***The 20th Century witnessed fantastic advancement in all branches of science. In the span of 66 years, man took off from the ground into air, and eventually into space. One man changed the face of science once and for all with his general theory of relativity. As penicillin was discovered to save lives, so was invented the atomic bomb to kill. With the advent of computer, and subsequently the Internet, the world truly became a small place. It has indeed been a century of science.****

1900 : Sigmund Freud publishes The Interpretation of Dreams 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. Lansteiner will also discover the Rh factor

1902 : Scottish cardiologist James Mackenzie Invents the polygraph machine, better known as the Ue detector

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

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

German chemist Walther Nernst explains why absolute zero (about -273°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

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

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

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

Publication of Volume 1 of Principa 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 Austrian-American physicist Victor Hess detects radiation coming from outer space; it is later dubbed cosmic rays

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

Charles Dawson announces that he has found the fossilised 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 treatment of leprosy and sleeping sickness

1916 : Albert Einstein publishes his general theory' of relativity

1917 : US astronomer George Hale builds a 100-inch 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

A world-wide influenza epidemic kills more than 25 million people, including some 500.000 Americans

1919 : British physicist Ernest Rutherford artificially splits ■ an atom s r n 4 .

1921 : Swiss psychiatrist Hermann Rorschach introduces the inkblot test

Canadian physician Frederick Banting and colleagues find a treatment for diabetes: insulin isolated from the gancreas of fatal calves

ritish archaeologist Howard Carter opens the tomb of Tutankhamun, a little-known pharaoh who died in

1325 BC

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-fuelled rocket

1927 : Werner Heisenberg devises his "uncertainty principle' Belgian astronomer and priest Georges Lema'tre 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

American anthropologist Margaret Mead publishes Coming of Age in Samoa

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

Hungarian-born biochemist Albert ozent-Gyorgyi Isolates vitamin C

1929 : US astronomer Edwin Hubble provides evidence that the universe is expanding

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

1930 : US Astronomer Clyde Tombrugh discovers Pluto, the ninth planet ~

Austrian physicist Wolfgang nauli proposes the existence of neutrinos j ,

1933 Teams In Germany and Britain independently Invent -35 radar ,

1934 ; French physicists Irene and Frederic Jollot-Curie artificially induce radioactivity

1935 : US seismologist Charles Richter develops a scale lor measuring the strength of earthquakes

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

First use of lobotomy to treat mental illness

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

1938 : In Italy, electro convulsive therapy — controlled electric shocks that cause temporary loss of consciousness and seizure — is first used on mental patients

After analysing 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 Heinkcl

Swiss chemist Paul Muller determines that DDT is a powerful Insecticide

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

1641 : &^S&^SsSLyle 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

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

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

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

After accidentally swallowing synthetic LSD. Swiss chemist Albert Hofmann discovers the drug's hallucinogenic effects

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 : US pilots cruising at high altitudes discover powerful west-to-cast wind system, later called jet streams Raytheon technician Percy Spencer accidentally discovers microwave cooking when microwave signals melt a candy bar in his pocket

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

1947 : Bedouin shepherds find Dead Sea Scrolls hidden In clay jars in Israel's Qumran Cave, overlooking the Dead Sea American Edwin Land demonstrates the Polaroid camera he invented

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 colonised them

US Air Force test pilot Charles (Chuck) Yeager breaks the sound barrier

A research team at Bell Laboratories led by William Shockley. John Bardeen and Waller Brattain Invents the transistor publishes On Death and Dying

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

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

1972 : US 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 BC Chinese emperor s tomb near Xian

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

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. Connecticut, leads a group of Yale physicians to identify a new bacterial disease transmitted by ticks Deep-sea vents are found near the Galapagos Islands. The hot. sulphurous water around the vents supports new species of bacteria and sea life

Doctors use balloon angioplasty to unclog a coronary artery

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

To protect Earth's ozone layer, the US bans chlorofluorocarbons, which are used as propellants

1980 : Luis and Walter Alvarez speculate that an asteroid s crashing into Earth 65 million years ago wiped oul the dinosaurs and other species. In 1991 the putative impact

i o b j 3 . crater is found beneath Mexico's Yucatan peninsula The World Health Organisation declares «hat smallpox has been eradicated

1981 : Inaugural flight of America's space shuttle

Doctors in Los Angeles alert the Centres for Disease ■ Control to five cases of Peneumocystis carinil pneumonia in gay men. one of the earliest signs of the AIDS epidemic

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

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

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

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

1948 The US Air Force starts Projects Blue Book to gather v. ’data on UFO’ sightings

Alfred Kinsey publishes Sexual Behaviour in the Human Male

1952 : British physician Douglas Bevis describes ' amniocentesis, a prenatal test for genetic abnormalities A research team at Bell Laboratories led by William Shockley. John Bardeen and Walter Brattain invents the transistor

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

1948 : The US Air Force starts Projects Blue Book to gather data on UFO sightings

Alfred Kinsey publishes Sexual Behaviour in the Human Male

1952 : British physician Douglas Bevis describes amniocentesis, a prenatal lest for genetic abnormalities US virologist Jonas Salk develops the first effective polio vaccine

British chemist Rosalind Franklin's X-ray photographs of DNA show that the molecule has a helical structure 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 : US endocrinologists Gregory Pincus. John Rock and C. R. Garcia develop the birth-control pill

1956 : The US explodes a hydrogen bomb at Bikini Atoll, in the South Pacific

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

Soviets send the first artificial satellite. Sputnik. Into orbit around Earth

1958 : Electrical engineer Wilson Greatbatch Invents the first Implantable cardiac pacemaker; it is powered by a zincmercury battery

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

Engineer Robert Noyce makes the first Integrated

1 Marvin John WfCnHhi- ’establish the

Artificial Intelligence Laboratory at MIT.

1960 : The bathyscaph Trieste descends 35,800 fl In the , Mariana Trench to the deepest spot in the oceans

US physicist Theodore Maiman builds a working laser British ethologist Jane Goodall begins studying chimpanzee behaviour in Tanzania

The discovery of an 11th century Norse settlement al 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 ; US marine biologist Rachel Carson publishes Silent Spring

1963 : The tranquilliser Valium is Introduced

1964 : The US Surgeon General first warns that smoking can be hazardous to human health

US 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

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

1969 : American astronauts walk on the moon

Swiss-born psychiatrist Elisabeth KObler-Ross 1985 : Robert Gallo, of the US National Cancer Institute, ant Luc Montagnier. of France's Pasteur Institute, eacl publish the genetic sequence of the AIDS virus. The twi are identical

French and American oceanographers find the Titani< at a depth of nearly 13.000 feet in the /Xtlantic

1986 : The US space shuttle Challenger explodes 73 sec after lift-off

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

1987 : The US Food and Drug Administration approves the antidepressant Prozac

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

Harvard receives the first patent for a genetically-engineered animal

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

1989 : The tanker Exxon Valdez runs around In Alaska's Prince Wiliam Sound, spilling 11 million gallons of crude oil. It is the worst oil spill in US history

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

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

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 BC

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

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

199*1 : Comet Shoemaker-Levy 9 crashes into the planet Jupiter

Near France's Ard^che 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 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

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

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

Source: Time Magazine