Historians and sociologists have remarked upon the occurrence, in

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

, of "

multiple independent discovery Multiple may refer to: Economics *Multiple finance, a method used to analyze stock prices *Multiples of the price-to-earnings ratio *Chain stores, are also referred to as 'Multiples' *Box office multiple, the ratio of a film's total gross to tha ...

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 mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizati ...

Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, Theology, theologian, and author (described in his time as a "natural philosophy, natural philosopher"), widely ...

Gottfried Wilhelm Leibniz Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of ...

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 ...

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, hydr ...

Joseph Priestley Joseph Priestley (; 24 March 1733 – 6 February 1804) was an English chemist, natural philosopher, separatist theologian, grammarian, multi-subject educator, and liberal political theorist. He published over 150 works, and conducted ...

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 appropriat ...

, 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 Alfred Russel Wallace (8 January 1823 – 7 November 1913) was a British natural history, naturalist, explorer, geographer, anthropologist, biologist and illustrator. He is best known for independently conceiving the theory of evolution thro ...

. 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 Discovery may refer to: * Discovery (observation), observing or finding something unknown * Discovery (fiction), a character's learning something unknown * Discovery (law), a process in courts of law relating to evidence Discovery, The Discove ...

and an

invention 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 ...

, as discussed for example by Bolesław Prus. However, discoveries and inventions are inextricably related, in that discoveries lead to inventions, and inventions facilitate discoveries; and since the same phenomenon of

multiplicity Multiplicity may refer to: In science and the humanities * Multiplicity (mathematics), the number of times an element is repeated in a multiset * Multiplicity (philosophy), a philosophical concept * Multiplicity (psychology), having or using mult ...

occurs in relation to both discoveries and inventions, this article lists both multiple discoveries and multiple ''inventions''.

3rd century BCE

Aristarchus of Samos Aristarchus of Samos (; grc-gre, Ἀρίσταρχος ὁ Σάμιος, ''Aristarkhos ho Samios''; ) was an ancient Greek astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or ...

(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 Church, Catholic cano ...

(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 proper ...

(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 Sir Thomas Gresham the Elder (; c. 151921 November 1579), was an English merchant and financier who acted on behalf of King Edward VI (1547–1553) and Edward's half-sisters, queens Mary I (1553–1558) and Elizabeth I (1558–1603). In 1565 G ...

(16th century);

Henry Dunning Macleod Henry Dunning Macleod (31 March 1821 – 16 July 1902) was a Scottish economist. Life Henry Dunning Macleod was born in Edinburgh, and educated at Eton, Edinburgh University, and Trinity College, Cambridge, where he graduated in 1843. 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 In Ancient Greece, a deme or ( grc, δῆμος, plural: demoi, δημοι) was a suburb or a subdivision of Athens and other city-states ...

' comedy ''

The Frogs ''The Frogs'' ( grc-gre, Βάτραχοι, Bátrakhoi, Frogs; la, Ranae, often abbreviated ''Ran.'' or ''Ra.'') is a comedy written by the Ancient Greek playwright Aristophanes. It was performed at the Lenaia, one of the Festivals of Dionysus in ...

'' (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 was ...

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 Vertical pressure variation is the variation in pressure as a function of elevation. Depending on the fluid in question and the context being referred to, it may also vary significantly in dimensions perpendicular to elevation as well, and these va ...

(Stevin c. 1585, Galileo c. 1610). * Scipione dal Ferro (1520) and

Niccolò Tartaglia Niccolò is an Italian male given name, derived from the Greek Nikolaos meaning "Victor of people" or "People's champion". There are several male variations of the name: Nicolò, Niccolò, Nicolas, and Nicola. The female equivalent is Nicole. The f ...

(1535) independently developed a method for solving

cubic equations In algebra, a cubic equation in one variable is an equation of the form :ax^3+bx^2+cx+d=0 in which is nonzero. The solutions of this equation are called roots of the cubic function defined by the left-hand side of the equation. If all of th ...

. *

Olbers' paradox Olbers's paradox, also known as the dark night sky paradox, is an argument in astrophysics and physical cosmology that says that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. In the hyp ...

(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 Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...

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 physics, mathematical physicist and engineer born in Belfast. Professor of Natural Philosophy (Glasgow), Professor of Natural Philoso ...

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 wide ...

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

Big Bang The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

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. Acc ...

. *

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 pla ...

, 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 Abraham Ortelius (; also Ortels, Orthellius, Wortels; 4 or 14 April 152728 June 1598) was a Brabantian cartographer, geographer, and cosmographer, conventionally recognized as the creator of the first modern atlas, the ''Theatrum Orbis Terraru ...

, 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, p ...

(1801 and 1845),

Antonio Snider-Pellegrini Antonio Snider-Pellegrini (1802–1885) was a French geographer and scientist who theorized about the possibility of continental drift, anticipating Wegener's theories concerning Pangaea by several decades. In 1858, Snider-Pellegrini published h ...

Charles Lyell Sir Charles Lyell, 1st Baronet, (14 November 1797 – 22 February 1875) was a Scottish geologist who demonstrated the power of known natural causes in explaining the earth's history. He is best known as the author of ''Principles of Geolo ...

, Franklin Coxworthy (between 1848 and 1890),

Roberto Mantovani Roberto Mantovani (25 March 1854 – 10 January 1933), was an Italian geologist and violinist. He proposed an early model of continental drift in which a single continent broke up and the continents were displaced by thermal expansion and volca ...

(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 Observ ...

(1907),

Frank Bursley Taylor Frank Bursley Taylor (1860 – 1938) was an American geologist, the son of a lawyer in Fort Wayne, Indiana. although Taylor himself disapproved of the hyphenated name. But even with Wegener's extensive extra research the idea did not achieve ac ...

(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 Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

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

Sunspot Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sun ...

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 cont ...

(England, 1610),

Johannes Johannes is a Medieval Latin form of the personal name that usually appears as "John" in English language contexts. It is a variant of the Greek and Classical Latin variants (Ιωάννης, ''Ioannes''), itself derived from the Hebrew name '' Yeh ...

and

David Fabricius David Fabricius (9 March 1564 – 7 May 1617) was a German pastor who made two major discoveries in the early days of telescopic astronomy, jointly with his eldest son, Johannes Fabricius (1587–1615). David Fabricius (Latinization of his proper n ...

(

Frisia Frisia is a cross-border cultural region in Northwestern Europe. Stretching along the Wadden Sea, it encompasses the north of the Netherlands and parts of northwestern Germany. The region is traditionally inhabited by the Frisians, a West Ger ...

, 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 markgrava ...

(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 o ...

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 Ioann ...

(

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

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

Analytic geometry In classical mathematics, analytic geometry, also known as coordinate geometry or Cartesian geometry, is the study of geometry using a coordinate system. This contrasts with synthetic geometry. Analytic geometry is used in physics and engineerin ...

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. Mathem ...

Pierre de Fermat Pierre de Fermat (; between 31 October and 6 December 1607 – 12 January 1665) was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he ...

. *

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

(France, 1654),

Blaise Pascal Blaise Pascal ( , , ; ; 19 June 1623 – 19 August 1662) was a French mathematician, physicist, inventor, philosopher, and Catholic Church, Catholic writer. He was a child prodigy who was educated by his father, a tax collector in Rouen. Pa ...

(France, 1654), and Huygens (Holland, 1657). *

Determinant In mathematics, the determinant is a scalar value that is a function of the entries of a square matrix. It characterizes some properties of the matrix and the linear map represented by the matrix. In particular, the determinant is nonzero if and ...

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 ...

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. Boyle ...

and basis of derivation for the

ideal gas law The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first stat ...

, 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). The de ...

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 th ...

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 caus ...

Robert Boyle Robert Boyle (; 25 January 1627 – 31 December 1691) was an Anglo-Irish natural philosopher, chemist, physicist, alchemist and inventor. Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of ...

who published the original law in 1662. The French physicist

Edme Mariotte Edme Mariotte (; ; c. 162012 May 1684) was a French physicist and priest ( abbé). He is particularly well known for formulating Boyle's law independently of Robert Boyle. Mariotte is also credited with designing the first Newton's cradle. Biogr ...

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),

(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 L ...

Jakob Bernoulli Jacob Bernoulli (also known as James or Jacques; – 16 August 1705) was one of the many prominent mathematicians in the Bernoulli family. He was an early proponent of Leibnizian calculus and sided with Gottfried Wilhelm Leibniz during the Leib ...

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 A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...

: Patent granted to

Thomas Savery Thomas Savery (; c. 1650 – 15 May 1715) was an English inventor and engineer. He invented the first commercially used steam-powered device, a steam pump which is often referred to as the "Savery engine". Savery's steam pump was a revolutiona ...

in 1698. The invention has often been credited to

Thomas Newcomen Thomas Newcomen (; February 1664 – 5 August 1729) was an English inventor who created the atmospheric engine, the first practical fuel-burning engine in 1712. He was an ironmonger by trade and a Baptist lay preacher by calling. He ...

(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 Giovanni Branca (22 April 1571 – 24 January 1645) was an Italian engineer and architect, chiefly remembered today for what some commentators have taken to be an early steam turbine. Life Branca was born on 22 April 1571 in Sant'Angelo in L ...

(1629),

Cosimo de' Medici Cosimo di Giovanni de' Medici (27 September 1389 – 1 August 1464) was an Italian banker and politician who established the Medici family as effective rulers of Florence during much of the Italian Renaissance. His power derived from his wealth ...

(1641),

Evangelista Torricelli Evangelista Torricelli ( , also , ; 15 October 160825 October 1647) was an Italian physicist and mathematician, and a student of Galileo. He is best known for his invention of the barometer, but is also known for his advances in optics and work o ...

(1643),

Otto Von Guericke Otto von Guericke ( , , ; spelled Gericke until 1666; November 20, 1602 – May 11, 1686 ; November 30, 1602 – May 21, 1686 ) was a German scientist, inventor, and politician. His pioneering scientific work, the development of experimental me ...

(1672),

Denis Papin Denis Papin FRS (; 22 August 1647 – 26 August 1713) was a French physicist, mathematician and inventor, best known for his pioneering invention of the steam digester, the forerunner of the pressure cooker and of the steam engine. Early lif ...

(1679), and many others.

18th century

Palazzina dei servi, interni, medaglione wilhelm scheele

Platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinu ...

Antonio de Ulloa Antonio de Ulloa y de la Torre-Giralt, FRS, FRSA, KOS (12 January 1716 – 3 July 1795) was a Spanish naval officer, scientist, and administrator. At the age of nineteen, he joined the French Geodesic Mission to what is now the country o ...

and Charles Wood (both in the 1740s). *

Leyden Jar A Leyden jar (or Leiden jar, or archaically, sometimes Kleistian jar) is an electrical component that stores a high-voltage electric charge (from an external source) between electrical conductors on the inside and outside of a glass jar. It typi ...

Ewald Georg von Kleist A member of the von Kleist family, Ewald was born in Wicewo (Wicewo) in Farther Pomerania. He studied jurisprudence at the University of Leipzig and the University of Leyden and may have started his interest in electricity at the latter universit ...

(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 Benjamin Franklin ( April 17, 1790) was an American polymath who was active as a writer, scientist, inventor, statesman, diplomat, printer, publisher, and political philosopher. Encyclopædia Britannica, Wood, 2021 Among the leading inte ...

(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 Mikhail Vasilyevich Lomonosov (; russian: Михаил (Михайло) Васильевич Ломоносов, p=mʲɪxɐˈil vɐˈsʲilʲjɪvʲɪtɕ , a=Ru-Mikhail Vasilyevich Lomonosov.ogg; – ) was a Russian Empire, Russian polymath, s ...

, 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 wel ...

(

Uppsala Uppsala (, or all ending in , ; archaically spelled ''Upsala'') is the county seat of Uppsala County and the List of urban areas in Sweden by population, fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inha ...

, 1773),

(

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 Michael Sendivogius (; pl, Michał Sędziwój; 2 February 1566 – 1636) was a Polish alchemist, philosopher, and medical doctor. A pioneer of chemistry, he developed ways of purification and creation of various acids, metals and other ch ...

( pl, Michał Sędziwój; 1566–1636) is claimed as an earlier discoverer of oxygen. * Black-hole theory

John Michell John Michell (; 25 December 1724 – 21 April 1793) was an English people, English natural philosophy, natural philosopher and clergyman who provided pioneering insights into a wide range of scientific fields including astronomy, geology, opti ...

, 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 Pierre-Simon, marquis de Laplace (; ; 23 March 1749 – 5 March 1827) was a French scholar and polymath whose work was important to the development of engineering, mathematics, statistics, physics, astronomy, and philosophy. He summarized ...

. Stephen Hawking, ''A Brief History of Time'', Bantam, 1996, pp. 43–45. *

Malthusian catastrophe Malthusianism is the idea that population growth is potentially exponential while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population die off. This event, c ...

Thomas Robert Malthus Thomas Robert Malthus (; 13/14 February 1766 – 29 December 1834) was an English cleric, scholar and influential economist in the fields of political economy and demography. In his 1798 book '' An Essay on the Principle of Population'', Mal ...

(1798),

Hong Liangji Hong Liangji (, 1746–1809), courtesy names Junzhi () and Zhicun (), was a Chinese scholar, statesman, political theorist, and philosopher. He was most famous for his critical essay to the Jiaqing Emperor, which resulted in his banishment to ...

(1793). * A method for measuring the

specific heat In thermodynamics, the specific heat capacity (symbol ) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capacity. Informally, it is the amount of heat t ...

of a soliddevised independently by

Benjamin Thompson Sir Benjamin Thompson, Count Rumford, FRS (german: Reichsgraf von Rumford; March 26, 1753August 21, 1814) was an American-born British physicist and inventor whose challenges to established physical theory were part of the 19th-century revolut ...

, Count Rumford; and by

Johan Wilcke Johan Carl Wilcke was a Swedish physicist. Biography Wilcke was born in Wismar, son of a clergyman who in 1739 was appointed second pastor of the German Church in Stockholm. He went to the German school in Stockholm and enrolled at the Univers ...

, 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 In mathematics, the discrete Fourier transform (DFT) converts a finite sequence of equally-spaced samples of a function into a same-length sequence of equally-spaced samples of the discrete-time Fourier transform (DTFT), which is a complex- ...

. 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 plane In mathematics, the complex plane is the plane formed by the complex numbers, with a Cartesian coordinate system such that the -axis, called the real axis, is formed by the real numbers, and the -axis, called the imaginary axis, is formed by the ...

Geometrical 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 John Warren may refer to: Medicine * John Warren (surgeon) (1753–1815), American surgeon during the Revolutionary War * John Collins Warren (1778–1856), American surgeon * John Collins Warren Jr. (1842–1927), American surgeon, son of John C ...

(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 John William Draper (May 5, 1811 – January 4, 1882) was an English-born American scientist, philosopher, physician, chemist, historian and photographer. He is credited with producing the first clear photograph of a female face (1839–40) and ...

. The law states that only that light which is absorbed by a system can bring about a photochemical change. *

Beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form mi ...

Friedrich Wöhler Friedrich Wöhler () FRS(For) HonFRSE (31 July 180023 September 1882) was a German chemist known for his work in inorganic chemistry, being the first to isolate the chemical elements beryllium and yttrium in pure metallic form. He was the firs ...

, A.A.B. Bussy (1828). *

Electromagnetic induction Electromagnetic or magnetic induction is the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831, and James Clerk ...

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 Joseph Henry (December 17, 1797– May 13, 1878) was an American scientist who served as the first Secretary of the Smithsonian Institution. He was the secretary for the National Institute for the Promotion of Science, a precursor of the Smith ...

in the U.S. *

Chloroform Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to ...

Samuel Guthrie in the United States (July 1831), and a few months later

Eugène Soubeiran Eugène Soubeiran (5 December 1797, in Paris – 17 November 1859, in Paris) was a French scientist. From 1823 he served as chief pharmacist at La Pitie Hospital in Paris. In 1832 he became director of ''Pharmacie Centrale'', a drug manufacturi ...

(France) and

Justus von Liebig Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at t ...

(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) is produced by the exhaustive halogenation of an acetyl group (, where R can be either a hydrogen atom, an alkyl or an aryl group), in the ...

. * 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 János Bolyai (; 15 December 1802 – 27 January 1860) or Johann Bolyai, was a Hungarian mathematician, who developed absolute geometry—a geometry that includes both Euclidean geometry and hyperbolic geometry. The discovery of a consisten ...

(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 In mathematics, Graeffe's method or Dandelin–Lobachesky–Graeffe method is an algorithm for finding all of the roots of a polynomial. It was developed independently by Germinal Pierre Dandelin in 1826 and Lobachevsky in 1834. In 1837 K ...

, 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 Computational problem, problems or to perform a computation. Algorithms are used as specificat ...

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 exa ...

, developed independently by

Germinal Pierre Dandelin Germinal Pierre Dandelin (12 April 1794 – 15 February 1847) was a French mathematician, soldier, and professor of engineering. Life He was born near Paris to a French father and Belgian mother, studying first at Ghent then returning to Par ...

Karl Heinrich Gräffe Karl Heinrich Gräffe (7 November 1799 – 2 December 1873) was a German mathematician, who was professor at University of Zurich. Life and work Gräffe's father migrated to North America, leaving the family business of jewelry in his hands. E ...

, 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 Samuel Finley Breese Morse (April 27, 1791 – April 2, 1872) was an American inventor and painter. After having established his reputation as a portrait painter, in his middle age Morse contributed to the invention of a single-wire telegraph ...

(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 amoun ...

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 Julius Robert von Mayer (25 November 1814 – 20 March 1878) was a German physician, chemist, and physicist and one of the founders of thermodynamics. He is best known for enunciating in 1841 one of the original statements of the conservation ...

, 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 Urbain Jean Joseph Le Verrier FRS (FOR) HFRSE (; 11 March 1811 – 23 September 1877) was a French astronomer and mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune using ...

and

John Couch Adams John Couch Adams (; 5 June 1819 – 21 January 1892) was a British mathematician and astronomer. He was born in Laneast, near Launceston, Cornwall, and died in Cambridge. His most famous achievement was predicting the existence and position o ...

, studying

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

's orbit, independently proved that another, farther planet must exist.

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

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 steelmaking, removal of impurities from the iron by ox ...

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 In mathematics, a Möbius strip, Möbius band, or Möbius loop is a surface that can be formed by attaching the ends of a strip of paper together with a half-twist. As a mathematical object, it was discovered by Johann Benedict Listing and Augu ...

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 his ...

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. Charle ...

(discovery about 1840),

(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 ar ...

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, natural satellite, moons, comets and galaxy, g ...

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 English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

astronomer

Norman Lockyer Sir Joseph Norman Lockyer (17 May 1836 – 16 August 1920) was an English scientist and astronomer. Along with the French scientist Pierre Janssen, he is credited with discovering the gas helium. Lockyer also is remembered for being the f ...

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 Per Teodor Cleve (10 February 1840 – 18 June 1905) was a Swedish chemist, biologist, mineralogist and oceanographer. He is best known for his discovery of the chemical elements holmium and thulium. Born in Stockholm in 1840, Cleve earned his B ...

and

Nils Abraham Langlet Nils Abraham Langlet (9 July 1868 – 30 March 1936; known by his second given name) was a Swedish chemist. Biography Langlet was born in Södertälje, Sweden. He was the son of architect Emil Victor Langlet (1824–1898) and his wife, author Cla ...

, 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 Cleveite is an impure radioactive variety of uraninite containing uranium, found in Norway. It has the composition UO2 with about 10% of the uranium substituted by rare-earth elements. It was named after Swedish chemist Per Teodor Cleve. Clevei ...

.) * 1869: Dmitri Ivanovich Mendeleyev published his

periodic table The periodic table, also known as the periodic table of the (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of ch ...

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:

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 ...

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 Christopher Kasparek (born 1945) is a Scottish-born writer of Polish descent who has translated works by numerous authors, including Ignacy Krasicki, Bolesław Prus, Florian Znaniecki, Władysław Tatarkiewicz, Marian Rejewski, and Władysław ...

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 Hermann Fol (23 July 1845, Saint-Mandé – 13 March 1892) was a Swiss people, Swiss zoologist and the father of modern Cell biology, cytology. After studying medicine and zoology with Ernst Haeckel (1834–1919) at the University of Jena where h ...

independently described the entry of

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...

into the

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

and the subsequent fusion of the egg and sperm nuclei to form a single new nucleus. * 1876: Elisha Gray and

Alexander Graham Bell Alexander Graham Bell (, born Alexander Bell; March 3, 1847 – August 2, 1922) was a Scottish-born inventor, scientist and engineer who is credited with patenting the first practical telephone. He also co-founded the American Telephone and Te ...

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 A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...

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 inventio ...

. * 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 An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...

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 An Integraph is a mechanical analog computing device for plotting the integral of a graphically defined function. History Gaspard-Gustave de Coriolis first described the fundamental principal of a mechanical integraph in 1836 in the ''Journal ...

was invented independently by the British physicist Sir

Charles Vernon Boys Sir Charles Vernon Boys, FRS (15 March 1855 – 30 March 1944) was a British physicist, known for his careful and innovative experimental work in the fields of thermodynamics and high-speed photography, and as a popular science communicator th ...

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 Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

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 and ...

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 Proof most often refers to: * Proof (truth), argument or sufficient evidence for the truth of a proposition * Alcohol proof, a measure of an alcoholic drink's strength Proof may also refer to: Mathematics and formal logic * Formal proof, a co ...

of the

prime number theorem In mathematics, the prime number theorem (PNT) describes the asymptotic distribution of the prime numbers among the positive integers. It formalizes the intuitive idea that primes become less common as they become larger by precisely quantifying ...

(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 P ...

and

Silvanus Thompson Silvanus Phillips Thompson (19 June 1851 – 12 June 1916) was a professor of physics at the City and Guilds Technical College in Finsbury, England. He was elected to the Royal Society in 1891 and was known for his work as an electrical eng ...

. * 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 me ...

radioactivity by

Gerhard Carl Schmidt Gerhard Carl Schmidt (5 July 1865 – 16 October 1949) was a German chemist. Life Schmidt was born in London to German parents. He studied chemistry and in 1890 received his PhD for work with Georg Wilhelm August Kahlbaum. In 1898, two months ...

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 ...

Filipp Fortunatov Filipp Fyodorovich Fortunatov ( rus, Фили́пп Фёдорович Фортуна́тов; – ) was a Russian philologist, Indo-Europeanist and Slavist, best known for establishing the Fortunatov–de Saussure law. Biography Fortunatov wa ...

and

Ferdinand de Saussure Ferdinand de Saussure (; ; 26 November 1857 – 22 February 1913) was a Swiss linguist, semiotician and philosopher. His ideas laid a foundation for many significant developments in both linguistics and semiotics in the 20th century. He is widel ...

independently formulated the

sound law A sound change, in historical linguistics, is a change in the pronunciation of a language. A sound change can involve the replacement of one speech sound (or, more generally, one phonetic feature value) by a different one (called phonetic chang ...

now known as the Fortunatov–de Saussure law. *

Vector calculus Vector calculus, or vector analysis, is concerned with differentiation and integration of vector fields, primarily in 3-dimensional Euclidean space \mathbb^3. The term "vector calculus" is sometimes used as a synonym for the broader subject ...

was invented independently by the American,

Josiah Willard Gibbs Josiah Willard Gibbs (; February 11, 1839 – April 28, 1903) was an American scientist who made significant theoretical contributions to physics, chemistry, and mathematics. His work on the applications of thermodynamics was instrumental in t ...

(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 vec ...

(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 Theodor Heinrich Boveri (12 October 1862 – 15 October 1915) was a German zoologist, comparative anatomist and co-founder of modern cytology. He was notable for the first hypothesis regarding cellular processes that cause cancer, and for descr ...

independently proposed that the

hereditary Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...

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 Léon Philippe Teisserenc de Bort (5 November 1855 in Paris, France – 2 January 1913 in Cannes, France) was a French meteorologist and a pioneer in the field of aerology. Together with Richard Assmann (1845-1918), he is credited as co-discovere ...

independently discovered the

stratosphere The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...

. * E = mc², though only Einstein provided the accepted interpretation

Henri Poincaré Jules Henri Poincaré ( S: stress final syllable ; 29 April 1854 – 17 July 1912) was a French mathematician, theoretical physicist, engineer, and philosopher of science. He is often described as a polymath, and in mathematics as "The ...

, 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 ant ...

, 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 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 and ...

synthesized independently by

Friedrich Stolz Friedrich Stolz (6 April 1860 – 2 April 1936) was a German chemist and, in 1904, the first person to artificially synthesize epinephrine (adrenaline). References

* 1860 births 1936 deaths 19th-century German chemists 20th-century Ger ...

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 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 ...

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 indi ...

—that males have XY, and females XX, sex chromosomes—was discovered independently by

Nettie Stevens Nettie Maria Stevens (July 7, 1861 – May 4, 1912) was an American geneticist who discovered sex chromosomes. In 1905, soon after the rediscovery of Mendel's paper on genetics in 1900, she observed that male mealworms produced two kinds of sper ...

, at

Bryn Mawr College Bryn Mawr College ( ; Welsh: ) is a women's liberal arts college in Bryn Mawr, Pennsylvania. Founded as a Quaker institution in 1885, Bryn Mawr is one of the Seven Sister colleges, a group of elite, historically women's colleges in the United St ...

, 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 The Hertzsprung–Russell diagram, abbreviated as H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosity, luminosities versus their stellar classifications or eff ...

, abbreviated ''H–R diagram'', ''HR diagram'', or ''HRD'' – a

scatter plot A scatter plot (also called a scatterplot, scatter graph, scatter chart, scattergram, or scatter diagram) is a type of plot or mathematical diagram using Cartesian coordinates to display values for typically two variables for a set of data. ...

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

s showing the relationship between the stars'

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

s or luminosities versus their

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

s or

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

s – a major step toward an understanding of

stellar evolution Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is cons ...

. In 1913 the Hertzsprung–Russell diagram was independently created by

Henry Norris Russell Henry Norris Russell ForMemRS HFRSE FRAS (October 25, 1877 – February 18, 1957) was an American astronomer who, along with Ejnar Hertzsprung, developed the Hertzsprung–Russell diagram (1910). In 1923, working with Frederick Saunders, he deve ...

. *

Frequency-hopping spread spectrum Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. The changes are controlled by a code known to both tr ...

in radio work was described by Johannes Zenneck (1908),

Leonard Danilewicz Leonard Stanisław Danilewicz was a Polish engineer and, for some ten years before the outbreak of World War II, one of the four directors of the AVA Radio Company in Warsaw, Poland. Cipher Bureau work AVA designed and built radio equipment for the ...

(1929),

Willem Broertjes Willem () is a Dutch name, Dutch and West Frisian language, West FrisianRienk de Haan, ''Fryske Foarnammen'', Leeuwarden, 2002 (Friese Pers Boekerij), , p. 158. masculine given name. The name is Germanic languages, Germanic, and can be seen as the ...

(1929), and

Hedy Lamarr Hedy Lamarr (; born Hedwig Eva Maria Kiesler; November 9, 1914 January 19, 2000) was an Austrian-born American film actress and inventor. A film star during Hollywood's golden age, Lamarr has been described as one of the greatest movie actress ...

and

George Antheil George Johann Carl Antheil (; July 8, 1900 – February 12, 1959) was an American avant-garde composer, pianist, author, and inventor whose modernist musical compositions explored the modern sounds – musical, industrial, and mechanical – of t ...

(1942 US patent). * By 1913,

vitamin A Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably bet ...

was independently discovered by

Elmer McCollum Elmer Verner McCollum (March 3, 1879 – November 15, 1967) was an American biochemist known for his work on the influence of diet on health.Kruse, 1961. McCollum is also remembered for starting the first rat colony in the United States to be u ...

and

Marguerite Davis Marguerite Davis (September 16, 1887 – September 19, 1967) was an American biochemist, co-discoverer of vitamins A and B with Elmer Verner McCollum in 1913. Their research greatly influenced later research on nutrition. Personal life Davis ...

at the

University of Wisconsin–Madison A university () is an educational institution, institution of higher education, higher (or Tertiary education, tertiary) education and research which awards academic degrees in several Discipline (academia), academic disciplines. Universities ty ...

, and by

Lafayette Mendel Lafayette Benedict Mendel (February 5, 1872 – December 9, 1935) was an American biochemist known for his work in nutrition, with longtime collaborator Thomas B. Osborne, including the study of Vitamin A, Vitamin B, lysine and tryptophan. ...

and Thomas Burr Osborne at

Yale University Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the wo ...

, who studied the role of fats in the diet. *

Bacteriophage A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bacteri ...

s (

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

es that infect

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

)

Frederick Twort Frederick William Twort FRS (22 October 1877 – 20 March 1950) was an English bacteriologist and was the original discoverer in 1915 of bacteriophages (viruses that infect bacteria). He studied medicine at St Thomas's Hospital, London, was super ...

(1915),

Félix d'Hérelle Félix d'Hérelle (25 April 1873 – 22 February 1949) was a French microbiologist. He was co-discoverer of bacteriophages (viruses that infect bacteria) and experimented with the possibility of phage therapy. D'Herelle has also been credited ...

(1917). * Rotor cipher machinesTheo A. van Hengel and R.P.C. Spengler (1915);

Edward Hebern Edward Hugh Hebern (April 23, 1869 – February 10, 1952) was an early inventor of rotor machines, devices for encryption. Background Edward Hugh Hebern was born in Streator, Illinois on April 23, 1869. His parents were Charles and Rosanna (Ro ...

(1917);

Arthur Scherbius Arthur Scherbius (30 October 1878 – 13 May 1929) was a German electrical engineer who invented the mechanical cipher Enigma machine. He patented the invention and later sold the machine under the brand name Enigma. Scherbius offered uneq ...

( Enigma machine, 1918);

Hugo Koch Hugo Alexander Koch (9 March 1870, Delft – 3 March 1928, Düsseldorf) was a Dutch inventor who conceived of and patented an idea for machine encryption — the rotor machine, although he was not the first to do so. He is sometimes errone ...

(1919); Arvid Damm (1919). *

Sound film A sound film is a motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film. The first known public exhibition of projected sound films took place in Paris in 1900, but decades passed before ...

Joseph Tykociński-Tykociner Joseph Tykociński-Tykociner (also known as Joseph T. Tykociner; 5 October 1877, in Włocławek, Congress Poland – 11 June 1969, in Urbana, Illinois, United States) was a Polish engineer and a pioneer of sound-on-film technology. In 1921 he bec ...

(1922),

Lee De Forest Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor and a fundamentally important early pioneer in electronics. He invented the first electronic device for controlling current flow; the three-element "Audion" triode va ...

(1923). * The

theory of the

—that the universe is expanding from a single original point—was developed from the independent derivation of the

Friedmann equations The Friedmann equations are a set of equations in physical cosmology that govern the expansion of space in homogeneous and isotropic models of the universe within the context of general relativity. They were first derived by Alexander Friedmann ...

from Albert Einstein's equations of general relativity by the Russian,

Alexander Friedmann Alexander Alexandrovich Friedmann (also spelled Friedman or Fridman ; russian: Алекса́ндр Алекса́ндрович Фри́дман) (June 16 .S. 4 1888 – September 16, 1925) was a Russian and Soviet physicist and mathematician ...

, in 1922, and by the Belgian,

Georges Lemaître Georges Henri Joseph Édouard Lemaître ( ; ; 17 July 1894 – 20 June 1966) was a Belgian Catholic priest, theoretical physicist, mathematician, astronomer, and professor of physics at the Catholic University of Louvain. He was the first to th ...

, in 1927. The Big Bang theory was confirmed in 1929 by the American astronomer

Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an Americans, American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects ...

's analysis of galactic

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

s. 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 Georgios Nikolaou Papanikolaou (or George Papanicolaou ; el, Γεώργιος Ν. Παπανικολάου ; 13 May 1883 – 19 February 1962) was a Greek physician who was a pioneer in cytopathology and early cancer detection, and inventor of ...

is credited with discovering as early as 1923 that

cervical cancer Cervical cancer is a cancer arising from the cervix. It is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body. Early on, typically no symptoms are seen. Later symptoms may include abnormal ...

cells can be detected microscopically, though his invention of the

Pap test The Papanicolaou test (abbreviated as Pap test, also known as Pap smear (AE), cervical smear (BE), cervical screening (BE), or smear test (BE)) is a method of cervical screening used to detect potentially precancerous and cancerous processes in t ...

went largely ignored by physicians until 1943. Aurel Babeş of

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

independently made similar discoveries in 1927. * "

Primordial soup Primordial soup, also known as, primordial goo, primordial ooze, prebiotic soup and prebiotic broth, is the hypothetical set of conditions present on the Earth around 3.7 to 4.0 billion years ago. It is an aspect of the heterotrophic theory (also k ...

" theory of the abiogenetic evolution of life from carbon-based molecules

Alexander Oparin Alexander Ivanovich Oparin (russian: Александр Иванович Опарин; – April 21, 1980) was a Soviet biochemist notable for his theories about the origin of life, and for his book ''The Origin of Life''. He also studied the b ...

(1924),

J.B.S. Haldane John Burdon Sanderson Haldane (; 5 November 18921 December 1964), nicknamed "Jack" or "JBS", was a British-Indian scientist who worked in physiology, genetics, evolutionary biology, and mathematics. With innovative use of statistics in biolog ...

(1925). *

Jet stream Jet streams are fast flowing, narrow, meandering thermal wind, air currents in the Atmosphere of Earth, atmospheres of some planets, including Earth. On Earth, the main jet streams are located near the altitude of the tropopause and are west ...

was detected in the 1920s by Japanese

meteorologist A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists in research, while t ...

Wasaburo Oishi was a Japanese meteorologist. Born in Tosu, Saga, he is best known for his discovery of the high-altitude air currents now known as the jet stream. He was also an important Esperantist, serving as the second Board President of the from 1930 to 194 ...

, whose work largely went unnoticed outside Japan because he published his findings in

Esperanto Esperanto ( or ) is the world's most widely spoken constructed international auxiliary language. Created by the Warsaw-based ophthalmologist L. L. Zamenhof in 1887, it was intended to be a universal second language for international communi ...

. Often given some credit for discovery of jet streams is American pilot

Wiley Post Wiley Hardeman Post (November 22, 1898 – August 15, 1935) was a famed American aviator during the interwar period and the first pilot to fly solo around the world. Also known for his work in high-altitude flying, Post helped develop on ...

, who in the year before his 1935 death noticed that at times his

ground speed Ground speed is the horizontal speed of an aircraft relative to the Earth’s surface. It is vital for accurate navigation that the pilot has an estimate of the ground speed that will be achieved during each leg of a flight. An aircraft diving ve ...

greatly exceeded his

air speed In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: * Indicated airspeed ("IAS"), what is read on an airspeed gauge connected to a Pitot-static system; * Calibrated a ...

. Real understanding of the nature of jet streams is often credited to experience in

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

military flights. *

Borůvka's algorithm Borůvka's algorithm is a greedy algorithm for finding a minimum spanning tree in a graph, or a minimum spanning forest in the case of a graph that is not connected. It was first published in 1926 by Otakar Borůvka as a method of constructing ...

, an algorithm for finding a minimum spanning tree in a graph, was first published in 1926 by

Otakar Borůvka Otakar Borůvka (10 May 1899 in Uherský Ostroh – 22 July 1995 in Brno) was a Czech mathematician best known today for his work in graph theory.. Education and career Borůvka was born in Uherský Ostroh, a town in Moravia (then in Austri ...

. The algorithm was rediscovered by Choquet in 1938; again by Florek, Łukasiewicz, Perkal, Steinhaus, and Zubrzycki; and again by Sollin in 1965. * 1927: The discovery of

phosphocreatine Phosphocreatine, also known as creatine phosphate (CP) or PCr (Pcr), is a phosphorylated form of creatine that serves as a rapidly mobilizable reserve of high-energy phosphates in skeletal muscle, myocardium and the brain to recycle adenosine tr ...

was reported by Grace Palmer Eggleton and

Philip Eggleton Philip Eggleton FRSE (19 March 1903 – 7 October 1954) was a British biochemist, physiologist, lecturer, and (with his wife Grace Palmer Eggleton), co-discoverer of Phosphagens. Life Eggleton was born at Kingston-on-Thames on 19 March 1903 ...

of the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

and separately by Cyrus H. Fiske and

Yellapragada Subbarow Yellapragada Subba Rao (12 January 1895 – 8 August 1948) was a pioneering Indian biochemist who discovered the function of adenosine triphosphate (ATP) as an energy source in the cell, developed methotrexate for the treatment of cancer ...

Harvard Medical School Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...

. * 1929:

Dmitri Skobeltsyn Dmitri Vladimirovich Skobeltsyn (russian: Дмитрий Владимирович Скобельцын) (November 24, 1892 in Saint Petersburg – November 16, 1990) was a Soviet physicist, academician of the Soviet Academy of Sciences (1946), Hero ...

first observed the

positron The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. It has an electric charge of +1 '' e'', a spin of 1/2 (the same as the electron), and the same mass as an electron. When a positron collides ...

in 1929.

Chung-Yao Chao Chung-Yao Chao (; 27 June 1902 – 28 May 1998) was a Chinese theoretical physicist. He studied the scattering of gamma rays in lead by pair production in 1930, without knowing that positrons were involved in the anomalously high scattering cro ...

also observed the positron in 1929, though he did not recognize it as such. *

Undefinability theorem Tarski's undefinability theorem, stated and proved by Alfred Tarski in 1933, is an important limitative result in mathematical logic, the foundations of mathematics, and in formal semantics. Informally, the theorem states that ''arithmetical truth ...

, an important limitative result in

mathematical logic Mathematical logic is the study of logic, formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory. Research in mathematical logic commonly addresses the mathematical properties of for ...

Kurt Gödel Kurt Friedrich Gödel ( , ; April 28, 1906 – January 14, 1978) was a logician, mathematician, and philosopher. Considered along with Aristotle and Gottlob Frege to be one of the most significant logicians in history, Gödel had an imme ...

(1930; described in a 1931 private letter, but not published);

Alfred Tarski Alfred Tarski (, born Alfred Teitelbaum;School of Mathematics and Statistics, University of St Andrews ''School of Mathematics and Statistics, University of St Andrews''. January 14, 1901 – October 26, 1983) was a Polish-American logician a ...

(1933). *

Chandrasekhar Limit The Chandrasekhar limit () is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about (). White dwarfs resist gravitational collapse primarily through electron degeneracy pressure, compared ...

—published by

Subramanyan Chandrasekhar Subrahmanyan Chandrasekhar (; ) (19 October 1910 – 21 August 1995) was an Indian-American theoretical physicist who spent his professional life in the United States. He shared the 1983 Nobel Prize for Physics with William A. Fowler for ".. ...

(1931–35); also computed by

Lev Landau Lev Davidovich Landau (russian: Лев Дави́дович Ланда́у; 22 January 1908 – 1 April 1968) was a Soviet- Azerbaijani physicist of Jewish descent who made fundamental contributions to many areas of theoretical physics. His a ...

(1932). * A theory of

protein denaturation In biochemistry, denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some external stress or comp ...

is widely attributed to

Alfred Mirsky Alfred Ezra Mirsky (October 17, 1900 – June 19, 1974) was an American pioneer in molecular biology. Mirsky graduated from Harvard College in 1922, after which he studied for two years at the Columbia University College of Physicians and Surgeon ...

and

Linus Pauling Linus Carl Pauling (; February 28, 1901August 19, 1994) was an American chemist, biochemist, chemical engineer, peace activist, author, and educator. He published more than 1,200 papers and books, of which about 850 dealt with scientific top ...

, who published their paper in 1936, though it had been independently discovered in 1931 by

Hsien Wu Hsien Wu (; 24 November 1893 – 8 August 1959) was a Chinese biochemist and geneticist. He was the first to propose that protein denaturation was a purely conformational change, i.e., corresponded to protein unfolding and not to some chemica ...

, whom some now recognize as the originator of the theory. *

Electroluminescence Electroluminescence (EL) is an optical phenomenon, optical and electrical phenomenon, in which a material emits light in response to the passage of an electric current or to a strong electric field. This is distinct from black body light emissi ...

silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal sin ...

, now known as the

LED A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...

, was discovered independently by

Oleg Losev Oleg Vladimirovich Losev (russian: Оле́г Влади́мирович Ло́сев, sometimes spelled Lossev or Lossew in English) (10 May 1903 – 22 January 1942) was a Russian scientist and inventor An English translatio M. A. Novikov ...

in 1927 and by

H.J. Round Captain Henry Joseph Round (2 June 1881 – 17 August 1966) was an English engineer and one of the early pioneers of radio. He was the first to report observation of electroluminescence from a solid state diode, leading to the discovery of the ...

in 1907, and possibly in 1936 in

zinc sulfide Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various ...

Georges Destriau Georges Destriau (1 August 1903 - 20 January 1960) was a French physicist and early observer of electroluminescence. Education and Research In 1926 Destriau became an engineer at the École Centrale des Arts et Manufactures in Paris. Thereafter ...

, who believed it was actually a form of incandescence. * 1934:

Natural deduction In logic and proof theory, natural deduction is a kind of proof calculus in which logical reasoning is expressed by inference rules closely related to the "natural" way of reasoning. This contrasts with Hilbert-style systems, which instead use ax ...

, an approach to

proof theory Proof theory is a major branchAccording to Wang (1981), pp. 3–4, proof theory is one of four domains mathematical logic, together with model theory, axiomatic set theory, and recursion theory. Jon Barwise, Barwise (1978) consists of four correspo ...

philosophical logic Understood in a narrow sense, philosophical logic is the area of logic that studies the application of logical methods to philosophical problems, often in the form of extended logical systems like modal logic. Some theorists conceive philosophical ...

discovered independently by

Gerhard Gentzen Gerhard Karl Erich Gentzen (24 November 1909 – 4 August 1945) was a German mathematician and logician. He made major contributions to the foundations of mathematics, proof theory, especially on natural deduction and sequent calculus. He died ...

and Stanisław Jaśkowski in 1934. * The

Gelfond–Schneider theorem In mathematics, the Gelfond–Schneider theorem establishes the transcendence of a large class of numbers. History It was originally proved independently in 1934 by Aleksandr Gelfond and Theodor Schneider. Statement : If ''a'' and ''b'' are ...

, in mathematics, establishes the transcendence of a large class of numbers. It was originally proved in 1934 by

Aleksandr Gelfond Alexander Osipovich Gelfond (russian: Алекса́ндр О́сипович Ге́льфонд; 24 October 1906 – 7 November 1968) was a Soviet mathematician. Gelfond's theorem, also known as the Gelfond-Schneider theorem is named after hi ...

, and again independently in 1935 by

Theodor Schneider __NOTOC__ Theodor Schneider (7 May 1911, Frankfurt am Main – 31 October 1988, Freiburg im Breisgau) was a German mathematician, best known for providing proof of what is now known as the Gelfond–Schneider theorem. Schneider studied from 19 ...

. * The

Penrose triangle The Penrose triangle, also known as the Penrose tribar, the impossible tribar, or the impossible triangle, is a triangular impossible object, an optical illusion consisting of an object which can be depicted in a perspective drawing, but cannot e ...

, also known as the "tribar", is an

impossible object An impossible object (also known as an impossible figure or an undecidable figure) is a type of optical illusion that consists of a two- dimensional figure which is instantly and naturally understood as representing a projection of a three-d ...

. It was first created by the Swedish artist

Oscar Reutersvärd Oscar Reutersvärd (29 November 1915 – 2 February 2002) was a Swedes, Swedish graphic artist, who in 1934 pioneered the art of 3D drawings that may initially appear feasible, yet cannot be physically constructed. He is sometimes described as "th ...

in 1934. The

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

Roger Penrose Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus fello ...

independently devised and popularised it in the 1950s. * 1936: In

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

, the concept of the "universal computing machine" (now generally called the "

Turing Machine A Turing machine is a mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules. Despite the model's simplicity, it is capable of implementing any computer algori ...

") was proposed by

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical com ...

, but also independently by

Emil Post Emil Leon Post (; February 11, 1897 – April 21, 1954) was an American mathematician and logician. He is best known for his work in the field that eventually became known as computability theory. Life Post was born in Augustów, Suwałki Gove ...

, both in 1936. Similar approaches, also aiming to cover the concept of universal computing, were introduced by S.C. Kleene,

Rózsa Péter Rózsa Péter, born Rózsa Politzer, (17 February 1905 – 16 February 1977) was a Hungarian mathematician and logician. She is best known as the "founding mother of recursion theory". Early life and education Péter was born in Budapest, ...

, and

Alonzo Church Alonzo Church (June 14, 1903 – August 11, 1995) was an American mathematician, computer scientist, logician, philosopher, professor and editor who made major contributions to mathematical logic and the foundations of theoretical computer scienc ...

that same year. Also in 1936,

Konrad Zuse Konrad Ernst Otto Zuse (; 22 June 1910 – 18 December 1995) was a German civil engineer, pioneering computer scientist, inventor and businessman. His greatest achievement was the world's first programmable computer; the functional program-c ...

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 John Vincent Atanasoff, , (October 4, 1903 – June 15, 1995) was an American physicist and inventor from mixed Bulgarian-Irish origin, best known for being credited with inventing the first electronic digital computer. Atanasoff invented the ...

and

Clifford Berry Clifford Edward Berry (April 19, 1918 – October 30, 1963) helped John Vincent Atanasoff create the first digital electronic computer in 1939, the Atanasoff–Berry computer (ABC). Biography Clifford Berry was born April 19, 1918, in Gladbr ...

, was the first fully

electronic Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductor * ''Electronics'' (magazine), a defunct American trade journal *Electronic storage, the storage of data using an electronic device *Electronic co ...

digital

computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...

device; while not programmable, it pioneered important elements of modern computing, including

binary arithmetic A binary number is a number expressed in the base-2 numeral system or binary numeral system, a method of mathematical expression which uses only two symbols: typically "0" (zero) and "1" (one). The base-2 numeral system is a positional notation ...

and electronic switching elements, though its special-purpose nature and lack of a changeable,

stored program A stored-program computer is a computer that stores program instructions in electronically or optically accessible memory. This contrasts with systems that stored the program instructions with plugboards or similar mechanisms. The definition ...

distinguish it from modern computers. * The

atom bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions (thermonuclear bomb), producing a nuclear explosion. Both bomb ...

was independently thought of by

Leó Szilárd Leo Szilard (; hu, Szilárd Leó, pronounced ; born Leó Spitz; February 11, 1898 – May 30, 1964) was a Hungarian-German-American physicist and inventor. He conceived the nuclear chain reaction in 1933, patented the idea of a nuclear ...

Józef Rotblat Sir Joseph Rotblat (4 November 1908 – 31 August 2005) was a Polish and British physicist. During World War II he worked on Tube Alloys and the Manhattan Project, but left the Los Alamos Laboratory on grounds of conscience after it became cl ...

and others. * The

jet engine A jet engine is a type of reaction engine discharging a fast-moving jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include rocket, Pump-jet, water jet, and hybrid propulsion, the term ...

, independently invented by

Hans von Ohain Hans Joachim Pabst von Ohain (14 December 191113 March 1998) was a German physicist, engineer, and the designer of the first operational jet engine. Together with Frank Whittle he is called the "father of the jet engine". His first test unit ran ...

(1939),

Secondo Campini Secondo Campini (August 28, 1904 – February 7, 1980) was an Italian engineer and one of the pioneers of the jet engine. Campini was born at Bologna, Emilia-Romagna. In 1931 he wrote a proposal for the Italian Air Ministry on the value of jet pr ...

(1940) and

Frank Whittle Air Commodore Sir Frank Whittle, (1 June 1907 – 8 August 1996) was an English engineer, inventor and Royal Air Force (RAF) air officer. He is credited with inventing the turbojet engine. A patent was submitted by Maxime Guillaume in 1921 for ...

(1941) and used in working aircraft. * In

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

, the ability of synthetic

auxins Auxins (plural of auxin ) are a class of plant hormones (or plant-growth regulators) with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essenti ...

2,4-D, 2,4,5-T, and

MCPA MCPA (2-methyl-4-chlorophenoxyacetic acid) is a powerful, selective, widely used phenoxy herbicide. The pure compound is a brown-colored powder. MCPA has been extensively used in agriculture to control broad-leaf weeds as a growth regulator prima ...

to act as hormone

herbicides Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...

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 The point-contact transistor was the first type of transistor to be successfully demonstrated. It was developed by research scientists John Bardeen and Walter Brattain at Bell Laboratories in December 1947. They worked in a group led by physicis ...

was independently invented in 1947 by Americans

William Shockley William Bradford Shockley Jr. (February 13, 1910 – August 12, 1989) was an American physicist and inventor. He was the manager of a research group at Bell Labs that included John Bardeen and Walter Brattain. The three scientists were jointly ...

John Bardeen John Bardeen (; May 23, 1908 – January 30, 1991) was an American physicist and engineer. He is the only person to be awarded the Nobel Prize in Physics twice: first in 1956 with William Shockley and Walter Brattain for the invention of the tran ...

and

Walter Brattain Walter Houser Brattain (; February 10, 1902 – October 13, 1987) was an American physicist at Bell Labs who, along with fellow scientists John Bardeen and William Shockley, invented the point-contact transistor in December 1947. They shared the ...

, working at

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

, and in 1948 by German physicists

Herbert Mataré Herbert Franz Mataré (22 September 1912 – 2 September 2011) was a German physicist. The focus of his research was the field of semiconductor research. His best-known work is the first functional European transistor, which he developed and paten ...

and

Heinrich Welker Heinrich Johann Welker (9 September 1912 in Ingolstadt – 25 December 1981 in Erlangen) was a German theoretical and applied physicist who invented the " transistron", a transistor made at Westinghouse independently of the first successful tran ...

, working at the ''Compagnie des Freins et Signaux'', a Westinghouse subsidiary located in

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

. The Americans were jointly awarded the 1956

Nobel Prize in Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

"for their researches on semiconductors and their discovery of the transistor effect." * 1949: A formal definition of

cliques A clique ( AusE, CanE, or ), in the social sciences, is a group of individuals who interact with one another and share similar interests. Interacting with cliques is part of normative social development regardless of gender, ethnicity, or popular ...

in graph theory was simultaneously introduced by Luce and Perry (1949) and Festinger (1949). *

NMR spectroscopy Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. The sample is placed in a magnetic fiel ...

was independently developed in the late 1940s and early 1950s by the Purcell group at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

and the Bloch group at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

Edward Mills Purcell Edward Mills Purcell (August 30, 1912 – March 7, 1997) was an American physicist who shared the 1952 Nobel Prize for Physics for his independent discovery (published 1946) of nuclear magnetic resonance in liquids and in solids. Nuclear magne ...

and

Felix Bloch Felix Bloch (23 October 1905 – 10 September 1983) was a Swiss-American physicist and Nobel physics laureate who worked mainly in the U.S. He and Edward Mills Purcell were awarded the 1952 Nobel Prize for Physics for "their development of ne ...

shared the 1952

for their discoveries. *

Polio vaccine Polio vaccines are vaccines used to prevent poliomyelitis (polio). Two types are used: an inactivated poliovirus given by injection (IPV) and a weakened poliovirus given by mouth (OPV). The World Health Organization (WHO) recommends all chil ...

(1950–63):

Hilary Koprowski Hilary Koprowski (5 December 191611 April 2013) was a Polish virologist and immunologist active in the United States who demonstrated the world's first effective live polio vaccine. He authored or co-authored over 875 scientific papers and co ...

Jonas Salk Jonas Edward Salk (; born Jonas Salk; October 28, 1914June 23, 1995) was an American virologist and medical researcher who developed one of the first successful polio vaccines. He was born in New York City and attended the City College of New ...

Albert Sabin Albert Bruce Sabin ( ; August 26, 1906 – March 3, 1993) was a Polish-American medical researcher, best known for developing the oral polio vaccine, which has played a key role in nearly eradicating the disease. In 1969–72, he served as the ...

. * The

integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...

was devised independently by

Jack Kilby Jack St. Clair Kilby (November 8, 1923 – June 20, 2005) was an American electrical engineer who took part (along with Robert Noyce of Fairchild) in the realization of the first integrated circuit while working at Texas Instruments (TI) in 1 ...

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 In numerical linear algebra, the QR algorithm or QR iteration is an eigenvalue algorithm: that is, a procedure to calculate the eigenvalues and eigenvectors of a matrix. The QR algorithm was developed in the late 1950s by John G. F. Francis and by ...

for calculating

eigenvalues and eigenvectors In linear algebra, an eigenvector () or characteristic vector of a linear transformation is a nonzero vector that changes at most by a scalar factor when that linear transformation is applied to it. The corresponding eigenvalue, often denoted b ...

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 In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and spec ...

and

renormalization Renormalization is a collection of techniques in quantum field theory, the statistical mechanics of fields, and the theory of self-similar geometric structures, that are used to treat infinities arising in calculated quantities by altering v ...

(1930s–40s):

Ernst Stueckelberg Ernst Carl Gerlach Stueckelberg (baptised as Johann Melchior Ernst Karl Gerlach Stückelberg, full name after 1911: Baron Ernst Carl Gerlach Stueckelberg von Breidenbach zu Breidenstein und Melsbach; 1 February 1905 – 4 September 1984) was a S ...

Julian Schwinger Julian Seymour Schwinger (; February 12, 1918 – July 16, 1994) was a Nobel Prize winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant ...

Richard Feynman Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superflu ...

, and Sin-Itiro Tomonaga, for which the latter 3 received the 1965

. * The

maser A maser (, an acronym for microwave amplification by stimulated emission of radiation) is a device that produces coherent electromagnetic waves through amplification by stimulated emission. The first maser was built by Charles H. Townes, Ja ...

, a precursor to the

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...

, was described by Russian scientists in 1952, and built independently by scientists at

in 1953. The

itself was developed independently by

Gordon Gould Gordon Gould (July 17, 1920 – September 16, 2005) was an American physicist who is sometimes credited with the invention of the laser and the optical amplifier. (Credit for the invention of the laser is disputed, since Charles Townes and ...

at Columbia University and by researchers at

, and by the Russian scientist Aleksandr Prokhorov. *

Kolmogorov complexity In algorithmic information theory (a subfield of computer science and mathematics), the Kolmogorov complexity of an object, such as a piece of text, is the length of a shortest computer program (in a predetermined programming language) that produ ...

, 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 Ray Solomonoff (July 25, 1926 – December 7, 2009) was the inventor of algorithmic probability, his General Theory of Inductive Inference (also known as Universal Inductive Inference),Samuel Rathmanner and Marcus Hutter. A philosophical treatise ...

Andrey Kolmogorov Andrey Nikolaevich Kolmogorov ( rus, Андре́й Никола́евич Колмого́ров, p=ɐnˈdrʲej nʲɪkɐˈlajɪvʲɪtɕ kəlmɐˈɡorəf, a=Ru-Andrey Nikolaevich Kolmogorov.ogg, 25 April 1903 – 20 October 1987) was a Sovi ...

and

Gregory Chaitin Gregory John Chaitin ( ; born 25 June 1947) is an Argentine-American mathematician and computer scientist. Beginning in the late 1960s, Chaitin made contributions to algorithmic information theory and metamathematics, in particular a computer-t ...

in the 1960s. * The concept of

packet switching In telecommunications, packet switching is a method of grouping Data (computing), data into ''network packet, packets'' that are transmitted over a digital Telecommunications network, network. Packets are made of a header (computing), header and ...

, a communications method in which discrete blocks of data ( packets) are routed between

nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two ...

over data links, was first explored by

Paul Baran Paul Baran (born Pesach Baran ; April 29, 1926 – March 26, 2011) was a Polish-American engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the dom ...

in the early 1960s, and then independently a few years later by

Donald Davies Donald Watts Davies, (7 June 1924 – 28 May 2000) was a Welsh computer scientist who was employed at the UK National Physical Laboratory (NPL). In 1965 he conceived of packet switching, which is today the dominant basis for data communic ...

. * The principles of

atomic layer deposition Atomic layer deposition (ALD) is a thin-film deposition technique based on the sequential use of a gas-phase chemical process; it is a subclass of chemical vapour deposition. The majority of ALD reactions use two chemicals called precursors (also ...

, a thin-film growth method that in the 2000s contributed to the continuation of semiconductor-device scaling in accord with

Moore's law Moore's law is the observation that the number of transistors in a dense integrated circuit (IC) doubles about every two years. Moore's law is an observation and projection of a historical trend. Rather than a law of physics, it is an empir ...

, were independently discovered in the early 1960s by the Soviet scientists

Valentin Aleskovsky Valentin Borisovich Aleskovsky (russian: Валенти́н Бори́сович Алеско́вский; 3 June 1912 - 29 January 2006) was a Soviet and Russian scientist and administrator known for his pioneering research on surface reactions ...

and Stanislav Koltsov and in 1974 by the Finnish inventor

Tuomo Suntola Tuomo Suntola (born 1943) is a Finnish physicist, inventor, and technology leader. He is best known for his pioneering research in materials science, developing the thin film growth technique called atomic layer deposition. Early life Suntola w ...

. * 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 The Vine–Matthews–Morley hypothesis, also known as the Morley–Vine–Matthews hypothesis, was the first key scientific test of the seafloor spreading theory of continental drift and plate tectonics. Its key impact was that it allowed the r ...

was independently proposed by

Lawrence Morley Lawrence Whitaker Morley (February 19, 1920 – April 22, 2013) was a Canadian geophysicist and remote sensing pioneer. He was best known for his studies on the magnetic properties of the oceanic crust and their effect on plate tectonics and for ...

, and by

Fred Vine Frederick John Vine FRS (born 17 June 1939) is an English marine geologist and geophysicist. He made key contributions to the theory of plate tectonics, helping to show that the seafloor spreads from mid-ocean ridges with a symmetrical patter ...

and

Drummond Matthews Drummond Hoyle Matthews FRS (5 February 1931 – 20 July 1997), known as "Drum", was a British marine geologist and geophysicist and a key contributor to the theory of plate tectonics. His work, along with that of fellow Briton Fred Vine a ...

, linking

seafloor spreading Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. History of study Earlier theories by Alfred Wegener an ...

and the symmetric "zebra pattern" of magnetic reversals in the

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

rocks on either side of mid-ocean ridges. *

Cosmic background radiation Cosmic background radiation is electromagnetic radiation from the Big Bang. The origin of this radiation depends on the region of the spectrum that is observed. One component is the cosmic microwave background. This component is redshifted pho ...

as a signature of the

was confirmed by

Arno Penzias Arno Allan Penzias (; born April 26, 1933) is an American physicist, radio astronomer and Nobel laureate in physics. Along with Robert Woodrow Wilson, he discovered the cosmic microwave background radiation, which helped establish the Big Bang ...

and Robert Wilson of

. 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 Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...

two physicists,

Robert Dicke Robert Henry Dicke (; May 6, 1916 – March 4, 1997) was an American astronomer and physicist who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity. He was the Albert Einstein Professor in Scienc ...

and

Jim Peebles Phillip James Edwin Peebles (born April 25, 1935) is a Canadian-American astrophysicist, astronomer, and theoretical cosmologist who is currently the Albert Einstein Professor in Science, Emeritus, at Princeton University. He is widely regard ...

, were working on a suggestion of

George Gamow George Gamow (March 4, 1904 – August 19, 1968), born Georgiy Antonovich Gamov ( uk, Георгій Антонович Гамов, russian: Георгий Антонович Гамов), was a Russian-born Soviet and American polymath, theoreti ...

's that the early universe had been hot and dense; they believed its hot glow could still be detected but would be so red-shifted that it would manifest as microwaves. When Penzias and 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 The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

in physics. *

Conductive polymers Conductive polymers or, more precisely, intrinsically conducting polymers (ICPs) are organic polymers that Electrical conductance, conduct electricity. Such compounds may have metallic conductivity or can be semiconductors. The biggest advantage ...

: 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 "

." * 1964: The relativistic model for the

Higgs mechanism In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons. Without the Higgs mechanism, all bosons (one of the two classes of particles, the other bein ...

was developed by three independent groups:

Robert Brout Robert Brout (; June 14, 1928 – May 3, 2011) was an American theoretical physicist who made significant contributions in elementary particle physics. He was a professor of physics at Université Libre de Bruxelles where he had created, together ...

and

François Englert François, Baron Englert (; born 6 November 1932) is a Belgian theoretical physicist and 2013 Nobel prize laureate. Englert is professor emeritus at the Université libre de Bruxelles (ULB), where he is a member of the Service de Physique Thé ...

;

Peter Higgs Peter Ware Higgs (born 29 May 1929) is a British theoretical physicist, Emeritus Professor in the University of Edinburgh,Griggs, Jessica (Summer 2008The Missing Piece ''Edit'' the University of Edinburgh Alumni Magazine, p. 17 and Nobel Prize ...

; and

Gerald Guralnik Gerald Stanford "Gerry" Guralnik (; September 17, 1936 – April 26, 2014) was the Chancellor’s Professor of Physics at Brown University. In 1964 he co-discovered the Higgs mechanism and Higgs boson with C. R. Hagen and Tom Kibble (GHK). As par ...

, Carl Richard Hagen, and

Tom Kibble Sir Thomas Walter Bannerman Kibble (; 23 December 1932 – 2 June 2016) was a British theoretical physicist, senior research investigator at the Blackett Laboratory and Emeritus Professor of Theoretical Physics at Imperial College London. His ...

. Slightly later, in 1965, it was also proposed by Soviet undergraduate students

Alexander Migdal Alexander Arkadyevich Migdal (russian: Александр Арка́дьевич Мигдал; born 22 July 1945) is a Russian-American physicist and entrepreneur, formerly at Landau Institute for Theoretical Physics, Space Research Institute, P ...

and

Alexander Markovich Polyakov Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Al ...

. The existence of the "

Higgs boson The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory. In the Stand ...

" was finally confirmed in 2012; Higgs and Englert were awarded a Nobel Prize in 2013. * The Cocke–Younger–Kasami algorithm was independently discovered three times: by T. Kasami (1965), by Daniel H. Younger (1967), and by John Cocke and Jacob T. Schwartz (1970). * The

Wagner–Fischer algorithm In computer science, the Wagner–Fischer algorithm is a dynamic programming algorithm that computes the edit distance between two strings of characters. History The Wagner–Fischer algorithm has a history of multiple invention. Navarro lists the ...

, in

, was discovered and published at least six times. * The

affine scaling In mathematical optimization, affine scaling is an algorithm for solving linear programming problems. Specifically, it is an interior point method, discovered by Soviet Union, Soviet mathematician I. I. Dikin in 1967 and reinvented in the United S ...

method for solving

linear programming Linear programming (LP), also called linear optimization, is a method to achieve the best outcome (such as maximum profit or lowest cost) in a mathematical model whose requirements are represented by linear function#As a polynomial function, li ...

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 The neutral theory of molecular evolution holds that most evolutionary changes occur at the molecular level, and most of the variation within and between species are due to random genetic drift of mutant alleles that are selectively neutral. The ...

was introduced by a Japanese biologist,

Motoo Kimura (November 13, 1924 – November 13, 1994) was a Japanese biologist best known for introducing the neutral theory of molecular evolution in 1968. He became one of the most influential theoretical population geneticists. He is remembered in geneti ...

, in 1968, and independently by two American biologists,

Jack Lester King Jack Lester King (March 9, 1934 – June 29, 1983) was an American evolutionary biologist best known for co-authoring (with Thomas H. Jukes) a seminal paper on the neutral theory of molecular evolution, "Non-Darwinian Evolution". King was bor ...

and Thomas Hughes Jukes, in 1969. * 1969:

Thyrotropin-releasing hormone Thyrotropin-releasing hormone (TRH) is a hypophysiotropic hormone produced by neurons in the hypothalamus that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary. TRH has been used clinicall ...

(TRH) structure was determined, and the

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

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

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

. * 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

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

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

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

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

Notes

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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