2,500,000 B.C.E.

Earliest known stone tools.

41,000 B.C.E.

Earliest mine: iron ore (used as pigments) in Swaziland.

4000–3500 B.C.E.

Copper alloy and smelting of gold and silver known by the Egyptians and Sumerians. Bamboo rafts used in China. Canals constructed in Iraq. Earliest known security lock.

3500–3000 B.C.E.

Potter’s wheel, wheeled vehicles, and linen in use. Egyptians use boats with sails. First known written language (Sumerian). Earliest known dam is constructed in Jordan. Construction of Stonehenge is begun.

3000–2500 B.C.E.

Weaving loom used in Europe. Egypt adopts a 365-day calendar. First iron objects forged. Great Pyramid of Giza built (ca. 2600 B.C.E). Chinese cul-tivate silkworms and weave silk.

2500–2000 B.C.E

Egyptians using papyrus. First form of plow used in Egypt. Bow and arrow used in warfare.

2000–1500 B.C.E.

Mercury used in Egypt. Contraceptives in use in Egypt. Earliest known metal water pipes in Egypt. Crete adopts a decimal counting system. The chariot becomes an effective battle vehicle.

1500–1000 B.C.E.

Iron Age in Syria and Palestine. First Chinese dictionary. Phoenicians import tin from England.

1000–900 B.C.E.

Natural fabric dyes used in Mediterranean area. Underground water system built in Jerusalem.

900–800 B.C.E.

Iron and steel production in Indo-Caucasian culture. Earliest known printed book.

800–700 B.C.E.

Hand cranks used by Etruscans. Spoked wheels and horseshoes in use in Europe.

700–600 B.C.E.

Assyrians devise water clocks. Phoenicians intro-duce the first war galleys. Earliest astronomical observatory in Korea. Lydia (ancient land of west-ern Asia minor) mints first coinage.

600–500 B.C.E.

Ore smelting and casting, water level, lock and key, and turning lathe credited to Theodorus of Samos. Persian Empire establishes postal service. Darius the Great (Persia) lays pontoon bridges across the Bosphorus and Danube.

500–400 B.C.E.

Cataract operations performed by Indian surgeon Susrata (ca. 500 B.C.E.). Democritus of Abdera pro-poses an atomic theory of the Universe.

400–300 B.C.E.

Siege catapults first in use. In Organon, Aristotle explains logical reasoning. Lathe in use in Egypt.

300–250 B.C.E.

The first lighthouse, the Pharos of Alexandria, is built. Greek prisoners of war introduce medicine to Romans.

250–200 B.C.E.

Parchment introduced at Pergamum. Eratosthenes of Alexandria makes close estimate of Earth’s circumference. Chinese weights and measures stan-dardized. Great Wall of China built. Ctesibus of Alexandria invents the force pump.

200–150 B.C.E.

Hipparchus of Nicaea invents trigonometry. Riding stirrups appear in India.

150–100 B.C.E.

Crates of Mallus makes a globe representing Earth. Mathematician Heron founds first college of tech-nology at Alexandria (ca. 105 B.C.E.).

100–50 B.C.E.

Pompey the Great’s trainer, Atticus of Naples, invents the medicine ball. Water mills in use in the Roman empire.

50–2 B.C.E.

Julian calendar introduces leap year.

1–100 C.E.

First reference to diamonds (ca. 16). Cranes first used in Greco–Roman world. Pliny reports the use of glass mirrors in the Roman world.

100–200

Chang Hêng (China) makes a seismometer. Galen uses plant juices as medicine (ca. 190). First wheel-barrow developed in China (ca. 200).

250–300

Compass probably first used in China. Cog wheel, lever, pulley, screw, and wedge described by Pappus of Alexandria.

300–350

Grand Canal of China begun with 120-mile (193 km) stretch: eventually finished between 1280 and 1300 to a length of 1,100 miles (1,700 km).

500–600

First paddle-wheel boats with animal drive. Book printing in China.

620

Porcelain produced in China.

650–750

Earliest known windmills in Persia (644). First printed newspaper appears in Beijing (748).

750–850

Pictorial book printing in Japan (765). Persian sci-entist and mathematician Muhammed Ibn-Musaal-Kwarazmi writes book on equations and invents the term algebra (810).

900–950

Paper manufacturing in Cairo. Persian doctor Abu-Bakr Muhammed Ibn-Zakariya al-Razi describes plague, consumption, smallpox, and rabies.

950–1000

Persian astronomer Abd-al-Rahman Al Sufi pro-vides the first documented observation of a star system outside our galaxy (963). Arabic numerals brought to Europe (975). Chinese perfect gunpow-der (1000).

1000–1200

Water-driven mechanical clock constructed in Beijing (1090). Chinese use explosives in warfare (1151). Trebuchet super-heavy siege stonethrower comes into use (1200).

1250–1300

Goose quill used for writing (1250). Earliest record of human dissection (1275).

1300–1350

First reference to eyeglasses (1303). Cannon used at Siege of Metz (1324). Invention of the sawmill (1328). First scientific weather forecast, by William Merlee of Oxford, England (1337).

1400–1450

Dutch fishermen first to use drift nets (1416). Coiled springs replace weights in clocks (1430).

1450–1500

Johannes Gutenberg (Germany) invents printing with movable metal type (1452). Leonardo da Vinci (Italy) draws a parachute (1480) and observes capil-lary action (1490). Earliest surviving terrestrial globe made in Nuremberg by geographer Martin Behaim (Germany) (1492).

1500–1550

Leonardo da Vinci (Italy) designs horizontal water wheel (water turbine) (1510). Spinning wheel in general use in Europe. Nicholas Copernicus (Poland) proposes that Earth and other planets move around the Sun (1530). Gerardus Mercator (Flanders, now Belgium) discovers Earth’s magnetic poles (1546).

1550–1600

Georgius Agricola (Germany) publishes a scientific text on mining and metallurgy, De Re Metallica (1556). Gerardus Mercator (Flanders, now Belgium) designs a flat world map that represents the spherical shape of Earth (the Mercator projec-tion, 1569). Galileo (Italy) invents the thermome-ter (1593). Sir John Harington (England) invents a flush toilet (1596).

1601–1620

Johannes Kepler (Germany) devises the three laws of planetary motion. Hans Lippershey (Germany) invents the telescope (1608).

1621–1630

Willebrord Snell (Holland) discovers the law of light refraction (Snell’s law, 1621). William Harvey (England) publishes his discovery of the circulation of the blood (1628).

1641–1650

Evangelista Torricelli (Italy) invents the barometer (1643). Athanasius Kircher (Germany) publishes a book showing the design for a projection lantern (magic lantern) (1646). Blaise Pascal (France) devises the basic laws of hydraulic systems (Pascal’s principle, 1647).

1651–1660

Christiaan Huygens (Holland) invents the pendu-lum clock (1656). Robert Hooke (England) invents the balance spring for watches (1658) and discovers the law of elasticity (1660).

1661–1670

Sir Isaac Newton (England) devises the first calcu-lus system (1660s). Robert Boyle (Ireland) coins the word element for a simple pure substance (1661) and discovers that the volume and pressure of a gas are inversely proportional (Boyle’s law, 1662). Robert Hooke (England) discovers plant cells (1665). Francesco Grimaldi (Italy) publishes a paper on the diffraction of light (1665).

1671–1680

Anton van Leeuwenhoek (Holland) discovers microorganisms (1670s). Sir Isaac Newton (England) invents the reflecting telescope (1671). Christiaan Huygens (Holland) discovers the polar-ization of light and proposes the wave theory of light (1678).

1681–1700

Sir Isaac Newton (England) proposes three laws of motion and a law of gravitation (1687). Plate glass is made for the first time (1688). Denis Papin (France) designs a steam piston engine (1690). Thomas Savery (England) invents the first practical steam engine (1698).

1701–1710

Charles Townshend (England) devises the four-field crop rotation system (the Norfolk system, 1700s). Sir Isaac Newton (England) demonstrates that white light is made up of different colors (1704). Thomas Newcomen (England) designs the first steam engine with a separate boiler (1705).

1711–1730

Gabriel Daniel Fahrenheit (Germany) invents the first accurate mercury thermometer (1714). James Puckle (England) invents the first machine gun (1718). Gabriel Daniel Fahrenheit (Germany) devises the Fahrenheit temperature scale (1724).

1731–1740

John Kay (England) invents the flying shuttle for textile manufacture (1733). John Harrison (England) invents the first marine chronometer for determining longitude (1735). Daniel Bernoulli (Holland) discovers the principle of fluid flow (Bernoulli’s principle, 1738).

1741–1750

Anders Celsius (Sweden) devises the original Celsius, or centigrade, temperature scale (1742). Ewald Jurgen von Kleist (Germany) invents the electric capacitor (1745).

1751–1770

Benjamin Franklin (United States) invents the lightning conductor (1753). Henry Cavendish (England) discovers that hydrogen is less dense than air. (1766). Nicolas Gugnot (France) con-structs the first steam carriage for use on roads (1769). James Watt (Britain) patents his design for a more efficient steam engine (1769).

1771–1780

Joseph Priestley (Britain) identifies oxygen. David Bushnell (United States) builds the first submarine (1776). Antoine Lavoisier (France) discovers that combustion occurs as a result of reactions with oxy-gen in air (1777). Abraham Darby III (Britain) con-structs the first cast-iron bridge (1779).

1783

Joseph and Jacques Montgolfier (France) invent the first passenger-carrying hot-air balloon. Jacques-Alexandre-César Charles (France) invents the hydrogen balloon.

1784

Joseph Bramah (Britain) designs an unpickable lock. Henry Shrapnel (Britain) invents a shell with an inner core of lead shot designed to explode over the enemy, the shrapnel shell. Pierre Aimé Argand (Switzerland) invents the first efficient oil lamp, the Argand burner. Henry Cavendish (England) deter-mines the composition of water.

1787

John Fitch (United States) builds the first success-ful steam-powered boat. Jacques-Alexandre-César Charles (France) discovers that under constant pressure the volume of a gas is directly propor-tional to its temperature (Charles’s law).

1788

James Watt (Britain) invents a centrifugal governor for steam engines.

1789

Antoine Lavoisier (France) devises the first list of chemical elements. First steam-driven cotton fac-tory, at Manchester, England. Antoine Jussieu (France) introduces modern plant classification in his book Genera plantarum. Oliver Evans (United States) patents a design for a high-pressure steam engine (1790).

1791–1795

William Murdock (Scotland) devises a method of making, purifying, and storing coal gas (1790s). Eli Whitney (United States) invents the cotton gin and the milling machine (1793). Joseph Bramah (Britain) invents the hydraulic press (1795).

1796–1800

J. T. Lowitz (Russia) prepares pure ethyl alcohol. Edward Jenner (Britain) develops the first success-ful vaccine (for smallpox). Alois Senefelder (Germany) invents lithography (1798). Alessandro Volta (Italy) invents the first electrical battery, the voltaic pile (1800).

1801–1810

Thomas Young (Britain) revives the wave theory of light and devises the trichromatic (three-color) the-ory of vision. Richard Trevithick (Britain) designs and constructs the first steam-driven railroad loco-motive (1804). Joseph-Marie Jacquard (France) invents a loom that uses a system of punched cards to control the weaving pattern (1805).

1811–1820

Friedrich Mohs (Germany) devises the scale of mineral hardness (the Mohs’s scale, 1812). Sir Humphry Davy (Britain) invents a safety lamp for miners. Robert Stirling (Britain) invents the gas engine (the Stirling engine, 1816). Hans Christian Oersted (Denmark) demonstrates that an electric current produces a magnetic effect (1819). René Théophile Hyacinthe Laënnec (France) invents the stethoscope (1819).

1821–1825

Charles Babbage (Britain) makes early attempts to construct mechanical computers (1820s). Sir Michael Faraday (Britain) produces an early electric motor (1821). Thomas Johann Seebeck (Estonia) discovers the thermoelectric effect (the Seebeck effect, 1822). André-Marie Ampère (France) establishes the laws of electrodynamics (1822). George Stephenson (Britain) builds the first public passenger steam railroad locomotive (1825). Hans Christian Oersted (Denmark) uses electrolysis to isolate aluminum from its ore (1825).

1826–1830

Joseph Nicéphore Niepce (France) produces the earliest surviving photograph (1826). Georg Simon Ohm (Germany) discovers that the electrical cur-rent in a resistor is directly proportional to the voltage and inversely proportional to the resistance (Ohm’s law, 1827). Joseph Henry (United States) discovers electromagnetic induction (1830) inde-pendently of Faraday.

1831–1835

Sir Michael Faraday (Britain) discovers electro-magnetic induction independently of Henry (1831) and produces the basic laws of electrolysis (Faraday’s laws of electrolysis, 1833). Samuel Colt (United States) invents the modern revolver (1830s). Thomas Davenport (United States) invents the electric streetcar (1834). Samuel Finley Breeze Morse (United States) invents the electric telegraph (1835).

1836–1840

Sir Francis Pettit Smith (Britain) and John Ericsson (Sweden) invent independently the screw propeller (1836). Louis Jacques Mandé Daguerre (France) invents the first useful photographic process (the daguerreotype process, 1837). William Henry Fox Talbot (Britain) invents negative–positive photography (1839). Charles Goodyear (United States) invents the vulcanization process for strengthening rubber.

1841–1845

Christian Johann Doppler (Austria) discovers the frequency change of a wave due to the relative motion between its source and the observer, the Doppler effect. Ada Lovelace (Britain) predicts the use of computers for nonmathematical func-tions and invents possibly the first computer program (1845).

1846–1850

William Thomas Morton (United States) pioneers the use of ether as an anesthetic (1846). William Thomson (Lord Kelvin) (Britain) devises the absolute temperature scale; the Kelvin scale (1848). Armand-Hippolyte-Louis Fizeau (France) makes the first accurate measurement of the speed of light (1849). Sir George Cayley (Britain) designs and constructs the first passenger-carrying glider (1849). Rudolf Clausius (Germany) formulates the Second Law of Thermodynamics and kinetic theory of gases (1850).

1851–1855

William Kelly (United States) invents a process of making steel, independently of Sir Henry Bessemer (1850s). Elisha Graves Otis (United States) invents an automatic safety device for elevators (1853). Alexander Parkes (Britain) discovers cellulose nitrate; parkensine (1855).

1856–1860

Sir Henry Bessemer (Britain) invents a process of making steel, the Bessemer process (1856), inde-pendently of William Kelly. Jean-Joseph Étienne Lenoir (Belgium) invents the first practical internal combustion engine (1860). Louis Pasteur (France) establishes that microorganisms are responsible for fermentation.

1861

Ernest Solvay (Belgium) invents a process for pro-ducing sodium carbonate; the Solvay process.

1862

Alphonse Eugène Beau de Rochas (France) patents the four-stroke internal combustion engine. Alfred Bernhard Nobel (Sweden) invents the mercury ful-minate detonator for nitroglycerine. Julius Sachs (Germany) demonstrates that starch is produced by photosynthesis.

1863

Pierre Émile Martin (France) invents the open-hearth process for the production of steel (the Siemens-Martin process).

1864

James Clerk Maxwell (Britain) formulates the fun-damental equations of electromagnetism. Louis Pasteur (France) demonstrates that microorgan-isms in foods such as wine and milk are destroyed by heating (pasteurization).

1865

Baron Joseph Lister (Britain) introduces the use of antiseptic techniques in surgery. Atlantic telegraph cable is completed. Thaddeus Lowe (United States) invents the ice machine.

1866

Alfred Bernhard Nobel (Sweden) invents dynamite. Georges Leclanché (France) invents the forerunner of the dry-cell battery (the Leclanché cell). Robert Whitehead (Britain) invents underwater torpedo.

1870–1875

Andrew Smith Hallidie (Britain) invents the cable car (1870s). Alfred Bernhard Nobel (Sweden) invents blasting gelatin, gelignite (1875).

1876

Alexander Graham Bell (Britain) invents the tele-phone. Thomas Alva Edison (United States) estab-lishes the first industrial research laboratory. Samuel Plimsoll (Britain) invents the load-line on ships (the Plimsoll mark).

1877

Thomas Alva Edison (United States) invents the phonograph. In the United States, the first public telephones are installed and used.

1878

Sir Joseph Wilson Swan (Britain) invents a carbon-filament lightbulb, independently of Edison. Carl Gustaf Patrik de Laval (Sweden) invents the first modern centrifuge.

1879

Thomas Alva Edison (United States) invents a carbon-filament lightbulb, independently of Swan. Lars Nilson (Sweden) discovers element scandium.

1880

Pierre Curie (France) discovers the piezoelectric effect. Louis Pasteur (France) discovers a chicken cholera vaccine. Charles Laveran (France) discov-ers parasite Plasmodium, which causes malaria.

1882

Robert Koch (Germany) discovers the microorgan-isms that cause tuberculosis. Thomas Alva Edison (United States) builds the first hydroelectric plant, at Appleton, Wisconsin.

1883

Robert Koch (Germany) discovers the microorgan-isms that cause cholera. Thomas Alva Edison (United States) discovers thermionic emission (the Edison Effect). Nikola Tesla (Serbia/United States) constructs the first induction motor.

1884

Sir Charles Algernon Parsons (Britain) invents the modern steam turbine. Svante August Arrhenius (Sweden) discovers electrolytic dissociation.

1885

Carl Benz (Germany) designs and builds the first practical automobile for use by the public. Louis Pasteur (France) devises rabies vaccine. Gottleib Daimler (Germany) builds the first motorcycle. Hiram Stevens Maxim (United States) demon-strates his fully automatic belt-fed machine gun.

1886

Paul Louis Toussaint Héult (France) and Charles M. Hall (United States) independently invent anelectrolytic process (the Hall-Héult process) for extracting aluminum from bauxite.

1887

William Holabird and Martin Roche (United States) design the first steel-frame skyscraper. Heinrich Rudolph Hertz (Germany) transmits and receives radio waves for the first time.

1888

John Boyd Dunlop (Britain) invents the pneumatic tire. George Eastman (United States) perfects the Kodak box camera.

1889

Gottlieb Daimler (Germany) designs and builds one of the earliest gasoline-powered motor cars. Alexandre Gustave Eiffel (France) constructs the Eiffel Tower.

1890

Rubber gloves used for the first time in surgery, at Johns Hopkins Hospital, Baltimore.

1891

Edward Goodrich Acheson (United States) devel-ops a method for synthesizing Carborundum (sili-con carbide). First automatic telephone exchange. Rudolf Christian Karl Diesel (Germany) patents a design for a compression-ignition engine (the diesel engine).

1892

Nikola Tesla (Serbia/United States) invents the Tesla coil and predicts the advent of the radio.

1895

Wilhelm Konrad Röontgen (Germany) discovers X rays. Guglielmo Marconi (Italy) invents radio telegraphy with experiments near Bologna. Louis and Auguste Lumière (France) invent the cinèatographe, the first successful film projector.

1896

Antoine Henri Becquerel (France) discovers radioactivity. George Washington Carver (United States) begins the process of revolutionizing farming in the southern states by developing commer-cial uses for agricultural crops such as peanuts. Ernest Rutherford (New Zealand) discovers the emission of alpha and beta particles during radio-active decay. Guglielmo Marconi (Italy) invents a successful system of radio telegraphy. Scipione Riva-Rocci (Italy) invents the sphygmomanometer.

1897

Sir Joseph John Thomson (Britain) discovers the electron. Ferdinand Braun (Germany) develops the cathode-ray tube.

1898

Marie Curie (Poland/France) and Pierre Curie (France) discover the radioactive elements radium and polonium.

1900

Max Karl Ernst Ludwig Planck (Germany) devises quantum theory. Ernest Rutherford (New Zealand) discovers the emission of gamma rays during radioactive decay.

1901

Karl Landsteiner (Austria) discovers human blood groups.

1902

Willis Haviland Carrier (United States) invents air conditioning.

1903

Wilbur and Orville Wright (United States) design, construct, and fly the first powered airplane, the Wright Flyer.

1904

Sir John Ambrose Fleming (Britain) invents the diode. The first ultraviolet lamps are made. First telegraphic transmission of photographs, by Arthur Korn (Germany).

1905

Albert Einstein (Germany) publishes a paper explaining the photoelectric effect and formulates the special theory of relativity.

1906

Lee De Forest (United States) invents the triode valve amplifier. Reginald Aubrey Fessenden (United States) broadcasts first voice-and-music radio program. Charles Franklin Kettering (United States) invents the electric cash register.

1907

Bertram Borden Boltwood (United States) discov-ers ionium, a radioactive isotope of thorium, and revolutionizes geology by introducing radioactive decay as a method of dating rocks and establishing the age of Earth.

1908

Fritz Haber (Germany) discovers how to manufac-ture ammonia from nitrogen and hydrogen (the Haber process). Hans Geiger (Germany) invents a device for detecting radiation (the Geiger counter).

1909

Paul Ehrlich (Germany) discovers salvarsan, a cure for syphilis. Louis Blériot (France) crosses English Channel by airplane. Leo H. Baekeland (Belgium) invents the first synthetic plastic (Bakelite).

1910

Georges Claude (France) invents neon lighting. Carl Bosch (Germany) develops the synthesis of ammonia on an industrial scale (the Haber-Bosch process).

1911

Heike Kamerlingh Onnes (Holland) discovers superconductivity. Ernest Rutherford (New Zealand) discovers the atomic nucleus.

1913

Neils Bohr (Denmark) propounds the orbiting electron theory of atomic structure. Irving Langmuir (United States) invents a gas-filled, tungsten-filament lightbulb.

1916

Albert Einstein (Germany) devises the general theory of relativity. Blood for transfusion is refrig-erated. F. W. Mott (Britain) suggests theory of shell shock.

1917

Allied Anti-Submarine Detection Investigation Committee produces prototype asdic, or sonar.

1920

Ernest Rutherford (New Zealand) discovers the proton and predicts the existence of the neutron.

1921

Sir Frederick Grant Banting (Canada) and Charles Herbert Best (United States) discover the hormone insulin and administer it to diabetic patients.

1924

Hans Berger (Germany) records brain waves for the first time. Clarence Birdseye (United States) invents a food-freezing process for use in retailing. John Logie Baird (Britain) invents mechanical television.

1925

George L. McCarthy patents a practical microfilm machine, the Checkograph.

1926

Robert Hutchings Goddard (United States) invents the first successful liquid-fuel rocket. Erwin Schrödinger (Austria) introduces wave mechanics.

1927

Werner Heisenberg (Germany) introduces the uncertainty principle of quantum physics.

1928

Sir Alexander Fleming (Britain) discovers the antibiotic penicillin. Hans Geiger (Germany) and Walther Müller (Germany) construct an improved Geiger counter (the Geiger-Müller tube).

1929

Hans Berger (Germany) invents the electro-encephalograph (EEG). Edwin Hubble (United States) establishes that the Universe is in a state of expansion.

1930

Ernest O. Lawrence (United States) invents the cyclotron particle accelerator. Clyde W. Tombaugh (United States) discovers the planet Pluto. Sir Frank Whittle (Britain) invents the turbojet engine.

1931

Ernst Ruska (Germany) invents the electron microscope. Julius A. Nieuwland (United States) devises a process for producing synthetic rubber (neoprene). Harold C. Urey (United States) dis-covers heavy hydrogen (deuterium).

1932

Sir James Chadwick (Britain) discovers the neu-tron. Sir John Douglas Cockcroft (Britain) and Ernest Thomas Sinton Walton (Ireland) invent the electrostatic accelerator. Francis Bacon (Britain) develops the first practical fuel cell.

1934

Ernest Rutherford (New Zealand) creates tritium in the first nuclear fusion reaction. Enrico Fermi (Italy) produces radioisotopes via neutron bombardment.

1935

Sir Robert Alexander Watson-Watt (Britain) invents and develops radar. Wallace Hume Carothers (United States) invents nylon.

1936

German dirigible Hindenburg makes first transat-lantic flight. Inge Lehmann (Denmark) postulates existence of Earth’s solid inner core by seismology.

1937

Alan Mathison Turing (Britain) develops the con-cept of a universal computing machine (the Turing Machine), forerunner of the digital computer.

1938

Chester F. Carlson (United States) invents xerogra-phy. Lazlo Biro (Hungary) invents the first practi-cal ballpoint pen.

1939

Otto Hahn (Germany), Lise Meitner (Austria), and Fritz Strassmann (Germany) discover nuclear fis-sion. German Heinkel HE178 is the world’s first jet aircraft to fly.

1941

Konrad Zuse (Germany) invents the first general-purpose calculator. Rex Whinfield (Britain) and James Dickson (Britain) invent polyester.

1942

Enrico Fermi (Italy) produces the first self-sustaining nuclear fission chain reaction at the University of Chicago. Igor Ivanovich Sikorsky (Ukraine/United States) invents the first practical helicopter, the VS-316A.

1943

Willem Johan Kolff (Netherlands) develops the first kidney dialysis machine. Jacques-Yves Cousteau (France) invents the aqualung with Émile Gagnan.

1945

J. Robert Oppenheimer and colleagues (United States) invent the atomic bomb.

1947

Dennis Gabor (Hungary/Britain) invents hologra-phy. Walter Houser Brattain (United States), John Bardeen (United States), and William Bradford Shockley (United States) invent the transistor. Willard Frank Libby (United States) develops the process of radiocarbon dating.

1948

Claude Elwood Shannon (United States) devises a theory of communication technology (information theory). Peter Goldmark (United States) invents the long-playing record.

1950

Alan Mathison Turing (Britain) devises a test of a computer’s capacity for "thought" (the Turing test).

1951

Eric Roberts Laithwaite (Britain) develops the first maglev train. Electric power produced from atomic energy at Arcon, Idaho.

1952

William Bradford Shockley (United States) pro-poses the field-effect transistor (FET). Donald A. Glaser (United States) invents the bubble chamber.

1953

John H. Gibbon Jr. (United States) invents the heart-lung machine. Charles Hard Townes (United States) invents the maser around the same time that it is also invented by the team of Nikolay Gennadiyevich Basov (Russia) and Alexsandr Mikhailovich Prokhorov (Russia). Francis Crick (Britain) and James Watson (United States) discover the helical structure of DNA.

1954

Hyman George Rickover (Russia/United States) heads the team that develops the first nuclear sub-marine, the Nautilus.

1956

Felix Wankel (Germany) invents the rotary engine. Clyde Cowan (United States) and Frederick Reines (United States) discover the neutrino, an elemen-tary particle. The video recorder is invented.

1957

John Bardeen (United States), Leon Niels Cooper (United States), and John Robert Schrieffer (United States) develop the BCS (Bardeen, Cooper, Schrieffer) theory of superconductivity. Sputnik I, the first orbiting satellite, is launched.

1958

The first modem is invented. Jack St. Clair Kilby (United States) invents the integrated circuit, independently of Robert Noyce.

1959

Robert Noyce (United States) invents the inte-grated circuit, independently of Jack St. Clair Kilby. Richard Feynman (United States) develops the theory of quantum electrodynamics (QED). Sir Christopher Cockerell (Britain) builds the first practical hovercraft.

1961

Edward Norton Lorenz (United States) discovers that chaos theory applies in weather systems. Theodore Maiman (United States) develops the laser. Yuri Gagarin (USSR) is first man in space and spends 89 minutes orbiting Earth in Vostok 1. Alan Shephard makes first U.S. suborbital rocket flight; John Glenn orbits Earth in 1962.

1963

Edward Norton Lorenz (United States) describes the "butterfly effect." The compact cassette tape recorder is introduced by Phillips.

1964

Murray Gell-Mann (United States) and George Zweig (United States) propose independently a theory of subatomic particles. Gell-Mann names these particles "quarks."

1965

Insulin is synthesized. Soviet cosmonaut Alexei A. Leonov makes first space walk. Mariner 4 space probe flies by Mars.

1967

Christiaan Neethling Barnard (South Africa) performs the first human heart transplant. Jocelyn Bell (Britain) and Antony Hewish (Britain) discover pulsars, collapsed neutron stars.

1969

U.S. astronauts make the first crewed Moon land-ing. George Smith (United States) and William Boyle (United States) invent the charge-coupled device at Bell Laboratories. An early form of the Internet, ARPANET, is established.

1971

Intel produces the first microprocessor, the 4004.

1974

The Internet’s transmission control protocol (TCP) and Internet protocol (IP) are devised.

1976

First Concorde supersonic airliner passenger flight. The lander module of the space probe Viking 1 lands successfully on Mars.

1977

The genetic code of the human growth hormone is determined. Raymond Damadian (United States) invents magnetic resonance imaging (MRI).

1978

The first global positioning satellite, GPS Block I, is launched. Birth of the first "test tube" baby.

1979

Seymour Cray (United States) invents the super-computer. Cellular phone invented.

1981

John F. Burke (United States) and Ionnis V. Yannas (United States) develop artificial skin to treat burns. Heinrich Rohrer (Switzerland) and Gerd Binnig (Switzerland) invent the scanning tunneling microscope. The first flight of the space shuttle takes place.

1982

Introduction of the audio compact disc (CD).

1983

Kary Mullis (United States) invents the polymerase chain reaction (PCR) for amplifying minute amounts of DNA. Luc Montagnier (France) identifies the human immunodeficiency virus (HIV), the virus responsible for AIDS.

1984

First successful cloning of a mammal, a sheep, with cells taken from an early post-fertilization stage of development, a process known as "twinning."

1985

Alec Jeffreys (Britain) devises genetic fingerprinting. The computer program Windows is released by Microsoft.

1986

Alex Müller (Switzerland) and Georg Bednorz (Germany) create a ceramic compound that superconducts at 30 K. Introduction of the antidepressive drug Prozac.

1989

Development of the World Wide Web begun by Tim Berners-Lee (Britain) and colleagues at CERN, Switzerland.

1990

Hubble Space Telescope is launched.

1992

The first web browser is introduced.

1993

The Pentium processor is introduced.

1995

Top quark is discovered at Fermilab.

1996

Ian Wilmut (Britain) heads the team that produces the first successful clone from an adult mammal, Dolly the sheep. The digital versatile disc (DVD) is introduced.

2001

Rough draft of the human genome is completed.