A Century of Science

By Andrea Dorfman and Mary Hart

Fruit flies and biplanes. Pap smears and CAT scans. Radar and lasers. Insulin, penicillin, LSD and ESP. Artificial hearts. Artificial intelligence. A few of the advances that powered this extraordinary century

--By Andrea Dorfman and Mary Hart

1900

1900 Sigmund Freud publishes The Interpretation of Dreams

1900 Max Planck presents his quantum theory at a meeting of the German Physical Society in Berlin

1901 Austrian physician Karl Landsteiner shows that there are at least three types of human blood, which he labels A, B and O. These distinctions make blood transfusions possible. Landsteiner will also discover the Rh factor

1902 Scottish cardiologist James Mackenzie invents the polygraph machine, better known as the lie detector

1903 Marie Curie shares the Nobel Prize for Physics with Henri Becquerel and her husband Pierre for their discovery of radioactivity; she will win a second Nobel, for Chemistry, in 1911, for isolating the radioactive element radium

1903 The Flyer, a plane built by American inventors Wilbur and Orville Wright, makes the first powered flight

1905 French psychologist Alfred Binet devises the first intelligence tests

1905 German chemist Walther Nernst explains why absolute zero (about -273[degrees]C) can never be reached; this becomes the third law of thermodynamics

1906 British biochemist Frederick Hopkins postulates that "accessory food factors" are required for human health; these are now known as vitamins

1906 German neurologist Alois Alzheimer identifies a disorder that causes the progressive loss of intellectual functioning

1907 Italian educator Maria Montessori establishes her first preschool, in Rome

1907 Belgian-American chemist Leo Baekeland patents Bakelite, the world's first true plastic

1908 Hans Geiger invents a machine that translates invisible nuclear radiation into audible clicks

1910

1910 German bacteriologist Paul Ehrlich uses a form of arsenic to combat syphilis; his work forms the basis of modern chemotherapy

1910 Working with fruit flies, U.S. biologist Thomas Hunt Morgan discovers that some genetic traits are sex-linked and that the genes governing these traits are located on chromosomes

1910 Publication of Volume I of Principia Mathematica, a three-volume work by Bertrand Russell and Alfred North Whitehead that attempts to link mathematics and logic

1911 Ernest Rutherford, Hans Geiger and Ernest Marsden discover the structure of the atom

1911 Austrian-American physicist Victor Hess detects radiation coming from outer space; it is later dubbed cosmic rays

1911 Hiram Bingham finds Machu Picchu, a 15th century Inca settlement high in the Peruvian Andes

1912 German meteorologist Alfred Wegener proposes the theory of continental drift

1912 Charles Dawson announces that he has found the fossilized remains of a human-like creature on Piltdown Common in Sussex, England. Christened Eoanthropus dawsoni, "Piltdown Man" will be exposed as a fraud in 1953

1913 Dr. Albert Schweitzer, a missionary, opens a hospital in Lambarene, French Equatorial Africa (now Gabon), for the treatment of leprosy and sleeping sickness

1914 The Panama Canal, which links the Atlantic and Pacific oceans, opens to commercial traffic

1914 Authorities institutionalize Mary Mallon, a cook popularly known as "Typhoid Mary," whose handling of food had led to at least 51 cases of the disease and three deaths since 1904

1916 Albert Einstein publishes his general theory of relativity

1917 U.S. astronomer George Hale builds a 100-in. reflecting telescope--the world's largest--on California's Mount Wilson

1918 American astronomer Harlow Shapley describes the size and structure of the Milky Way galaxy

1918 A worldwide influenza epidemic kills more than 25 million people, including some 500,000 Americans

1919 British physicist Ernest Rutherford artificially splits an atom

1920

1921 Swiss psychiatrist Hermann Rorschach introduces the inkblot test

1921 Canadian physician Frederick Banting and colleagues find a treatment for diabetes: insulin isolated from the pancreas of fetal calves

1922 British archaeologist Howard Carter opens the tomb of Tutankhamun, a little-known pharaoh who died in 1325 B.C.

1924 French physicist Louis de Broglie describes his theory that all matter behaves as both a particle and a wave, just as light does; this notion will lead to the electron microscope

1925 The teaching of evolution comes under fire at the Scopes "monkey trial" in Tennessee

1926 American physicist Robert Goddard conducts the first successful launch of a liquid-fueled rocket

1927 Werner Heisenberg devises his "uncertainty principle"

1927 Belgian astronomer and priest Georges Lemaitre proposes that the universe began with a big bang, the explosion of a highly condensed mass, which he refers to as a "cosmic egg"

1928 Scottish bacteriologist Alexander Fleming discovers penicillin

1928 American anthropologist Margaret Mead publishes Coming of Age in Samoa

1928 Greek-American physician George Papanicolaou develops the Pap smear, a screening test for cervical and uterine cancer

1928 Hungarian-born biochemist Albert Szent-Gyorgyi isolates vitamin C

1929 U.S. astronomer Edwin Hubble provides evidence that the universe is expanding

1929 American physicist Ernest Lawrence dreams up the cyclotron, the first atom smasher

1930

1930 U.S. astronomer Clyde Tombaugh discovers Pluto, the ninth planet

1930 Austrian physicist Wolfgang Pauli proposes the existence of neutrinos

1933-35 Teams in Germany and Britain independently invent radar

1934 French physicists Irene and Frederic Joliot-Curie artificially induce radioactivity

1935 U.S. seismologist Charles Richter develops a scale for measuring the strength of earthquakes

1935 Austrian zoologist Konrad Lorenz describes the process of imprinting, during which young birds attach themselves to a being or an object

1935 First use of lobotomy to treat mental illness

1936 John Maynard Keynes publishes The General Theory of Employment, Interest and Money

1938 In Italy, electroconvulsive therapy--controlled electric shocks that cause temporary loss of consciousness and seizure--is first used on mental patients

1938 After analyzing decades of temperature readings, British engineer George Callendar describes what is later known as the greenhouse effect

1939 First flight by a jet aircraft, built by Germany's Ernst Heinkel

1939 Swiss chemist Paul Muller determines that ddt is a powerful insecticide

1940

1940 French boys searching for their dog stumble onto the Lascaux cave, whose walls are covered with spectacular paintings and engravings dating from the Ice Age

1940 American surgeon Charles Drew devises a method for long-term storage of blood plasma, which can then be used for transfusions

1941 U.S. researchers Lyle Goodhue and William Sullivan adapt an earlier idea for dispersing liquids and powders in a spray. Result: the aerosol can

1942 A team headed by Italian physicist Enrico Fermi produces the first nuclear chain reaction

1942 Frenchmen Jacques-Yves Cousteau and Emile Gagnan perfect the Aqua-Lung, a self-contained underwater breathing apparatus, or scuba

1942 Germany successfully launches the V-2, a surface-to-surface missile developed with the help of rocket scientist Wernher von Braun

1943 British mathematician and cryptographer Alan Turing helps build an electronic computer, the Colossus, that will be used by the Allies to crack German codes

1943 Dutch physician Willem Kolff invents the dialysis machine, used to cleanse the blood when a patient's kidneys malfunction

1943 After accidentally swallowing synthetic lsd, Swiss chemist Albert Hofmann discovers the drug's hallucinogenic effects

1943 Publication of Being and Nothingness establishes Jean-Paul Sartre as the leading French existentialist

1944 In Mexico, American plant pathologist Norman Borlaug starts developing high-yield grains that, two decades later, will fuel the green revolution

1945 U.S. pilots cruising at high altitudes discover powerful west-to-east wind systems, later called jet streams

1945 U.S. planes drop atom bombs on Hiroshima and Nagasaki

1945 The U.S. Public Health Service begins adding fluoride to the water supply in order to reduce the incidence of tooth decay

1945 Raytheon technician Percy Spencer accidentally discovers microwave cooking when microwave signals melt a candy bar in his pocket

1946 John Mauchly and John Eckert unveil ENIAC, the first fully electronic computer

1946 American pediatrician Benjamin Spock publishes The Common Sense Book of Baby and Child Care

1947 Bedouin shepherds find Dead Sea Scrolls hidden in clay jars in Israel's Qumran Cave, overlooking the Dead Sea

1947 American Edwin Land demonstrates the Polaroid camera he invented

1947 Norwegian ethnologist Thor Heyerdahl sails from Peru to Polynesia on the wooden raft Kon-Tiki to support his theory that pre-Incan peoples reached South Pacific islands by sea and colonized them

1947 U.S. Air Force test pilot Charles (Chuck) Yeager breaks the sound barrier

1947 A research team at Bell Laboratories led by William Shockley, John Bardeen and Walter Brattain invents the transistor

1947 U.S. chemist Willard Libby develops radiocarbon dating, which can determine the age of objects made of organic materials, such as wood and bone

1948 The U.S. Air Force starts Project Blue Book to gather data on UFO sightings

1948 Alfred Kinsey publishes Sexual Behavior in the Human Male

1950

1952 British physician Douglas Bevis describes amniocentesis, a prenatal test for genetic abnormalities

1952 U.S. virologist Jonas Salk develops the first effective polio vaccine

1952 British chemist Rosalind Franklin's X-ray photographs of DNA show that the molecule has a helical structure

1952 The first sex-change operation is performed on a patient named George Jorgenson, later known as Christine Jorgenson

1953 James Watson and Francis Crick announce that they have deciphered the structure of DNA

1954 U.S. endocrinologists Gregory Pincus, John Rock and C.R. Garcia develop the birth-control pill

1956 The U.S. explodes a hydrogen bomb at Bikini Atoll, in the South Pacific

1957 A new sleeping pill, thalidomide, is prescribed in Britain and Germany. It is later found to cause severe birth defects and taken off the market

1957 Soviets send the first artificial satellite, Sputnik, into orbit around Earth

1958 John Kenneth Galbraith publishes The Affluent Society

1958 Electrical engineer Wilson Greatbatch invents the first implantable cardiac pacemaker; it is powered by a zinc-mercury battery

1959 In Tanzania's Olduvai Gorge, Mary Leakey finds the fossilized skull of a human ancestor who lived 1.8 million years ago

1959 Engineer Robert Noyce makes the first integrated circuit, or microchip

1959 Marvin Minsky and John McCarthy establish the Artificial Intelligence Laboratory at M.I.T.

1960

1960 The bathyscaphe Trieste descends 35,800 ft. in the Mariana Trench to the deepest spot in the oceans

1960 U.S. physicist Theodore Maiman builds a working laser

1960 British ethologist Jane Goodall begins studying chimpanzee behavior in Tanzania

1960 The discovery of an 11th century Norse settlement at L'Anse aux Meadows, Newfoundland, confirms that Europeans reached the New World centuries earlier than Columbus did

1961 American astronomers Allan Sandage and Thomas Matthews discover quasars

1962 U.S. marine biologist Rachel Carson publishes Silent Spring

1963 The tranquilizer Valium is introduced

1964 The U.S. Surgeon General first warns that smoking can be hazardous to human health

1964 U.S. surgeon Michael DeBakey performs the first successful coronary-artery bypass operation

1965 American radio astronomers Arno Penzias and Robert Wilson accidentally discover cosmic background radiation, which bolsters the Big Bang theory of the origin of the universe

1967 R. Buckminster Fuller's geodesic dome is a hit at the Montreal Exposition

1967 South African surgeon Christiaan Barnard performs the first successful human-heart transplant; his patient, Louis Washkansky, survives 18 days

1969 American astronauts walk on the moon

1969 Swiss-born psychiatrist Elisabeth Kubler-Ross publishes On Death and Dying

1970

1970 American biochemist Linus Pauling touts vitamin C as a cure for everything from cancer to the common cold

1971 British engineer Godfrey Hounsfield invents the computerized tomography scanner (CAT scan), which builds a 3-D image of the brain

1972 U.S. bans DDT because of its adverse effects on the environment

1974 Farmers discover an army of life-size terra-cotta human figures in a 3rd century B.C. Chinese emperor's tomb near Xian

1974 Arthur Laffer formulates his supply-side economic theories, which hold that reducing federal taxes spurs economic growth and, eventually, increases federal revenues

1974 In Hadar, Ethiopia, Donald Johanson and colleagues find a 3.2 million-year-old skeleton of a new human ancestor, later called Australopithecus afarensis; it is nicknamed Lucy

1975 Scientists discover a natural opiate, now known as an endorphin (endogenous morphine), in the brain

1976 The first supersonic commercial airplane, the Concorde, goes into service

1977 An unusual incidence of childhood arthritis in Lyme, Conn., leads a group of Yale physicians to identify a new bacterial disease transmitted by ticks

1977 Deep-sea vents are found near the Galapagos Islands. The hot, sulfurous water around the vents supports new species of bacteria and sea life

1977 Doctors use balloon angioplasty to unclog a coronary artery

1978 Louise Brown, the world's first test-tube baby, is born in England

1978 To protect Earth's ozone layer, the U.S. bans chlorofluorocarbons, which are used as propellants

1980

1980 Luis and Walter Alvarez speculate that an asteroid's crashing into Earth 65 million years ago wiped out the dinosaurs and other species. In 1991 the putative impact crater is found beneath Mexico's Yucatan peninsula

1980 The World Health Organization declares that smallpox has been eradicated

1981 Inaugural flight of America's space shuttle

1981 Doctors in Los Angeles alert the Centers for Disease Control to five cases of Pneumocystis carinii pneumonia in gay men, one of the earliest signs of the AIDS epidemic

1982 The U.S. Food and Drug Administration approves the first genetically engineered drug: bacteria-produced insulin for diabetics

1982 Surgeons at the University of Utah Medical Center, led by William DeVries, replace Barney Clark's failing heart with a mechanical one designed by Robert Jarvik; Clark dies 112 days later

1984 Alec Jeffreys and colleagues at the University of Leicester, England, develop "genetic fingerprinting," which uses unique sequences of DNA to identify individuals

1985 Robert Gallo, of the U.S. National Cancer Institute, and Luc Montagnier, of France's Pasteur Institute, each publish the genetic sequence of the AIDS virus. The two are identical

1985 French and American oceanographers find the Titanic at a depth of nearly 13,000 ft. in the Atlantic

1986 The U.S. space shuttle Challenger explodes 73 sec. after lift-off

1986 An explosion at an aging nuclear reactor in Chernobyl, Ukraine, releases radiation into the atmosphere

1987 The U.S. Food and Drug Administration approves the antidepressant Prozac

1988 A Brief History of Time, by British physicist Stephen Hawking, becomes a surprise best seller

1988 Harvard receives the first patent for a genetically engineered animal

1988 The French government approves use of RU 486, the so-called abortion pill

1989 The tanker Exxon Valdez runs aground in Alaska's Prince William Sound, spilling 11 million gal. of crude oil. It is the worst oil spill in U.S. history

1990

1990 Formal start of the Human Genome Project, an international effort to map and sequence all human DNA

1990 Launch of the Hubble Space Telescope. It fails to operate properly, but is repaired three years later by space-walking astronauts

1990 Jack Kevorkian, also known as "Dr. Death," performs his first assisted suicide

1991 Tourists hiking in the Tyrolean Alps discover, protruding from a glacier, the freeze-dried remains of a man who died about 3300 B.C.

1993 Princeton mathematician Andrew Wiles reveals his proof for Fermat's Last Theorem, which was proposed in the 17th century

1993 Researchers at George Washington University clone human embryos and nurture them in vitro for several days

1994 Comet Shoemaker-Levy 9 crashes into the planet Jupiter

1994 Near France's Ardeche River, explorers discover the Chauvet cave, whose paintings are believed to be more than 30,000 years old

1996 A British government report on "mad-cow disease" raises questions about the safety of British beef

1996 NASA reports that a Martian meteorite may contain the remains of ancient microbes. The evidence is later challenged

1997 Scottish researchers clone a sheep named Dolly from cells of an adult ewe

1997 A computer called Deep Blue beats world chess champion Garry Kasparov in a six-game match

1997 NASA's Sojourner spacecraft roams the surface of Mars and sends pictures back to Earth

1998 The impotence drug Viagra goes on sale in the U.S.

2000

On Jan. 1 a coding error could cause computers around the world to malfunction