c. 140 ---Claudius Ptolmaeus (Ptolemy) writes "He Mathematike Syntaxis" (known 1000 years later as "Almagest"), proposing his world system.
- 313---The Roman Emperor Constantinus adops Christianity; in 330 he builds new capital and names it Constantinople (now Istanbul, Turkey). Roman empire gradually divides into western and eastern parts ("Byzantine Empire"), with capitals at Rome and Constantinople.
- 410---Alaric, leader of the Visigoths, captures and sacks Rome. Decline of Rome: Attila king of the Huns devastates much of its empire, reaches the gates of Constantinople and later (452) of Rome.
Beginning of Europe's "dark ages" which continue to the Renaissance (see below): cities decay, trade, shipping, literacy, scholarship and life expectancy all decline.
- 622---Mohammed flees to the city of Medina, marking the beginning of Islam (and the starting date of the Moslem calendar). His followers conquer the Near East, North Africa and Spain.
c. 820 ---Caliph Al Ma'mun establishes "House of Wisdom" in Baghdad (see link below).
c. 780-850---Al Khorezmi. (c. 780-850)
- 1000-1400 Age of feudal lords in Europe: castles, knights, religious fervor, only very rudimentary science and technology. Also age of Vikings, some of whom sailed as far as Greenland and America. Mongols overrun and subjugate southern Russia.
1054--A supernova appears in the constellation of the Crab, and is observed by Chinese astronomers, who call it the "guest star."
- 1095-1291 Crusades
- 1460 Johann Gutenberg invents the printing press with movable type. Combined with paper (a Chinese invention which gradually reached Europe and displaced parchement), the printed book is the major force behind a cultural and technical growth spurt, the Renaissance (French for "rebirth").
1492 Columbus discovers America, followed by Spanish (and some Portugese) explorers. The main powers in Europe are Spain, France, England, Turkey and a confederation of German princes ("Holy Roman Empire.")
1543---Nicholaus Copernicus (1473-1543) publishes his theory of the solar system.
1572---Tycho Brahe (1546-1601) observes a "new star." (See also here.)
1582---Pope Gregory the 13th reforms the calendar.
1588 The "Spanish Armada," a fleet attacking Britain, is destroyed by the British navy and by storms. For the first time Britain is able to claim part of the American continent.
- Europe and Asia are introduced to American crops--potatoes, tomatoes, corn. Europe´s diet is also gradually enriched by sugar, oranges and pepper, originating in India.
1609---Galileo Galilei (1564-1642) builds the first astronomical telescope and observes for the first time craters on the Moon, satellites around Jupiter, and the way Venus goes through phases like the Moon (crescent, etc.) .
1610 (approx) Sunspots and their rotation with the Sun were discovered independently by Galileo Galilei, Johann Fabricius (Holland) and Christopher Scheiner. All used the recently-invented telescope, and Scheiner apparently introduced the safe method of projecting the Sun's image on a flat surface.
---Johann Kepler (1571-1630), using Tycho's observations, formulates his first two laws of planetary motion (3rd law in 1619).
- After a failed attempt (1586) to establish a colony on Roanoke Island, Virginia (now part of N. Carolina), Jamestown is founded in Virginia in 1607, and the first English settlers land in Massachussetts Bay in 1620 (the "Pilgrims").
- 1618-1648---The 30 years' war. A century after Martin Luther broke away from the Roman church, a great religious war sweeps Europe, devastates Germany and establishes Sweden as a major military power. In the civil war in England, parliament suspends monarchy 1645-1660, king beheaded 1649.
---1672 Jean Richer, a French astronomer, derives the parallax of Mars, and uses Kepler's 3rd law to obtain the first modern estimate of the astronomical unit, within abut 30%.
---1676 Ole Roemer, a Danish astronomer working in Paris, a French astronomer, tabulates the eclipses of Jupiter's innermost moon Io. His observations suggest that light has a great but finite velocity.
- 1683---The Turkish army reaches Vienna but is repelled; among the booty the victors discover coffee, develop a taste for it. Englishmen begin smoking tobacco, an American plant.
1686---Isaac Newton (1642-1727) publishes "Philosophie Naturalis Principia Mathematica," outlining laws of mechanics and law of gravity.
1704--Isaac Newton publishes his "Opticks" describing (among other things) his work with prisms.
- 1708---Abraham Darby begins extensive iron production in England, based on roasted coal (coke). As firewood gets scarce, coal becomes England's choice fuel and coke replaces charcoal in iron production. To run the pumps that keep coal mines dry, Newcomen in 1712 invents a crude steam engine.
- 1712---Russia's king (czar) Peter the Great "opens a window to the West" by founding a new capital, which he names St. Petersburg and which becomes Russia's main port on the Baltic sea.
1769---James Watt (1736-1819) devises the modern steam engine.
- 1775-83---US War of Independence. Britain's colonies in America achieve a growing degree of self-sufficiency. Benjamin Franklin prints books in Philadelphia, also demonstrates (1749) that lightning is an electrical phenomenon. Later (1775-1783) the colonies rebel against Britain, win their independence and form a confederation. In 1787 they write a constitution and form a federal republic.
- 1781---William Herschel, a German musician settled in Britain, discovers the planet Uranus with a mirror telescope he had constructed.
- 1783---The Montgolfière brothers in France, owners of a paper factory, build the first hot air balloons; balloons lifted by hydrogen follow.
- 1789---The French Revolution: France rebels against its king, who is later deposed and executed. The French follow the US example and set up a republic, but a military officer, Napoleon Bonaparte, gradually gains power. From 1798 to 1815 France under Napoleon fights a series of wars and for a while rules or controls most of the European continent.
- 1793---Alexander Mackenzie crosses Canada from coast to coast.
- 1796---Edward Jenner in Britain introduces vaccination against smallpox.
1798---Henry Cavendish (1731-1810) first measures the force of gravity between two objects in his laboratory.
- 1803---US purchases Louisiana from Napoleon. To explore the new lands and the mountains beyond, Meriwether Lewis and William Clark cross the continent from St. Louis to the mouth of the Columbia River.
1806---William Congreve devises military rockets; used 13 September 1814 in British attack on Baltimore.
- 1807---Robert Fulton uses steam to run the first commercial paddlewheeler on the Hudson river;
- 1803---John Dalton, a chemist, argues that observations in chemistry require matter to be composed of atoms.
1807--Humphrey Davy isolates a new metal, sodium, by the action of an electric current
1811--Amadeo Avogadro links the laws of gases and chemistry, providing a vital confirmation of the atomic nature of matter. His work was widely recognized only after 1860.
- 1811---Simón Bolivar begins a series of wars to liberate Spain's colonies in South America, leading to the independence of Venezuela, Bolivia, Ecuador and Peru.
1820--
Hans Christian Oersted observes the magnetic effect of electric currents.
1820--Andre-Marie Ampere describes magnetism as the force between electric currents (see link above).
- The Industrial revolution: George Stephenson in Britain (1825) and Peter Cooper in the US (1830) found successful railroads, run by steam. Mass production of fabric and paper. Henry Bessemer in 1856 finds a way to mass-produce steel.
- 1826---crude photography by L.J.M. Daguerre, greatly improved in the decades that follow.
- 1829--Joseph Ressel (a Czech forester employed by the Austrian Navy in Trieste) builds and tries out a simple ship's propeller. Later in 1836 John Ericsson patents the propeller and develops it further.
1833--Michael Faraday derives the laws of electrical separation of compounds (as used by Davy in 1807), suggesting that atoms contain electrical charges.
1835---Gaspard Coriolis (1792-1843) publishes the laws of mechanics in rotating frame, including an extra force on moving objects.
- 1837--Samuel Morse invents his telegraph; in 1844 first commercial telegraph line opens, by 1866 undersea telegraph cables link Europe and America.
1838---Friedrich Bessel and others first measure the distance to the star 61 Cygni, using the diameter of the Earth's orbit as baseline.
1840--- Louis Agassiz (1807-1873) publishes "Etudes sur les glaciers", proposes that giant glaciers once covered central Europe.
1842---Christian Doppler in Austria deduces the "Doppler effect," the change of observed wavelength when observer or source move.
1843---James Prescott Joule (1818-89) measures the "exchange rate" between mechanical energy and heat.
- 1846---Anesthesia by ether is introduced by William T. Morton in Boston.
- 1849---California gold rush.
1851--The 11-year sunspot cycle (observed in 1843 by Heinrich Schwabe) is generally recognized.
1852---Radanath Sikhdar (1813-70) identifies the highest peak on Earth, later named for Sir George Everest (1790-1866).
1854--Hermann von Helmholtz proposes that the Sun derives its energy from gravitational shrinkage.
1855--James Clerk Maxwell extends the 3-color theory of vision, following earlier work by Thomas Young.
- 1856---Commodore Perry and a US fleet open up Japan to western culture and technology; rapid modernization follows, enabling Japan to defeat Russia in war less than 50 years later.
1857--- Christophorus Henricus Didericus Buys Ballot (1817-90) proposes the rule for the swirl direction of large storms and hurricanes.
- 1859---Charles Darwin publishes "Origin of the Species"
- 1859---Edwin Drake extracts petroleum from an oil well in Titusville, Pennsylvania. Beginning of a world-wide effort to find and extract oil, refine it and use its constituents for light, heat and later to run gasoline and diesel engines.
- 1861---Italy unified under the king of Piedmont; 1850-70, Germany unified under Prussian leadership.
- 1860-65---US Civil War
1864--James Clerk Maxwell proposes his equations of electromagnetism and suggests that light is an electomagnetic wave.
- 1865---Joseph Lister introduces antiseptics to surgery, cutting its risks.
1869--Norman Lockyer finds that a yellow spectral line observed in the Sun's spectrum during the 1868 eclipse must belong to a new element (later named helium)
- The Industrial revolution continues: bicycles are introduced (high-wheelers, then "safety models"), mass production of fabrics, also Brooklyn Bridge (1883), Statue of Liberty (1886), Eiffel Tower (1889).
- 1870---Suez Canal opens, a shortcut between Europe and Asia. Age of exploration and colonization in Africa.
- 1870---Railroad across the US. In 1891-1905, the trans-Siberian railroad is built.
- 1876---Telephone invented
- 1879---Edison invents the electric lightbulb, initially using a fragile carbon filament.
- 1882---Electric power stations in London and New York. Large scale refrigeration.
- 1885-1900---After the introduction of electric train engines, the construction of subways begins in the major cities of Europe (starting with London, then Budapest) and the US (starting with Boston, then New York).
1883---Ernst Mach (1838-1916) publishes a critical study of Newtonian mechanics.
- 1884---Charles Parsons invents his steam turbine, which ultimately becomes the preferred power plant of electric power stations and ships. Diesel engine introduced in 1897 by Rudolf Diesel.
1885--Johann Balmer discovers a simple formula which characterizes the atomic spectrum of hydrogen, an early clue to quantum physics.
1886--Heinrich Hertz produces and detects electromagnetic waves, of what is later called "radio."
- The beginning of automobiles (Marcus 1864 in Austria; Benz, 1887 in Germany; Duryea, 1893 in the US).
- 1890---Nitrocellulose photographic film introduced (George Eastman of Kodak, Rochester NY), making possible the first "movies."
1892--George Ellery Hale devises the "spectroheliograph" taking pictures of the Sun in the light of a single spectral color.
1895--William Ramsay extracts helium from a terrestrial mineral.
1895--Wilhelm Röntgen discovers X-rays.
1895--Henri Becquerel discovers radioactivity.
1896--Svante Arrhenius credits carbon dioxide with the "greenhouse effect" warming the Earth.
1897--J.J. Thompson discovers the electron.
1899, 19 October---Robert Goddard (1882-1945) climbs cherry tree, resolves to pursue his dream of spaceflight.
1900--Max Planck explains the way hot objects radiate light by postulating that light energy can only be emitted in discrete packets, later called "photons"
1903, 17 December---First successful flight by the Wright brothers at Kitty Hawk, North Carolina.
1905--Einstein shows that the way light knocks electrons out of metals suggests it can only transmit energy in "photons" that depend on its wavelength.
- 1906---Lee De Forest invents the triode--the vacuum-tube device (based on the Edison effect) by which weak electric signals can be greatly amplified. It makes possible radio, sound films, loudspeakers and later a whole generation of electronic devices.
1908--George Ellery Hale finds that sunspots must be intensely magnetic.
- 1909---L.H.Baekeland introduces "bakelite", first mass-produced plastic material. It is widely used as electrical insulator.
- 1904-1914---Panama canal is built.
1911---Andre Bing in Belgium patents multistage rocket.
1911--Ernest Rutherford conducts his experiments with the scattering of alpha particles off atoms, concludes that the atom's mass and positive charge are concentrated in a tiny nucleus.
- 1911---Amundsen reaches South Pole.
- 1912---Emperor overthrown in China, republic proclaimed.
1914 --Niels Bohr devises a model of the hydrogen atom, based on somewhat arbitrary quantum rules but giving correct values for emitted wavelengths.
- 1914-1918---World War I. The main opponents are Germany, Austria and Turkey, lined up against Russia, France, Britain, Italy. In 1917 Russia withdrew, defeated, and the Czar was overthrown by Communist workers (Russian Revolution) but the US entered to help Britain, whose side prevailed. A very large, destructive war, the first in which technology played a major role, including airplanes, tanks, machine guns, submarines and poison gas.
1916---Goddard tests rockets with De-Laval nozzles.
1926, 16 March---Goddard launches his first liquid-fuel rocket.
1926 ---Erwin Schrödinger devises the "quantum wave theory" of the atom, with related efforts by Werner Heisenberg, Niels Bohr, Max Born and Paul Dirac.
- 1922 to 1925---Fascism, the creed of a strong, all-controlling government, gains power in Italy under Benito Mussolini.
- 1924---In Russia, Communist leader V.I. Lenin, dies; after that Joseph Stalin gradually gains power, kills or exiles all his rivals and institutes a reign of terror.
1927, 5 July---German "Society for Space Travel" founded.
- 1927---Charles Lindbergh flies solo from the US to Paris.
- 1929---The New York stock market crashes, beginning a long economic depression, in the US and across the world.
- 1929---Edwin Hubble concludes from astronomical observations that distant galaxies recede from us in all directions, and that therefore the universe is expanding.
- 1927-1930---Talking films (black and white). "The Wizard of Oz" (1939) pioneers color movies, but more than 10 years pass before color films become prevalent.
- 1930---In Germany, hard-hit by the economic hardships following WW-I and by the world-wide depression, the Fascist Nazi party under Adolph Hitler comes 2nd in the polls in 1930, takes power 1933.
1932---1 November--Wernher Von Braun (1912-1977) starts conducting rocket research for the German army.
1932--James Chadwick discovers the neutron.
1936---Theodore von Karman starts the Guggenheim Aeronautical Lab at the California Institute of Technology, later leading to JPL.
- 1936---The DC-3, the first modern airliner, can reach 210 mph with 21 passengers.
1938--Hans Bethe proposes a nuclear fusion reaction for releasing energy in stars
1939--Nuclear fission discovered by Hahn, Meitner and Strassmann: when a uranium nucleus absorbs a neutron, it can be shaken up to the point that it splits in two fragments of comparable size, releasing a great amount of energy.
- 1939-1945 World War II. A world-wide conflict is started by Hitler's Germany, whose army annexed Austria and Czechoslovakia, then attacked Poland. Germany was allied with Italy and after December 1941 with Japan, which launched its own war of expansion (it had invaded China years before that). A war with unsurpassed destruction and cruelty, including Hitler's attempt to exterminate the Jewish people, of whom about 6 million were killed in a deliberate plan. Technology played an even greater role than in World War I, including long-range bombing raids, improved submarines, jet engines, radar and towards the end, large military rockets and nuclear bombs. Opposing Hitler were France (which fell to the Germans), Britain, Russia and after 1941, the United States: 1941-3 the Germans became bogged down in brutal winter fighting in Russia, in 1943 the US and its allies invaded Italy and forced its surrender, then in 1944 they invaded France and in 1945 first Germany and then Japan surrendered. In 1945 in San Francisco, the victors formed the "United Nations", an international union whose major role was to ensure peace and arbitrate conflicts.
1942, 2 December--The first nuclear reactor, designed by Enrico Fermi, is successfully operated in Chicago.
- 1943---Oswald Avery at the Rockefeller Institute in New York proves that DNA, a hitherto unexplained substance in all nuclei of living cells, carries the genetic information.
