Nikola Tesla

   Nikola Tesla ( 10 July 1856 – 7 January 1943) was a Serbian American Inventor, physicst,mechanical engineer, electrical engineer and futurist. He was an important contributor to the use of commerical electricity and is best known for developing the modern alternating current (AC) electrical supply system. His many revolutionary developments in the field of electromagnetism in the late 19th and early 20th centuries were based on the theories of electromagnetic technology discovered by Michael Faraday. Teslas's parents and theoretical work also formed the basis of wireless communication and the radio.Born to Serbian parents in the village of Smiljan  (now part of Gospic, present day Croatia), Tesla was a subject of the Austrian Empire by birth and later became an American citizen.Because of his 1894 demonstration of short range wireless communication through radio and his eventual victory in the "War of Currents", 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 to power electronic devices in 1891, and aspired to intercontinental wireless transmission of industrial power in his unfinished Wardenclyffe Tower project.

      In the end of his life in the 1930s, Tesla became reclusive, living alone in a New York City hotel room and only appearing occasionally to make unusual statements to the press. Because of his pronouncements and the nature of his work over the years Tesla gained a reputation in popular culture as the archetypal "mad scientist". He died penniless and in debt in January, 1943.Tesla's work fell into relative obscurity after his death, but since the 1990s, his reputation has experienced a popular culture comeback. In 2005, he was listed amongst the top 100 nominees in the TV show "The Greatest American", an open access popularity poll conducted by AOL and The Discovery Channel.  

  Briefly worked with Thomas Edison before the two parted ways.He died on January 7, 1943, in New York City.He sold several patent rights, including those to his alternating-current machinery, to George Westinghouse. His 1891 invention, the Tesla coil, is used in radio technology. The SI unit measuring magnetic field B (magnetic flux / intensity / induction), the TESLA , was named in his honor.

Hans Christian Orsted

    Danish physicist and philosopher Hans Christian Orsted is best known for discoverering the connection between electricity and magnetism known as electromagnetism. Orsted was born in Rudkobing on the Danish island of Lolland. Orsted became interested in science while working as a young boy for his father, Soren Christian Orsted, who owned a pharmacy. Educated primarily through self-study at home, both Orsted and his brother, Anders Sandoe Orsted, went to Copenhagen in 1793 to take entrance exams for Copenhagen University. The brothers passed and distinguished themselves academically at the University. By 1796, Orsted receivied honors for his papers in both aesthetics and medicine.Although he passed his pharmaceutical examination in 1797, Orsted continued his education and, in 1801 received a travel scholarship and public grant that was to profoundly affect his future. With the awards, Orsted spent three years traveling in Europe. 

        In 1820, which Orsted described as the happiest year of his life, Orsted considered a lecture for his students focusing on electricity and magnetism that would involve a new electric battery. During a classroom demonstration,Orsted saw that a compass needle deflected from magnetic north when the electric current from the battery was switched on or off. This deflection interestred Orsted convincing him that magnetic fields might radiate from all sides of a live wire just as light and heat do. However, the initial reaction was so slight that Orsted put off further research for three months until he began more intensive investigations. Shortly afterwards, Orsted's findings were published, proving that an electric current produces a magnetic field as it flows through a wire. This discovery revealed the fundamental connection between electricity and magnetism, which most scientists thought to be completely unrelated phenomena. The result was an intensive effort throughout the scientific community in electrodynamics research, including French physicist André-Marie Ampère's (1775-1836) developments of a single mathematical form to represent the magnetic forces between current-carrying conductors. Orsted's discovery also represented a major step toward a unified concept of energy.

Although some accounts of Orsted's discovery described the event as purely accidental, Orsted's earlier travels in Europe and wide range of studies had drawn him to a believe in the unity of nature, and that a relationship therefore must exist between most natural phenomena, including electricity and magnetism. If Orsted had not been looking for such a relationship, he possibly would not have placed the compass near an electrical current to see if there was an effect. Orsted's discovery, which laid the foundation for the theory of electromagnetism, led toresearch that created much of the technology in common use today, including radio, television, and fiber optics . In honor of its discoverer, the physical unit of magnetic field strength was named Oersted in 1932.

        Among Orsted's continued scientific works, he was one of the first scientists to produce pure aluminum and to conduct experiments in the compressibility of fluids . Orsted had a wide range of interests, including education, philosophy, politics, and literary affairs. Orsted, who married Birgitte Ballum and had eight children, spent over 50 years at Copenhagen University and the Technological College. To the Danish people, Orsted is as much revered for his efforts as a teacher and educator as for his discovery of electromagnetism. His combination of scientific thought and wide-ranging efforts in cultural and political activities helped to transform Danish society. Orsted believed that Denmark would best progress as a country through a close cooperation between research and industry. To help ensure that all of the small country's human resources were fully utilized, Orsted emphasized the need for a comprehensive nationwide system of education and training. At the time of his death in 1851, orsted was head of the Polytechnical Institute at Copenhagen University. In 1993, nearly a century and a half after his death, the first Dutch satellite was named in Orsted's honor.