Historical Profiles of Scientists and Engineers

Biographies of Scientific Personalities - Electrical Engineering

Prepared by J. R. Lucas

A: Ampere, Archimedes. B: Babbage, Becquerel, Bell, Bohr, Boole, Boltzmann. C: Celsius, CockcroftCoulomb, Curie. D: Davy, dArsonval, Debye, Deri, Dirac. E: Edison, Einstein. F: Fahrenheit, Faraday, Farnsworth, Fermi, Fleming, Foucault, Fourier, Franklin. G: Galileo, Galvani, Gauss, Gilbert, Giorgi. H: Hall, Heaviside, Helmholtz, Henry, Hertz, Hollerith, Huygens. J: Josephson, Joule. K: Kelvin, Kirchhoff. L: Laplace, LagrangeLangmuir, Lenz, Lichtenberg, Lorentz. M: Marconi, Maxwell, Morse. N: Napier, Newton, Norton, Nyquist. O: Oersted, Ohm. P: Pascal, Planck. R: Rayleigh, Richardson, Rentgen, Rutherford. S: Shannon, Schredinger, Schottky, Siemens, Shockley, Stanley, Steinmetz, Swan. T: Tesla, Thales, Thevenin, Torricelli, Turing. V: Van de Graaff, Volta. W: Walton, Watt, Weber, Westinghouse, Wheatstone, Wimalasurendra. Z: Zipernowsky.

, Andre-Marie

Andre-Marie Ampere (1775-1836) French Scientist who invented the electromagnet and the ammeter, was born in Lyons, France.

Despite not attending school, Andre-Marie was to be given an excellent education. He first attracted attention by a treatise on the "Theory of Probability," published in 1802, and obtained a post as teacher and ultimately as professor, at the polytechnic school in Paris. Ampere formulated the laws of electromagnetics and laid the foundation for electrodynamics. He was the first to show that two parallel conductors carrying currents traveling in the same direction attract each other and, if traveling in opposite directions repel each other. He defined electric current based on this and developed a way of measuring it. He  and invented the electromagnet and the ammeter.   Ampere also invented the astatic needle, which made possible the modern astatic galvanometer.

In the early 1820s, Ampere attempted to give a combined theory of electricity and magnetism after hearing about experimental results by the Danish physicist Hans Christian Oested. Ampere formulated a circuit force law and treated magnetism by postulating small closed circuits inside the magnetised substance.

His publications include Recueil d'observations electrodynamiques (Collection of Observations on Electrodynamics, 1822),  Theorie des phenomenes electrodynamiques (Theory of Electrodynamic Phenomena, 1826).

The Unit of electric current, the ampere,   A,     a Base Unit is named in his honour.

The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 e 10-7 newton per meter of length [1948].


Archimedes (287-212 BC) Greek mathematician and inventor, who discovered the law of hydrostatics and invented the hydraulic screw was born in Syracuse, Sicily.

Archimedes was educated in Alexandria, Egypt. He anticipated many of the discoveries of modern science, such as the integral calculus. He also proved that the volume of a sphere is two-thirds the volume of a cylinder that circumscribes the sphere.

Archimedes defined the principle of the lever and is credited with inventing the compound pulley. He invented the hydraulic screw for raising water from a lower to a higher level. He is best known for discovering the law of hydrostatics, often called Archimedes' principle. This discovery is said to have been made as Archimedes stepped into his bath and perceived the displaced water overflowing.

Archimedes did not hold any public office, but during the Roman conquest of Sicily, several of his mechanical devices were employed in the defense of Syracuse. Among the war machines attributed to him are the catapult and the legendary -  mirror system for focusing the sun's rays on invaders' boats to ignite them.

Archimedes was killed by a Roman soldier who found him drawing a mathematical diagram in the sand. It is said that Archimedes was so absorbed in calculation that he offended the soldier by remarking, "Do not disturb my diagrams."

His surviving works include Floating Bodies, The Sand Reckoner, Measurement of the Circle, Spirals, and Sphere and Cylinder.

, Charles

Charles Babbage (1792-1871) British mathematician and inventor who designed the Difference Engine was born in Teignmouth, Devonshire.

Babbage was educated at the University of Cambridge. In the years 1815-1817 he contributed three papers on the "Calculus of Functions" to the Philosophical Transactions. He became a fellow of the Royal Society in 1816 and was active in the founding of the Analytical, the Royal Astronomical, and the Statistical societies.

In the 1820s Babbage developed his Difference Engine, a mechanical device to perform simple mathematical calculations. Due to lack of funding, Babbage was unable to complete building his Difference Engine, but in 1991, British scientists following Babbage's detailed drawings and specifications, constructed the Difference Engine which worked flawlessly. It calculated up to a precision of 31 digits, proving that Babbage's design was sound. In the 1830s Babbage began developing his Analytical Engine, which was designed to carry out more complicated calculations, but this device was never built.

Babbage's book Economy of Machines and Manufactures (1832) initiated the field of study known today as operational research.

, Antoine Henri

Antoine Henri Becquerel (1852-1908) French physicist and Nobel laureate who discovered radioactivity in uranium was born in Paris, France.

Becquerel became professor of physics at the Museum of Natural History in 1892 and at the Polytechnical School in 1895. In 1896 he accidentally discovered the phenomenon of radioactivity in the course of his research on fluorescence. After placing uranium salts on a photographic plate in a dark area, Becquerel found that the plate had become blackened. This proved that uranium must give off its own energy, which later became known as radiation.

Becquerel also conducted important research on phosphorescence, spectrum analysis, and the absorption of light. In 1903 Becquerel shared the Nobel Prize in physics with the French physicists Pierre Curie and Marie Curie for their work on radioactivity, a term Marie Curie coined.

His works include Recherches sur la phosphorescence (Research on Phosphorescence, 1882-1897) and Decouverte des radiations invisibles emises par l'uranium (Discovery of the Invisible Radiation Emitted by Uranium, 1896-1897).

The becquerel ( Bq) is the SI derived unit of radioactivity and is named in his honor.

The bequerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second and is therefore equivalent to s-1. The older unit of radioactivity was the curie (Ci). 1 Bq = 2.7e10-11 Ci.

, Alexander Graham

Alexander Graham Bell (1847-1922) American inventor and teacher of the deaf, who invented the telephone was born in Edinburgh, Scotland.

Bell, the son of a well-known speech teacher, was educated at the universities of Edinburgh and London. In 1872 Bell founded a school for deaf-mutes in Boston, Massachusetts. The school subsequently became part of Boston University, where Bell was appointed professor of vocal physiology. Since the age of 18, Bell had been working on the idea of transmitting speech. In 1874, while working on a multiple telegraph, he developed the basic ideas for the telephone. His experiments with his assistant Thomas Watson finally proved successful on March 10, 1876, when the first complete sentence was transmitted: "Watson, come here; I want you." In 1880 France bestowed on Bell the Volta Prize, worth 50,000 francs, for his invention. With this money he founded the Volta Laboratory in Washington, D.C., where, in that same year, he and his associates invented the photophone, which transmits speech by light rays. Other inventions include the audiometer, used to measure acuity in hearing; the induction balance, used to locate metal objects in human bodies; and the first wax recording cylinder, introduced in 1886. The cylinder, together with the flat wax disc, formed the basis of the modern phonograph.

The bel, the logarithmic power-comparison unit is named in his honor.  The decibel which is one-tenth this unit is the more commonly used unit.

, Niels Henrik David

Niels Henrik David Bohr (1885-1962) Danish physicist and Nobel laureate, who formulated the theory of the atomic structure was born in Copenhagen, Denmark.

Bohr was educated at the University of Copenhagen, where he earned his doctorate in 1911. Bohr's theory of atomic structure, for which he received the Nobel Prize in physics in 1922, was published in papers between 1913 and 1915. His work drew on Rutherford's nuclear model of the atom, in which the atom is seen as a compact nucleus surrounded by a swarm of much lighter electrons. Bohr's atomic model made use of quantum theory and the Planck constant (the ratio between quantum size and radiation frequency).  This model contributed enormously to future developments of theoretical atomic physics.

In 1916 Bohr returned to the University of Copenhagen as a professor of physics, and in 1920 he was made director of the university's newly formed Institute for Theoretical Physics.

Bohr demonstrated that uranium-235 is the particular isotope of uranium that undergoes nuclear fission. In 1945 Bohr began working to develop peaceful uses for atomic energy. He organized the first Atoms for Peace Conference in Geneva, held in 1955, and two years later he received the first Atoms for Peace Award. 

, Ludwig Eduard

Ludwig Eduard Boltzmann (1844-1906) Austrian physicist who made important contributions to the kinetic theory of gases and helped lay the foundation for statistical mechanics was born in Vienna.

Boltzmann was educated at the universities of Vienna and Oxford. He was a professor of physics at various German and Austrian universities for more than 40 years. During the 1870s Boltzmann published a series of papers that showed that the second law of thermodynamics could be explained by statistically analyzing the motions of atoms. In these papers Boltzmann utilized the central principle of statistical mechanics: that large-scale, visible phenomena, such as the second law of thermodynamics, can be explained by statistically examining the microscopic properties of a system, such as the motions of atoms. Boltzmann also formulated the law of thermal radiation, named for him and the Austrian physicist Josef Stefan. The Stefan-Boltzmann law states that the total radiation from a blackbody, which is an ideal surface that absorbs all radiant energy that strikes it, is proportional to the fourth power of the absolute temperature of the blackbody. Boltzmann also made important contributions to the kinetic theory of gases. Boltzmann's work was strongly attacked by scientists of his time but much of his work was substantiated by experimental data soon after he committed suicide in 1906.

Boltzmann Constant is named in honour.

Boltzmann Constant, designated  k, relates the average kinetic energy of particles in a gas to the temperature of the gas and has a value of about 1.38 e 10-23 joules per kelvin.

The ideal-gas law states that PV = NkT,
where P is pressure, V volume, N the number of molecules,  T absolute temperature and  k the Boltzmann constant,

, George

George Boole (1815-1864) British mathematician and logician who developed Boolean algebra was born in England.

Boole, largely self-educated was raised in a working class family. In 1849 he was appointed professor of mathematics at Queen's College (now University College) in Cork, Ireland. He was very interested in mathematics and read books by some great masters such as Gauss and Laplace, which led him to have new ideas on the calculus of variations which were even published in The Cambridge Mathematical Journal. He was later awarded a gold medal by the Royal Society of Mathematics for his numerous articles. In 1854, in An Investigation of the Laws of Thought, Boole described an algebraic system that later became known as Boolean algebra. His idea was to represent information only with the two logic states true or false. He gave the mathematics ideas and formulas to do calculations on this information.

"The Laws of Thought" was an important basis for work leading to the foundations of modern mathematics. In Boolean algebra, logical propositions are denoted by symbols and can be acted on by abstract mathematical operators that correspond to the laws of logic. Boolean algebra is of prime importance to the study of pure mathematics and to the design of modern computers.

, Anders

Anders Celsius (1701-1744) Swedish Astronomer, who devised the centigrade scale of measuring thermodynamic temperature was born in Uppsala, Germany.

Celsius, who was a very talented in mathematics from an early age, was appointed professor of astronomy in 1730. In those days, geographical measurements, meteorological observations and other things, were included in the work of an astronomy professor.

For his meteorological observations he constructed his world famous Celsius thermometer, with 0 for the boiling point of water and 100 for the freezing point. After his death in 1744 the scale was reversed to its present form.

Together with his assistant Olof Hiorter he also was the first to realize that the aurora phenomenon has magnetic causes through observing the inclination of a compass-needle and finding that the larger deviations correlated with stronger aurora activity. In astronomy he made observations of eclipses and various astronomical objects. He published catalogues of carefully determined magnitudes for a total of 300 stars using his own photometric system (mean error=0.4 mag).

The Unit of thermodynamic temperature, the degrees celsius,   oC,    is named in his honour.

The Celsius scale is an international thermometric scale on which the interval between the triple point of water and the boiling point of water is divided into 99.99 degrees with 0.01o representing the triple point and 100o the boiling point.

Celsius degrees are the same size as kelvin but the zero point is shifted to the triple point of water, minus 0.01 K.(0 oC = 273.15 K).
Note: The thermodynamic temperature of the triple point of water is 273.16 K

, Sir John Douglas

Sir John Douglas Cockcroft (1897-1967) British physicist and Nobel laureate who together with Walton developed an accelerator for sub-atomic particles for his work on the nature of the atomic nucleus was born in Todmorden, England.

Cockcroft was educated at the University of Manchester and Saint John's College, University of Cambridge.  In 1928 Cockcroft became a fellow at St. John's College, a post he held until 1946. In 1932 Cockcroft, in collaboration with British physicist Ernest Walton, became the first to disintegrate an atomic nucleus with artificially accelerated subatomic particles. The two scientists used an accelerator they developed, called the Cockcroft-Walton accelerator, to bombard lithium atoms with protons. Some of the lithium atoms absorbed a proton and disintegrated into two helium atoms. The Cockcroft-Walton accelerator became an important experimental tool in laboratories throughout the world.

His nuclear work with lithium and hydrogen proved of great importance in the development of the hydrogen bomb. He was knighted in 1948 and with Walton shared the 1951 Nobel Prize in physics. Cockcroft received the Niels Bohr Medal in 1958 and the Atoms for Peace Award in 1961.

, Charles Augustin de

Charles Augustin de Coulomb (1736-1806) French physicist who formulated the Coulomb's law of electrostatics was born in Angouleme, France.

Coulomb served as a military engineer for France in the West Indies.  In 1777 he invented the torsion balance for measuring the force of magnetic and electrical attraction. With this invention, Coulomb was able to formulate the principle, now known as Coulomb's law, governing the interaction between electric charges.

In 1779 Coulomb published the treatise Theorie des machines simples (Theory of Simple Machines), an analysis of friction in machinery.

The Unit of electric charge, the coulomb,   C,     a derived Unit is named in his honour.

The coulomb is the SI unit of electric charge. One coulomb is equal to the amount of charge accumulated in one second by a current of one ampere.

, Marie & Pierre

Marie Curie (1867-1934) & Pierre Curie (1859-1906) French physicists and Nobel laureates - wife and husband - who discovered new radio-active elements were born in Warsaw-Poland and Paris-France respectively.

Marie Curie was originally named Marja Sklodowska. She went to Paris in 1891 and enrolled in the Sorbonne and passed the examination for her degree in physics, ranking in first place. She met Pierre Curie in 1894, and they married in 1895.

Pierre Curie studied science at the Sorbonne. In 1880 he and his brother Jacques observed that an electric potential is produced when pressure is exerted on a quartz crystal. The brothers named the phenomenon piezoelectricity. In the course of later studies of magnetism, Pierre Curie discovered a certain temperature (the Curie point) at which magnetic substances lose their magnetism. In 1895 he was named professor in the School of Physics and Chemistry in Paris.

Marie Curie began studying uranium radiations, and, using piezoelectric techniques devised by her husband, carefully measured the radiations in pitchblende, an ore containing uranium. When she found that the radiations from the ore were more intense than those from uranium itself, she realized that unknown elements, even more radioactive than uranium, must be present. Marie Curie was the first to use the term radioactive to describe elements that give off radiations as their nuclei break down.

Pierre Curie ended his own work on magnetism to join his wife's research, and in 1898 the Curies announced their discovery of two new elements: polonium (named in honor of Poland) and radium.  They shared the 1903 Nobel Prize in physics with Becquerel for the discovery of radioactive elements. Marie Curie was the first female recipient of a Nobel Prize. In 1904 Pierre Curie was appointed professor of physics at the University of Paris, and in 1905 he was named a member of the French Academy.  In 1911 Marie received an unprecedented second Nobel Prize, this time in chemistry, for her work on radium and radium compounds. She became head of the Paris Institute of Radium in 1914 and helped found the Curie Institute.

The curie (Ci) is an older unit of radioactivity.  2.7e10-11 Ci = 1 Bq .

, Sir Humphry

Sir Humphry Davy (1778-1829) British chemist who invented the electric arc lamp and the miner's safety lamp was born in Penzance, England.

Davy was a lecturer of Chemistry at the Royal Institution in London early in his career. Among his applied uses of chemistry are the miner's safety lamp, the anesthetic effects of nitrous oxide (laughing gas), and sheathing for ships. During his career, Davy isolated the elements of potassium, calcium, and sodium by electrolysis (passing an electrical current through a solution). He is also credited with the discovery of boron and the discovery that diamonds are composed of carbon. Davy demonstrated that the "rare earth elements" are really metal oxides rather than pure substances. In another area of chemistry, he demonstrated that acids contain hydrogen which accounts for their properties. In 1809 Humphry Davy invented the first electric light - the first arc lamp.

During his career, Davy was awarded the Napoleon Prize by the Institut de France, the gold and silver Rumford medals of the Royal Society, a baronetcy, and Presidency of the Royal Society.

His writings include Elements of Chemical Philosophy (1812) and Elements of Agricultural Chemistry (1813).

, Jacques-Arsene

Jacques-Arsene d'Arsonval (1851-1940) French physicist and physician, who invented the d'Arsonval's galvanometer was born in Canton Saint-Germain-les-Belles.

Arsene deArsonval studied in the Imperial College of Limoges (now Lycee Gay-Lussac), and then in Sainte-Barbe college in Paris (the College bears his name since 1959). He was professor at the Sorbonne from 1894 to 1932.

He studied the medical application of high-frequency currents. Among his inventions were dielectric heating and various measuring devices, including the thermocouple ammeter and moving-coil galvanometer. These measuring tools helped establish the science of electrical engineering. The d'Arsonval's galvanometer, which he invented in 1882 for measuring weak electric currents, became the basis for almost all panel-type pointer meters. He was also involved in the industrial application of electricity.

, Peter Joseph Wilhelm

Peter Joseph Wilhelm Debye (1884-1966) Dutch-American theoretical physicist and Nobel laureate, who is known for his work in molecular structure and dipole movements was born in Maastricht.

Debye was educated at the University of Munich. From 1911 to 1935 he held the post of professor of physics successively at several universities in Switzerland, the Netherlands, and Germany. He then became director of the Kaiser Wilhelm Institute for Physics in Berlin. In the U.S., he served as professor of chemistry at Cornell University from 1940 to 1952. He received the 1936 Nobel Prize in chemistry for his studies in molecular structure, dipole movements, and the diffraction of X rays and electrons in gases.

In 1912 Debye modified the specific-heat theory put forth by Albert Einstein by calculating the probability of any frequency of molecular vibration up to a maximum frequency; the theory of specific heat constituted one of the earliest theoretical successes of the quantum theory. Debye also applied the quantum theory to explain the heat conductivity of crystals at low temperature, the variation of saturation intensity of magnetization with temperature, the theory of space quantization (with the German physicist Arnold Sommerfeld, 1868-1951), and the phenomena of scattering of X rays (with the American physicist Arthur Holly Compton). In 1923 Debye developed a theory of ionization of electrolytes (now called the Debye-Heckel theory), which is important in chemistry. Later he worked on the theory of quantum mechanics, including its applications to the diffraction of electrons in gases. In 1963 he was awarded the Priestley Medal by the American Chemical Society.

His writings include Quantum Theory and Chemistry (1928), Polar Molecules (1929), and Molecule Structure (1931).

, Miksa

Miksa Deri (1854-1938) engineer who became world famous with the invention of the alternating electric transformer system was born in Becs.

Deri obtained his diploma in hydraulic engineering in 1877 at the Technical University of Vienna. Between 1878 and 1882 he was engaged in designing of the Duna and Tisza river control systems. At the same time he studied electrotechnics.

Miksa Deri, together with Otto Blethy and Keroly Zipernowsky became world famous with the invention of the alternating electric transformer system. This system made it possible to send electric energy to great distances and divide it over large areas.  The experimentation was mainly done by Deri. He had many other inventions among which is the Deri-repulsion motor with which, elevators could be safely used. This had not been achieved by any other type of motor until then.

In 1882 Deri started working at the Ganz factory as an engineer and later the factory's director. Along with Zipernowsky, they developed a self-excited AC generator, which they began manufacturing in 1883. From 1833 Miksa Deri worked in Vienna as the Austrian representative of the Ganz factory electrical department.

, Paul Adrien Maurice

Paul Adrien Maurice Dirac (1902-84) British theoretical physicist and Nobel laureate who predicted the existence of the positron was born in Bristol, England.

He was educated at the universities of Bristol and Cambridge. His quantum theory of electron motion led him in 1928 to postulate the existence of a particle identical to the electron in every aspect but charge, the electron having a negative charge and this hypothetical particle a positive one. Dirac's theory was confirmed in 1932 when the American physicist Carl Anderson discovered the positron (or antielectron). In 1933 Dirac shared the Nobel Prize in physics with the Austrian physicist Erwin Schredinger, and in 1939 he was made a fellow of the Royal Society. He was a professor of mathematics at Cambridge from 1932 to 1968, a professor of physics at Florida State University from 1971, and a member of the Institute for Advanced Study periodically between 1934 and 1959.

Dirac's writings include Principles of Quantum Mechanics (1930).

, Thomas Alva

Thomas Alva Edison (1847-1931) American inventor, who developed an incandescent electric light bulb was born in Milan, Ohio.

Edison attended formal school for only three months, in Port Huron, Michigan. When he was 12 years old he began selling newspapers on the Grand Trunk Railway, devoting his spare time mainly to experimentation with printing presses and with electrical and mechanical apparatus. For saving the life of a station official's child, he was rewarded by being taught telegraphy. While working as a telegraph operator, he made his first important invention, a telegraphic repeating instrument that enabled messages to be transmitted automatically over a second line without the presence of an operator. Edison's crowning achievement in telegraphy was his invention of machines that made possible simultaneous transmission of several messages on one line.

In 1877 Edison invented a phonograph by which sound could be recorded mechanically on a tinfoil cylinder and in 1879 exhibited publicly his incandescent electric light bulb, his most important invention and the one requiring the most careful research and experimentation to perfect. In 1882 he developed and installed the world's first large central electric-power station, located in New York City using of direct current.

In 1888 he invented the kinetoscope, the first machine to produce motion pictures by a rapid succession of individual views. Among his later noteworthy inventions was the Edison storage battery (an alkaline, nickel-iron storage battery). He also developed a phonograph in which the sound was impressed on a disk instead of a cylinder. This phonograph had a diamond needle and other improved features. By synchronizing his phonograph and kinetoscope, he produced, in 1913, the first talking moving pictures.

Altogether, Edison patented more than 1000 inventions. He was a technologist rather than a scientist, adding little to original scientific knowledge. In 1883, however, he did observe the flow of electrons from a heated filament-the so-called Edison effect.

Edison was appointed Chevalier (1878) and Commander (1889) of the Legion of Honor of France . In 1892 he was awarded the Albert Medal of the Society of Arts of Great Britain and in 1928 received the Congressional Gold Medal "for development and application of inventions that have revolutionized civilization in the last century."

, Albert

Albert Einstein (1879-1955) German-born American physicist and Nobel laureate best known as the creator of the theory of relativity was born in Ulm, Germany.

Einstein did not talk until the age of three, but even as a youth he showed a brilliant curiosity about nature and an ability to understand difficult mathematical concepts. At the age of 12 he taught himself Euclidean geometry. Einstein hated the dull regimentation and unimaginative spirit of school in Munich. His professors did not think highly of him and would not recommend him for a university position. For two years Einstein worked as a tutor and substitute teacher. In 1902 he secured a position as an examiner in the Swiss patent office in Bern.

In 1905 Einstein received his doctorate from the University of Zurich for a theoretical dissertation on the dimensions of molecules, and he also published three theoretical papers of central importance to the development of 20th-century physics.
In the first of these papers, on Brownian motion, he made significant predictions about the motion of particles that are randomly distributed in a fluid. These predictions were later confirmed by experiment.
The second paper, on the photoelectric effect, contained a revolutionary hypothesis concerning the nature of light. Einstein not only proposed that under certain circumstances light can be considered as consisting of particles, but he also hypothesized that the energy carried by any light particle, called a photon, is proportional to the frequency of the radiation.
Einstein's third major paper in 1905, "On the Electrodynamics of Moving Bodies," contained what became known as the special theory of relativity (The theory included his famous equation e=mc2). At the heart of his special theory of relativity was the realization that all measurements of time and space depend on judgments as to whether two distant events occur simultaneously. The full general theory of relativity was not published until 1916. In this theory the interactions of bodies, which heretofore had been ascribed to gravitational forces, are explained as the influence of bodies on the geometry of space-time (four-dimensional space, a mathematical abstraction, having the three dimensions from Euclidean space and time as the fourth dimension). On the basis of the general theory of relativity, Einstein accounted for the previously unexplained variations in the orbital motion of the planets and predicted the bending of starlight in the vicinity of a massive body such as the sun. The confirmation of this latter phenomenon during an eclipse of the sun in 1919 became a media event, and Einstein's fame spread worldwide.

, Gabriel Daniel

Gabriel Daniel Fahrenheit (1686-1736) German physicist who constructed the first mercury thermometer was born in Danzig (now Gdansk, Poland).

Fahrenheit settled in Holland and engaged in the manufacture of meteorological instruments. In 1714 he constructed the first thermometer employing mercury instead of alcohol. Using this thermometer he devised the temperature scale (now known as the Fahrenheit scale). Fahrenheit also invented a hygrometer of improved design. He discovered that other liquids besides water have a fixed boiling point and that these boiling points vary with changes in atmospheric pressure.

In the Fahrenheit scale, at standard atmospheric pressure, the freezing point (and melting point of ice) is 32e F, and the boiling point is 212e F.

, Michael

Michael Faraday (1791-1867) English Chemist and Physicist, who discovered of electromagnetic induction and the laws of electrolysis, was born in Newington, Surrey, England.

Faraday was the son of a blacksmith and received little formal education. While apprenticed to a bookbinder in London, he read books on scientific subjects and experimented with electricity. Later he was assistant to the great Chemist Sir Humphry Davy at the Royal Institution.

Faraday's earliest researches were in the field of chemistry, following the lead of Davy. A study of chlorine, which Faraday included in his researches, led to the discovery of two new chlorides of carbon. He also discovered benzene. Faraday investigated a number of new varieties of optical glass. In a series of experiments he was successful in liquefying a number of common gases. 

Faraday's discovery of electromagnetic induction occurred in 1831. He discovered the two fundamental laws of electrolysis. Faraday also established the principle that different dielectric substances have different specific inductive capacities. In 1821 Faraday also designed  an electric motor.

In experimenting with magnetism, Faraday made two discoveries of great importance; one was the existence of diamagnetism, and the other was the fact that a magnetic field has the power to rotate the plane of polarized light passing through certain types of glass.

Faraday was the recipient of many scientific honors, including the Royal and Rumford medals of the Royal Society; he was also offered the presidency of the society but declined the honor.

His writings include Chemical Manipulation (1827), Experimental Researches in Electricity (1844-55), and Experimental Researches in Chemistry and Physics (1859).

Faradays Laws of Electrolysis: The amount of chemical action produced by an electrical current in an electrolyte is proportional to the amount of electricity passing through the electrolyte. The amount of a substance deposited from an electrolyte by the action of a current is proportional to the chemical equivalent weight of the substance. 

The Unit of electric capacitance, the farad,   F,     a derived Unit is named in his honour.

The farad is the SI unit of electric capacitance. One farad is defined as the ability to store one coulomb of charge per volt of potential difference between the two conductors.

, Philo Taylor

Philo Taylor Farnsworth (1906-1971) who is credited with the invention of the television was born in Indian Creek, Utah.

Farnsworth was born in a log cabin. When he was 12, his family moved to a ranch in Rigby, Idaho, which was four miles from the nearest high school, thus necessitating his daily horseback rides. Because he was intrigued with the electron and electricity, he persuaded his chemistry teacher, Justin Tolman, to give him special instruction and to allow him to audit a senior course.

At the age 14, Farnsworth conceived the idea of electronic television-the moment of inspiration coming, according to legend, while he was tilling a potato field back and forth with a horse-drawn harrow and realized that an electron beam could scan images the same way, line by line, just as you read a book.

Many years later, testifying at a patent interference case, Tolman said Farnsworth's explanation of the theory of relativity was the clearest and most concise he had ever heard. Remember, this would have been in 1921, and Farnsworth would have been all of 15. With only two years of high school behind him, Farnsworth gained admission to Brigham Young University. He had a working device of the television at the age of 21 and transmitted the first electronic image.

, Enrico

Enrico Fermi (1901-54) Italian-American physicist and Nobel laureate who achieved the first controlled nuclear reaction was born in Rome.

Fermi was educated at the University of Pisa and in some of the leading centres  for theoretical physics in Europe. In 1926 he became professor of theoretical physics at the University of Rome. There he developed a new kind of statistics for explaining the behavior of electrons. He also developed a theory of beta decay and, from 1934 on, investigated the production of artificial radioactivity by bombarding elements with neutrons. For the latter work he was awarded the 1938 Nobel Prize in physics.

Fermi and his family immigrated to the United States, where he became professor of physics at Columbia University.  He created the first controlled nuclear fission chain reaction in December 1942 at the University of Chicago and worked for the rest of World War II  at Los Alamos, New Mexico, on the atomic bomb. Later, he opposed the development of the hydrogen bomb on ethical grounds.

After the war, in 1946, Fermi became a professor of physics and the director of the new Institute of Nuclear Studies at the University of Chicago.  The Enrico Fermi Award honoring his memory is given annually to the individual who has contributed most to the development, use, or control of atomic energy.

, Sir John Ambrose

Sir John Ambrose Fleming (1849 - 1945) English electrical engineer who invented the thermionic diode  was born in Lancaster, England.

Fleming's invention of the thermionic valve (Vacuum diode) jump started modern electronics. He also made many other contributions to the field of electrical machinery. After studying at University College, London, and at Cambridge University, Fleming was a consultant for the Edison Electric Light Company in London. He later became an adviser to the Marconi Wireless Telegraph Company and a popular teacher at University College London from 1885 to 1926, where he was the first to hold the title of professor of electrical engineering.

Early in his career Fleming investigated photometry, worked with high-voltage alternating currents and designed some of the first electric lighting for ships. In addition, Fleming designed the transmitter that made Marconi's first transatlantic transmission in 1901 possible.

The invention of the diode was an idea that revolutionized radio telegraphy, but it had little impact at first. "Valves" were expensive to make, and in less than two years, the "cat's whisker" was produced, a crude form of semiconductor rectifier. This was more convenient than Fleming's diode and it soon caught on. Fleming authored more than 100 scientific papers and books.

His writings include The Principles of Electric Wave Telegraphy (1906) and The Propagation of Electric Currents in Telephone and Telegraph Conductors (1911).

, Jean Bernard Leon

Jean Bernard Leon Foucault (1819-68) French physicist who was the first to show the existence of the eddy currents generated by magnetic fields was born in Paris, France.

Foucault worked with the French physicist Armand Fizeau in making determinations of the speed of light. Foucault proved independently that the speed of light in air is greater than it is in water. In 1851 he gave a spectacular demonstration of the rotation of the earth by suspending a pendulum on a long wire from the dome of the Pantheon in Paris; the movement of the pendulum duplicated the rotation of the earth on its axis. Foucault was one of the first to show the existence of the eddy currents generated by magnetic fields, and he also devised a method of measuring the curvature of telescope mirrors. Other devices he developed include a polarizing prism and the form of gyroscope that is the basis of the modern gyrocompass.

, Jean Baptiste Joseph, Baron

Baron Jean Baptiste Joseph Fourier (1768-1830) French mathematician who developed the trigonometric series called the Fourier series was born in Auxerre, France.

Fourier was educated at the monastery of Saint-Benoet-sur-Loire. He taught at the ecole Normale (1795), where he had been a student, and at the ecole Polytechnique in Paris from 1795 to 1798 when he joined the campaign of Napoleon I in Egypt. After returning to France in 1802 he published important material on Egyptian antiquities and was, until 1815, prefect of Isere Department. He was created a baron by Napoleon in 1808. In 1816 he was elected to the Academy of Sciences and in 1827 to the French Academy. His fame rests on his work in mathematics and mathematical physics. Like most of his contemporaries, Fourier was swept into the politics of the French Revolution.

He employed a trigonometric series, usually called the Fourier series, by means of which discontinuous functions can be expressed as the sum of an infinite series of sines and cosines.

His writings include a treatise The Analytical Theory of Heat (1822)

, Benjamin

Benjamin Franklin (1706-1790) American printer, author, diplomat, philosopher, and scientist who invented the lightning rod was born in Boston.

Franklin engaged in many public projects. In 1731 he founded what was probably the first public library in America, chartered in 1742 as the Philadelphia Library. He organized the first fire company in that city and introduced methods for the improvement of street paving and lighting. Always interested in scientific studies, he devised means to correct the excessive smoking of chimneys and invented, around 1744, the Franklin stove, which furnished greater heat with a reduced consumption of fuel.

In 1747 Franklin began his electrical experiments with a simple apparatus that he received from Peter Collinson in England. He advanced a tenable theory of the Leyden jar, supported the hypothesis that lightning is an electrical phenomenon, and proposed an effective method of demonstrating this fact. His plan was published in London and carried out in England and France before he himself performed his celebrated experiment with the kite in 1752 and invented the lightning rod.

In 1747 he offered what is called the "one-fluid" theory in explanation of the two kinds of electricity, positive and negative. In recognition of his impressive scientific accomplishments, Franklin received honorary degrees from the University of St. Andrews and the University of Oxford. He also became a fellow of the Royal Society of London for Improving Natural Knowledge and, in 1753, was awarded its Copley Medal for distinguished contributions to experimental science. Franklin also exerted a great influence on education in Pennsylvania. In 1749 he wrote Proposals Relating to the Education of Youth in Pennsylvania; its publication led to the establishment in 1751 of the Philadelphia Academy, later to become the University of Pennsylvania. The curriculum he suggested was a considerable departure from the program of classical studies then in vogue. English and modern foreign languages were to be emphasized as well as mathematics and science.


Galileo Galilei (1564-1642) Italian physicist and astronomer whose observations with a telescope revolutionized astronomy  was born in Pisa, Italy.

Galileo went to the University of Pisa in 1581 in order to study Medicine. During the studies he got interested in Physics and in 1583 stated the theory of the isochronism of the pendulum, which he guessed by observing the oscillations of a lamp inside the Pisa Cathedral. In 1585 he quit the University, and began his activity in Physics and Mathematics inventing the hydrostatic balance in 1586. In 1588 he obtained a chair at the Pisa University. He got interested in the motion of the falling bodies and wrote "De Motu". In 1592 Galileo obtained a chair of Mathematics (Geometry and Astronomy) at the Padova University, where he stayed until 1610.   In 1606 he invented the thermoscope, a primitive thermometer. In 1604 Galileo observed a supernova, which appeared in the sky during the fall of the year. Galileo invented a calculating compass for the practical solution of mathematical problems.

By December 1609, Galileo had built a telescopeof 20 times magnification, and used it in observation and the discovery of sunspots, lunar mountains and valleys, the four largest satellites of Jupiter, and the phases of Venus. He published these findings in March 1610 in The Starry Messenger. He published a book on floating bodies in 1612. In 1613 he published a work on sunspots and predicted victory for the Copernican theory. In 1624 Galileo began a book "Dialogue on the Tides," in which he discussed the Ptolemaic and Copernican hypotheses in relation to the physics of tides. The title was altered to Dialogue on the Two Chief World Systems by the censors and published at Florence in 1632.

Galileo's final book, Discourses Concerning Two New Sciences, which was published at Leiden in 1638, reviews and refines his earlier studies of motion and, in general, the principles of mechanics. The book opened a road that was to lead Newton to the law of universal gravitation that linked Kepler's planetary laws with Galileo's mathematical physics. Galileo's most valuable scientific contribution was his founding of physics on precise measurements rather than on metaphysical principles and formal logic.

Galileo wrote a long, open letter on the irrelevance of biblical passages in scientific arguments, holding that interpretation of the Bible should be adapted to increasing knowledge and that no scientific position should ever be made an article of Roman Catholic faith. Galileo was summoned to Rome by the Inquisition to stand trial for "grave suspicion of heresy." [In October 1992 a papal commission acknowledged the Vatican's error.] He set forth his views on scientific reasoning in a book on comets, The Assayer (1623). Galileo's lifelong struggle to free scientific inquiry from restriction by philosophical and theological interference stands beyond science.

, Luigi

Luigi Galvani (1737 - 1798) Italian physiologist who studied the effects of electricity on animal nerves and muscles was Born in Bologna.

Galvani was a medical student and later professor of anatomy at the University of Bologna. He studied  the effects of electricity on animal nerves and muscles and discovered that the legs of a frog twitched when touched with an electrically charged scalpel. He was correct in attributing muscular contractions to electrical stimuli (1791).  In honor of Galvani, Volta coined the term galvanism for a direct current of electricity produced by chemical action. Galvani's name is still associated with electricity in the words galvanism and galvanization.

Galvanization is the process of coating a base metal, such as iron, with a thin layer of zinc to protect the base metal from corrosion. The zinc layer protects the base metal even when there are cracks or small gaps in the coating, because oxygen reacts more readily with zinc than with the exposed base metal.

The galvanometer, an instrument for measuring a small electric current, was also named after Galvani.

, Carl Friedrich

Carl Friedrich Gauss (1777-1855) German mathematician  who developed the Gaussian distribution and noted for his study of electromagnetism was born in Braunschweig, Germany.

Gauss became interested in mathematics at the age of 17,  and attempted a solution of the classical problem of constructing a regular heptagon, with ruler and compass. He not only succeeded in proving this construction impossible, but proved that the construction, with compass and ruler, of a regular polygon with an odd number of sides was possible only when the number of sides was a prime number of the series 3, 5, 17, 257, and 65,537 or was a multiple of two or more of these numbers.

He studied at the University of Gettingen from 1795 to 1798 and submitted a proof that every algebraic equation has at least one root, or solution for his doctoral thesis. This theorem, which had challenged mathematicians for centuries, is still called the fundamental theorem of algebra. His volume on the theory of numbers, Disquisitiones Arithmeticae (Inquiries into Arithmetic, 1801), is a classic work in the field of mathematics. Gauss next turned his attention to astronomy.  He worked out a new method for calculating the orbits of heavenly bodies. In 1807 Gauss was appointed professor of mathematics and director of the observatory at Gettingen. In probability theory, he developed the important method of least squares and the fundamental laws of probability distribution. The normal probability graph is still called the Gaussian curve. He made geodetic surveys, and applied mathematics to geodesy. With the German physicist Wilhelm Eduard Weber, Gauss did extensive research on magnetism. His applications of mathematics to both magnetism and electricity are among his most important works. He also carried out research in optics, particularly in systems of lenses.

An older Unit of magnetic induction, the gauss   was named in his honour.

The gauss is a unit of magnetic induction. One gauss is the magnetic induction corresponding to a magnetic field intensity of 1 oersted in a medium of unit magnetic permeability.

, William

William Gilbert (1544-1603) English physicist and physician who experimentally  demonstrated the magnetic nature of the earth and coined the term electric was born in Colchester, England.

Gilbert was educated at Saint John's College, University of Cambridge. He began to practice medicine in London in 1573 and in 1601 was appointed physician to Elizabeth I, queen of England.

Gilbert found that many substances, such as amber, had the power to attract light objects when rubbed, and he applied the term electric to the force these substances exert after being rubbed. He was the first to use the terms electric force, electric attraction, and magnetic pole. Perhaps Gilbert's most important contribution was the experimental demonstration of the magnetic nature of the earth. He was also the first exponent in England of the Copernican system of celestial mechanics, and he postulated that fixed stars were not all at the same distance from the earth.

His most important work was of Magnets, Magnetic Bodies, and the Great Magnet of the Earth De Magnete ("On the Magnet") was published in 1600 and quickly became the standard work throughout Europe on electrical and magnetic phenomena. Europeans were making long voyages across oceans, and the magnetic compass was one of the few instruments that could save them from being hopelessly lost.

His theory that the earth exerted a magnetic influence throughout the solar system was a precursor to the modern conception of gravity as an attracting force between masses. Gilbert was among the first to divide substances into electrics (spar, glass, amber) and nonelectrics.

An older unit of magnetomotive force, the gilbert, was named in his honor.

The gibert is the c.g.s. electromagnetic unit of magnetomotive force. One gilbert is equal to 10/4p of the ampere.

The gilbert, a unit equal to one centimeter-gram-second of magnetomotive force, is named for him.

, Giovani

Giovani Giorgi (1871-1950) Italian scientist and engineer whose work on introducing a base quantity of electrical nature led to the formulation of the SI Units was born in Italy.

Giorge reformulated the then existing three-dimensional system of units into a four-dimensional one in October 1901. This led to the International System of Units, or SI Units. In Giorgies opinion, dimensions should express the true nature of a physical quantity. He saw the need to introduce - together with the base quantities of length, mass and time - a fourth base quantity of electrical nature, the ampere. "It is evident that by assuming the current as a fundamental concept, the definition of any other electromagnetic quantity easily follows," he wrote.

The SI Units is a system of units founded on older metric systems and adopted by the General Conference on Weights and Measures, the highest international authority on units. The SI consists of seven base units, metre (length), kilogram (weight), second (time), ampere (electric current), kelvin (thermodynamic temperature), mole (amount of substance) and candela (luminous intensity) that are independent of one another. These base units can be combined to create derived units defining new quantities. The base and derived units form the coherent SI units.

, Edwin Herbert

Edwin Herbert Hall (1855-1938) American Physicist  who discovered the "Hall effect" was born in Great Falls , Maine.

Hall was educated at Johns Hopkins University, Baltimore. He discovered the "Hall effect" in 1879 while working on his doctoral thesis in Physics under the supervision of Professor Henry Augustus Rowland. Hall was pursuing the question first posed by Maxwell as to whether the resistance of a coil excited by a current was affected by the presence of a magnet. Does the force act on the conductor or the current? Through a myriad of experiments and failures, Hall discovered that a magnetic field would skew equipotential lines in a current-carrying conductor. This effect is observed as a voltage (Hall voltage) perpendicular to the direction of current in the conductor. Hall conducted an experiment by putting a thin gold leaf on a glass plate and then tapping off the gold leaf at points down its length. He then conducted other experiments using various materials in place of the gold leaf, and various experimental placements of tapping points. In 1880, full details of Hall's experimentation with this phenomenon formed his doctoral thesis and was published in the American Journal of Science and in the Philosophical Magazine.

, Oliver

Oliver Heaviside (1850-1925) British physicist, who correctly predicted the existence of an electrically conducting layer in the atmosphere, was born in London.

Heaviside was self-educated. He worked as a telegrapher until deafness forced him to retire. He contributed to electromagnetic theory by applying mathematics to the study of electric circuits and, later, wave motion. His mathematics also contributed to the development of practical long-distance telephony. In 1902 Heaviside predicted the existence of an electrically conducting layer in the atmosphere, by means of which radio signals could be transmitted around the earth's curvature. This was later proven to be the ionosphere, a prediction made that same year by the American engineer Arthur Edwin Kennelly, and the ionosphere was long called the Kennelly-Heaviside layer.

, Hermann Ludwig von

Hermann Ludwig von Helmholtz (1821-1894) German physicist and physiologist who also independantly formulated the law of conservation of energy was born in Potsdam.

Helmholtz became the Professor of physiology in Kenigsberg, Bonn and Heidelberg and professor of physics in Berlin. In 1888 he became the head of the newly founded Physikalisch-Technische Reichsanstalt in Charlottenburg.

He worked on acoustics, hydrodynamics, electrodynamics, thermodynamics, meteorology, optics, non-euclidian geometry and philosophy of natural sciences.

In 1847 he formulated (independently of Joule) the law of conservation of energy: "eber die Erhaltung der Kraft" (Berlin, 1847).

He is also known for his invention of the first ophthalmoscope: "Beschreibung eines Augenspiegels", (Berlin, 1851).

, Joseph

Joseph Henry (1797-1878) American Physicist, who discovered self induction was born in Albany, New York, England.

Henry graduated from the Albany Academy and taught philosophy at Princeton University from 1832 to1846. He discovered electromagnetic induction before Faraday but failed to publish it.  He was appointed Professor of mathematics and natural philosophy at Albany Academy in 1826 and Professor of natural philosophy at Princeton University in 1832. Henry however announced the discovery of the phenomenon of self-inductance  in 1832, and this is attributed to him. He developed powerful electromagnets that could lift objects weighing thousands of Pounds.

The Unit of electric inductance, the henry,   H,     a derived Unit is named in his honour.

The henry is the SI unit of electric inductance.   One henry is equal to the inductance of a closed circuit in which an electromotive force of 1 volt is produced when the electric current in the circuit varies uniformly at the rate of 1 ampere per second.

, Heinrich Rudolf

Heinrich Rudolf Hertz (1857-1894) German experimental physicist who proved that electricity can be transmitted in electromagnetic waves was born in Hamburg, Germany.

Hertz  attended the University of  Berlin and completed his doctorate under Hermann von Helmholtz. He was a professor of physics at the technical school in Karlsruhe from 1885 to 1889 and after 1889 a professor of physics at the university in Bonn. Hertz clarified and expanded the electromagnetic theory of light that had been put forth by the British physicist James Clerk Maxwell in 1884. Hertz proved that electricity can be transmitted in electromagnetic waves, which travel at the speed of light and which possess many other properties of light. His experiments with these electromagnetic waves led to the development of the wireless telegraph and the radio.

The Unit of frequency, the hertz,   Hz,     a derived Unit is named in his honour.

The hertz is the SI unit of frequency. One hertz is equal to one cycle per second.

, Herman

Herman Hollerith (1860-1929) American inventor who devised the punched cards used in early computers was born in Buffalo, New York.

Hollerith was educated at Columbia University and devised a system of encoding data on cards through a series of punched holes. This system proved useful in statistical work and was important in the development of the digital computer. Hollerith's machine, used in the 1890 U.S. census, "read" the cards by passing them through electrical contacts. Closed circuits, which indicated hole positions, could then be selected and counted. His Tabulating Machine Company (1896) was a predecessor to the International Business Machines Corporation.

, Christiaan

Christiaan Huygens (1629-95) Dutch astronomer, mathematician, and physicist who developed the wave theory of light and the pendulum clock was born in The Hague.

Huygens made numerous, original scientific discoveries which won him wide recognition and honors among scientists of the 17th century. Among his discoveries was the principle (Huygens Principle) that states that every point on the front of an advancing wave is itself a source of new waves. From this principle he developed the wave theory of light. In 1655 he found a new method of grinding and polishing lenses. The sharper definitions obtained enabled him to discover a satellite of Saturn and to give the first accurate description of the rings of Saturn. The need for an exact measure of time for observing the heavens led to his applying the pendulum to regulate the movement of clocks (Pendulum clock). In 1656 he devised an eyepiece for the telescope that bears his name. In Horologium Oscillatorium (1673) he determined the true relation between the length of a pendulum and the period of oscillation and developed theories on centrifugal force in circular motion that assisted the English mathematician Sir Isaac Newton in formulating the laws of gravity. In 1678 he discovered the polarization of light by double refraction in calcite.

, Brian David

Brian David Josephson (1940 - ) British physicist and Nobel Laureate (1973), who predicted the Josephson Effect was born in England.

Josephson predicted the existence of the flow of electric current, in the form of electron pairs, between two superconducting materials that are separated by an extremely thin insulator (now known as the Josephson effect). The current flow is termed Josephson current, and the penetration of the insulator by the electron pairs is known as Josephson tunneling. Rapidly alternating currents occur within the insulator when a steady voltage, as from a battery, is applied across the superconductors. A steady flow of current through the insulator can be induced by a steady magnetic field. The Josephson effect has found application in devices that detect and generate high-energy electromagnetic radiation, and in the detection of extremely weak magnetic fields.

, James Prescott

James Prescott Joule (1818-1889) British physicist who formulated the law, now known as Joule's law, was born in Salford, Lancashire, England.

Joule in the course of his investigations of the heat emitted in an electrical circuit, formulated the law, now known as Joule's law, of electric heating, which states that the amount of heat produced each second in a conductor by a current of electricity is proportional to the resistance of the conductor and to the square of the current. Joule experimentally verified the law of conservation of energy in his study of the transfer of mechanical energy into heat energy. Using many independent methods, Joule determined the numerical relation between heat and mechanical energy, or the mechanical equivalent of heat. Together with the physicist Lord Kelvin, Joule found that the temperature of a gas falls when it expands without doing any work. This principle, which became known as the Joule-Thomson effect, underlies the operation of common refrigeration and air conditioning systems. His Scientific Papers were published in two volumes in 1885 and 1887.

The Unit of work or energy, the joule,   J,     a derived Unit is named in his honour.

The joule is the SI unit of work or energy. One joule is defined to be the work done by a force of one newton acting to move an object through a distance of one meter in the direction in which the force is applied.

, Lord William Thomson

William Thomson Kelvin, 1st Baron (1824-1907) British mathematician and physicist, who proposed the absolute scale of temperature was born in Belfast, Ireland.

Lord Kelvin was a professor at the University of Glasgow from 1846 to 1899. In the field of thermodynamics Kelvin developed the work done by the British physicist James Prescott Joule on the interrelation of heat and mechanical energy, and in 1852 they collaborated to investigate the phenomenon that became known as the Joule-Thomson cooling effect. In 1848 Kelvin proposed the absolute scale of temperature.  His work in the field of electricity was of practical importance in telegraphy.
He studied the mathematical theory of cable signaling and devised improvements in the manufacture of cables and in the construction of the mirror galvanometer and the siphon recorder.

With the German physiologist and physicist Hermann Ludwig Ferdinand von Helmholtz, Kelvin estimated the age of the sun and calculated the energy radiated from its surface. Among the devices he invented or improved were a tide predictor, a harmonic analyzer, and an apparatus for taking soundings in shallow and deep waters.

Kelvin was knighted in 1866 and was raised to the peerage with the title of Baron Kelvin of Largs in 1892. He was president of the Royal Society in 1890 and in 1902 received the Order of Merit.

Many of his scientific papers were collected in his Reprint of Papers on Electricity and Magnetism (1872), Mathematical and Physical Papers (1882, 1883, 1890), and Popular Lectures and Addresses (1889-94).

The Unit of thermodynamic temperature, the kelvin,   K,     a Base Unit is named in his honour.

The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water [1967].

, Gustav Robert

Gustav Robert Kirchhoff (1824-1887) German Physicist who postulated two rules, now known as Kirchhoff's laws of networks,  was born in Kenigsberg, East Prussia (now Kaliningrad, Russia).

Kirchhoff was Professor of physics at the universities of Breslau, Heidelberg, and Berlin. With the German chemist Robert Wilhelm Bunsen, Kirchhoff developed the modern spectroscope for chemical analysis. This led to the discovery of cesium in 1860 and rubidium in 1861.  Kirchhoff is also credited with the Kirchhoff's law of radiation.

He is the first to publish a systematic formulation of the principles governing the behaviour of electric circuits which embodied two rules - a current law and a voltage law - known as Kirchhoff's laws of networks.  These together with Ohm's law form the basis of electric circuit theory.

, Pierre Simon, Marquis de

Marquis Pierre Simon de Laplace (1749-1827) French astronomer and mathematician who presented a transform that bears his name was born in Normandy, France.

Laplace was educated at the military school in Beaumont. In 1767 he became professor of mathematics at the ecole Militaire in Paris and in 1785 he was elected to the Academy of Sciences. Laplace's great work was done in developing the mathematical analysis of the system of gravitational astronomy worked out by Sir Isaac Newton. Laplace proved that planetary motions are stable, and that perturbations produced by mutual influence of planets or by external bodies, such as comets, are only temporary. He attempted to give a rational theory of the origin of the solar system in his nebular hypothesis of stellar evolution. In Traite de mecanique celeste (Treatise on Celestial Mechanics, 5 vol., 1799-1825). Laplace systematized all the mathematical work that had been done on gravitation. Exposition du systeme du monde (Explanation of the World System, 1796) contained a summary of the history of astronomy. He also worked on the theory of probabilities in his Theorie analytique des probabilites (Analytical Theory of Probabilities, 1812) and Philosophical Essay on Probabilities (1814; trans. 1905).

He devised the Laplace transform which is the basis of most analysis and design procedures for control analysis.

, Joseph Louis, Comte de

Joseph Louis de Lagrange (1736-1813) French mathematician and astronomer was born in Turin, Italy.

Lagrange was educated at the University of Turin. He was appointed professor of geometry at the Turin military academy at the age of 19, and in 1758 he founded a society that later developed into the Turin Academy of Sciences. In 1766 he was appointed director of the Berlin Academy of Sciences and 20 years later, at the invitation of King Louis XVI of France, went to Paris. During the period of the French Revolution he was in charge of the commission for establishing a new system of weights and measures. He was made professor in the newly established ecole Normale after the French Revolution, and under Napoleon he was made a member of the Senate and given the rank of count.

One of the greatest mathematicians of the 18th century, he created the calculus of variations for dealing with mechanics along with Euler and the Bernoullis, systematized the field of differential equations, and worked on the theory of numbers. He was responsible for laying the groundwork for a different way of writing down Newton's Equations of Motion. This is what has been called Lagrangian Mechanics.

Among his investigations in astronomy were calculations of the libration of the moon and motions of the planets. His greatest work is Mecanique analytique (1788).

, Irving

Irving Langmuir (1881-1957) American chemist and Nobel laureate who is known for his work in theoretical and applied chemistry was born in Brooklyn, New York.

Langmuir was educated at Columbia University and the University of Gettingen. In 1932 he became associate director of the research laboratory of the General Electric Company and served in that capacity until his retirement in 1950. He worked on the development of gas-filled tungsten lamps, electron-discharge apparatus, high-vacuum pumps, and the atomic-hydrogen welding torch. Langmuir and the American chemist Gilbert Lewis developed a theory of chemical attraction and valence based on the structure of the atom, known as the Langmuir-Lewis theory. Langmuir's research in cloud physics led to the artificial stimulation of rainfall by cloud seeding. For his work on monomolecular films and surface chemistry he was awarded the 1932 Nobel Prize in chemistry.

, Heinrich Friedrich Emil

Heinrich Friedrich Emil Lenz (1804 - 1865) Russian Physicist who formulated the Lenz's Law of electromagnetics was born at Dorpat (now Tartu, Estonia).

Lenz was professor at St. Petersburg University. As a geophysical scientist, Lenz accompanied Otto von Kotzebue on his third expedition around the world 1823-26. On his return, Lenz joined the St Petersburg Academy of Science, and from 1840 held posts at the University of St Petersburg. On his voyage with Kotzebue, Lenz studied climatic conditions such as barometric pressure, and made extremely accurate measurements of the salinity, temperature, and specific gravity of sea water. On a later expedition he measured the level of the Caspian Sea.

Lenz's studies of electromagnetism date from 1831. He is known for the formulation of the Lenz's Law (1834). Lenz's law is in fact a special case of the law of conservation of energy. If the induced current were to flow in the opposite direction, it would assist the motion of the magnet or wire and energy would increase without any work being done, which is impossible.

Lenz's Law states that an induced current flows in the direction that tends to oppose the motion producing it.

, Georg Christoph

Georg Christoph Lichtenberg (1742-1799) who was one of the prominent German experimental physicists of his time was born in Darmstadt.

Lichtenberg studied mathematics and natural sciences at the High School from 1763-1766. In 1770 he became a professor of experimental physics at the University of Goettingen. In 1777 he discovered the "Lichtenberg figures". Lichtenberg also worked in the areas of geodesy, meteorology and astronomy.

, Hendrik Antoon

Hendrik Antoon Lorentz (1853-1928) Dutch physicist and Nobel laureate who developed the electromagnetic theory of light was born in Arnhem, The Netherlands.

Lorentz entered the University of Leyden in 1870, after the 5th form and a year of study of the classics. He obtained his B.Sc. degree in mathematics and physics in 1871, and returned to Arnhem in 1872 to become a night-school teacher, at the same time preparing for his doctoral thesis on the reflection and refraction of light. In 1875, at the early age of 22, he obtained his doctor's degree, and only three years later he was appointed to the Chair of Theoretical Physics at Leyden, newly created for him. He developed the electromagnetic theory of light and the electron theory of matter and formulated a consistent theory of electricity, magnetism, and light. With the Irish physicist George Francis Fitzgerald, he formulated a theory on the change in shape of a body resulting from its motion; the effect, known as the Lorentz-Fitzgerald contraction, was one of several important contributions that Lorentz made to the development of the theory of relativity. For his explanation of the phenomenon known as the Zeeman effect, Lorentz shared the 1902 Nobel Prize in physics with the Dutch physicist Pieter Zeeman.

In 1878, he published an essay on the relation between the velocity of light in a medium and the density and composition thereof. The resulting formula, proposed almost simultaneously by the Danish physicist Lorenz, has become known as the Lorenz-Lorentz formula.

Lorentz also made fundamental contributions to the study of the phenomena of moving bodies. In an extensive treatise on the aberration of light and the problems arising in connection with it, he followed A.J. Fresnel's hypothesis of the existence of an immovable ether, which freely penetrates all bodies. This assumption formed the basis of a general theory of the electrical and optical phenomena of moving bodies.

From Lorentz stems the conception of the electron; his view that his minute, electrically charged particle plays a role during electromagnetic phenomena in ponderable matter made it possible to apply the molecular theory to the theory of electricity, and to explain the behaviour of light waves passing through moving, transparent bodies.

The so-called Lorentz transformation (1904) was based on the fact that electromagnetic forces between charges are subject to slight alterations due to their motion, resulting in a minute contraction in the size of moving bodies. It not only adequately explains the apparent absence of the relative motion of the Earth with respect to the ether, as indicated by the experiments of Michelson and Morley, but also paved the way for Einstein's special theory of relativity.

, Guglielmo, Marchese

Marchese Guglielmo Marconi (1874-1937) Italian electrical engineer and Nobel laureate who invented the first practical radio-signaling system was born in Bologna, Italy.

Marconi was educated at the University of Bologna and as early as 1890 he became interested in wireless telegraphy. By 1895 he had developed apparatus with which he succeeded in sending signals to a point a few kilometers away by means of a directional antenna. After patenting his system in Great Britain, he formed (1897) Marconi's Wireless Telegraph Company, Ltd., in London. In 1899 he established communication across the English Channel between England and France, and in 1901 he communicated signals across the Atlantic Ocean between Poldhu, in Cornwall, England, and Saint John's, in Newfoundland, Canada. His system was soon adopted by the British and Italian navies, and by 1907 had been so much improved that transatlantic wireless telegraph service was established for public use. Marconi was awarded honors by many countries and received, jointly with the German physicist Karl Ferdinand Braun, the 1909 Nobel Prize in physics for his work in wireless telegraphy. During World War I he was in charge of the Italian wireless service and developed shortwave transmission as a means of secret communication. In the remaining years of his life he experimented with shortwaves and microwaves.

, James Clerk

James Clerk Maxwell (1831-1879) British physicist who is well-known for his equations on electromagnetic fields was born in Edinburgh Scotland. 

Maxwell was educated at the universities of Edinburgh and Cambridge. He was professor of physics at the University of Aberdeen from 1856 to 1860. In 1871 he became the first professor of experimental physics at Cambridge, where he supervised the construction of the Cavendish laboratory.  Maxwell also developed the kinetic theory of gases, which explains the physical properties and nature of a gas. His other accomplishments include the investigation of color vision and the principles of thermodynamics.

Maxwell expanded on the research that the British scientist Michael Faraday had conducted on electromagnetic fields. Maxwell demonstrated the mathematical relation between electric and magnetic fields. He also showed that light is made up of electromagnetic waves. His greatest work is Treatise on Electricity and Magnetism (1873), in which he first published his set of four differential equations (now known as Maxwell's equations) that describe the nature of electromagnetic fields in terms of space and time.

An older Unit of magnetic flux density, the maxwell   was named in his honour.

The maxwell is a unit of magnetic flux density. One maxwell is equal to the magnetic flux  through one square centimetre normal to a magnetic field of intensity 1 gauss.

, Samuel Finley Breese

Samuel Finley Breese Morse (1791-1872) American artist and inventor who invented the electric telegraph and the Morse code was born in Charlestown, Massachusetts (now part of Boston), USA.

Morse was educated at Yale College (now Yale University) and the Royal Academy of Arts in London. He became a successful portrait painter and sculptor. In 1825 he helped found the National Academy of Design in New York City, and the following year he became the first president of the institution. He continued his painting and became a professor of painting and sculpture at New York University in 1832. About that time he became interested in chemical and electrical experiments and developed apparatus for an electromagnetic telegraph that he completed in 1836. The US Senate gave funds for Morse to construct a telegraph line between Baltimore and Washington. He also invented a code of dots and dashes, now known as the Morse code, for use with his telegraph instrument.

, John

John Napier (1550-1617) Scottish mathematician and inventor of logarithms was born in Merchiston Castle in Edinburgh, Scotland.

Napier was educated at the University of St. Andrews. He became an adherent of the Reformation movement in Scotland while still at college, and in later years he took an active part in Protestant political affairs. He was the author of A Plaine Discovery of the Whole Revelation of Saint John (1593), the first important Scottish interpretation of the Bible.

Napier is best known as the inventor of the first system of logarithms, described in Canonis Descriptio (1614). The common and natural systems of logarithms used today do not employ the same base as Napier's logarithms, although natural logarithms are sometimes called Napierian logarithms. Napier was one of the first, if not the first, to use the decimal point in expressing decimal fractions in a systematic way and according to the modern system of decimal notation. He also invented mechanical systems for performing arithmetical computations, described in Rabdologia (1617).

, Sir Isaac

Sir Isaac Newton (1642-1727) English mathematician and physicist who formulated the law of universal gravitation was born in Woolsthorpe, near Grantham in Lincolnshire, England.

Newton was one of the inventors of the branch of mathematics called calculus. He also solved the mysteries of light and optics, formulated the three laws of motion, and derived from them the law of universal gravitation.

Newton's first achievement was in mathematics. He generalized the methods that were being used to draw tangents to curves and to calculate the area swept by curves, and he recognized that the two procedures were inverse operations. In 1669 Newton was appointed as Lucasian Professor of Mathematics at the University of Cambridge.

Optics was another area of Newton's early interests. In trying to explain how colors occur, he arrived at the idea that sunlight is a heterogeneous blend of different rays. Newton demonstrated his theory of colors by passing a beam of sunlight through a type of prism, which split the beam into separate colors. In 1704, however, Newton published Opticks, which explained his theories in detail.

Newton is probably best known for discovering universal gravitation, which explains that all bodies in space and on earth are affected by the force called gravity. He published this theory in his book Philosophiae Naturalis Principia Mathematica in 1687.

The Unit of force, the newton,   N,     a derived Unit is named in his honour.

The newton is the SI unit of force. One newton is equal to the force required to accelerate a body with the mass one kilogram by one metre per second per second.

, Edward Lawry

Edward Lawry Norton (1898-1983) American electrical engineer for whom the Norton equivalent circuit is named was born in Rockland, Maine.

Norton served as a radio operator in the U.S Navy between 1917 and 1919. He attended the University of Maine for one year before and for one year after his wartime service, then transferred to M.I.T. in 1920, receiving his B.S. degree (electrical engineering) in 1922. He started work in 1922 at the Western Electric Corporation in New York City, which eventually became Bell Laboratories in 1925. While working for Western Electric, he earned a M.A. degree in electrical engineering from Columbia University in 1925.

Among his publications are Constant resistance networks with applications to filter groups in the Bell System Technical Journal, Magnetic fluxmeter in the Bell Laboratories Record and Dynamic measurements on electromagnetic devices in the Transactions of the AIEE.

The Norton's equivalent circuit is named after him.

, Harry

Harry Nyquist (1889-1976) Swedish electrical engineer who developed the Nyquist diagram for determining the stability of feedback systems was born in Nilsby, Sweden.

Nyquist attended the University of North Dakota, Grand Forks, and received the B.S. and M.S. degrees in electrical engineering in 1914 and 1915, respectively. He attended Yale University, New Haven, Conn., and was awarded the Ph.D. degree in 1917.

From 1917 to 1934 Nyquist was employed by the American Telephone and Telegraph Company in the Department of Development and Research Transmission, where he was concerned with studies on telegraph picture and voice transmission. From 1934 to 1954 he was with the Bell Telephone Laboratories, Inc. where he received 138 U. S. patents and published twelve technical articles. His many important contributions to the radio art include the first quantitative explanation of thermal noise, signal transmission studies which laid the foundation for modern information theory and data transmission, the invention of the vestigial sideband transmission system now widely-used in television broadcasting, and the well-known Nyquist diagram for determining the stability of feedback systems.

Nyquist received many honors for his outstanding work in communications. He was the fourth person to receive the National Academy of Engineer's Founder's Medal, "in recognition of his many fundamental contributions to engineering." In 1960, he received and the IRE Medal of Honor eFor fundamental contributions to a quantitative understanding of thermal noise, data transmission and negative feedback." Nyquist was also awarded the Stuart Ballantine Medal of the Franklin Institute in 1960, and the Mervin J. Kelly award in 1961.

, Hans Christian

Hans Christian Oersted (1777-1851) Danish physicist and chemist who discovered that a magnetic needle is deflected at right angles to a wire carrying an electric current was born in Rudkebing.

Oersted was educated at the University of Copenhagen and was appointed professor of physics at the University of Copenhagen in 1806. In 1819 he discovered that a magnetic needle is deflected at right angles to a wire carrying an electric current, thus confirming the relationship of electricity and magnetism. He was also the first to isolate (1825) aluminum. His Manual of Mechanical Physics appeared in 1844.

An older Unit of magnetic field intensity, in the c.g.s. electromagnetic units, the oersted   was named in his honour.

The oersted is a unit of magnetic field strength. One oersted is the force in dynes which a unit magnetic pole would experience at any point in a magnetic field.

, Georg Simon

Georg Simon Ohm (1787-1854) German Physicist, who formulated  Ohm's law was born in Erlangen, Bavaria.

Ohm was director of the Polytechnic Institute of Nuremberg from 1833 to 1849, and from then onwards he was the Professor of experimental physics at the University of Munich. He formulated the relationship between current, electromotive force, and resistance, known as Ohm's law (1826). He was awarded the Copley Medal in 1841 by the Royal Society of London.

The Unit of electric potential, the ohm,   W,     a derived Unit is named in his honour.

The ohm is the SI unit of electric resistance. One ohm is equal to the electric resistance between two points of a conductor when a constant potential difference of 1 V, applied to these points, produces in the conductor a current of 1 A, the conductor not being the seat of any electromotive force.

, Blaise

Blaise Pascal (1623-62) French philosopher, mathematician, and physicist who derived the Pascal's law of fluid pressure transmission was born in Clermont-Ferrand, France.

Pascal proved himself a mathematical prodigy, and at the age of 16 he formulated one of the basic theorems of projective geometry, known as Pascal's theorem and described in his Essai pour les coniques (Essay on Conics, 1639). In 1642 he invented the first mechanical adding machine. Pascal proved by experimentation in 1648 that the level of the mercury column in a barometer is determined by an increase or decrease in the surrounding atmospheric pressure rather than by a vacuum, as previously believed. This discovery verified the hypothesis of the Italian physicist Evangelista Torricelli concerning the effect of atmospheric pressure on the equilibrium of liquids. Six years later, in conjunction with the French mathematician Pierre de Fermat, Pascal formulated the mathematical theory of probability, which has become important in such fields as actuarial, mathematical, and social statistics and as a fundamental element in the calculations of modern theoretical physics. Pascal's other important scientific contributions include the derivation of Pascal's law or principle, which states that fluids transmit pressures equally in all directions, and his investigations in the geometry of infinitesimals.

The Unit of pressure, the pascal,   Pa,     a derived Unit is named in his honour.

The pascal is the SI unit of pressure. One pascal is equal to the force of one newton exerted on one square meter.

, Max Karl Ernst Ludwing

Max Karl Ernst Ludwing Planck (1858-1947) German physicist and Nobel laureate who was the originator of the quantum theory was born in Kiel.

Planck was educated at the universities of Munich and Berlin. He was appointed professor of physics at the University of Kiel in 1885, and from 1889 until 1928 filled the same position at the University of Berlin. In 1900 Planck postulated that energy is radiated in small, discrete units, which he called quanta. Developing his quantum theory further, he discovered a universal constant of nature, which came to be known as Planck's constant. His discoveries did not, however, supersede the theory that radiation from light or matter is emitted in waves.

Planck received many honors for his work, notably the 1918 Nobel Prize in physics. In 1930 Planck was elected president of the Kaiser Wilhelm Society for the Advancement of Science, the leading association of German scientists, which was later renamed the Max Planck Society. He endangered himself by openly criticizing the Nazi regime that came to power in Germany in 1933 and was forced out of the society, but became president again after World War II.

Among his writings that have been translated into English are Introduction to Theoretical Physics (5 vol., 1932-33) and Philosophy of Physics (1936).

Planck's law states that the energy of each quantum is equal to the frequency of the radiation multiplied by the universal constant.

, John William Strutt, 3rd Baron

John William Strutt Rayleigh, 3rd Baron (1842-1919) British mathematician, physicist, and Nobel laureate who was responsible for the determination of electrical units of measurement. was born in Lanford Grove, near Maldon, England.

Rayleigh was educated at the University of Cambridge. He served as professor of experimental physics and director of the Cavendish Laboratory at Cambridge from 1879 to 1884 and as professor of natural philosophy at the Royal Institution, London, from 1887 to 1905. He became chancellor of Cambridge in 1908.

Rayleigh engaged in research into physical optics, light, color, and electricity and the dynamics of resonance and vibrations of gas and elastic solids. He was also responsible for the determination of electrical units of measurement. Rayleigh was awarded the 1904 Nobel Prize in physics.

He derived an equation to account for the variation of light-scattering with wavelength. He also developed an equation describing the distribution of wavelengths in blackbody radiation, but it applied only to long wavelengths.

, Owen Willans

Owen Willans Richardson (1879-1959) British Scientist and Nobel laureate, well known for his work on thermionics was born at Dewsbury, Yorkshire, England.

Richardson was educated at Batley Grammar School and proceeded to Cambridge in 1897. Having obtained an Entrance Major Scholarship at Trinity College, he gained First Class Honours in Natural Science at the examinations of the Universities of Cambridge and London, with particular distinctions in Physics and Chemistry. After graduating at Cambridge in 1900, he began to investigate the emission of electricity from hot bodies at the Cavendish Laboratory. In 1902 he was elected a Fellow of Trinity College, Cambridge. The law for the discovery of which the Nobel Prize was specially given, was first announced by him in a paper read before the Cambridge Philosophical Society in November 1901. He was appointed Professor of Physics at Princeton University in America, where he remained until the end of 1913, working at thermionic emission, photoelectric action, and the gyromagnetic effect. In 1911 he was elected a member of the American Philosophical Society, and in 1913 a Fellow of the Royal Society, whereupon (1914) he returned to England as Wheatstone Professor of Physics at King's College in the University of London. Among his publications are: The Electron Theory of Matter in 1914, The Emission of Electricity from Hot Bodies in 1916, Molecular Hydrogen and its Spectrum in 1934.

He was awarded the Hughes Medal by the Royal Society (1920), especially for work on thermionics.  He was appointed Yarrow Research Professor of the Royal Society, London (1926-1944), and knighted in 1939. He received honorary degrees from the Universities of St. Andrews, Leeds, and London.

, Wilhelm Conrad

Wilhelm Conrad Rontgen (1845-1923) German physicist and Nobel laureate who discovered X rays was born in Lennep (now part of Remscheid, Germany).

Rontgen was educated at the University of Zerich. In November 1895 he read before the Physico-Medical Society of Werzburg a paper reporting his discovery of short-wave radiations that he called X rays. Subsequently these rays were given his name, but Rontgen rays are still popularly known as X rays. Among many honors for his great discovery, which revolutionized physics and medicine, he received the Rumford Medal of the Royal Society of London in 1896, and the first Nobel Prize in physics in 1901. He also made discoveries in mechanics, heat, and electricity.

, Claude Elwood

Claude Elwood Shannon (1916- ) American applied mathematician and electrical engineer, noted for his development of information theory was born in Gaylord, Michigan.

Shannon attended the University of Michigan and in 1940 obtained his doctorate from the Massachusetts Institute of Technology, where he became a faculty member in 1956 after working at Bell Telephone Laboratories. In 1948 Shannon published "The Mathematical Theory of Communication" an article in which he presented his initial concept for a unifying theory of the transmitting and processing of information. Information in this context includes all forms of transmitted messages, including those sent along the nerve networks of living organisms; information theory is now important in many fields.

, Ernest, 1st Baron of Nelson and Cambridge

Baron Ernest Rutherford of Nelson and Cambridge (1871-1937) British physicist and Nobel laureate who developed the theory of the structure of the atom, was born in Nelson, New Zealand.

Rutherford was educated at the University of New Zealand and the University of Cambridge. He was professor of physics at McGill University in Montreal, Quebec, from 1898 to 1907 and at the University of Manchester in England during the following 12 years. After 1919 he was professor of experimental physics and director of the Cavendish Laboratory at the University of Cambridge and also held a professorship, after 1920, at the Royal Institution of Great Britain in London.

Rutherford was one of the first and most important researchers in nuclear physics. Soon after the discovery of radioactivity in 1896 by the French physicist Antoine Henri Becquerel, Rutherford identified the three main components of radiation and named them alpha, beta, and gamma rays. He also showed that alpha particles are helium nuclei. His study of radiation led to his formulation of a theory of atomic structure, which was the first to describe the atom as a dense nucleus about which electrons circulate in orbits.

In 1919 Rutherford conducted an important experiment in nuclear physics when he bombarded nitrogen gas with alpha particles and obtained atoms of an oxygen isotope and protons. This transmutation of nitrogen into oxygen was the first artificially induced nuclear reaction. It inspired the intensive research of later scientists on other nuclear transformations and on the nature and properties of radiation. Rutherford and the British physicist Frederick Soddy developed the explanation of radioactivity that scientists accept today.

Rutherford was elected a fellow of the Royal Society in 1903 and served as president of that institution from 1925 to 1930. He was awarded the 1908 Nobel Prize in chemistry, was knighted in 1914, and was made a baron in 1931.

His writings include Radioactivity (1904); Radiations from Radioactive Substances (1930), which he wrote with British physicists Sir James Chadwick and Charles Drummond Ellis, and The Newer Alchemy (1937).

The rutherford, a unit of radioactivity was named in his honor.

, Erwin

Erwin Schrodinger (1887-1961) Austrian physicist and Nobel laureate best known for his mathematical studies of the wave mechanics of orbiting electrons was born in Vienna.

Schrodinger was educated at the University of Vienna. He taught physics at the universities of Stuttgart, Germany; Breslau, Poland; Zerich, Switzerland; Berlin, Germany; Oxford, England; and Graz, Austria. He was director of the school of theoretical physics of the Institute of Advanced Study in Dublin, Ireland, from 1940 until his retirement in 1955. Schredinger's most important contribution to the understanding of the atom was his development of an elegant and rigorous mathematical description of the discrete standing waves that electrons must follow in their orbits around atomic nuclei (Schrodinger's equation). Schredinger proved that his theory, published in 1926, was mathematically equivalent to the theories of matrix mechanics advanced the previous year by the German physicist Werner Heisenberg. Together, their theories formed much of the foundation of quantum mechanics. Schredinger shared the 1933 Nobel Prize in physics with the British physicist Paul A. M. Dirac for his contribution to the development of quantum mechanics. His research included important work on atomic spectra, statistical thermodynamics, and wave mechanics. 

Schredinger's books include Collected Papers on Wave Mechanics (1928), Modern Atomic Theory (1934), Statistical Thermodynamics (1945), and Expanding Universes (1956).

, Walter

Walter Schottky (1886-1976) German physicist whose research in solid-state physics and electronics yielded many effects and devices was born in Zurich, Switzerland.

Schottky entered the Humboldt University in Berlin in 1904, where he studied physics. In 1912, he was awarded a doctorate in Berlin for his thesis on the Special Theory of Relativity, which Albert Einstein had announced only seven years earlier. Schottky's tutor was Max Planck, the originator of the Quantum Theory and a man at the heart of modern physics. After receiving his Ph.D., Schottky moved to Jena, Germany, where he worked under Max Wien. It was here that he turned away from relativity theory and began what would become his life's work- the interaction of electrons and ions in vacuum and solid bodies. His research in solid-state physics and electronics yielded many effects and devices that now bear his name (Schottky effect, Schottky barrier, Schottky diode)

, Ernst Werner von

Ernst Werner von Siemens  (1816e1892) German electrical engineer and inventor who was a co-inventor of an electroplating process was born in Lenthe, Germany.

Siemens was co-inventor of an electroplating process (1841), and alone developed an electric dynamo. He laid the first telegraph line and built the first electric railway in Germany and, with his brother Sir William Siemens, developed (1866) a widely used process of steelmaking. In 1884 he founded a research laboratory at Charlottenburg and  was a founder and director of Siemens and Halske.

The Unit of electric conductance, the siemens,   S,     a derived Unit is named in his honour.

The siemens is the SI unit of electric conductance. One siemens is equal to the conductance between two points of a conductor having a resistance of 1 . siemens is the reciprocal of the ohm.

, William Bradford

William Bradford Shockley (1910 - 1989) American physicist, Nobel laureate who was the co-inventor of the transistor was born in London.

Shockley worked at Bell Telephone Laboratories from 1936 to 1956, when he became director of the Shockley Transistor Corp. in Palo Alto, California. He lectured at Stanford University beginning in 1958 and became professor of engineering science in 1963. His research on semiconductors led to the development of the transistor in 1948. For this research he shared the 1956 Nobel Prize in physics with his associates John Bardeen and Walter H. Brattain.

, William

William Stanley (1858-1916) American Engineer who discovered that a parallel circuit was inherently self-regulating was born in Brooklyn, New York.

Stanley attended schools in Great Barrington and in Bridgeport, Connecticut. He attended the Williston Academy in East Hampton, Massachusetts, graduating in 1877.  In 1880 Stanley went to work as an assistant to inventor Hiram Maxim at the United States Electric Company, a manufacturer of electric lamps. Two years later he worked for Swan Electric Company of Boston. 1883 to 1884 was spent in a private laboratory in Englewood, New Jersey.

Stanley held ten patents pertaining to the electric lamp and its manufacture by 1885. On the strength of the background of this work, in 1884 he was contracted by H. H. Westinghouse to develop a lamp manufacturing facility at Westinghouse's Pittsburgh plant. While working for Westinghouse, Stanley had access to the British Gaulard & Gibbs system of induction coils on which Westinghouse had taken an option. Stanley recognized the weakness of the Gaulard & Gibbs system as not being self-regulating, because its induction coils were wired in series. Using a parallel circuit allowed the potential (voltage) to be constant and inherently self-regulating. His discovery of this effect appears in a notebook entry of September 18, 1883. Powered by a 25 h.p. Westinghouse automatic steam engine and energized by a 500 volt Siemens alternator, Stanley wired a system to transmit current at 500 V along two wires the length of Main Street. Voltages were reduced to 100 V by Stanley's "exhorter," or transformers, to power incandescent lamps of 16, 50, & 150 candle power in the businesses of 25 subscribers. The system was tried on March 6th, 1886, and officially tested on March 16th, 1886 and was an instant success. 

In 1890 Stanley decided to sever his ties with Westinghouse. With John Kelley and Cummings C. Chesnay, Stanley formed the Stanley Manufacturing Company, and focused on the area he had pioneered: transformers. The company soon was involved in the biggest power-transmissions jobs in California, and by the late 1890s it had become a valuable and profitable business.

The American Institute of Electrical Engineers (AIEE) meeting in Pittsfield in 1911 made Stanley the guest of honor to mark the 25th anniversary of the development of the alternating current system. He was awarded the AIEE Edison Medal in 1912, "For meritorious achievement in invention and development of alternating current systems and apparatus."

, Charles Proteus

Charles Proteus Steinmetz (1865-1923) German-Austrian-American electrical engineer and inventor, introduced the phasor method in alternating current theory, was born in Breslau, Germany (now Wroclaw, Poland).

Steinmetz was initially named Karl August Rudolf Steinmetz. Forced to leave Germany because of his socialist activities. In 1889 he immigrated to the U.S. and four years later he was appointed consulting engineer of the General Electric Company. In 1902 he became professor of electrophysics at Union College and University, Schenectady, New York, thereafter serving in both positions. Steinmetz is best known for his research in the field of electricity, particularly on the nature and use of alternating current. He also introduced the phasor method in alternating current theory. His work contributed greatly to the utilization of electricity as a source of power and light in industry. Among his many inventions is the metallic electrode arc lamp. In 1901 he became the president of the American Institute of Electrical Engineers (now known as IEEE).

The steinmetz constant is named in his honour.

, Sir Joseph Wilson

Sir Joseph Wilson Swan (1828 - 1914) chemist, physicist, and inventor who invented a carbon filament incandescent lamp was born in Sunderland, England.

Swan was a particularly inquisitive child interested in creative endeavors.  He began an apprenticeship with a pharmacist when he was 13. Afterwards, he began as an assistant in a firm of manufacturing chemists, in which he worked his way up, eventually becoming a partner.

The chemical company that employed Swan, among other goods and services, produced photographic plates, which led Swan to some of his most impressive scientific innovations. In 1862, he patented the first commercially feasible procedure for carbon printing in photography. Then, having observed that heat increases the sensitivity of silver bromide emulsions, Swan invented the dry plate in 1871, followed by the development of bromide photographic paper in 1879.

Beginning in the 1840s Swan undertook his most important studies. It was at this time that he began his experiments with incandescence for illumination purposes. It was not until 1860, however, that Swan received a patent for a carbon filament incandescent lamp, which operated in a partial vacuum. The most significant feature of Swan's lamp was that it lacked enough residual oxygen in the vacuum tube to ignite the filament, thus allowing the tungsten to glow almost white-hot without catching fire. Swan's first electric lamps did not provide a significant amount of illumination and required a battery source to be located close to the light source. These limitations compromised the practicality of his invention until 1879 when Swan was able to demonstrate an advanced light bulb in Britain.

While searching for a better filament for his light bulb, Swan inadvertently made another advance. He developed and patented a process for squeezing nitro-cellulose through holes to form fibers. His newly established Swan Electric Company, which by merger was to become the Edison and Swan United Company, used the cellulose filaments in their bulbs.

Swan was elected to the Royal Society in 1894 and was president of the Institution of Electrical Engineers from 1898 to 1899. He also served as president of the Society of Chemical Industry in 1901, the same year he was awarded an honorary doctorate degree from Durham University. Knighted in 1904.

, Nikola

Nikola Tesla (1856-1943) Croatian-American electrical engineer and inventor recognized as the inventor of the first induction motor, was born in Smiljan, Croatia.

Tesla designed the first practical system of generating and transmitting alternating current for electric power in 1888 . The American rights to this epoch-making invention were bought by the American inventor George Westinghouse, who demonstrated (1893) the system for the first time at the World's Columbian Exposition in Chicago. Tesla had an intuitive way of sensing scientific secrets, and using his inventive talents to prove and apply his hypotheses. After seeing the Gramme dynamo (which, operated in one direction is a generator, and when reversed, is an electric motor), Tesla visualized a rotating magnetic field, and then developed plans for an induction motor applying the concept. The polyphase induction motor developed in 1883 would become the first step toward the successful use of alternating-current.  Tesla's alternating-current motors were installed at the Niagara Falls power project.

Tesla's many inventions include high-frequency generators (1890) and the Tesla coil (1891) and a transformer with important applications in the field of radio communications.

The Unit of magnetic flux density, the tesla,   T,     a derived Unit is named in his honour.

The tesla is the SI unit of magnetic flux density. One tesla is defined as the field intensity generating one newton of force per ampere of current per meter of conductor.

of Miletus

Thales (approx 625-546 BC) Greek philosopher was born in Miletus, Asia Minor.

Thales was the founder of Greek philosophy, and was considered one of the Seven Wise Men of Greece. Thales became famed for his knowledge of astronomy after predicting the eclipse of the sun that occurred on May 28, 585 BC. He is also said to have introduced geometry in Greece. According to Thales, the original principle of all things is water, from which everything proceeds and into which everything is again resolved. Before Thales, explanations of the universe were mythological, and his concentration on the basic physical substance of the world marks the birth of scientific thought. He is also thought to have been the first to have thought of a force between bodies charged with static electricity. Thales left no writings - knowledge of him is derived from an account in Aristotle's Metaphysics.

, Leon-Charles

Leon-Charles Thevenin (1857-1926) French telegraph engineer who extended Ohmes Law to the analysis of complex electrical circuits was born in Paris, France.

Thevenin graduated from the Ecole Polytechnique in Paris in 1876. In 1878 joined the corps of Telegraph Engineers ( which subsequently became the French PTT ).There he initially worked on the development of long-distance underground telegraph lines. Appointed a teaching inspector at the Ecole Superisure in 1882, he became increasingly interested in the problems of measurement in electrical circuits. As a result of studying Kirchhoff s Law, which were essentially derived from Ohmes Law, he developed his now- famous theorem - Thevenin's Theorem - which made it possible to calculate the currents in more complex electrical circuits. As well as becoming Head of the Bureau des Lignes, he also found time for teaching other subjects outside the Ecole, including a course in mechanics at the Institut National Agronomique. In 1896 he was appointed Director of the Telegraph Engineering School, then ,in 1901, Engineer-in-Chief of the telegraph workshops.

, Evangelista

Evangelista Torricelli (1608-47) Italian  mathematician and physicist who constructed the first mercury barometer was born in Faenza, Italy.

He educated at the  Collegio diSapienza in Rome and was secretary and companion of Galileo during the last three months of his life in 1641-1642.  Torricelli succeeded him as professor of philosophy and mathematics at the Florentine Academy. In investigating vacuums, he  constructed the first mercury barometer in 1643. He correctly attributed the fact that the height of the mercury was only 1/14 that of a water barometer to the fact that mercury is fourteen times as dense as water. He also noticed that the level of mercury varied from day to day, and observed that the space above the mercury in the barometer must contain a vacuum.

Torricelli also developed the concepts of momentum and impetus, and solved Fermat's triangle problem for the Torricelli point.

The unit of measuring pressure torr is named in his honor. 

, Alan Mathison

Alan Mathison Turing (1912-1954) British mathematician who pioneered in computer theory was born in London.

Turin was educated at Cambridge and Princeton universities. In 1936, while he was still a graduate student, Turing published a paper called "On Computable Numbers," which introduced the concept of a theoretical computing device now known as a Turing machine. The concept of this machine, which could theoretically perform any mathematical calculation, was important in the development of the digital computer. Turing also extended his mathematical work to the study of artificial intelligence and biological forms. He proposed a method called the Turing test, to determine whether machines could have the ability to think. During World War II (1939-1945), Turing worked as a cryptographer for the British Foreign Office. In 1951 Turing was named a Fellow of the Royal Society and in 1952 he began to publish his work on the mathematical aspects of pattern and form development in living organisms.

, Robert J.

Robert J. Van de Graaff (1901 - 1967) American engineer developed a particle accelerator for sub-atomic particles.

Van de Graaff, after a study of some years in Paris, where he attended the conferences of Marie Curie, dedicated his research to the Field of the Atomic Physics. Working in the University of Oxford, Van de Graaff felt the necessity to develop a subatomic particle source of high energy. He created the particle accelerator that received his name. It found wide application, not only in the Atomic Physics but also in Medicine and Industry.

Van de Graaff, who was a professor at MIT, originally built the generator to be used as a research tool in early atom-smashing and high energy X-ray experiments. As newer methods of atomic acceleration became available, the machine was used for instructional purposes only. Finally, it was donated to the Museum, where it now stands on public display.

In the Van de Graaff generator, an engine puts into motion an isolating leather strap that passes over two pulleys. Through metallic tips the leather strap receives electric charges from a high-voltage generator. The electrified leather strap carries charges until the interior of the metallic sphere, where they are collected by metallic and lead tips for the external surface of the sphere. The sphere can reach a potential of up to 10 million volts, in the case of the generators used for experiences of atomic Physics.

, Count Alessandro Antonio

Count Alessandro Antonio Volta (1745-1827) Italian Physicist who developed the voltaic pile, the forerunner of the electric battery was born in Como, Italy.

Volta became Professor of physics at the Royal School in Como in 1774.  In 1776-77 he applied himself to chemistry, studying atmospheric electricity and devising experiments such as the ignition of gases by an electric spark in a closed vessel. In 1779 became Professor of physics at the University of Pavia, a chair he occupied for 25 years. In 1799 he developed the voltaic pile, the forerunner of the electric battery, which provided the first continuous flow of electricity. The publication of his work in 1800 marked the beginning of electric circuit theory.

The Unit of electric potential, the volt,   V,     a derived Unit is named in his honour.

The volt is the SI unit of electric potential. One volt is equal to the potential difference between two points of a conducting wire carrying a constant current of 1 A, when the power dissipated between these points is equal to 1 W.

, Ernest Thomas Sinton

Ernest Thomas Sinton Walton (1903-1995) British Physicist was born at Dungarvan, County Waterford, Ireland.

Walton was the son of a Methodist Minister from County Tipperary and the ministry demanded that his father move from place to place every few years. In 1915 he was sent as a boarder to the Methodist College, Belfast, where he excelled in mathematics and science, and in 1922 he entered Trinity College, Dublin , on a scholarship. He read the honours courses in both mathematics and experimental science, specializing in physics, and graduated in 1926 with first class honours in both subjects. He received his M.Sc. degree in 1927.

In 1927, he was awarded a Research Scholarship by the Royal Commissioners for the Exhibition of 1851 and he went to Cambridge University to work in the Cavendish Laboratory under Lord Rutherford. He continued at Cambridge after receiving a senior research award of the Department of Scientific and Industrial Research in 1930, and received his Ph.D. in 1931. Walton was Clerk Maxwell Scholar from 1932 to 1934 when he returned to Trinity College, Dublin, as Fellow. He was appointed Erasmus Smith's Professor of Natural and Experimental Philosophy in 1946, and in 1960 he was elected Senior Fellow of Trinity College.

Prof. Walton's first researches involved theoretical and experimental studies in hydrodynamics and, at the Cavendish Laboratory. He worked on indirect methods for producing fast particles, working on the linear accelerator and on what was later to become known as the betatron. He followed this with work on the direct method of producing fast particles by the use of high voltages this work being done jointly with J.D. Cockcroft. A suitable apparatus was built which made it possible to show that various light elements could be disintegrated by bombardment with fast protons Cockroft Walton accelerator. They were directly responsible for disintegrating the nucleus of the lithium atom by bombardment with accelerated protons, and for identifying the products as helium nuclei.

Prof. Walton has taken part in many activities outside his academic work, and he has served on committees connected with the Dublin Institute for Advanced Studies, the Institute for Industrial Research and Standards, the Royal City of Dublin Hospital, the Royal Irish Academy, the Royal Dublin Society, Wesley College, Dublin, and many government and church committees.

He has had numerous scientific papers published in the journals of learned societies, particularly on the subjects of hydrodynamics, nuclear physics, and microwaves.

He was awarded the Hughes Medal, jointly with Sir John Cockcroft, by the Royal Society of London in 1938, and in 1959 he received an honorary Doctor of Science degree from Queen's University, Belfast.

, James

James Watt (1736-1819) Scottish inventor and mechanical engineer, renowned for his improvements of the steam engine was born in Greenock, Scotland.

Watt worked as a mathematical-instrument maker from the age of 19 and soon became interested in improving the steam engines, invented by the English engineers Thomas Savery and Thomas Newcomen, which were used at the time to pump water from mines. Watt determined the properties of steam, especially the relation of its density to its temperature and pressure, and designed a separate condensing chamber for the steam engine that prevented enormous losses of steam in the cylinder and enhanced the vacuum conditions. Watt's first patent, in 1769, covered this device and other improvements on Newcomen's engine, such as steam-jacketing, oil lubrication, and insulation of the cylinder in order to maintain the high temperatures necessary for maximum efficiency. The misconception that Watt was the actual inventor of the steam engine arose from the fundamental nature of his contributions to its development. The centrifugal or flyball governor, which he invented in 1788, and which automatically regulated the speed of an engine, is of particular interest today. It embodies the feedback principle of a servomechanism, linking output to input, which is the basic concept of automation. Watt was also a renowned civil engineer, making several surveys of canal routes. He invented, in 1767, an attachment that adapted telescopes for use in measurement of distances.

The Unit of power, the watt,   W,     a derived Unit is named in his honour.

The watt is the SI unit of power. One watt is equal to a power rate of one joule of work per second of time.

, Wilhelm Eduard

Wilhelm Eduard Weber (1804-1891) German physicist who invented the electrodynamometer for absolute measurements, was born in in Wittenberg, Germany.

Weber was elected to the physics chair at the University of Leipzig in 1843.  In 1849 he returned to  Gettingen and became the director of the astronomical observatory where in 1833 he collaborated with Gauss in the study of geomagnetism and connected their two laboratories with an electric telegraph-one of the earliest recorded uses of telegraphic communication. At Leipzig he developed several instruments for measuring electric current, in particular his electrodynamometer for absolute measurements. His most important work was done at Leipzig where, with German physicist Friedrich Wilhelm Kohlrausch, he determined the ratio of the electrostatic and electrodynamic units of charge (Weber's constant). This constant turned out to be the velocity of light and was later used by British physicist James Clerk Maxwell to support his electromagnetic theory.

The Unit of magnetic flux, the weber,   Wb,     a derived Unit is named in his honour.

The weber is the SI unit of magnetic flux. One weber is equal to the magnetic flux which, linking a circuit of one turn, would produce in it an electromotive force of 1 V if it were reduced to zero at a uniform rate of 1 s.

, George

George Westinghouse (1846-1914) American inventor, engineer, and industrialist who was a pioneer in the use of alternating-current power in the U.S. was born in Central Bridge, New York.

Westinghouse was educated at what is now Union College and the University at Schenectady, New York. His first important invention, developed while he was employed in his father's factory in Schenectady, was a "railway frog", a device permitting trains to cross from one track to another. He devised his most famous invention, the air brake, about 1868. Although successfully demonstrated in 1868, the air brake did not become standard equipment until after the passage of the Railroad Safety Appliance Act in 1893.

Westinghouse invented many other safety devices, especially for automatic railway signaling. He also developed a system for transporting natural gas and acquired more than 400 patents, including many for alternating-current machinery. With Charles Steinmetz, he pioneered in the use of alternating-current power in the U.S.

, Sir Charles

Sir Charles Wheatstone (1802-75) British physicist and inventor who used the Wheatstone bridge to measure resistance in electric circuits was born in Gloucester, England.

Wheatstone was apprenticed in 1816 to his uncle, a musical-instrument maker in London. In 1823 he inherited the business, and in 1827 he invented micophone and in 1829 the concertina (Accordion). Self-educated in science, in 1834 he was appointed professor of experimental philosophy at the University of London, and in 1837, with the British electrical engineer Sir William Fothergill Cooke, he patented the first British electric telegraph. The electrical instrument known as the Wheatstone bridge, although invented by the British scientist Samuel Hunter Christie, bears his name because he was the first to apply it for measuring resistance in electric circuits. Wheatstone also invented (1838) the stereoscope. He was knighted in 1868.

, Devapura Jayasena

Devapura Jayasena Wimalasurendra (1874-1953) the Father of Hydropower Development in Sri Lanka was born in Galle on September 17, 1874

D. J. Wimalasurendra was the eldest son of a master craftsman Mudaliyar Don Juan Wimalasurendra of Galle. He had his early education at Ananda College, Colombo and continued his studies at the Ceylon Technical College and the Faraday House in London. He joined the Public Works Department (PWD) as a head overseer (this was usual those days) and subsequently as Junior Engineer.  Wimalasurendra's interest in Hydro Power development dates back to 1901, when he was sent to Kelani Valley as a Junior Assistant Engineer to prospect for minerals. He not only identified mineral deposits but also potential and profitable resources such as water and forests, in particular the beautiful Laxapana Falls, the cascading water of which he described as 'white coal'. From the day he saw Laxapana, his interest was to harness it and other falls for generation of hydro electricity. He obtained Corporate membership of the Institution of Electrical Engineers and the Institution of Civil Engineers of United Kingdom.

Wimalasurendra was responsible for designing the "looping the loop" railway track at Ella railway station, which still remains as an edifice for his creativity. In 1913 he was involved in the construction of the first ever, small hydro electric power station at Blackpool to supply electricity to Nuwara Eliya town, using the town water supply scheme.

In 1918, Wimalasurendra read a paper titled "Economics of Power Utilization in Ceylon" to the Engineering Association (now the Institution of Engineers, Sri Lanka) wherein he argued the case for the development of hydro potential of the country. He estimated that 114.5 MW could be developed from Kehelgamuwa Oya. The engineering fraternity, who were essentially Englishmen at that time were sceptic of the whole project. Besides they wondered what the country would do with 114.5 MW of power. He countered them and pointed out the need for cheap power for setting up heavy industries for the development of the country. This included the electrification a section of the railway.

In 1923, the government accepted the proposal for constructing a hydro-electric project and the PWD were entrusted with the work sidetracking Wimalasurendra. Bitter about the treatment meted out to him, he went on long leave to England and returned to the island only at the request of the Colonial Secretary. In 1926, he was appointed the Chief Engineer of the PWD. He recommended the separation of the electrical section of the PWD and nationalization of the Colombo electricity scheme, established in 1918 by Boustead Brothers. He also recommended the installation of thermal plant. The Department of Government Electrical Undertaking (DGEU) was established in 1927 and the Colombo Electricity scheme was vested in it. A thermal power station on the banks of Dematagoda ela was commissioned in 1929 and named after the then Governor, Sir Stanley.

His mission unaccomplished, and his pet project muddled, Wimalasurendra retired from public service in 1930 as a frustrated man. The defiant and indefatigable Wimalasurendra, successfully contested for the State Council from Ratnapura. With courage of conviction he fought for the speedy implementation of the hydro-electric scheme. In 1933 he proposed the setting up of a "Central Electricity Authority". In 1935, the State Council passed the "Electricity Board Establishment Ordinance No. 38 of 1935. Alas his happiness was short lived as the Board was dissolved in 1937 and DGEU was re-established. With all his efforts, the scheme on which work was started in 1923 was completed only in 1950.

"Although it was not my fortune to execute the scheme I have originated, I am happy that I lived to see it brought to fruition by my countrymen, and that I should have, in the evening of my life, able to see in reality the dawn which I saw in the mind's eye over half a century ago. Now, if I leave this world, I leave fulfilled" were the frustrated but joyous words uttered by late D. J. Wimalasurendra,  when in 1950 he visited the Hydro Electric Scheme stage 1 works. 

The Wimalasurendra Power Station is named in his honor.

His contributions at the State Council ranged from suggestions on Technical Education to Industrialization. He was not a politician with greed for power, nor was he guided by any political or economic dogmas, but acted on his convictions. He is an engineer par excellence, committed to the upliftment of the society in which he lived. That was his only goal.  D.J. Wimalasurendra was a devout Buddhist and very close to his heart was the designing of the golden pinnacle of Dutugemunu's Ruwanweli Maha Seya, a great honour that was accorded to him by the State and one which he cherished more than anything else.

, Karoly

Karoly Zipernowsky (1853-1942), Austrian electrical engineer who invented a transformer together with his colleagues was born in Wien, Austria.

 Zipernowsky received his primary education at the Piarist grammar school in Pest, but he did not make his way directly towards the Technical University. He came to the idea of becoming an engineer during his pharmacist years in Kecskemet. Having worked as an apothecary for three years, he matriculated to the faculty of mechanical engineering of the Technical University. His interest gradually brought him to the electrical engineering. When he was a fourth-year student, he already gave lectures at the meetings of the Engineers' Society on the subject of electrical engineering. During his university years, he worked as a draftsman in the office of the Austrian State Railway Company and in his little free time, he created electrical appliances. He completed his studies with excellent marks. His way led him to the Ganz Works Company.

He was instrumental in developing a transformer together with his colleagues Deri and Blathy. Zipernowsky also made many other contributions to electrical engineering.


  1. Microsoft Encarta 96 Encyclopedia CD, 1993-1995 Microsoft Corporation, Funk & Wagnalls Corporation.
  2. Landry, Peter, "Biographies, The Scientists: A List", http://www.blupete.com/Literature/Biographies/Science/Scients.htm, Dartmouth, Nova Scotia,Canada
  3. "The MacTutor History of Mathematics archive" http://www-gap.dcs.st-and.ac.uk/~history/
  4. "Famous Scientists: greatly contributed to electro science: Scientists born 1851-1900", http://chem.ch.huji.ac.il/~eugeniik/history/electrochemists4.htm
  5. "Indexes of Biographies", http://www-gap.dcs.st-and.ac.uk/~history/BiogIndex.html
  6. Reinhardt, Joachim "Pictures of Famous Physicists" http://www.th.physik.uni-frankfurt.de/~jr/physlist.html
  7. "Biographical Index" http://www.sacklunch.net/biography/A/index.html
  8. "Nobel e-Museum: The Official Web Site of The Nobel Foundation  ", http://www.nobel.se/index.html
  9. "Nobel e-Museum: The Nobel Prize in Physics - Laureates", http://www.nobel.se/physics/laureates/index.html
  10. "The History of Famous Inventors - Past and Present", http://inventors.about.com/cs/famousinventors/
  11. "Nineteenth century inventions 1800 to 1899 - Inventions of the 1800s", http://inventors.about.com/library/weekly/aa111100a.htm and http://inventors.about.com/library/weekly/aa111100b.htm
  12. "Spotlight Biography: Inventors" http://educate.si.edu/spotlight/inventors1.html
  13. "Sala de Fesica: Fotos de Fesicos", Origin of Photos: A Science Odissey, Physics Biographies, University of Frankfurt, University of Texas http://geocities.yahoo.com.br/saladefisica3/
  14. "IEEE Virtual Museum-The story of electricity, electronics, and computers", http://www.ieee-virtual-museum.org/
  15. Alexander, Charles K. and Sadiky, Matthew N.O., "Fundamentals of Electric Circuits", McGraw Hill, USA
  16. del Toro, Vincent, "Electrical Engineering fundamentals", 2nd Edition, Prentice Hall of India, New Delhi, 1996
  17. Internet and other sources

First Launched on 13 February 2003/J R Lucas