sources have claimed that because of their animosity toward each other neither was given the award, despite their scientific contributions; that each sought to minimize the other's achievements and right to win the award; that both refused to ever accept the award if the other received it first; and that both rejected any possibility of sharing it.

In the years after these rumors, neither Tesla nor Edison won the Prize (although Edison did receive one of 38 possible bids in 1915, and Tesla did receive one bid out of 38 in 1937).
Earlier, Tesla alone was rumored to have been nominated for the Nobel Prize of 1912
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...

. The rumored nomination was primarily for his experiments with tuned circuits using high-voltage high-frequency resonant transformers.

Later years

In 1915, Tesla filed a lawsuit against Marconi attempting, unsuccessfully, to obtain a court injunction against Marconi's claims. After Wardenclyffe, Tesla built the Telefunken
Telefunken
Telefunken is a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the Allgemeine Elektricitäts-Gesellschaft...

 Wireless Station in Sayville, Long Island. Some of what he wanted to achieve at Wardenclyffe was accomplished with the Telefunken Wireless. In 1917, the facility was seized and torn down by the Marines
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...

, because it was suspected that it could be used by German spies.

Before World War I, Tesla looked overseas for investors to fund his research. When the war started, Tesla lost the funding he was receiving from his patents in European countries. After the war ended, Tesla made predictions regarding the relevant issues of the post-World War I environment, in a printed article (20 December 1914). Tesla believed that the League of Nations
League of Nations
The League of Nations was an intergovernmental organization founded as a result of the Paris Peace Conference that ended the First World War. It was the first permanent international organization whose principal mission was to maintain world peace...

 was not a remedy for the times and issues. Tesla started to exhibit pronounced symptoms of obsessive-compulsive disorder
Obsessive-compulsive disorder
Obsessive–compulsive disorder is an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry, by repetitive behaviors aimed at reducing the associated anxiety, or by a combination of such obsessions and compulsions...

 in the years following. He became obsessed with the number three; he often felt compelled to walk around a block three times before entering a building, demanded a stack of three folded cloth napkins beside his plate at every meal, etc. The nature of OCD was little understood at the time and no treatments were available, so his symptoms were considered by some to be evidence of partial insanity, and this undoubtedly hurt what was left of his reputation.

At this time, he was staying at The Waldorf-Astoria Hotel, renting in an arrangement for deferred payments. Eventually, the Wardenclyffe deed was turned over to George Boldt
George Boldt
George Charles Boldt was a Prussian-born American hotelier. A self-made millionaire, he influenced the development of the urban hotel as a civic social center and luxury destination.-Philadelphia:...

, proprietor of the Waldorf-Astoria, to pay a US$20,000 debt. In 1917, around the time that the Wardenclyffe Tower was demolished by Boldt to make the land a more viable real estate asset, Tesla received AIEE's
American Institute of Electrical Engineers
The American Institute of Electrical Engineers was a United States based organization of electrical engineers that existed between 1884 and 1963, when it merged with the Institute of Radio Engineers to form the Institute of Electrical and Electronics Engineers .- History :The 1884 founders of the...

 highest honor, the Edison Medal.

Tesla, in August 1917, first established principles regarding frequency and power level for the first primitive radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 units.

In 1934, Émile Girardeau
Emile Girardeau
Émile Girardeau was a French engineer, famous for being the first person to patent the original system of frequencies that is used today and known as the radar...

, working with the first French radar systems, stated he was building them "according to the principles stated by Tesla". By the 1920s, Tesla was reportedly negotiating with the United Kingdom government about a ray system. Tesla had also stated that efforts had been made to steal the so called "death ray". It is suggested that the removal of the Chamberlain
Neville Chamberlain
Arthur Neville Chamberlain FRS was a British Conservative politician who served as Prime Minister of the United Kingdom from May 1937 to May 1940. Chamberlain is best known for his appeasement foreign policy, and in particular for his signing of the Munich Agreement in 1938, conceding the...

 government ended negotiations.

On Tesla's 75th birthday in 1931, Time magazine put him on its cover. The cover caption noted his contribution to electrical power generation
Electricity generation
Electricity generation is the process of generating electric energy from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...

. Tesla received his last patent in 1928 for an apparatus for aerial transportation
Aviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...

 which was the first instance of VTOL aircraft. By the end of 1931, Tesla released "On Future Motive Power" which covered an ocean thermal energy conversion
Ocean thermal energy conversion
Ocean Thermal Energy Conversion uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity....

 system. In 1934, Tesla wrote to consul Janković of his homeland. The letter contained a message of gratitude to Mihajlo Pupin
Mihajlo Pupin
Mihajlo Idvorski Pupin, Ph.D, LL.D. , also known as Michael I. Pupin, was a Serbian physicist and physical chemist...

 who had initiated a donation scheme by which American companies could support Tesla. Tesla refused the assistance, choosing instead to live on a modest pension received from Yugoslavia, and to continue his research.
In 1936, replying to a birthday telegram from Vladko Maček
Vladko Macek
Vladko Maček was a Croatian politician active within the Kingdom of Yugoslavia in the first half of the 20th century. He led the Croatian Peasant Party following the assassination of Stjepan Radić, and all through World War II.- Early life :Maček was born to a Slovene-Czech family in the village...

, Tesla said he was "equally proud" of his "Serbian origin and Croatian homeland", a phrase often paraphrased in conciliatory context at modern-day joint Croatian-Serbian Tesla celebrations.
In addition, in the same telegram, Tesla wrote "Long live all Yugoslavs." When others tried to co-opt him into ethnic and other conflicts in Yugoslavia, Tesla once replied: "If your hate could be turned into electricity, it would light up the whole world."

Field theories

When he was 81, Tesla stated he had completed a "dynamic theory of gravity". He stated that it was "worked out in all details" and that he hoped to soon give it to the world.
The theory was never published.

The bulk of the theory was developed between 1892 and 1894, during the period that he was conducting experiments with high frequency and high potential
Potential
*In linguistics, the potential mood*The mathematical study of potentials is known as potential theory; it is the study of harmonic functions on manifolds...

 electromagnetism and patenting devices for their use. Reminiscent of Mach's principle
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach....

, Tesla stated in 1925 that:


Tesla was critical of Einstein's relativity work, calling it:
Tesla also argued:
Tesla also believed that much of Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...

's relativity theory
Theory of relativity
The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. However, the word relativity is sometimes used in reference to Galilean invariance....

 had already been proposed by Ruđer Bošković, stating in an unpublished interview:

Directed-energy weapon

Later in life, Tesla made remarkable claims concerning a "teleforce
Teleforce
Teleforce was Nikola Tesla's charged particle beam projector, first mentioned publicly in the New York Sun and New York Times on July 11, 1934.-Introduction:...

" weapon. The press called it a "peace ray" or death ray
Death ray
The death ray or death beam was a theoretical particle beam or electromagnetic weapon of the 1920s through the 1930s that was claimed to have been invented independently by Nikola Tesla, Edwin R. Scott, Harry Grindell Matthews, and Graichen, as well as others...

. In total, the components and methods included:
  • An apparatus for producing manifestations of energy in free air instead of in a high vacuum
    Vacuum
    In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...

     as in the past. This, according to Tesla in 1934, was accomplished.
  • A mechanism for generating tremendous electrical force. This, according to Tesla, was also accomplished.
  • A means of intensifying and amplifying the force developed by the second mechanism.
  • A new method for producing a tremendous electrical repelling force. This would be the projector, or gun, of the invention.


Tesla worked on plans for a directed-energy weapon
Directed-energy weapon
A directed-energy weapon emits energy in an aimed direction without the means of a projectile. It transfers energy to a target for a desired effect. Intended effects may be non-lethal or lethal...

 from the early 1900s until his death. In 1937, Tesla wrote a treatise entitled "The Art of Projecting Concentrated Non-dispersive Energy through the Natural Media", which concerned charged particle beam
Charged particle beam
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same velocity . The kinetic energies of the particles are typically measured in keV or MeV, much larger than the energies of particles at ambient temperature...

s. Tesla published the document in an attempt to expound on the technical description of a "superweapon
Superweapon
A superweapon is an extremely powerful weapon by the standards of its time and its scale. Examples include the Tsar Bomba , various superguns and other various weapons employed to give a decisive advantage over opposing countries or forces. The given advantage is usually based on intimidation and...

 that would put an end to all war." This treatise describing the particle beam
Particle beam
A particle beam is a stream of charged or neutral particles which may be directed by magnets and focused by electrostatic lenses, although they may also be self-focusing ....

 is currently in the Nikola Tesla Museum
Nikola Tesla Museum
The Nikola Tesla Museum is located in the central area of Belgrade. It holds more than 160,000 original documents, over 2,000 books and journals, over 1,200 historical technical exhibits, over 1,500 photographs and photo plates of original, technical objects, instruments and apparatus, and over...

 archive in Belgrade
Belgrade
Belgrade is the capital and largest city of Serbia. It is located at the confluence of the Sava and Danube rivers, where the Pannonian Plain meets the Balkans. According to official results of Census 2011, the city has a population of 1,639,121. It is one of the 15 largest cities in Europe...

. It describes an open-ended vacuum tube with a gas jet seal that allows particles to exit, a method of charging particles to millions of volts, and a method of creating and directing nondispersive particle streams (through electrostatic repulsion).

His records indicate that the device is based on a narrow stream of atomic clusters
Superatom
Superatoms are clusters of atoms that seem to exhibit some of the properties of elemental atoms.Sodium atoms, when cooled from vapor, naturally condense into clusters, preferentially containing a magic number of atoms . The first two of these can be recognized as the numbers of electrons needed to...

 of liquid mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

 or tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

 accelerated via high voltage (by means akin to his magnifying transformer
Magnifying transmitter
The magnifying transmitter is an advanced version of Tesla coil transmitter. It is a high power harmonic oscillator that Nikola Tesla intended for the wireless transmission of electrical energy...

). Tesla gives the following description concerning the particle gun
Charged particle beam
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same velocity . The kinetic energies of the particles are typically measured in keV or MeV, much larger than the energies of particles at ambient temperature...

s operation:

The weapon could be used against ground based infantry or for antiaircraft purposes. Tesla tried to interest the US War Department
United States Department of Defense
The United States Department of Defense is the U.S...

 in the device. He also offered this invention to European countries. None of the governments purchased a contract to build the device. He was unable to act on his plans.

Theoretical inventions

Another of Tesla's theorized inventions is commonly referred to as Tesla's Flying Machine, which appears to resemble an ion-propelled aircraft
Ionocraft
An ionocraft or ion-propelled aircraft, commonly known as a lifter or hexalifter, is an electrohydrodynamic device to produce thrust in the air, without requiring any combustion or moving parts. The term "Ionocraft" dates back to the 1960s, an era in which EHD experiments were at their peak...

. Tesla claimed that one of his life goals was to create a flying machine that would run without the use of an airplane engine, wings, ailerons, propellers, or an onboard fuel source. Initially, Tesla pondered about the idea of a flying craft that would fly using an electric motor powered by grounded base stations. As time progressed, Tesla suggested that perhaps such an aircraft could be run entirely electro-mechanically. The theorized appearance would typically take the form of a cigar or saucer.

Personal life

Nikola Tesla was a polyglot
Polyglot
Polyglot may refer to:*Polyglot , someone who uses many languages*Polyglot , a book that contains the same text in more than one language*Polyglot , a computer program that is valid in more than one programming language...

, and along with his native tongue he also spoke Czech, English, French, German, Hungarian, Italian, and Latin.

During his second year of study at Graumltz, Tesla developed a passion for (and became very proficient at) billiards, chess and card-playing, sometimes spending more than 48 hours in a stretch at a gaming table. Tesla by nature required little sleep, claiming to never sleep more than two hours. On one occasion at his laboratory Tesla worked for a period of 84 hours without sleep or rest.

Tesla may have suffered from obsessive-compulsive disorder
Obsessive-compulsive disorder
Obsessive–compulsive disorder is an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry, by repetitive behaviors aimed at reducing the associated anxiety, or by a combination of such obsessions and compulsions...

, and had many unusual quirks and phobias. He did things in threes, and was adamant about staying in a hotel room with a number divisible by three. Tesla was physically revolted by jewelry, notably pearl earrings. He was fastidious about cleanliness and hygiene, and was by all accounts mysophobic
Mysophobia
Mysophobia is a term used to describe a pathological fear of contamination and germs. Someone who has such a fear is referred to as a mysophobe. The term was introduced by Dr. William Alexander Hammond in 1879 when describing a case of obsessive-compulsive disorder exhibited in repeatedly washing...

.

Tesla was obsessed with pigeons, ordering special seeds for the pigeons he fed in Central Park
Central Park
Central Park is a public park in the center of Manhattan in New York City, United States. The park initially opened in 1857, on of city-owned land. In 1858, Frederick Law Olmsted and Calvert Vaux won a design competition to improve and expand the park with a plan they entitled the Greensward Plan...

 and even bringing injured ones into his hotel room to nurse them back to health. Tesla was an animal-lover, often reflecting contentedly about a childhood cat, "The Magnificent Mačak." Tesla never married. He was celibate
Celibacy
Celibacy is a personal commitment to avoiding sexual relations, in particular a vow from marriage. Typically celibacy involves avoiding all romantic relationships of any kind. An individual may choose celibacy for religious reasons, such as is the case for priests in some religions, for reasons of...

 and claimed that his chastity was very helpful to his scientific abilities. Nonetheless there have been numerous accounts of women vying for Tesla's affection, even some madly in love with him. Tesla, though polite, behaved rather ambivalently to these women in the romantic sense.

Tesla was prone to alienating himself and was generally soft-spoken. However, when he did engage in a social life, many people spoke very positively and admiringly of him. Robert Underwood Johnson described him as attaining a "distinguished sweetness, sincerity, modesty, refinement, generosity, and force." His loyal secretary, Dorothy Skerrit, wrote: "his genial smile and nobility of bearing always denoted the gentlemanly characteristics that were so ingrained in his soul." Tesla's friend Hawthorne wrote that "seldom did one meet a scientist or engineer who was also a poet, a philosopher, an appreciator of fine music, a linguist, and a connoisseur of food and drink."

Nevertheless, Tesla could be harsh at times; he openly expressed his disgust for overweight people, once firing a secretary because of her weight. He was quick to criticize others' clothing as well, on several occasions directing a subordinate to go home and change her dress.

Tesla was widely known for his great showmanship, presenting his innovations and demonstrations to the public as an artform, almost like a magician. This seems to conflict with his observed reclusiveness; Tesla was a complicated figure. He refused to hold conventions without his Tesla coil blasting electricity throughout the room, despite the audience often being terrified, though he assured them everything was perfectly safe.

In middle age, Tesla became close friends with Mark Twain
Mark Twain
Samuel Langhorne Clemens , better known by his pen name Mark Twain, was an American author and humorist...

. They spent a lot of time together in his lab and elsewhere.

Tesla remained bitter in the aftermath of his dispute with Edison. The day after Edison died the New York Times contained extensive coverage of Edison's life, with the only negative opinion coming from Tesla, who was quoted as saying:
Shortly before he died, Edison said that his biggest mistake had been in trying to develop direct current, rather than the superior alternating current system that Tesla had put within his grasp.

Tesla was good friends with Robert Underwood Johnson
Robert Underwood Johnson
Robert Underwood Johnson was a U.S. writer and diplomat. His wife was Katharine Johnson.-Biography:A native of Washington, D.C., Johnson joined the staff of The Century Magazine in 1873...

. He had amicable relations with Francis Marion Crawford
Francis Marion Crawford
Francis Marion Crawford was an American writer noted for his many novels, especially those set in Italy, and for his classic weird and fantastic stories.-Life:...

, Stanford White
Stanford White
Stanford White was an American architect and partner in the architectural firm of McKim, Mead & White, the frontrunner among Beaux-Arts firms. He designed a long series of houses for the rich and the very rich, and various public, institutional, and religious buildings, some of which can be found...

, Fritz Lowenstein, George Scherff, and Kenneth Swezey. He ripped up a Westinghouse contract that would have made him the world's first billionaire, in part because of the implications it would have on his future vision of free power, and in part because it would run Westinghouse out of business, and Tesla had no desire to deal with the creditors.

Tesla lived the last ten years of his life in a two-room suite on the 33rd floor of the Hotel New Yorker, room 3327. There, near the end of his life, Tesla showed signs of encroaching senility, claiming to be visited by a specific white pigeon daily. Several biographers note that Tesla viewed the death of the pigeon as a "final blow" to himself and his work.

Tesla believed that war could not be avoided until the cause for its recurrence was removed, but was opposed to wars in general. However, Tesla came to find exceptions in which he thought certain situations and wars were justifiable. Tesla sought to reduce distance, such as in communication for better understanding, transportation, and transmission of energy, as a means to ensure friendly international relations
International relations
International relations is the study of relationships between countries, including the roles of states, inter-governmental organizations , international nongovernmental organizations , non-governmental organizations and multinational corporations...

.

Tesla was a life-long bachelor. Like many of his era, he became a proponent of an imposed selective breeding
Selective breeding
Selective breeding is the process of breeding plants and animals for particular genetic traits. Typically, strains that are selectively bred are domesticated, and the breeding is sometimes done by a professional breeder. Bred animals are known as breeds, while bred plants are known as varieties,...

 version of eugenics
Eugenics
Eugenics is the "applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population", usually referring to human populations. The origins of the concept of eugenics began with certain interpretations of Mendelian inheritance,...

. In a 1937 interview, he stated:
In 1926, Tesla commented on the ills of the social subservience of women and the struggle of women toward gender equality
Gender equality
Gender equality is the goal of the equality of the genders, stemming from a belief in the injustice of myriad forms of gender inequality.- Concept :...

, indicated that humanity's future would be run by "Queen Bees". He believed that women would become the dominant sex in the future.

In his later years Tesla became a vegetarian. In an article for Century Illustrated Magazine he wrote: "It is certainly preferable to raise vegetables, and I think, therefore, that vegetarianism is a commendable departure from the established barbarous habit." Tesla argued that it is wrong to eat uneconomic meat when large numbers of people are starving; he also believed that plant food was "superior to [meat] in regard to both mechanical and mental performance". He also argued that animal slaughter was "wanton and cruel".

In his final years he suffered from extreme sensitivity to light, sound and other influences.

Death

Tesla died on January 7, 1943 in the 86th year of his life, from the consequences of a heart thrombus, alone in room 3327 of the New Yorker Hotel
New Yorker Hotel
The New Yorker Hotel, is a hotel located 481 Eighth Avenue in New York City. The 43-story Art Deco hotel opened in 1930.-General:The New Yorker Hotel is a 900 room, mid-priced hotel. It is located in Manhattan's Garment Center, central to Pennsylvania Station, Madison Square Garden, Times Square...

. A few days after Tesla's death, the information center of the Yugoslav royal government-in-exile released a statement giving a short review of Tesla's achievements and the schedule for his memorial service and funeral. The speech, written by Louis Adamic, was read in a live broadcast on Radio New York by the mayor of New York City, Fiorello La Guardia, on January 10, 1943. The remains of Nikola Tesla were taken to Campbell cemetery. The protocol anticipated the funeral service would be conducted on January 12 in the cathedral of Cathedral of Saint John the Divine
Cathedral of Saint John the Divine
The Cathedral of St. John the Divine, officially the Cathedral Church of Saint John the Divine in the City and Diocese of New York, is the cathedral of the Episcopal Diocese of New York...

 in Manhattan
Manhattan
Manhattan is the oldest and the most densely populated of the five boroughs of New York City. Located primarily on the island of Manhattan at the mouth of the Hudson River, the boundaries of the borough are identical to those of New York County, an original county of the state of New York...

. Bishop William T. Manning delivered the introductory and the last prayer in English. The funeral service was conducted in the name of the Serbian Orthodox Church by priest Dusan Sukletovic, the superior of the Church of St. Sava of the New York parish. The bereaved family members present at the funeral were Sava Kosanovic and Nikola Trbojevic. A state funeral was attended by 2000 people. Tesla's casket was draped with U. S. and Yugoslav flags. The pallbearers were Nobel prize winners. Telegrams of condolence were received from many notables including the first lady, Mrs Eleanor Roosevelt
Eleanor Roosevelt
Anna Eleanor Roosevelt was the First Lady of the United States from 1933 to 1945. She supported the New Deal policies of her husband, distant cousin Franklin Delano Roosevelt, and became an advocate for civil rights. After her husband's death in 1945, Roosevelt continued to be an international...

 and Vice-President Henry A. Wallace
Henry A. Wallace
Henry Agard Wallace was the 33rd Vice President of the United States , the Secretary of Agriculture , and the Secretary of Commerce . In the 1948 presidential election, Wallace was the nominee of the Progressive Party.-Early life:Henry A...

. Tesla's body was cremated and his ashes taken to Belgrade, Serbia, then-Yugoslavia in 1957. The urn containing his ashes was placed in the Nikola Tesla Museum
Nikola Tesla Museum
The Nikola Tesla Museum is located in the central area of Belgrade. It holds more than 160,000 original documents, over 2,000 books and journals, over 1,200 historical technical exhibits, over 1,500 photographs and photo plates of original, technical objects, instruments and apparatus, and over...

 in Belgrade. Despite having sold his AC electricity patents, Tesla died with significant debts. Later that year the US Supreme Court
Supreme Court of the United States
The Supreme Court of the United States is the highest court in the United States. It has ultimate appellate jurisdiction over all state and federal courts, and original jurisdiction over a small range of cases...

 upheld Tesla's patent number 645576 in a ruling that served as the basis for patented radio technology in the United States.
Soon after his death Tesla's safe was opened by his nephew Sava Kosanović. Shortly thereafter Tesla's papers and other property were impounded by the United States' Alien Property Custodian
Alien Property Custodian
An Alien Property Custodian was an office within the Government of the United States during World War I and again during World War II, serving as a Custodian of Enemy Property to property that belonged to US enemies.-World War I:...

 office in Tesla's compound at the Manhattan Warehouse, even though he was a naturalized citizen
United States nationality law
Article I, section 8, clause 4 of the United States Constitution expressly gives the United States Congress the power to establish a uniform rule of naturalization. The Immigration and Naturalization Act sets forth the legal requirements for the acquisition of, and divestiture from, citizenship of...

.

Dr. John G. Trump was the main government official who went over Tesla's secret papers after his death in 1943. At the time, Trump was a well-known electrical engineer serving as a technical aide to the National Defense Research Committee of the Office of Scientific Research & Development, Technical Aids, Div. 14, NTRC (predecessor agency to the CIA's Office of Scientific Intelligence). Trump was also a professor at M.I.T., and had his feelings hurt by Tesla's 1938 review and critique of M.I.T.'s huge Van de Graaff generator with its two thirty-foot towers and two 15 feet (4.6 m) balls, mounted on railroad tracks—which Tesla showed could be out-performed in both voltage and current by one of his tiny coils about two feet tall. Trump was asked to participate in the examination of Tesla's papers at the Manhattan Warehouse & Storage Co. Trump reported afterwards that no examination had been made of the vast amount of Tesla's property, that had been in the basement of the New Yorker Hotel, ten years prior to Tesla's death, or of any of his papers, except those in his immediate possession at the time of his death. Trump concluded in his report, that there was nothing that would constitute a hazard in unfriendly hands.

At the time of his death, Tesla had been working on the Teleforce
Teleforce
Teleforce was Nikola Tesla's charged particle beam projector, first mentioned publicly in the New York Sun and New York Times on July 11, 1934.-Introduction:...

 weapon, or 'death ray,' that he had unsuccessfully marketed to the US War Department. It appears that Teleforce was related to his research into ball lightning
Ball lightning
Ball lightning is an unexplained atmospheric electrical phenomenon. The term refers to reports of luminous, usually spherical objects which vary from pea-sized to several metres in diameter. It is usually associated with thunderstorms, but lasts considerably longer than the split-second flash of a...

 and plasma
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...

, and was conceived as a particle beam weapon
Particle beam weapon
A particle beam weapon uses an ultra-high-energy beam of atoms or electrons to damage a material target by hitting it, and thus disrupting its atomic and molecular structure. A particle beam weapon is a type of directed-energy weapon, which directs energy in a particular direction by a means of...

. The US government did not find a prototype of the device in the safe.

After the FBI was contacted by the War Department, his papers were declared to be top secret
Classified information
Classified information is sensitive information to which access is restricted by law or regulation to particular groups of persons. A formal security clearance is required to handle classified documents or access classified data. The clearance process requires a satisfactory background investigation...

. The personal effects were sequestered on the advice of presidential advisers; J. Edgar Hoover
J. Edgar Hoover
John Edgar Hoover was the first Director of the Federal Bureau of Investigation of the United States. Appointed director of the Bureau of Investigation—predecessor to the FBI—in 1924, he was instrumental in founding the FBI in 1935, where he remained director until his death in 1972...

 declared the case most secret, because of the nature of Tesla's inventions and patents. One document stated that "[he] is reported to have some 80 trunks in different places containing transcripts and plans having to do with his experiments [...]". Altogether, in Tesla's effects, there were the contents of his safe, two truckloads of papers and apparati from his hotel, another 75 packing crates and trunks in a storage facility, and another 80 large storage trunks in another storage facility. The Navy and several "federal officials" spent two days microfilming some of the material at the Office of Alien Properties storage facility in 1943, and that was it, until Oct., 1945.

Tesla's family and the Yugoslav embassy struggled with the American authorities to gain these items after his death because of the potential significance of some of his research. Eventually Mr. Kosanović won possession of the materials, which are now housed in the Nikola Tesla Museum
Nikola Tesla Museum
The Nikola Tesla Museum is located in the central area of Belgrade. It holds more than 160,000 original documents, over 2,000 books and journals, over 1,200 historical technical exhibits, over 1,500 photographs and photo plates of original, technical objects, instruments and apparatus, and over...

.

Literary works

Apart from doing pure work on inventing things, Tesla also wrote a number of books and articles for magazines and journals.

Among his books are My Inventions: The Autobiography of Nikola Tesla
My Inventions: The Autobiography of Nikola Tesla
My Inventions: The Autobiography of Nikola Tesla is a book compiled and edited by Ben Johnston detailing the work of Nikola Tesla...

, The Fantastic Inventions of Nikola Tesla
The Fantastic Inventions of Nikola Tesla
The Fantastic Inventions of Nikola Tesla is a book compiled and edited by David Hatcher Childress detailing the work of Nikola Tesla. Additional content of the book, besides the patent cover pages and lectures of Tesla, is provided by Childress....

 and The Tesla Papers.

A number of Tesla's writings are freely available on the web,
including the article The Problem of Increasing Human Energy which he wrote for The Century Magazine
The Century Magazine
The Century Magazine was first published in the United States in 1881 by The Century Company of New York City as a successor to Scribner's Monthly Magazine...

,
and the article Experiments With Alternate Currents Of High Potential And High Frequency published in his book Inventions, Researches and Writings of Nikola Tesla.

Legacy and honors

  • The tesla
    Tesla (unit)
    The tesla is the SI derived unit of magnetic field B . One tesla is equal to one weber per square meter, and it was defined in 1960 in honour of the inventor, physicist, and electrical engineer Nikola Tesla...

     (symbol T) – compound derived SI unit of magnetic flux density.
  • Tesla
    Tesla (crater)
    Tesla is a lunar crater that is located on the Moon's far side, just to the southeast of the larger H. G. Wells. About one crater diameter to the southwest of Tesla is Kidinnu, and to the southeast is Van Maanen.This is a circular, bowl-shaped feature...

     – a crater on the far side of the moon of 26 kilometers in diameter at −2,0° width, −132.0° height.
  • 2244 Tesla
    2244 Tesla
    2244 Tesla is a minor planet or asteroid. It was discovered on October 22, 1952 by Milorad B. Protić at Belgrade, Federal People's Republic of Yugoslavia, now Serbia....

     – a minor planet.
  • TPP Nikola Tesla
    TPP Nikola Tesla
    TPP Nikola Tesla is a power plant complex operated by EPS, located on the right bank of the river Sava, approximately 40 km upstream from Belgrade, near the town of Obrenovac. By far the largest one in Serbia, the complex generates around 16 TWh annually , which covers almost half of Serbia's needs...

     – the largest power plant in Serbia.
  • The rock band Tesla
    Tesla (band)
    Tesla is an American hard rock band formed in Sacramento, California in 1984. They have sold 14 million albums in the United States.-Formation and Mechanical Resonance :...

     takes its name from Nikola Tesla.
  • An electric car
    Battery electric vehicle
    A battery electric vehicle, or BEV, is a type of electric vehicle that uses chemical energy stored in rechargeable battery packs. BEVs use electric motors and motor controllers instead of, or in addition to, internal combustion engines for propulsion.A battery-only electric vehicle or...

     company, Tesla Motors
    Tesla Motors
    Tesla Motors, Inc. is a Silicon Valley-based company that designs, manufactures and sells electric cars and electric vehicle powertrain components. It was the only automaker building and selling a zero-emission sports car, the Tesla Roadster, in serial production...

    , named their company in tribute to Tesla.
  • The Belgrade Nikola Tesla Airport
    Belgrade Nikola Tesla Airport
    Belgrade Nikola Tesla Airport is Serbia's busiest airport, also known as Surčin , after a nearby Belgrade district.Named after Nikola Tesla, the airport is situated west, of central Belgrade, in the Municipality of Surčin, surrounded by Syrmia's fertile lowlands...

     is named in his honor.
  • Google
    Google
    Google Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its AdWords program...

     honoured Tesla on his birthday on 10 July 2009 by displaying a doodle
    Google logo
    Google has had several logos since its renaming from BackRub. The current official Google logo was designed by Ruth Kedar, and is a wordmark based on the Catull typeface....

     in the Google search home page, that showed the G as a tesla coil
    Tesla coil
    A Tesla coil is a type of resonant transformer circuit invented by Nikola Tesla around 1891. It is used to produce high voltage, low current, high frequency alternating current electricity. Tesla coils produce higher current than the other source of high voltage discharges, electrostatic machines...

    .
  • The Czechoslovakia
    Czechoslovakia
    Czechoslovakia or Czecho-Slovakia was a sovereign state in Central Europe which existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until 1992...

    n electro-technical company Tesla
    Tesla (company)
    TESLA was a large, state-owned electrotechnical conglomerate in the former Czechoslovakia....


Monuments

The Nikola Tesla Memorial Centre located in his birthplace of Smiljan
Smiljan
Smiljan is a village in the mountainous region of Lika in Croatia. It is located northwest of Gospić, and fifteen kilometers from the Zagreb-Split highway; its population is 417 .-Tesla:...

 near the town of Gospić
Gospic
Gospić is a town in the mountainous and sparsely populated region of Lika, Croatia. It is the administrative centre of Lika-Senj county. Gospić is located near the Lika River in the middle of a karst field....

 in Croatia opened in 2006 features a statue of Tesla designed by sculptor Mile Blažević. On 7 July 2006 on the corner of Masarykova and Preradovićeva streets in the Lower Town
Donji Grad
Donji grad is one of the 17 city districts of Zagreb, the capital of Croatia. It is located in the central part of the city and has 45,108 inhabitants . The official name of the district is rarely used, for it is dubbed centar by most of the Zagreb residents....

 area in Zagreb
Zagreb
Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...

 the monument to Tesla was unveiled. This monument was designed by Ivan Meštrović
Ivan Meštrovic
Ivan Meštrović was a Croatian and Yugoslav sculptor and architect born in Vrpolje, Croatia...

 in 1952 and was transferred from the Zagreb-based Ruđer Bošković Institute where it had spent previous decades.

A monument to Tesla was established at Niagara Falls
Niagara Falls, New York
Niagara Falls is a city in Niagara County, New York, United States. As of the 2010 census, the city had a total population of 50,193, down from the 55,593 recorded in the 2000 census. It is across the Niagara River from Niagara Falls, Ontario , both named after the famed Niagara Falls which they...

, New York. This monument, sculpted by Frano Kršinić
Frano Kršinić
Frano Kršinić was a renowned Croatian sculptor. Along with Ivan Meštrović and Antun Augustinčić he is considered one of the three most important Croatian sculptors of the 20th century...

 and portraying Tesla reading a set of notes, was presented to the United States by Yugoslavia in 1976 and is an identical copy of the monument standing in front of the University of Belgrade Faculty of Electrical Engineering
University of Belgrade Faculty of Electrical Engineering
The Faculty of Electrical Engineering is a constituent body of the University of Belgrade. It is the largest electrical engineering and informatics school in Serbia....

. Another monument to Tesla, featuring him standing on a portion of an alternator, was established at Queen Victoria Park
Queen Victoria Park
Queen Victoria Park is the main parkland located in Niagara Falls, Ontario, Canada opposite the American and Canadian Horseshoe Falls. Established by a Provincial Park Act in 1885 and opened in 1888, the park is operated by the Niagara Parks Commission and is considered the centerpiece of the...

 in Niagara Falls, Ontario, Canada. The monument was officially unveiled on 9 July 2006 on the 150th anniversary of Tesla's birth. The monument was sponsored by St. George Serbian Church, Niagara Falls
Niagara Falls
The Niagara Falls, located on the Niagara River draining Lake Erie into Lake Ontario, is the collective name for the Horseshoe Falls and the adjacent American Falls along with the comparatively small Bridal Veil Falls, which combined form the highest flow rate of any waterfalls in the world and has...

, and designed by Les Drysdale of Hamilton, Ontario
Hamilton, Ontario
Hamilton is a port city in the Canadian province of Ontario. Conceived by George Hamilton when he purchased the Durand farm shortly after the War of 1812, Hamilton has become the centre of a densely populated and industrialized region at the west end of Lake Ontario known as the Golden Horseshoe...

. Drysdale's design was the winning design from an international competition.

In 1994, acting on the advice of the President's Advisory Council on Historic Preservation, a formal nomination process was initiated by the Tesla Wardenclyffe Project seeking placement of the Wardenclyffe laboratory-office building and the Tesla tower foundation on both the New York State and National Registers of Historic Places. This would result in the creation of a monument to Tesla out of the Wardenclyffe site itself.

Portrayals in popular culture

Nikola Tesla has appeared in popular culture as a character in books, films, radio, TV, music, live theatre, comics and video games. The lack of recognition received by Tesla during his own lifetime has made him a tragic and inspirational character well suited to dramatic fiction. The impact of the technologies invented by Tesla is a recurring theme in several types of science fiction.

See also

  • List of Tesla patents
  • Electrical Experimenter
    Electrical Experimenter
    The Electrical Experimenter was a technical science magazine that was published monthly. It was first published in May 1913, as the successor to Modern Electrics, a combination of a magazine and mail-order catalog that had been published by Hugo Gernsback starting in 1908...

  • Timeline of low-temperature technology
    Timeline of low-temperature technology
    The following is a timeline of low-temperature technology and cryogenic technology .-16th century BCE – 17th century CE :...


Sources

  • Lomas, Robert, The Man who Invented the Twentieth Century. Lecture to South Western Branch of Instititute of Physics.
  • Martin, Thomas Commerford
    Thomas Commerford Martin
    Thomas Commerford Martin was an American electrical engineer and editor, born in London, England. His father worked with Lord Kelvin and other pioneers of submarine telegraph cables, and Martin spent much time on the cable-laying ship SS Great Eastern. Educated as a theological student, Martin...

    , The Inventions, Researches, and Writings of Nikola Tesla, New York: The Electrical Engineer, 1894 (3rd Ed.); reprinted by Barnes & Noble, 1995 ISBN-X
  • Penner, John R.H. The Strange Life of Nikola Tesla, corrupted version of "My Inventions".
  • Pratt, H., Nikola Tesla 1856–1943, Proceedings of the IRE, Vol. 44, September, 1956.
  • Weisstein, Eric W., Tesla, Nikola (1856–1943). Eric Weisstein's World of Science.
  • Dimitrijevic, Milan S., Belgrade Astronomical Observatory Historical Review. Publ. Astron. Obs. Belgrade,, 162–170. Also, Srpski asteroidi, Tesla. Astronomski magazine.
  • Roguin, Ariel, Historical Note: Nikola Tesla: The man behind the magnetic field unit. J. Magn. Reson. Imaging 2004;19:369–374. 2004 Wiley-Liss, Inc.
  • Sellon, J. L., The impact of Nikola Tesla on the cement industry. Behrent Eng. Co., Wheat Ridge, Colorado. Cement Industry Technical Conference. 1997. XXXIX Conference Record., 1997 IEEE/PC. Page(s) 125–133. ISBN
  • Valentinuzzi, M.E., Nikola Tesla: why was he so much resisted and forgotten? Inst. de Bioingenieria, Univ. Nacional de Tucuman; Engineering in Medicine and Biology Magazine, IEEE. July/August 1998, 17:4, pp. 74–75. ISSN
  • Secor, H. Winfield, Tesla's views on Electricity and the War, Electrical Experimenter, Volume 5, Number 4, August, 1917.
  • Florey, Glen, Tesla and the Military. Engineering 24, 5 December 2000.
  • Corum, K. L., J. F. Corum, Nikola Tesla, Lightning Observations, and Stationary Waves. 1994.
  • Corum, K. L., J. F. Corum, and A. H. Aidinejad, Atmospheric Fields, Tesla's Receivers and Regenerative Detectors. 1994.
  • Meyl, Konstantin, H. Weidner, E. Zentgraf, T. Senkel, T. Junker, and P. Winkels, Experiments to proof the evidence of scalar waves Tests with a Tesla reproduction. Institut für Gravitationsforschung (IGF), Am Heerbach 5, D-63857 Waldaschaff.
  • Anderson, L. I., John Stone Stone on Nikola Tesla's Priority in Radio and Continuous Wave Radiofrequency Apparatus. The AWA Review
    The AWA Review
    The AWA Review is a series of annual softcover books of articles on the history of radio published by the Antique Wireless Association, a membership organization based in Bloomfield, New York, USA. Volume 1 was published in 1986 and Volume 24 was published in 2011...

    , Vol. 1, 1986, pp. 18–41.
  • Anderson, L. I., Priority in Invention of Radio, Tesla v. Marconi. Antique Wireless Association monograph, March 1980.
  • Marincic, A., and D. Budimir, Tesla's contribution to radiowave propagation. Dept. of Electron. Eng., Belgrade Univ. (5th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2001. TELSIKS 2001. pp. 327–331 vol.1) ISBN-X
  • Page, R.M., The Early History of Radar, Proceedings of the IRE, Volume 50, Number 5, May, 1962, (special 50th Anniversary Issue).
  • C Mackechnie Jarvis Nikola Tesla and the induction motor. 1970 Phys. Educ. 5 280–287.
  • Giant Eye to See Round the World (DOC)
  • Toby Grotz, The Influence of Vedic Philosophy on Nikola Tesla's Understanding of Free Energy.


Publications


Books

  • Tesla, Nikola, "My Inventions" Parts I through V published in the Electrical Experimenter monthly magazine from February through June, 1919. Part VI published October, 1919. Reprint edition with introductory notes by Ben Johnson, New York: Barnes and Noble,1982, ISBN; also online at Lucid Cafe, et cetera as My Inventions: The Autobiography of Nikola Tesla
    My Inventions: The Autobiography of Nikola Tesla
    My Inventions: The Autobiography of Nikola Tesla is a book compiled and edited by Ben Johnston detailing the work of Nikola Tesla...

    , 1919. ISBN
  • Martin, Thomas C.
    Thomas Commerford Martin
    Thomas Commerford Martin was an American electrical engineer and editor, born in London, England. His father worked with Lord Kelvin and other pioneers of submarine telegraph cables, and Martin spent much time on the cable-laying ship SS Great Eastern. Educated as a theological student, Martin...

    , The Inventions, Researches, and Writings of Nikola Tesla
    The Inventions, Researches, and Writings of Nikola Tesla
    The Inventions, Researches and Writings of Nikola Tesla is a book compiled and edited by Thomas Commerford Martin detailing the work of Nikola Tesla. The book is a comprehensive compilation of Tesla's work with many illustrations.-Overview:...

    , 1894 . ISBN-X
  • Auster, Paul
    Paul Auster
    Paul Benjamin Auster is an American author known for works blending absurdism, existentialism, crime fiction and the search for identity and personal meaning in works such as The New York Trilogy , Moon Palace , The Music of Chance , The Book of Illusions and The Brooklyn Follies...

    , Moon Palace
    Moon Palace
    Moon Palace is a novel written by Paul Auster that was first published in 1989.The novel is set in Manhattan and the U.S. Midwest, and centres on the life of the narrator Marco Stanley Fogg and the two previous generations of his family.- Plot summary:...

    , 1989. Tells Tesla's story within the history of the United States.
  • Lomas, Robert
    Robert Lomas
    Roberto Lomas is a British writer and business studies academic. He writes primarily about the history of Freemasonry as well as the Neolithic period, ancient engineering and archaeoastronomy...

    , The Man Who Invented the Twentieth Century: Nikola Tesla, forgotten genius of electricity
    The Man Who Invented the Twentieth Century
    The Man Who Invented the Twentieth Century: Nikola Tesla, forgotten genius of electricity is a book by Robert Lomas detailing the life of Nikola Tesla. Lomas covers the times of the electric engineer in the United States and the inventors' work....

    , 1999. ISBN
  • Childress, David H., The Fantastic Inventions of Nikola Tesla
    The Fantastic Inventions of Nikola Tesla
    The Fantastic Inventions of Nikola Tesla is a book compiled and edited by David Hatcher Childress detailing the work of Nikola Tesla. Additional content of the book, besides the patent cover pages and lectures of Tesla, is provided by Childress....

    , 1993. ISBN
  • Glenn, Jim, The Complete Patents of Nikola Tesla
    The Complete Patents of Nikola Tesla
    The Complete Patents of Nikola Tesla is a book compiled and edited by Jim Glenn detailing the patents of Nikola Tesla....

    , 1994. ISBN
  • Trinkaus, George TESLA: The Lost Inventions, High Voltage Press, 2002. ISBN 09-7096-182-0
  • Valone, Thomas, Harnessing the Wheelwork of Nature: Tesla's Science of Energy, 2002. ISBN
  • McNichol, Tom, AC/DC The Savage Tale of the First Standards War, Jossey-Bass 2006 ISBN 078798267-9


Journals

  • Carlson, W. Bernard, "Inventor of dreams". Scientific American
    Scientific American
    Scientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...

    , March 2005 Vol. 292 Issue 3 p. 78(7).
  • Jatras, Stella L., "The genius of Nikola Tesla". The New American, 28 July 2003 Vol. 19 Issue 15 p. 9(1)
  • Rybak, James P., "Nikola Tesla: Scientific Savant". Popular Electronics
    Popular Electronics
    Popular Electronics was an American magazine started by Ziff-Davis Publishing in October 1954 for electronics hobbyists and experimenters. It soon became the "World's Largest-Selling Electronics Magazine". The circulation was 240,151 in April 1957 and 400,000 by 1963. Ziff-Davis published Popular...

    , 1042170X, November 1999, Vol. 16, Issue 11.
  • Lawren, B., "Rediscovering Tesla". Omni
    Omni (magazine)
    OMNI was a science and science fiction magazine published in the US and the UK. It contained articles on science fact and short works of science fiction...

    , March 1988, Vol. 10 Issue 6.


Filmography

  • There are at least two films describing Tesla's life. In the first, filmed in 1977, arranged for TV, Tesla was portrayed by Rade Šerbedžija
    Rade Šerbedžija
    Rade Šerbedžija , occasionally credited as Rade Sherbedgia in some English-language productions, is a Croatian actor, director and musician of Serb origin. He was one of the most popular Yugoslav actors in the 1970s and 1980s. He is now internationally known mainly for his supporting roles in...

    . In 1980, Orson Welles
    Orson Welles
    George Orson Welles , best known as Orson Welles, was an American film director, actor, theatre director, screenwriter, and producer, who worked extensively in film, theatre, television and radio...

     produced a Yugoslav
    Socialist Federal Republic of Yugoslavia
    The Socialist Federal Republic of Yugoslavia was the Yugoslav state that existed from the abolition of the Yugoslav monarchy until it was dissolved in 1992 amid the Yugoslav Wars. It was a socialist state and a federation made up of six socialist republics: Bosnia and Herzegovina, Croatia,...

     film named Tajna Nikole Tesle (The Secret of Nikola Tesla), in which Welles himself played the part of Tesla's patron, J.P. Morgan. The film was directed by Krsto Papić
    Krsto Papic
    Krsto Papić is a Croatian screenwriter and film director whose career spans several decades....

    , and Nikola Tesla was portrayed by Petar Božović
    Petar Božovic
    Petar Božović is a popular actor from Serbia.-Selected filmography:* U raskoraku * Leptirica * The Secret of Nikola Tesla * Pogled sa Ajfelovog tornja * Optimisti...

    .
  • "Tesla: Master of Lightning". 1999. ISBN (Book) ISBN (PBS Video)
  • Lost Lightning: The Missing Secrets of Nikola Tesla (at Google Video.) Tesla's designs for free energy and defensive weapons systems.
  • David Bowie
    David Bowie
    David Bowie is an English musician, actor, record producer and arranger. A major figure for over four decades in the world of popular music, Bowie is widely regarded as an innovator, particularly for his work in the 1970s...

     portrayed Tesla in the 2006 film The Prestige
    The Prestige (film)
    The Prestige is a 2006 mystery thriller film written, directed and co-produced by Christopher Nolan, with a screenplay adapted from Christopher Priest's 1995 novel of the same name. The story follows Robert Angier and Alfred Borden, rival stage magicians in London at the end of the 19th century...

    . Tesla's time in Colorado Springs was the focus of several scenes in the film, which featured speculations on the explosive power of Tesla's electrical experiments.
  • Tesla: Master of Lightning, produced by Robert Uth for New Voyage Communications in 2003, tapped Stacy Keach
    Stacy Keach
    Stacy Keach is an American actor and narrator. He is most famous for his dramatic roles; however, he has done narration work in educational programming on PBS and the Discovery Channel, as well as some comedy and musical...

     to supply the voice of Tesla.


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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