A Chronology of Significant Events in the History of Science and Technology

c. 2725 B.C. - Imhotep in Egypt considered the first medical doctor

c. 2000 B.C. - Chinese discovered magnetic attraction

c. 700 B.C. - Greeks discovered electric attraction produced by rubbing amber

c. 600 B.C. - Anaximander discovered the ecliptic (the angle between the plane of the earth's rotation and the plane of the solar system)

c. 600 B.C. - Thales proposed that nature should be understood by replacing myth with logic; that all matter is made of water

c. 585 B.C. - Thales correctly predicted solar eclipse

c. 530 B.C. - Pythagoras developed mathematical theory

c. 450 B.C. - Anaxagoras proposed the first clearly materialist philosophy - the universe is made entirely of matter in motion

c. 370 B.C. - Leucippus and Democritus proposed that matter is made of small, indestructible particles

c. 300 B.C. - Euclid wrote "Elements", a treatise on geometry

c. 300 B.C. - Aristarchus proposed that the earth revolves around the sun; calculated diameter of the earth

c. 300 B.C. - The number of volumes in the Library of Alexandria reached 500,000

c. 220 B.C. - Archimedes made discoveries in mathematics and mechanics

c. 150 A.D. - Ptolemy studied mathematics, science, geography; proposed that the earth is the center of the solar system

190 - Chinese mathematicians calculated pi to five decimal places

271 - Chinese mathematicians invented the magnetic compass

415 - A mob of rioters burned down the Library of Alexandria, and much of the recorded knowledge of the western world was lost

450-1000 - the "Dark Ages" in Europe

1232 - Rockets invented in China to defend city of Kaifeng against Mongol invaders

1390 - The first paper mill began operating in Germany

1455 - The Gutenberg Bible became the first book printed with movable metal type

1543 - Copernicus formed the hypothesis that the planets revolve around the sun.

1543 - Vasalius published treatise on human anatomy

1570 - Brahe discovered supernova in constellation Cassiopeia

1600 - Gilbert discovered that electricity occurs in things other than amber; wrote a book on magnetism

1608 - Lippershey invented the telescope

1609 - Galileo built 20X telescope, discovered craters and mountains on the moon

1619 - Kepler announced his 3rd law

1620 - Bacon published "Novum Organum" (scientific method and inductive reasoning)

1628 - Harvey published a book describing blood circulation

1637 - Descartes Published "Geometry"

1642 - Pascal invented the mechanical adding machine

1652 - Pascal discovered laws of fluid pressure

1666 - Newton invented the calculus

1675 - Leibniz independently invented the calculus

1687 - Newton published "Principia", describing the laws of motion

1738 - Bernoulli proposed laws of fluid mechanics

1758 - Linnaeus developed taxonomy of species, proposed binomial nomenclature

1777 - Lavoisier proposed idea of chemical compounds made of elements

1785 - Coulomb confirmed the inverse square law for electric force

1787 - Berthollet proposed system of chemical nomenclature

1793 - Whitney invented the cotton gin

1796 - Jenner discovered smallpox vaccination

1831 - Faraday (England) and Henry (U.S.) independently discovered that a current is produced in a wire when it is moved near a magnet

1849 - Fizeau measured the velocity of light

1853 - Bessemer in Britain and Kelly in U.S. invented the Bessemer steel process

1856 - Neanderthal fossil found in Germany

1859 - Darwin published "On The Origin of Species"

1866 - Mendel wrote a paper on his findings about heredity in plants

1868 - Cro-Magnon fossil found in France

1869 - Mendeleyev used a periodic table of known elements to correctly predict the properties then undiscovered elements

1873 - Maxwell published "Treatise on Electricity and Magnetism"

1885 - Benz invented the gasoline-powered automobile

1885 - Eastman invented the box camera

1888 - Hertz discovered radio waves, verifying Maxwell's prediction of electromagnetic waves

1888 - Edison invented the kinetoscope

1895 - Roentgen discovered x-rays

1895 - Marconi invented antenna and wireless telegraph (short distance)

1896 - Becquerel discovered radioactivity

1897 - Marconi increased range of wireless telegraph to 29 km; first ship-to-shore message

1898 - Curie and Curie announced their discovery of radium and polonium

1900 - First public awareness of Mendel's findings in genetics, when his 1865-1866 papers were found

1900 - Planck proposed that energy can only be absorbed or emitted by matter in discrete amounts (quanta)

1902 - Discovery of Tyrannosaurus Rex

1903 - The botanist De Vries discovered mutations in plants

1903 - Wright brothers' airplane remained in flight for 12 seconds

1904 - Genetics experiments by Thomas Morgan, discovery of sex-linked mutations (among a group of fruit flies with normal red or unusual white eyes, all of the white-eyed offspring were male).

1905 - Einstein published papers on Brownian motion, the photoelectric effect, and the special theory of relativity

1906 - Thomson discovered the electron

1908 - Wegener proposed theory of continental drift

1911 - Rutherford discovered that the positive charge in an atom is concentrated in a small nucleus; proposed a planetary model of the atom

1916 - Lewis proposed the idea of covalent bonds

1916 - Einstein published the general theory of relativity

1919 - Eddington recorded data on the sun's gravitational deflection of starlight during a solar eclipse, confirming Einstein's general theory of relativity

1924 - Discovery of Australopithecus Africanus, its human-sized brain too large to be that of an ape, but having the canine teeth of a gorilla

1924 - De Broglie proposed that all matter has wave properties

1926 - Schrodinger developed the wave equation

1927 - Heisenberg proposed the Uncertainty Principle (we cannot simultaneously determine the position and momentum of a subatomic particle)

1927 - the first television transmission (England)

1928 - Dirac developed the relativistic quantum theory

1927 - Big bang theory introduced

1929 - Hubble discovered that the galaxies are moving away from each other, causing an expansion of the universe

1932 - Chadwick discovered the neutron

1936 - the first regular television broadcast (England)

1937 - Discovery of the muon

1938 - Hahn, Strassmann, Meitner and Frisch discovered nuclear fission

1938 - Bethe hypothesized that nuclear fusion is the source of energy in stars

1942 - Fermi produced the first nuclear chain reaction in an experiment

1942 - Establishment of the Manhattan Project to develop an atomic bomb

1946 - The University of Pennsylvania developed the ENIAC computer, containing 18,000 vacuum tubes

1947 - W. F. Libby invented radiocarbon dating

1947 - Researchers at Bell Labs invented the transistor

1951 - Franklin discovered nucleic acids (RNA and DNA), helical shape

1953 - Watson and Crick discovered DNA has double helix, composed of ATCG bases occuring in pairs (A with T, and C with G)

1953 - Miller produced amino acids from inorganic compounds and sparks

1956 - Discovery of the neutrino (predicted by Pauli in 1930)

1958 - U.S. Congress established NASA

1959 - First unmanned spacecraft hit the moon (Soviet Union)

1960 - Goodall studied chimpanzees in Tanzania

1963 - Gell-Mann proposed protons and neutrons are made of smaller particles (quarks)

1964 - Discovery of a quasar

1964 - Wilson and Penzias discovered the background microwave radiation of the universe

1967 - Bell and Hewish discover pulsars

1969 - People walked on the moon for the first time (Apollo 11)

1969 - Meteorite in Australia found to contain amino acids

1972 - Discovery of a 2 million year old humanlike fossil, Homo habilis, in Africa

1974 - Discovery of "Lucy" in Africa, an almost complete homonid skelton over 3 million years old, only 3 and a half feet tall but having adult teeth, a small brain, walked upright

1976 - Cosmic string theory was introduced

1979 - First "test tube baby" from artificial insemination

1979 - Voyager 1 and 2 photographed Jupiter

1980 - Voyager 2 photographed Saturn

1980 - Introduction of the the communication protocol that led to the Internet

1981 - Binnig and Rohrer invented the scanning tunneling microscope

1984 - Discovery of ozone hole over Antarctica

1986 - Development of the first high temperature superconductors

1992 - Pope John Paul II acknowledged the Vatican's error in the condemnation of Galileo

1994 - Hubble Space Telescope confirmed existence of a black hole

1995 - Discovery of the top quark at Fermilab

1996 - Pope John Paul II affirmed evolution by natural selection

1997 - Microscopic analysis of meteorite led to belief in ancient life on Mars