Nikola Tesla (10 July 1856 – 7 January 1943) was a Serbian-American inventor, electrical engineer, mechanical engineer, and physicist. His work focused particularly on the generation, transmission, and distribution of electric power. Tesla is renowned for his contributions to the development of alternating current (AC) electricity, a fundamental component of modern electrical systems. In addition, he conducted research on induction motors, transformers, wireless energy transfer, and radio technologies.

Tesla’s methods and experimental work significantly contributed to the establishment of standards in electrical engineering applications from the late 19th century onward. The competition in the United States between Thomas Edison’s direct current (DC) system and Tesla’s alternating current (AC) system was decisive in shaping the energy sector of the era. Tesla left an impact not only in the field of engineering through his scientific work and patents but also in the advancement of modern physics and technology.

Childhood

Nikola Tesla was born on 10 July 1856 in Smiljan, a small village within the borders of the Austro-Hungarian Empire at the time (present-day Croatia). His father, Milutin Tesla, served as a priest in the Serbian Orthodox Church and wished for his son to follow the same path. His mother, Đuka Mandić, had no formal education but was known for her exceptional memory and practical inventions related to household tools. Tesla later stated that he inherited his creativity and memory from his mother. He had three sisters and one brother; his older brother Dane died at age twelve in a horse-riding accident, an event that had a profound psychological impact on Tesla during his childhood.

Educational Life

Tesla began his primary education at the elementary school in Smiljan, where he learned basic subjects as well as German. After his family moved to Gospić, he continued his education there. He then enrolled at the Higher Real Gymnasium in Karlovac, where he demonstrated extraordinary achievement in science and mathematics. His ability to perform complex integral calculations mentally attracted the attention of his teachers; he was even falsely accused of cheating because of this skill. He graduated from this school in 1873. However, in the same year he contracted a severe case of cholera. He fought for nearly nine months and repeatedly came close to death. His father promised that if he recovered, he would not force him to become a priest but would allow him to study engineering. Tesla narrowly survived the illness and redirected his life toward science.

In 1874, to avoid compulsory military service in the Austro-Hungarian Army, Tesla hid in the mountainous regions near Tomingaj. He spent this time in solitude, taking long walks in nature and reading extensively. Among the books he read, those by Mark Twain held a special place; Tesla frequently spoke in later years about the influence Twain’s writings had on him during his youth.

In 1875, Tesla enrolled at the Austrian Polytechnic in Graz on a scholarship for border regions. During his first year, he attended all classes regularly and attracted the attention of his instructors through his exceptional diligence. His interest in electrical engineering deepened during this period, and he began developing his first ideas about an alternating current motor. However, problems emerged from his second year onward. He lost his scholarship, developed a gambling habit, and suffered financial losses. He began missing classes and failed his examinations. In December 1878, he left Graz and never officially graduated. During this time, he severed ties with his family, and false reports even circulated that he had died.

In 1879, Tesla worked briefly as a technical draftsman in Maribor. His father died the same year. He returned to Karlovac and worked as a teacher for a period. In 1880, with the support of relatives, he went to Prague with the aim of studying at Charles-Ferdinand University. However, he could not register as a formal student due to insufficient language proficiency, particularly in Greek and Czech. Nevertheless, he attended some lectures as an auditor but never received grades or a diploma.

Engineering Career

Nikola Tesla’s engineering career began in 1881 in Budapest, where he was employed as an electrical engineer at the newly established Budapest Telephone Exchange. Tesla worked on improving the plant’s electrical equipment and installing new telephone systems. It is known that during this period he often took walks to clear his mind. One day in a city park, while explaining the concept of a rotating magnetic field to a companion by drawing shapes in the sand, he made one of his most important theoretical breakthroughs. This idea later formed the foundation of the alternating current induction motor.^【1】 

In 1882, Tesla moved to Paris to work for the Continental Edison Company. There he focused on the design and maintenance of machines operating on direct current (DC). During a posting in Strasbourg, he constructed a prototype AC induction motor using his own resources. Although the prototype functioned successfully, it failed to attract interest from European investors. Tesla realized after this experience that his radical ideas would not find support in Europe.^【2】 

In 1884, Tesla decided to emigrate to the United States. Upon arriving in New York, he had only a few cents, some technical drawings, and a letter of recommendation from Charles Batchelor to Thomas Edison. Tesla began working in Edison’s laboratory, where he was assigned to improve direct current generators. While Edison championed the direct current (DC) system for power transmission, Tesla advocated for the alternating current (AC) system as more efficient for long-distance energy transmission.^【3】 

This differing approach quickly turned into a serious disagreement. Edison supported DC to protect his existing infrastructure and investments, while Tesla argued that AC was the future of energy systems. Their ideological conflict grew into what would become known in history as the “War of Currents.” During his time with Edison, Tesla failed to gain support for his own ideas and soon left him. Tesla’s work during this period established him both as the theorist of the rotating magnetic field and as the first developer of the alternating current motor. These early career years laid the scientific and technical foundation for his later collaborations and large-scale projects.

Alternating Current

Nikola Tesla’s most important contribution to science was the development of the polyphase alternating current (AC) system. In 1888, at a presentation to the American Institute of Electrical Engineers, he introduced AC motors and transformer systems. This system enabled electricity to be transmitted over long distances with minimal losses and made it suitable for industrial use. In the same year, businessman George Westinghouse purchased Tesla’s patents related to the AC system and hired him as a consultant. Thus, the Tesla-Westinghouse partnership entered the historic “War of Currents” against Edison’s direct current (DC) system. Although Edison campaigned publicly to portray AC as dangerous, the technical superiority of AC quickly became evident. Ultimately, Tesla and Westinghouse’s system prevailed and formed the foundation of 20th-century electrical infrastructure.^【4】 

Tesla’s Tesla coil (1891) and the induction motor he developed became fundamental components of modern electrical grids. The Tesla coil, functioning as a transformer producing high-frequency alternating current, found applications in fields ranging from radio technology to television. The induction motor revolutionized the conversion of electrical energy into mechanical energy and became widely used in industry and household electronics.

Major Projects and Experiments

In 1893, Tesla introduced the AC system to the general public at the World’s Columbian Exposition in Chicago. The Westinghouse Company equipped the fair’s electrical infrastructure with Tesla’s AC system, making the exposition the first large-scale application of electric lighting in history. In 1895, Tesla played a key role in designing the world’s first large-scale hydroelectric power plant at Niagara Falls. This project symbolized the permanent victory of the AC system and the mass adoption of electric power.^【5】 

In 1899, Tesla established a laboratory in Colorado Springs, where he conducted high-voltage and high-frequency electrical experiments. There he produced electrical discharges up to 30 meters in length, created artificial lightning, and investigated wireless energy transmission. He also theorized during these experiments that the Earth itself could act as a conductor and respond to specific electrical vibrations.^【6】 

In 1901, with the support of J.P. Morgan, Tesla began construction of the Wardenclyffe Tower on Long Island, New York. This project was the physical realization of Tesla’s vision for global wireless communication and energy transmission. However, due to rising costs and the withdrawal of investor support, the project was never completed. In 1917, the tower was demolished for security reasons, leaving Tesla’s dream of wireless energy unrealized.^【7】 

Scientific Contributions and Misattributions

Throughout his life, Tesla acquired over 700 patents, covering electrical engineering, mechanical systems, and radio technologies. His radio transmission experiments in the 1890s overlapped with those of Guglielmo Marconi. In 1909, Marconi received the Nobel Prize for the invention of radio, but in 1943 the U.S. Supreme Court recognized Tesla’s priority in radio patents and affirmed him as one of the true inventors of the technology.^【8】 

However, some inventions attributed to Tesla actually belong to other scientists. For example, the electric light bulb was developed by Thomas Edison and Joseph Swan, and certain types of lasers and modern electric motors were developed by later researchers in the 20th century. Tesla’s role was primarily to refine existing ideas, popularize them, and adapt them to new applications.^【9】 

Final Years and Death

In his later years, Nikola Tesla faced severe financial difficulties. Most of his work struggled to secure financial backing, and many of his projects remained unfinished. In the 1930s, his health began to deteriorate; due to fatigue and heart problems, he preferred a reclusive lifestyle. He settled in the New Yorker Hotel in New York, where he spent the last decade of his life. Although he became increasingly isolated from the scientific community, he remained a public figure in the press. He was especially known for his affection for pigeons; it is documented that he fed them in his hotel room and even took some into his care. Tesla died on 7 January 1943 at the age of 86 in his hotel room. His funeral was held with state honors in New York; his ashes were later transported to the Nikola Tesla Museum in Belgrade and displayed inside a golden sphere, his favorite shape.

Legacy and Honors

Although Tesla did not achieve the same financial success as his contemporary Thomas Edison, he is recognized as a pioneering figure in modern electrical engineering and the history of science. His work was decisive in establishing alternating current as the global standard for electrical systems.

Throughout his life and after his death, he received numerous honors:

• In 1917, the Edison Medal was awarded to him by the American Institute of Electrical Engineers.
• In 1960, the International System of Units named the unit of magnetic flux density, the “tesla,” in his honor.
• In 1975, Tesla was inducted into the Inventors Hall of Fame.
• In 1983, the United States Postal Service issued a commemorative stamp in his honor.
• A corner at the intersection of 40th Street and 6th Avenue in New York is named “Nikola Tesla Corner”; a statue of Tesla was also erected at Niagara Falls in honor of the hydroelectric plant that implemented his inventions.

Today, Tesla’s name lives on not only in scientific units but also in popular culture and technology brands. His legacy is regarded as one of the foundational pillars of modern electrical grids and is remembered as an enduring symbol in the history of engineering.