Historians and sociologists have remarked upon the occurrence, in

science Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earli ...

, of " multiple independent discovery".

Robert K. Merton Robert King Merton (born Meyer Robert Schkolnick; July 4, 1910 – February 23, 2003) was an American sociologist who is considered a founding father of modern sociology, and a major contributor to the subfield of criminology. He served as th ...

defined such "multiples" as instances in which similar discoveries are made by scientists working independently of each other. "Sometimes," writes Merton, "the discoveries are simultaneous or almost so; sometimes a scientist will make a new discovery which, unknown to him, somebody else has made years before." Commonly cited examples of multiple independent discovery are the 17th-century independent formulation of

calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

by Isaac Newton, Gottfried Wilhelm Leibniz and others, described by A. Rupert Hall; the 18th-century discovery of

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

Carl Wilhelm Scheele Carl Wilhelm Scheele (, ; 9 December 1742 – 21 May 1786) was a Swedish German pharmaceutical chemist. Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified molybdenum, tungsten, barium, hyd ...

, Joseph Priestley,

Antoine Lavoisier Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794),
CNRS (

theory of the evolution of

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, independently advanced in the 19th century by

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...

and Alfred Russel Wallace. Multiple independent discovery, however, is not limited to such famous historic instances. Merton believed that it is multiple discoveries, rather than unique ones, that represent the ''common'' pattern in science. Merton contrasted a "multiple" with a "singleton"—a discovery that has been made uniquely by a single scientist or group of scientists working together. A distinction is drawn between a discovery and an invention, as discussed for example by

Bolesław Prus Aleksander Głowacki (20 August 1847 – 19 May 1912), better known by his pen name Bolesław Prus (), was a Polish novelist, a leading figure in the history of Polish literature and philosophy, as well as a distinctive voice in world li ...

. However, discoveries and inventions are inextricably related, in that discoveries lead to inventions, and inventions facilitate discoveries; and since the same phenomenon of multiplicity occurs in relation to both discoveries and inventions, this article lists both multiple discoveries and multiple ''inventions''.

3rd century BCE

* Aristarchus of Samos (c. 310 – c. 230 BCE) was the first known originator of a heliocentric (solar) system. Such a system was formulated again some 18 centuries later by

Nicolaus Copernicus Nicolaus Copernicus (; pl, Mikołaj Kopernik; gml, Niklas Koppernigk, german: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance polymath, active as a mathematician, astronomer, and Catholic canon, who formulated ...

(1473–1543).

13th century CE

* 1242first description of the function of

pulmonary circulation The pulmonary circulation is a division of the circulatory system in all vertebrates. The circuit begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs ...

, in Egypt, by Ibn al-Nafis. Later independently rediscovered by the Europeans

Michael Servetus Michael Servetus (; es, Miguel Serveto as real name; french: Michel Servet; also known as ''Miguel Servet'', ''Miguel de Villanueva'', ''Revés'', or ''Michel de Villeneuve''; 29 September 1509 or 1511 – 27 October 1553) was a Spanish th ...

(1553) and

William Harvey William Harvey (1 April 1578 – 3 June 1657) was an English physician who made influential contributions in anatomy and physiology. He was the first known physician to describe completely, and in detail, the systemic circulation and propert ...

(1616).

14th century

* Gresham's (Copernicus') law:

Nicole Oresme Nicole Oresme (; c. 1320–1325 – 11 July 1382), also known as Nicolas Oresme, Nicholas Oresme, or Nicolas d'Oresme, was a French philosopher of the later Middle Ages. He wrote influential works on economics, mathematics, physics, astrology an ...

(c. 1370);

(1519); Thomas Gresham (16th century); Henry Dunning Macleod (1857). Ancient references to the same concept include one in

Aristophanes Aristophanes (; grc, Ἀριστοφάνης, ; c. 446 – c. 386 BC), son of Philippus, of the deme Kydathenaion ( la, Cydathenaeum), was a comic playwright or comedy-writer of ancient Athens and a poet of Old Attic Comedy. Eleven of his for ...

' comedy '' The Frogs'' (405 BCE), which compares bad politicians to bad coin (bad politicians and bad coin, respectively, drive good politicians and good coin out of circulation).

16th century

Galileo Galilei by Ottavio Leoni Marucelliana (cropped)

Galileo Galilei Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He wa ...

and

Simon Stevin Simon Stevin (; 1548–1620), sometimes called Stevinus, was a Flemish mathematician, scientist and music theorist. He made various contributions in many areas of science and engineering, both theoretical and practical. He also translated vario ...

: heavy and light balls fall together (''contra'' Aristotle). * Galileo Galilei and Simon Stevin: Hydrostatic paradox (Stevin c. 1585, Galileo c. 1610). * Scipione dal Ferro (1520) and Niccolò Tartaglia (1535) independently developed a method for solving cubic equations. * Olbers' paradox (the "dark-night-sky paradox") was described by

Thomas Digges Thomas Digges (; c. 1546 – 24 August 1595) was an English mathematician and astronomer. He was the first to expound the Copernican system in English but discarded the notion of a fixed shell of immoveable stars to postulate infinitely many s ...

in the 16th century, by Johannes Kepler in the 17th century (1610), by

Edmond Halley Edmond (or Edmund) Halley (; – ) was an English astronomer, mathematician and physicist. He was the second Astronomer Royal in Britain, succeeding John Flamsteed in 1720. From an observatory he constructed on Saint Helena in 1676–77, H ...

and by Jean-Philippe de Chéseaux in the 18th century, by

Heinrich Wilhelm Matthias Olbers Heinrich Wilhelm Matthias Olbers (; ; 11 October 1758 – 2 March 1840) was a German physician and astronomer. Life and career Olbers was born in Arbergen, Germany, today part of Bremen, and studied to be a physician at Göttingen (1777–80 ...

in the 19th century (1823), and definitively by

Lord Kelvin William Thomson, 1st Baron Kelvin, (26 June 182417 December 1907) was a British mathematician, mathematical physicist and engineer born in Belfast. Professor of Natural Philosophy at the University of Glasgow for 53 years, he did important ...

in the 20th century (1901); some aspects of Kelvin's argument had been anticipated in the poet and short-story writer

Edgar Allan Poe Edgar Allan Poe (; Edgar Poe; January 19, 1809 – October 7, 1849) was an American writer, poet, editor, and literary critic. Poe is best known for his poetry and short stories, particularly his tales of mystery and the macabre. He is wid ...

's essay, '' Eureka: A Prose Poem'' (1848), which also presaged by three-quarters of a century the Big Bang theory of the

universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. ...

. *

Continental drift Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pl ...

, in varying independent

iteration Iteration is the repetition of a process in order to generate a (possibly unbounded) sequence of outcomes. Each repetition of the process is a single iteration, and the outcome of each iteration is then the starting point of the next iteration. ...

s, was proposed by Abraham Ortelius , Theodor Christoph Lilienthal (1756),

Alexander von Humboldt Friedrich Wilhelm Heinrich Alexander von Humboldt (14 September 17696 May 1859) was a German polymath, geographer, naturalist, explorer, and proponent of Romantic philosophy and science. He was the younger brother of the Prussian minister, ...

(1801 and 1845), Antonio Snider-Pellegrini , Alfred Russel Wallace, Charles Lyell, Franklin Coxworthy (between 1848 and 1890), Roberto Mantovani (between 1889 and 1909),

William Henry Pickering William Henry Pickering (February 15, 1858 – January 16, 1938) was an American astronomer. Pickering constructed and established several observatories or astronomical observation stations, notably including Percival Lowell's Flagstaff Obser ...

(1907), Frank Bursley Taylor (1908), and

Alfred Wegener Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher. During his lifetime he was primarily known for his achievements in meteorology and ...

(1912). In addition, in 1885

Eduard Suess Eduard Suess (; 20 August 1831 - 26 April 1914) was an Austrian geologist and an expert on the geography of the Alps. He is responsible for hypothesising two major former geographical features, the supercontinent Gondwana (proposed in 1861) and t ...

had proposed a supercontinent Gondwana and in 1893 the

Tethys Ocean The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

, assuming a land-bridge between the present continents submerged in the form of a

geosyncline A geosyncline (originally called a geosynclinal) is an obsolete geological concept to explain orogens, which was developed in the late 19th and early 20th centuries, before the theory of plate tectonics was envisaged. Şengör (1982), p. 11 A geo ...

; and in 1895 John Perry had written a paper proposing that the earth's interior was fluid, and disagreeing with

on the age of the earth.

17th century

Gottfried Wilhelm Leibniz, Bernhard Christoph Francke

* Sunspots

Thomas Harriot Thomas Harriot (; – 2 July 1621), also spelled Harriott, Hariot or Heriot, was an English astronomer, mathematician, ethnographer and translator to whom the theory of refraction is attributed. Thomas Harriot was also recognized for his con ...

(England, 1610), Johannes and David Fabricius ( Frisia, 1611),

(Italy, 1612),

Christoph Scheiner Christoph Scheiner SJ (25 July 1573 (or 1575) – 18 June 1650) was a Jesuit priest, physicist and astronomer in Ingolstadt. Biography Augsburg/Dillingen: 1591–1605 Scheiner was born in Markt Wald near Mindelheim in Swabia, earlier markgrav ...

(Germany, 1612). *

Logarithm In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a number to the base is the exponent to which must be raised, to produce . For example, since , the ''logarithm base'' 10 of ...

John Napier John Napier of Merchiston (; 1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8th Laird of Merchiston. His Latinized name was Ioan ...

(

Scotland Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...

, 1614) and Joost Bürgi (Switzerland, 1618). * Analytic geometry

René Descartes René Descartes ( or ; ; Latinized: Renatus Cartesius; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and science. Ma ...

, Pierre de Fermat. *

Problem of points The problem of points, also called the problem of division of the stakes, is a classical problem in probability theory. One of the famous problems that motivated the beginnings of modern probability theory in the 17th century, it led Blaise Pascal ...

solved by both Pierre de Fermat (France, 1654), Blaise Pascal (France, 1654), and Huygens (Holland, 1657). * Determinants Gottfried Wilhelm Leibniz and Seki Kōwa. *

Calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

Isaac Newton, Gottfried Wilhelm Leibniz, Pierre de Fermat and others. *

Boyle's law Boyle's law, also referred to as the Boyle–Mariotte law, or Mariotte's law (especially in France), is an experimental gas law that describes the relationship between pressure and volume of a confined gas. Boyle's law has been stated as: The ...

(sometimes referred to as the "Boyle-Mariotte law") is one of the

gas laws The gas laws were developed at the end of the 18th century, when scientists began to realize that relationships between pressure, volume and temperature of a sample of gas could be obtained which would hold to approximation for all gases. Boyl ...

and basis of derivation for the ideal gas law, which describes the relationship between the product

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...

and

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...

within a

closed system A closed system is a natural physical system that does not allow transfer of matter in or out of the system, although — in contexts such as physics, chemistry or engineering — the transfer of energy (''e.g.'' as work or heat) is allowed. In ...

as constant when temperature remains at a fixed measure. The law was named for

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe t ...

and

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

Robert Boyle who published the original law in 1662. The French physicist Edme Mariotte discovered the same law independently of Boyle in 1676. *

Newton–Raphson method In numerical analysis, Newton's method, also known as the Newton–Raphson method, named after Isaac Newton and Joseph Raphson, is a root-finding algorithm which produces successively better approximations to the roots (or zeroes) of a real-va ...

Joseph Raphson Joseph Raphson (c. 1668 – c. 1715) was an English mathematician and intellectual known best for the Newton–Raphson method. Biography Very little is known about Raphson's life. Connor and Robertson give his date of birth as 1668 based on a 1 ...

(1690), Isaac Newton (Newton's work was written in 1671, but not published until 1736). *

Brachistochrone In physics and mathematics, a brachistochrone curve (), or curve of fastest descent, is the one lying on the plane between a point ''A'' and a lower point ''B'', where ''B'' is not directly below ''A'', on which a bead slides frictionlessly under ...

problem solved by

Johann Bernoulli Johann Bernoulli (also known as Jean or John; – 1 January 1748) was a Swiss mathematician and was one of the many prominent mathematicians in the Bernoulli family. He is known for his contributions to infinitesimal calculus and educating Le ...

, Jakob Bernoulli, Isaac Newton, Gottfried Wilhelm Leibniz,

Guillaume de l'Hôpital Guillaume François Antoine, Marquis de l'Hôpital (; sometimes spelled L'Hospital; 1661 – 2 February 1704), also known as Guillaume-François-Antoine Marquis de l'Hôpital, Marquis de Sainte-Mesme, Comte d'Entremont, and Seigneur d'Ouques-la- ...

, and Ehrenfried Walther von Tschirnhaus. The problem was posed in 1696 by Johann Bernoulli, and its solutions were published next year. * Steam engine: Patent granted to Thomas Savery in 1698. The invention has often been credited to Thomas Newcomen (1712). Other early inventors have included Taqī al-Dīn (1551), Jerónimo de Ayanz y Beaumont (1606),

Giambattista della Porta Giambattista della Porta (; 1535 – 4 February 1615), also known as Giovanni Battista Della Porta, was an Italian scholar, polymath and playwright who lived in Naples at the time of the Renaissance, Scientific Revolution and Reformation. Giamb ...

, Giovanni Branca (1629), Cosimo de' Medici (1641), Evangelista Torricelli (1643), Otto Von Guericke (1672), Denis Papin (1679), and many others.

18th century

Palazzina dei servi, interni, medaglione wilhelm scheele

* Platinum Antonio de Ulloa and Charles Wood (both in the 1740s). * Leyden Jar Ewald Georg von Kleist (1745) and

Pieter van Musschenbroek Pieter van Musschenbroek (14 March 1692 – 19 September 1761) was a Dutch scientist. He was a professor in Duisburg, Utrecht, and Leiden, where he held positions in mathematics, philosophy, medicine, and astronomy. He is credited with the inven ...

(1745–46). *

Lightning rod A lightning rod or lightning conductor (British English) is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. If lightning hits the structure, it will preferentially strike the rod and be conducte ...

Benjamin Franklin (1749) and

Prokop Diviš Dom (title), Dom Prokop Diviš, Premonstratensian, O.Praem. () (26 March 1698 – 21 December 1765) was a Czech people, Czech canon regular, theologian and natural scientist. In an attempt to prevent thunderstorms from occurring, he inadve ...

(1754) (debated: Diviš's apparatus is assumed to have been more effective than Franklin's lightning rods in 1754, but was intended for a different purpose than lightning protection). * Law of conservation of matterdiscovered by Mikhail Lomonosov, 1756; and independently by

Antoine Lavoisier Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794),
CNRS (

Oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

(

Uppsala Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019. Located north of the c ...

, 1773), Joseph Priestley (

Wiltshire Wiltshire (; abbreviated Wilts) is a historic and ceremonial county in South West England with an area of . It is landlocked and borders the counties of Dorset to the southwest, Somerset to the west, Hampshire to the southeast, Gloucestershire ...

, 1774). The term was coined by

Antoine Lavoisier Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794),
CNRS (

Michael Sendivogius ( pl, Michał Sędziwój; 1566–1636) is claimed as an earlier discoverer of oxygen. * Black-hole theory John Michell, in a 1783 paper in ''

The Philosophical Transactions of the Royal Society ''Philosophical Transactions of the Royal Society'' is a scientific journal published by the Royal Society. In its earliest days, it was a private venture of the Royal Society's secretary. It was established in 1665, making it the first journa ...

'', wrote: "If the semi-diameter of a sphere of the same density as the Sun in the proportion of five hundred to one, and by supposing light to be attracted by the same force in proportion to its asswith other bodies, all light emitted from such a body would be made to return towards it, by its own proper gravity." A few years later, a similar idea was suggested independently by Pierre-Simon Laplace. Stephen Hawking, ''A Brief History of Time'', Bantam, 1996, pp. 43–45. * Malthusian catastrophe Thomas Robert Malthus (1798), Hong Liangji (1793). * A method for measuring the specific heat of a soliddevised independently by Benjamin Thompson, Count Rumford; and by Johan Wilcke, who published his discovery first (apparently not later than 1796, when he died).

19th century

* In a treatise written in 1805 and published in 1866,

Carl Friedrich Gauss Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...

describes an efficient algorithm to compute the discrete Fourier transform. James W. Cooley and

John W. Tukey John Wilder Tukey (; June 16, 1915 – July 26, 2000) was an American mathematician and statistician, best known for the development of the fast Fourier Transform (FFT) algorithm and box plot. The Tukey range test, the Tukey lambda distribut ...

reinvented a similar algorithm in 1965. * Complex planeGeometrical representation of complex numbers was discovered independently by

Caspar Wessel Caspar Wessel (8 June 1745, Vestby – 25 March 1818, Copenhagen) was a Danish– Norwegian mathematician and cartographer. In 1799, Wessel was the first person to describe the geometrical interpretation of complex numbers as points in the comp ...

(1799),

Jean-Robert Argand Jean-Robert Argand (, , ; July 18, 1768 – August 13, 1822) was an amateur mathematician. In 1806, while managing a bookstore in Paris, he published the idea of geometrical interpretation of complex numbers known as the Argand diagram and is know ...

(1806), John Warren (1828), and

(1831). *

Cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

Friedrich Strohmeyer, K.S.L Hermann (both in 1817). * Grotthuss–Draper law (aka the Principle of Photochemical Activation)first proposed in 1817 by

Theodor Grotthuss Freiherr Christian Johann Dietrich Theodor von Grotthuss (20 January 1785 – 26 March 1822) was a Baltic German scientist known for establishing the first theory of electrolysis in 1806 and formulating the first law of photochemistry in 1817. His ...

, then independently, in 1842, by John William Draper. The law states that only that light which is absorbed by a system can bring about a photochemical change. * Beryllium Friedrich Wöhler, A.A.B. Bussy (1828). * Electromagnetic induction was discovered by

Michael Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic inducti ...

in England in 1831, and independently about the same time by Joseph Henry in the U.S. * Chloroform Samuel Guthrie in the United States (July 1831), and a few months later Eugène Soubeiran (France) and Justus von Liebig (Germany), all of them using variations of the

haloform reaction In chemistry, the haloform reaction is a chemical reaction in which a haloform (, where X is a halogen The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), ...

. * Non-Euclidean geometry (

hyperbolic geometry In mathematics, hyperbolic geometry (also called Lobachevskian geometry or Bolyai–Lobachevskian geometry) is a non-Euclidean geometry. The parallel postulate of Euclidean geometry is replaced with: :For any given line ''R'' and point ''P ...

)

Nikolai Ivanovich Lobachevsky Nikolai Ivanovich Lobachevsky ( rus, Никола́й Ива́нович Лобаче́вский, p=nʲikɐˈlaj ɪˈvanəvʲɪtɕ ləbɐˈtɕɛfskʲɪj, a=Ru-Nikolai_Ivanovich_Lobachevsky.ogg; – ) was a Russian mathematician and geometer, kn ...

(1830), János Bolyai (1832); preceded by

Gauss Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...

(unpublished result) c. 1805. * Dandelin–Gräffe method, aka Lobachevsky methodan

algorithm In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing ...

for finding multiple roots of a

polynomial In mathematics, a polynomial is an expression consisting of indeterminates (also called variables) and coefficients, that involves only the operations of addition, subtraction, multiplication, and positive-integer powers of variables. An example ...

, developed independently by Germinal Pierre Dandelin, Karl Heinrich Gräffe, and

. *

Electrical telegraph Electrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems ...

Charles Wheatstone Sir Charles Wheatstone FRS FRSE DCL LLD (6 February 1802 – 19 October 1875), was an English scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope (a device for di ...

(England), 1837, Samuel F.B. Morse (United States), 1837. *

First law of thermodynamics The first law of thermodynamics is a formulation of the law of conservation of energy, adapted for thermodynamic processes. It distinguishes in principle two forms of energy transfer, heat and thermodynamic work for a system of a constant amou ...

In the late 19th century, various scientists independently stated that energy and matter are persistent, although this was later to be disregarded under subatomic conditions. Hess's Law ( Germain Hess), Julius Robert von Mayer, and

James Joule James Prescott Joule (; 24 December 1818 11 October 1889) was an English physicist, mathematician and brewer, born in Salford, Lancashire. Joule studied the nature of heat, and discovered its relationship to mechanical work (see energy). T ...

were some of the first. * 1846: Urbain Le Verrier and John Couch Adams, studying

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus ( Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars), grandfather of Zeus (Jupiter) and father of ...

's orbit, independently proved that another, farther planet must exist. Neptune was found at the predicted moment and position. *

Bessemer Process The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation ...

The process of removing impurities from steel on an industrial level using oxidation, developed in 1851 by American William Kelly and independently developed and patented in 1855 by eponymous Englishman

Sir Henry Bessemer Sir Henry Bessemer (19 January 1813 – 15 March 1898) was an English inventor, whose steel-making process would become the most important technique for making steel in the nineteenth century for almost one hundred years from 1856 to 1950. He ...

. * The Möbius strip was discovered independently by the German astronomer–mathematician

August Ferdinand Möbius August Ferdinand Möbius (, ; ; 17 November 1790 – 26 September 1868) was a German mathematician and theoretical astronomer. Early life and education Möbius was born in Schulpforta, Electorate of Saxony, and was descended on hi ...

and the German mathematician

Johann Benedict Listing Johann Benedict Listing (25 July 1808 – 24 December 1882) was a German mathematician. J. B. Listing was born in Frankfurt and died in Göttingen. He first introduced the term "topology" to replace the older term "geometria situs" (also called ...

in 1858. *

Theory of evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variatio ...

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Cha ...

(discovery about 1840), Alfred Russel Wallace (discovery about 1857–58)joint publication, 1859. * 1862: 109P/Swift–Tuttle, the

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ...

generating the Perseid meteor shower, was independently discovered by

Lewis Swift Lewis A. Swift (February 29, 1820 – January 5, 1913) was an American astronomer who discovered 13 comets and 1,248 previously uncatalogued nebulae. Only William Herschel discovered more nebulae visually. Discoveries Swift discovered or co-discov ...

on 16 July 1862, and by

Horace Parnell Tuttle Horace Parnell Tuttle (March 17, 1837 – August 16, 1923) was an American astronomer, an American Civil War veteran and brother of astronomer Charles Wesley Tuttle (November 1, 1829 – July 17, 1881). Biography Early life H. P. Tuttle was born ...

on 19 July 1862. The comet made a return appearance in 1992, when it was rediscovered by Japanese

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

Tsuruhiko Kiuchi. * 1868: French astronomer

Pierre Janssen Pierre Jules César Janssen (22 February 1824 – 23 December 1907), usually known as Jules Janssen, was a French astronomer who, along with English scientist Joseph Norman Lockyer, is credited with discovering the gaseous nature of the solar ...

and English astronomer Norman Lockyer independently discovered evidence in the solar spectrum for a new element that Lockyer named "helium". (The formal discovery of the element was made in 1895 by two

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

chemists, Per Teodor Cleve and Nils Abraham Langlet, who found helium emanating from the

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 Apr ...

cleveite.) * 1869: Dmitri Ivanovich Mendeleyev published his periodic table of chemical elements, and the following year (1870)

Julius Lothar Meyer Julius Lothar Meyer (19 August 1830 – 11 April 1895) was a German chemist. He was one of the pioneers in developing the earliest versions of the periodic table of the chemical elements. Russian chemist Dmitri Mendeleev (his chief rival) and he ...

published his independently constructed version. * 1873:

propounded a "law of combination" describing the making of discoveries and

inventions An invention is a unique or novel device, method, composition, idea or process. An invention may be an improvement upon a machine, product, or process for increasing efficiency or lowering cost. It may also be an entirely new concept. If an i ...

: “Any new discovery or invention is a combination of earlier discoveries and inventions, or rests on them.” In 1978, Christopher Kasparek independently proposed an identical model of discovery and invention which he termed "recombinant conceptualization." * 1876:

Oskar Hertwig Oscar Hertwig (21 April 1849 in Friedberg – 25 October 1922 in Berlin) was a German embryologist and zoologist known for his research in developmental biology and evolution. Hertwig is credited as the first man to observe sexual reproduction ...

and Hermann Fol independently described the entry of sperm into the egg and the subsequent fusion of the egg and sperm nuclei to form a single new nucleus. * 1876: Elisha Gray and Alexander Graham Bell independently, on the same day, filed patents for invention of the telephone. * 1877:

Charles Cros Charles Cros or Émile-Hortensius-Charles Cros (October 1, 1842 – August 9, 1888) was a French poet and inventor. He was born in Fabrezan, Aude. Cros was a well-regarded poet and humorous writer. As an inventor, he was interested in the field ...

described the principles of the phonograph that was, independently, constructed the following year (1878) by

Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventi ...

. * British physicist-chemist

Joseph Swan Sir Joseph Wilson Swan FRS (31 October 1828 – 27 May 1914) was an English physicist, chemist, and inventor. He is known as an independent early developer of a successful incandescent light bulb, and is the person responsible for develop ...

independently developed an incandescent light bulb at the same time as American inventor

was independently working on ''his'' incandescent light bulb. Swan's first successful electric light bulb and Edison's electric light bulb were both patented in 1879. * Circa 1880: the integraph was invented independently by the British physicist Sir Charles Vernon Boys and by the Polish mathematician, inventor, and electrical engineer

Bruno Abakanowicz Bruno Abdank-Abakanowicz (6 October 1852 – 29 August 1900) was a Polish mathematician, inventor, and electrical engineer. Life Abakanowicz was born in 1852 in the Russian Empire (now Lithuania). After graduating from the Riga Technical Univ ...

. Abakanowicz's design was produced by the Swiss firm Coradi of Zurich. * 1886: The

Hall–Héroult process The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) (obtained most often from bauxite, aluminium's chief ore, through the Bayer process) in molten cryolite, and el ...

for inexpensively producing aluminum was independently discovered by the American engineer-inventor

Charles Martin Hall Charles Martin Hall (December 6, 1863 – December 27, 1914) was an American inventor, businessman, and chemist. He is best known for his invention in 1886 of an inexpensive method for producing aluminum, which became the first metal to atta ...

and the French scientist

Paul Héroult Paul (Louis-Toussaint) Héroult (10 April 1863 – 9 May 1914) was a French scientist. He was the inventor of the aluminium electrolysis and developed the first successful commercial electric arc furnace. He lived in Thury-Harcourt, Normandy. ...

. * 1895:

Adrenaline Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands an ...

was discovered by the Polish physiologist Napoleon Cybulski. It was independently discovered in 1900 by the Japanese chemist Jōkichi Takamine and his assistant Keizo Uenaka. * 1896: Two proofs of the prime number theorem (the asymptotic law of the distribution of prime numbers) were obtained independently by

Jacques Hadamard Jacques Salomon Hadamard (; 8 December 1865 – 17 October 1963) was a French mathematician who made major contributions in number theory, complex analysis, differential geometry and partial differential equations. Biography The son of a teac ...

and Charles de la Vallée-Poussin and appeared the same year. * 1896: Discovery of radioactivity independently by

Henri Becquerel Antoine Henri Becquerel (; 15 December 1852 – 25 August 1908) was a French engineer, physicist, Nobel laureate, and the first person to discover evidence of radioactivity. For work in this field he, along with Marie Skłodowska-Curie and Pie ...

and Silvanus Thompson. * 1898: Discovery of

thorium Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high ...

radioactivity by Gerhard Carl Schmidt and

Marie Curie Marie Salomea Skłodowska–Curie ( , , ; born Maria Salomea Skłodowska, ; 7 November 1867 – 4 July 1934) was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. She was the first ...

. *

Linguist Linguistics is the scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, objective, and precise analysis of all aspects of language, particularly its nature and structure. Linguis ...

s Filipp Fortunatov and Ferdinand de Saussure independently formulated the sound law now known as the Fortunatov–de Saussure law. * Vector calculus was invented independently by the American, Josiah Willard Gibbs (1839–1903), and by the Englishman,

Oliver Heaviside Oliver Heaviside FRS (; 18 May 1850 – 3 February 1925) was an English self-taught mathematician and physicist who invented a new technique for solving differential equations (equivalent to the Laplace transform), independently developed ...

(1850–1925).

20th century

Walter Alvarez at the 97th Annual Faculty Research Lectures, University of California Berkeley

Françoise Barré-Sinoussi-press conference Dec 06th, 2008-1

* 1902:

Walter Sutton Walter Stanborough Sutton (April 5, 1877 – November 10, 1916) was an American geneticist and physician whose most significant contribution to present-day biology was his theory that the Mendelian laws of inheritance could be applied to chrom ...

and Theodor Boveri independently proposed that the hereditary information is carried in the

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

s. * 1902: Richard Assmann and Léon Teisserenc de Bort independently discovered the stratosphere. * E = mc², though only Einstein provided the accepted interpretation Henri Poincaré, 1900; Olinto De Pretto, 1903;

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...

, 1905;

Paul Langevin Paul Langevin (; ; 23 January 1872 – 19 December 1946) was a French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the ''Comité de vigilance des intellectuels antifascistes'', an an ...

, 1906. *

Brownian motion Brownian motion, or pedesis (from grc, πήδησις "leaping"), is the random motion of particles suspended in a medium (a liquid or a gas). This pattern of motion typically consists of random fluctuations in a particle's position insi ...

was independently explained by

(in one of his 1905 papers) and by Marian Smoluchowski in 1906. * The Einstein Relation was revealed independently by William Sutherland in 1905, by

in 1905, and by Marian Smoluchowski in 1906. * 1904: Epinephrine synthesized independently by Friedrich Stolz and by

Henry Drysdale Dakin Henry Drysdale Dakin FRS (12 March 188010 February 1952) was an English chemist. He was born in London as the youngest of 8 children to a family of steel merchants from Leeds. As a school boy, he conducted water analysis with the Leeds City Ana ...

. * 1905: The chromosomal

XY sex-determination system The XY sex-determination system is a sex-determination system used to classify many mammals, including humans, some insects (''Drosophila''), some snakes, some fish ( guppies), and some plants ('' Ginkgo'' tree). In this system, the sex of an i ...

—that males have XY, and females XX, sex chromosomes—was discovered independently by Nettie Stevens, at Bryn Mawr College, and by

Edmund Beecher Wilson Edmund Beecher Wilson (October 19, 1856 – March 3, 1939) was a pioneering American zoologist and geneticist. He wrote one of the most influential textbooks in modern biology, ''The Cell''. Career Wilson was born in Geneva, Illinois, the so ...

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

. * 1907:

Lutetium Lutetium is a chemical element with the symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted am ...

discovered independently by French scientist

Georges Urbain Georges Urbain (12 April 1872 – 5 November 1938) was a French chemist, a professor of the Sorbonne, a member of the Institut de France, and director of the Institute of Chemistry in Paris. Much of his work focused on the rare earths, isolating a ...

and by Austrian mineralogist Baron

Carl Auer von Welsbach Carl Auer von Welsbach (1 September 1858 – 4 August 1929), who received the Austrian noble title of Freiherr Auer von Welsbach in 1901, was an Austrian scientist and inventor, who separated didymium into the elements neodymium and praseo ...

. * 1907: Hilbert space representation theorem, also known as

Riesz representation theorem :''This article describes a theorem concerning the dual of a Hilbert space. For the theorems relating linear functionals to measures, see Riesz–Markov–Kakutani representation theorem.'' The Riesz representation theorem, sometimes called the R ...

, the mathematical justification of the Bra-ket notation in the theory of

quantum mechanics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...

independently proved by

Frigyes Riesz Frigyes Riesz ( hu, Riesz Frigyes, , sometimes spelled as Frederic; 22 January 1880 – 28 February 1956) was a HungarianEberhard Zeidler: Nonlinear Functional Analysis and Its Applications: Linear monotone operators. Springer, 199/ref> mathema ...

and

Maurice René Fréchet Maurice may refer to: People *Saint Maurice (died 287), Roman legionary and Christian martyr *Maurice (emperor) or Flavius Mauricius Tiberius Augustus (539–602), Byzantine emperor *Maurice (bishop of London) (died 1107), Lord Chancellor and Lo ...

. * The

Hardy–Weinberg principle In population genetics, the Hardy–Weinberg principle, also known as the Hardy–Weinberg equilibrium, model, theorem, or law, states that allele and genotype frequencies in a population will remain constant from generation to generation in t ...

is a principle of

population genetics Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and pop ...

that states that, in the absence of other evolutionary influences,

allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...

and

genotype frequencies Genetic variation in populations can be analyzed and quantified by the frequency of alleles. Two fundamental calculations are central to population genetics: allele frequencies and genotype frequencies. Genotype frequency in a population is the n ...

in a population will remain constant from generation to generation. This law was formulated in 1908 independently by German obstetrician-gynecologist

Wilhelm Weinberg Wilhelm Weinberg ( Stuttgart, 25 December 1862 – 27 November 1937, Tübingen) was a German obstetrician-gynecologist, practicing in Stuttgart, who in a 1908 paper, published in German in ''Jahresheft des Vereins für vaterländische Naturkun ...

and, a little later and a little less rigorously, by British mathematician

G.H. Hardy Godfrey Harold Hardy (7 February 1877 – 1 December 1947) was an English mathematician, known for his achievements in number theory and mathematical analysis. In biology, he is known for the Hardy–Weinberg principle, a basic principle of pop ...

. * The Stark–Einstein law (aka photochemical equivalence law, or photoequivalence law)independently formulated between 1908 and 1913 by

Johannes Stark Johannes Stark (, 15 April 1874 – 21 June 1957) was a German physicist who was awarded the Nobel Prize in Physics in 1919 "for his discovery of the Doppler effect in canal rays and the splitting of spectral lines in electric fields". This phe ...

and

. It states that every

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always ...

that is absorbed will cause a (primary) chemical or physical reaction. * In 1911

Ejnar Hertzsprung Ejnar Hertzsprung (; Copenhagen, 8 October 1873 – 21 October 1967, Roskilde) was a Danish chemist and astronomer. Career Hertzsprung was born in Frederiksberg, Denmark, the son of Severin and Henriette. He studied chemical engineering at Cop ...

created the Hertzsprung–Russell diagram, abbreviated ''H–R diagram'', ''HR diagram'', or ''HRD'' – a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosity, luminosities versus their stellar classifications or effective temperatures – a major step toward an understanding of stellar evolution. In 1913 the Hertzsprung–Russell diagram was independently created by Henry Norris Russell. * Frequency-hopping spread spectrum#Multiple inventors, Frequency-hopping spread spectrum in radio work was described by Johannes Zenneck (1908), Leonard Danilewicz (1929), Willem Broertjes (1929), and Hedy Lamarr and George Antheil (1942 US patent). * By 1913, vitamin A was independently discovered by Elmer McCollum and Marguerite Davis at the University of Wisconsin–Madison, and by Lafayette Mendel and Thomas Burr Osborne (chemist), Thomas Burr Osborne at Yale University, who studied the role of fats in the diet. * Bacteriophages (viruses that infect bacteria)Frederick Twort (1915), Félix d'Hérelle (1917). * Rotor machine, Rotor cipher machinesTheo A. van Hengel and R.P.C. Spengler (1915); Edward Hebern (1917); Arthur Scherbius (Enigma machine, 1918); Hugo Koch (1919); Arvid Damm (1919). * Sound film#Crucial innovations, Sound filmJoseph Tykociński-Tykociner (1922), Lee De Forest (1923). * The Big Bang theory of the

—that the universe is expanding from a single original point—was developed from the independent derivation of the Friedmann equations from Einstein field equations, Albert Einstein's equations of general relativity by the Russian, Alexander Friedmann, in 1922, and by the Belgian, Georges Lemaître, in 1927. The Big Bang theory was confirmed in 1929 by the American astronomer Edwin Hubble's analysis of galactic redshifts. But the Big Bang theory had been presaged three-quarters of a century earlier in the American poet and short-story writer

's then much-derided essay, '' Eureka: A Prose Poem'' (1848). * Georgios Papanikolaou is credited with discovering as early as 1923 that cervical cancer cells can be detected microscopically, though his invention of the Pap test went largely ignored by physicians until 1943. Aurel Babeş of Romania independently made similar discoveries in 1927. * "Abiogenesis, Primordial soup" theory of the abiogenesis, abiogenetic evolution of life from carbon-based moleculesAlexander Oparin (1924), J.B.S. Haldane (1925). * Jet stream was detected in the 1920s by Japanese meteorologist Wasaburo Oishi, whose work largely went unnoticed outside Japan because he published his findings in Esperanto. Often given some credit for discovery of jet streams is American pilot Wiley Post, who in the year before his 1935 death noticed that at times his ground speed greatly exceeded his air speed. Real understanding of the nature of jet streams is often credited to experience in World War II military flights. * Borůvka's algorithm, an algorithm for finding a minimum spanning tree in a graph, was first published in 1926 by Otakar Borůvka. The algorithm was rediscovered by Gustave Choquet, Choquet in 1938; again by Kazimierz Florek, Florek, Jan Łukasiewicz, Łukasiewicz, Julian Perkal, Perkal, Hugo Steinhaus, Steinhaus, and Stefan Zubrzycki, Zubrzycki; and again by Sollin in 1965. * 1927: The discovery of phosphocreatine was reported by Grace Palmer Eggleton and Philip Eggleton of the University of Cambridge and separately by Cyrus H. Fiske and Yellapragada Subbarow of Harvard Medical School. * 1929: Dmitri Skobeltsyn first observed the positron in 1929. Chung-Yao Chao also observed the positron in 1929, though he did not recognize it as such. * Tarski's undefinability theorem, Undefinability theorem, an important limitative result in mathematical logicKurt Gödel (1930; described in a 1931 private letter, but not published); Alfred Tarski (1933). * Chandrasekhar Limit—published by Subramanyan Chandrasekhar (1931–35); also computed by Lev Davidovich Landau, Lev Landau (1932). * A theory of Denaturation (biochemistry), protein denaturation is widely attributed to Alfred Mirsky and Linus Pauling, who published their paper in 1936, though it had been independently discovered in 1931 by Hsien Wu, whom some now recognize as the originator of the theory. * Electroluminescence in silicon carbide, now known as the LED, was discovered independently by Oleg Losev in 1927 and by H.J. Round in 1907, and possibly in 1936 in zinc sulfide by Georges Destriau, who believed it was actually a form of incandescence. * 1934: Natural deduction, an approach to proof theory in philosophical logicdiscovered independently by Gerhard Gentzen and Stanisław Jaśkowski in 1934. * The Gelfond–Schneider theorem, in mathematics, establishes the transcendental number, transcendence of a large class of numbers. It was originally proved in 1934 by Aleksandr Gelfond, and again independently in 1935 by Theodor Schneider. * The Penrose triangle, also known as the "tribar", is an impossible object. It was first created by the Swedish artist Oscar Reutersvärd in 1934. The mathematician Roger Penrose independently devised and popularised it in the 1950s. * 1936: In computer science, the concept of the "universal computing machine" (now generally called the "Turing Machine") was proposed by Alan Turing, but also independently by Emil Leon Post, Emil Post, both in 1936. Similar approaches, also aiming to cover the concept of universal computing, were introduced by Stephen Cole Kleene, S.C. Kleene, Rózsa Péter, and Alonzo Church that same year. Also in 1936, Konrad Zuse tried to build a binary electrically driven mechanical calculator with limited programability; however, Zuse's machine was never fully functional. The later Atanasoff–Berry Computer ("ABC"), designed by John Vincent Atanasoff and Clifford Berry, was the first fully electronics, electronic Digital data, digital computing device; while not programmable, it pioneered important elements of modern computing, including binary arithmetic and Electronics, electronic switching elements, though its special-purpose nature and lack of a changeable, stored program distinguish it from modern computers. * The atom bomb was independently thought of by Leó Szilárd, Józef Rotblat and others. * The jet engine, independently invented by Hans von Ohain (1939), Secondo Campini (1940) and Frank Whittle (1941) and used in working aircraft. * In agriculture, the ability of synthetic auxins 2,4-D, 2,4,5-T, and MCPA to act as hormone herbicides was discovered independently by four groups in the United States and Great Britain: William G. Templeman and coworkers (1941); Philip Nutman, Gerard Thornton, and Juda Quastel (1942); Franklin Jones (1942); and Ezra Kraus, John W. Mitchell, and Charles L. Hamner (1943). All four groups were subject to various aspects of wartime secrecy, and the exact order of discovery is a matter of some debate. * The point-contact transistor was independently invented in 1947 by Americans William Shockley, John Bardeen and Walter Brattain, working at Bell Labs, and in 1948 by German physicists Herbert Mataré and Heinrich Welker, working at the ''Compagnie des Freins et Signaux'', a Westinghouse Electric (1886), Westinghouse subsidiary located in Paris. The Americans were jointly awarded the 1956 Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect." * 1949: A formal definition of Clique (graph theory), cliques in graph theory was simultaneously introduced by Luce and Perry (1949) and Festinger (1949). * NMR spectroscopy was independently developed in the late 1940s and early 1950s by the Purcell group at Harvard University and the Bloch group at Stanford University. Edward Mills Purcell and Felix Bloch shared the 1952 Nobel Prize in Physics for their discoveries. * Polio vaccine (1950–63): Hilary Koprowski, Jonas Salk, Albert Sabin. * The integrated circuit was devised independently by Jack Kilby in 1958''The Chip that Jack Built''
c. 2008, HTML, Texas Instruments, retrieved 29 May 2008. and half a year later by Robert Noyce. Kilby won the 2000 Nobel Prize in Physics for his part in the invention of the integrated circuit. * The QR algorithm for calculating eigenvalues and eigenvectors of matrices was developed independently in the late 1950s by John G. F. Francis and by Vera N. Kublanovskaya. The algorithm is considered one of the most important developments in numerical linear algebra of the 20th century. * Quantum electrodynamics and renormalization (1930s–40s): Ernst Stueckelberg, Julian Schwinger, Richard Feynman, and Sin-Itiro Tomonaga, for which the latter 3 received the 1965 Nobel Prize in Physics. * The maser, a precursor to the laser, was described by Russian scientists in 1952, and built independently by scientists at

in 1953. The laser itself was developed independently by Gordon Gould at Columbia University and by researchers at Bell Labs, and by the Russian scientist Alexander Prokhorov, Aleksandr Prokhorov. * Kolmogorov complexity, also known as "Kolmogorov–Chaitin complexity", descriptive complexity, etc., of an object such as a piece of text is a measure of the computational resources needed to specify the object. The concept was independently introduced by Ray Solomonoff, Andrey Kolmogorov and Gregory Chaitin in the 1960s. * The concept of packet switching, a communications method in which discrete blocks of data (Packet (information technology), packets) are routing, routed between node (networking), nodes over data links, was first explored by Paul Baran in the early 1960s, and then independently a few years later by Donald Davies. * The principles of atomic layer deposition, a thin-film growth method that in the 2000s contributed to the continuation of semiconductor-device scaling in accord with Moore's law, were independently discovered in the early 1960s by the Soviet scientists Valentin Aleskovsky and Stanislav Koltsov and in 1974 by the Finnish inventor Tuomo Suntola. * Capital asset pricing model#Inventors, Capital Asset Pricing Model (CAPM) is a popular model in finance for trading off risk versus return. Three separate authors published it in academic journals and a fourth circulated unpublished papers. * 1963: In a major advance in the development of plate tectonics theory, the Vine–Matthews–Morley hypothesis was independently proposed by Lawrence Morley, and by Fred Vine and Drummond Matthews, linking seafloor spreading and the symmetric "zebra pattern" of magnetic reversals in the basalt rocks on either side of mid-ocean ridges. * Cosmic background radiation as a signature of the Big Bang was confirmed by Arno Penzias and Robert Woodrow Wilson, Robert Wilson of Bell Labs. Penzias and Wilson had been testing a very sensitive microwave detector when they noticed that their equipment was picking up a strange noise that was independent of the orientation (direction) of their instrument. At first they thought the noise was generated due to pigeon droppings in the detector, but even after they removed the droppings the noise was still detected. Meanwhile, at nearby Princeton University two physicists, Robert H. Dicke, Robert Dicke and Jim Peebles, were working on a suggestion of George Gamow's that the early universe had been hot and dense; they believed its hot glow could still be detected but would be so red shift, red-shifted that it would manifest as microwaves. When Arno Penzias, Penzias and Robert Woodrow Wilson, Wilson learned about this, they realized that they had already detected the red-shifted microwaves and (to the disappointment of Dicke and Peebles) were awarded the 1978 Nobel Prize in physics. * Conductive polymers: Between 1963 and 1977, doped and oxidized highly conductive polyacetylene derivatives were independently discovered, "lost", and then rediscovered at least four times. The last rediscovery won the 2000 Nobel prize in Chemistry, for the "discovery and development of conductive polymers". This was without reference to the previous discoveries. Citations in article "Conductive polymers." * 1964: The relativistic model for the Higgs mechanism was developed by three independent groups: Robert Brout and François Englert; Peter Higgs; and Gerald Guralnik, Carl Richard Hagen, and Tom Kibble. Slightly later, in 1965, it was also proposed by Soviet undergraduate students Alexander Migdal and Alexander Markovich Polyakov. The existence of the "Higgs boson" was finally confirmed in 2012; Higgs and Englert were awarded a Nobel Prize in 2013. * The CYK algorithm, Cocke–Younger–Kasami algorithm was independently discovered three times: by T. Kasami (1965), by Daniel H. Younger (1967), and by John Cocke (computer scientist), John Cocke and Jacob T. Schwartz (1970). * The Wagner–Fischer algorithm, in computer science, was discovered and published at least six times. * The affine scaling method for solving linear programming was discovered by Soviet mathematician I.I. Dikin in 1967. It went unnoticed in the West for two decades, until two groups of researchers in the U.S. reinvented it in 1985. * Neutral theory of molecular evolution was introduced by a Japanese biologist, Motoo Kimura, in 1968, and independently by two American biologists, Jack Lester King and Thomas H. Jukes, Thomas Hughes Jukes, in 1969. * 1969: Thyrotropin-releasing hormone (TRH) structure was determined, and the hormone synthesized, independently by Andrew V. Schally and Roger Guillemin, who shared the 1977 Nobel Prize in Medicine. * 1970: Howard Temin and David Baltimore independently discovered reverse transcriptase enzymes. * The Knuth–Morris–Pratt algorithm, Knuth–Morris–Pratt string searching algorithm was developed by Donald Knuth and Vaughan Pratt and independently by J. H. Morris. * The Cook–Levin theorem (also known as "Cook's theorem"), a result in computational complexity theory, was proven independently by Stephen Cook (1971 in the U.S.) and by Leonid Levin (1973 in the Soviet Union, USSR). Levin was not aware of Cook's achievement because of communication difficulties between East and West during the Cold War. The other way round, Levin's work was not widely known in the West until around 1978. * Mevastatin (compactin; ML-236B) was independently discovered by Akira Endo in Japan in a culture of ''Penicillium citrinium'' and by a British group in a culture of ''Penicillium brevicompactum''. Both reports were published in 1976. * The Bohlen–Pierce scale, a harmonic, non-octave musical scale, was independently discovered by Heinz Bohlen (1972), Kees van Prooijen (1978) and John R. Pierce (1984). * RSA (algorithm), RSA, an algorithm suitable for digital signature, signing and encryption in public-key cryptography, was publicly described in 1977 by Ron Rivest, Adi Shamir and Leonard Adleman. An equivalent system had been described in 1973 in an internal document by Clifford Cocks, a British mathematician working for the UK intelligence agency Government Communications Headquarters, GCHQ, but his work was not revealed until 1997 due to its top-secret classification. * 1973: Asymptotic freedom, which states that the strong interaction, strong nuclear interaction between quarks decreases with decreasing distance, was discovered in 1973 by David Gross and Frank Wilczek, and by David Politzer, and was published in the same 1973 edition of the journal ''Physical Review Letters''. For their work the three received the Nobel Prize in Physics in 2004. * 1974: The J/ψ meson was independently discovered by a group at the Stanford Linear Accelerator Center, headed by Burton Richter, and by a group at Brookhaven National Laboratory, headed by Samuel Ting of MIT. Both announced their discoveries on 11 November 1974. For their shared discovery, Richter and Ting shared the 1976 Nobel Prize in Physics. * 1975: Endorphins were discovered independently in Scotland and the US in 1975. * 1975: Two English biologists, Robin Holliday and John Pugh, and an American biologist, Arthur Riggs, independently suggested that methylation, a chemical modification of DNA that is heritable and can be induced by Environment (biophysical), environmental influences, including physical and emotional Stress (biology), stresses, has an important part in controlling gene expression. This concept has become foundational for the field of epigenetics, with its multifarious implications for physical and mental health and for sociopolitics. * 1980: The asteroid cause of the Cretaceous-Tertiary extinction that wiped out much life on Earth, including all dinosaurs except for birds, was published in ''Science (journal), Science'' by Luis Walter Alvarez, Luis and Walter Alvarez ''et al.''; and independently 2 weeks earlier, in ''Nature (journal), Nature'', by Dutch geologist Jan Smit and Belgian geologist Jan Hertogen. * 1983: Two separate research groups led by American Robert Gallo and French investigators and Luc Montagnier independently declared that a novel retrovirus may have been infecting AIDS patients, and published their findings in the same issue of the journal ''Science (journal), Science''. A third contemporaneous group, at the University of California, San Francisco, led by Dr. Jay Levy, in 1983 independently discovered an AIDS virus which was very different from that reported by the Montagnier and Gallo groups and which indicated, for the first time, the heterogeneity of HIV isolates. * Quantum cryptography—the first cryptography, cryptographic method to rely not on mathematical complexity but on the laws of physics—was first postulated in 1984 by Charles H. Bennett (computer scientist), Charles Bennett and Gilles Brassard, working together, and later independently, in 1991, by Artur Ekert. The earlier scheme has proven the more practical. * 1984: Comet Levy-Rudenko was discovered independently by David H. Levy on 13 November 1984 and the next evening by Michael Rudenko. (It was the first of 23 comets discovered by Levy, who is famous as the 1993 co-discoverer of Comet Shoemaker-Levy 9, the first comet ever observed crashing into a planet, Jupiter.) * 1985: The use of elliptic curves in cryptography (elliptic curve cryptography) was suggested independently by Neal Koblitz and Victor S. Miller in 1985. * 1987: The Immerman–Szelepcsényi theorem, another fundamental result in computational complexity theory, was proven independently by Neil Immerman and Róbert Szelepcsényi in 1987. * In 1989, Thomas R. Cech (Colorado) and Sidney Altman (Yale) won the Nobel Prize in chemistry for their independent discovery in the 1980s of ribozymesfor the "discovery of catalytic properties of RNA"using different approaches. Catalytic RNA was an unexpected finding, something they were not looking for, and it required rigorous proof that there was no contaminating protein enzyme. * In 1993, groups led by Donald S. Bethune at IBM and Sumio Iijima at NEC independently discovered Carbon nanotubes#Single-walled, single-wall carbon nanotubes and methods to produce them using transition-metal catalysts. * 1998: Saul Perlmutter, Adam G. Riess, and Brian P. Schmidt—working as members of two independent projects, the Supernova Cosmology Project and the High-Z Supernova Search Team—simultaneously discovered in 1998 the accelerating universe, accelerating expansion of the universe through observations of distant supernovae. For this, they were jointly awarded the 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics.

21st century

* In 2001 four different authors published different implementations of a distributed hash table. * The Super Kamiokande and SNOLAB collaborations, whose findings were published in 1998 and 2001 respectively, both proved that neutrinos have mass. The 2015 Nobel Prize in Physics was shared by Takaaki Kajita of Japan and Arthur B. McDonald of Canada as a result. *James P. Allison, James Allison of MD Anderson Cancer Center at the University of Texas at Houston discovered a mechanism enabling cancer immunotherapy in 1996. Tasuku Honjo of Kyoto University discovered another such mechanism in 2002. This outcome, which led to them sharing the 2018 Nobel Prize in Physiology or Medicine, has been described as follows: "Each independently discovered that our immune system is restrained from attacking tumors by molecules that function as 'brakes.' Releasing these brakes (or 'brake receptors') allows our body to powerfully combat cancer." * In 2014, Paul Erdős' conjecture about prime gaps was proved by Kevin Ford, Ben Green (mathematician), Ben Green, Sergei Konyagin, and Terence Tao, working together, and independently by James Maynard (mathematician), James Maynard. * 2020: Half of the 2020 Nobel Prize in Physics was awarded to Reinhard Genzel and Andrea Ghez, who each have led a group of astronomers focused since the early 1990s on a region at the center of the Milky Way galaxy called Sagittarius A*, finding an extremely heavy, invisible object (black hole) that pulls on a jumble of stars, causing them to rush around at dizzying speeds. Some 4 million solar masses are packed together in a region no larger than our solar system. * 2021 Nobel Prize in Physiology or Medicine was shared by David Julius, of the University of California, San Francisco, and Ardem Patapoutian, of Scripps Research, in La Jolla, California, a UCSF postdoctoral alumnus, for their independent discoveries of receptors for temperature and touch."Surprise! It's a Nobel Prize", ''UCSF Magazine'', Winter 2022, pp. 28–29.

Quotations

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References

Bibliography

* * Isaac Asimov, ''Asimov's Biographical Encyclopedia of Science and Technology'', second revised edition, New York, Doubleday, 1982. * * * Tim Folger, "The Quantum Hack: Quantum computers will render today's cryptographic methods obsolete. What happens then?" ''Scientific American'', vol. 314, no. 2 (February 2016), pp. 48–55. * * Owen Gingerich, "Did Copernicus Owe a Debt to Aristarchus?" ''Journal for the History of Astronomy'', vol. 16, no. 1 (February 1985), pp. 37–42.

* Brian Greene, "Why He [Albert Einstein] Matters: The fruits of one mind shaped civilization more than seems possible", ''Scientific American'', vol. 313, no. 3 (September 2015), pp. 34–37. * A. Rupert Hall, ''Philosophers at War'', New York, Cambridge University Press, 1980. * Lawrence M. Krauss, "What Einstein Got Wrong: Cosmology (Everyone makes mistakes. But those of the legendary physicist are particularly illuminating)", ''Scientific American'', vol. 313, no. 3 (September 2015), pp. 50–55. * David Lamb, ''Multiple Discovery: The Pattern of Scientific Progress'', Amersham, Avebury Press, 1984. * David H. Levy, "My Life as a Comet Hunter: The need to pass a French test, of all things, spurred half a century of cosmic sleuthing", ''Scientific American'', vol. 314, no. 2 (February 2016), pp. 70–71. * *

, ''The Sociology of Science: Theoretical and Empirical Investigations'', University of Chicago Press, 1973. *

, ''On Social Structure and Science'', edited and with an introduction by Piotr Sztompka, University of Chicago Press, 1996. * Robert William Reid, ''

'', New York, New American Library, 1974, . * Marilynne Robinson, "On Edgar Allan Poe", ''The New York Review of Books'', vol. LXII, no. 2 (5 February 2015), pp. 4, 6. * * Joshua Rothman (journalist), Joshua Rothman, "The Rules of the Game: How does science really work?" (review of Michael Strevens, ''The Knowledge Machine: How Irrationality Created Modern Science'', Liveright), ''The New Yorker'', 5 October 2020, pp. 67–71. * Harriet Zuckerman, ''Scientific Elite: Nobel Laureates in the United States'', New York, Free Press, 1977.

External links

Annals of Innovation: In the Air: Who says big ideas are rare?
Malcolm Gladwell, ''The New Yorker'', May 12, 2008
The Technium: Simultaneous Invention
Kevin Kelly, May 9, 2008 * , Peter Turney, January 15, 2007

by B.A. Trakhtenbrot, in the ''Annals of the History of Computing'', 6(4):384–400, 1984. {{DEFAULTSORT:Multiple Discoveries Science-related lists Lists of inventions or discoveries Scientific method Discovery and invention controversies

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