Electricity has been a subject of scientific interest since at least the early 17th century.
William Gilbert was a prominent early electrical scientist, and was the first to draw a clear distinction between
magnetism and
static electricity. He is credited with establishing the term "electricity". He also designed the
versorium: a device that detects the presence of statically charged objects. In 1762 Swedish professor
Johan Wilcke invented a device later named
electrophorus that produced a static electric charge. By 1800
Alessandro Volta had developed the
voltaic pile, a forerunner of the electric battery.
19th century formed the foundation of electric motor technology. In the 19th century, research into the subject started to intensify. Notable developments in this century include the work of
Hans Christian Ørsted, who discovered in 1820 that an electric current produces a magnetic field that will deflect a compass needle; of
William Sturgeon, who in 1825 invented the
electromagnet; of
Joseph Henry and
Edward Davy, who invented the
electrical relay in 1835; of
Georg Ohm, who in 1827 quantified the relationship between the
electric current and
potential difference in a
conductor; of
Michael Faraday, the discoverer of
electromagnetic induction in 1831; and of
James Clerk Maxwell, who in 1873 published a unified
theory of electricity and
magnetism in his treatise
Electricity and Magnetism. In 1782,
Georges-Louis Le Sage developed and presented in
Berlin probably the world's first form of
electric telegraphy, using 24 different wires, one for each letter of the alphabet. This telegraph connected two rooms. It was an electrostatic telegraph that moved gold leaf through electrical conduction. In 1795,
Francisco Salva Campillo proposed an electrostatic telegraph system. Between 1803 and 1804, he worked on electrical telegraphy, and in 1804, he presented his report at the Royal Academy of Natural Sciences and Arts of Barcelona. Salva's electrolyte telegraph system was very innovative though it was greatly influenced by and based upon two discoveries made in Europe in 1800—Alessandro Volta's electric battery for generating an electric current and William Nicholson and Anthony Carlyle's electrolysis of water.
Electrical telegraphy may be considered the first example of electrical engineering. Electrical engineering became a profession in the later 19th century. Practitioners had created a global
electric telegraph network, and the first professional electrical engineering institutions were founded in the UK and the US to support the new discipline.
Francis Ronalds created an electric telegraph system in 1816 and documented his vision of how the world could be transformed by electricity. Over 50 years later, he joined the new Society of Telegraph Engineers (soon to be renamed the
Institution of Electrical Engineers) where he was regarded by other members as the first of their cohort. By the end of the 19th century, the world had been forever changed by the rapid communication made possible by the engineering development of land-lines,
submarine cables, and, from about 1890,
wireless telegraphy. Practical applications and advances in such fields created an increasing need for standardized
units of measure. They led to the international standardization of the units
volt,
ampere,
coulomb,
ohm,
farad, and
henry. This was achieved at an international conference in
Chicago in 1893. The publication of these standards formed the basis of future advances in standardization in various industries, and in many countries, the definitions were immediately recognized in relevant legislation. During these years, the study of electricity was largely considered to be a subfield of
physics since early electrical technology was considered
electromechanical in nature. The
Technische Universität Darmstadt founded the world's first department of electrical engineering in 1882 and introduced the first-degree course in electrical engineering in 1883. The first electrical engineering degree program in the United States was started at
Massachusetts Institute of Technology (MIT) in the physics department under Professor Charles Cross, though it was
Cornell University to produce the world's first electrical engineering graduates in 1885. The first course in electrical engineering was taught in 1883 in Cornell's
Sibley College of Mechanical Engineering and Mechanic Arts. In about 1885, Cornell President
Andrew Dickson White established the first Department of Electrical Engineering in the United States. In the same year,
University College London founded the first chair of electrical engineering in Great Britain. Professor Mendell P. Weinbach at
University of Missouri established the electrical engineering department in 1886. Afterwards, universities and
institutes of technology gradually started to offer electrical engineering programs to their students all over the world. During these decades the use of electrical engineering increased dramatically. In 1882,
Thomas Edison switched on the world's first large-scale electric power network that provided 110 volts—
direct current (DC)—to 59 customers on
Manhattan Island in New York City. In 1884,
Sir Charles Parsons invented the
steam turbine allowing for more efficient electric power generation.
Alternating current, with its ability to transmit power more efficiently over long distances via the use of
transformers, developed rapidly in the 1880s and 1890s with transformer designs by
Károly Zipernowsky,
Ottó Bláthy and
Miksa Déri (later called ZBD transformers),
Lucien Gaulard,
John Dixon Gibbs and
William Stanley Jr. Practical
AC motor designs including
induction motors were independently invented by
Galileo Ferraris and
Nikola Tesla and further developed into a practical
three-phase form by
Mikhail Dolivo-Dobrovolsky and
Charles Eugene Lancelot Brown.
Charles Steinmetz and
Oliver Heaviside contributed to the theoretical basis of alternating current engineering. The spread in the use of AC set off in the United States what has been called the
war of the currents between a
George Westinghouse backed AC system and a Thomas Edison backed DC power system, with AC being adopted as the overall standard.
Early 20th century , known for his pioneering work on long-distance
radio transmission During the
development of radio, many scientists and inventors contributed to
radio technology and electronics. The mathematical work of
James Clerk Maxwell during the 1850s had shown the relationship of different forms of
electromagnetic radiation, including the possibility of invisible airborne waves (later called "radio waves"). In his classic physics experiments of 1888,
Heinrich Hertz proved Maxwell's theory by transmitting
radio waves with a
spark-gap transmitter, and detected them by using simple electrical devices. Other physicists experimented with these new waves and, in the process, developed devices for transmitting and detecting them. In 1895,
Guglielmo Marconi began work on a way to adapt the known methods of transmitting and detecting these "Hertzian waves" into a purpose-built commercial
wireless telegraphic system. Early on, he sent wireless signals over a distance of one and a half miles. In December 1901, he sent wireless waves that were not affected by the curvature of the Earth. Marconi later transmitted the wireless signals across the Atlantic between Poldhu,
Cornwall, and St. John's,
Newfoundland, a distance of .
Millimetre wave communication was first investigated by
Jagadish Chandra Bose during 18941896, when he reached an
extremely high frequency of up to 60
GHz in his experiments. He also introduced the use of
semiconductor junctions to detect radio waves, when he patented the radio
crystal detector in 1901. In 1897,
Karl Ferdinand Braun introduced the
cathode-ray tube as part of an
oscilloscope, a crucial enabling technology for
electronic television.
John Fleming invented the first radio tube, the
diode, in 1904. Two years later,
Robert von Lieben and
Lee De Forest independently developed the amplifier tube, called the
triode. In 1920,
Albert Hull developed the
magnetron which would eventually lead to the development of the
microwave oven in 1946 by
Percy Spencer. In 1934, the
British military began to make strides toward
radar (which also uses the magnetron) under the direction of Dr Wimperis, culminating in the operation of the first radar station at
Bawdsey in August 1936. In 1941,
Konrad Zuse presented the
Z3, the world's first fully functional and programmable computer using electromechanical parts. In 1943,
Tommy Flowers designed and built the
Colossus, the world's first fully functional, electronic, digital and programmable computer. In 1946, the
ENIAC (Electronic Numerical Integrator and Computer) of
John Presper Eckert and
John Mauchly followed, beginning the computing era. The arithmetic performance of these machines allowed engineers to develop completely new technologies and achieve new objectives. In 1948,
Claude Shannon published "A Mathematical Theory of Communication" which mathematically describes the passage of information with uncertainty (
electrical noise).
Solid-state electronics , a
point-contact transistor (MOSFET), the basic building block of modern
electronics The first working
transistor was a
point-contact transistor invented by
John Bardeen and
Walter Houser Brattain while working under
William Shockley at the
Bell Telephone Laboratories (BTL) in 1947. They then invented the
bipolar junction transistor in 1948. While early
junction transistors were relatively bulky devices that were difficult to manufacture on a
mass-production basis, they opened the door for more compact devices. The first
integrated circuits were the
hybrid integrated circuit invented by
Jack Kilby at
Texas Instruments in 1958 and the monolithic integrated circuit chip invented by
Robert Noyce at
Fairchild Semiconductor in 1959. The
MOSFET (metal–oxide–semiconductor field-effect transistor, or MOS transistor) was invented by
Mohamed Atalla and
Dawon Kahng at BTL in 1959. It was the first truly compact transistor that could be miniaturised and mass-produced for a wide range of uses. becoming the most widely used electronic device in the world. The MOSFET made it possible to build
high-density integrated circuit chips. MOS technology enabled
Moore's law, the
doubling of transistors on an IC chip every two years, predicted by
Gordon Moore in 1965.
Silicon-gate MOS technology was developed by
Federico Faggin at Fairchild in 1968. Since then, the MOSFET has been the basic building block of modern electronics. The mass-production of silicon MOSFETs and MOS integrated circuit chips, along with continuous
MOSFET scaling miniaturization at an exponential pace (as predicted by Moore's law), has since led to revolutionary changes in technology, economy, culture and thinking. The
Apollo program which culminated in
landing astronauts on the Moon with
Apollo 11 in 1969 was enabled by
NASA's adoption of advances in
semiconductor electronic technology, including MOSFETs in the
Interplanetary Monitoring Platform (IMP) and silicon integrated circuit chips in the
Apollo Guidance Computer (AGC). The development of MOS integrated circuit technology in the 1960s led to the invention of the
microprocessor in the early 1970s. The first single-chip microprocessor was the
Intel 4004, released in 1971. The microprocessor led to the development of
microcomputers and personal computers, and the
microcomputer revolution.
Electrical Engineering and Artificial Intelligence In recent times, the subject of
machine learning (including speech systems,
computer vision and
reinforcement learning) has had significant overlap with electrical engineering fields such as signal processing, image processing and control engineering, and is, as such, studied often by electrical engineers. Machine learning techniques are also used in electrical engineering systems in subfields such as electronic design automation, stochastic and adaptive control, smart grids, adaptive signal processing, etc. ==Subfields==