timelinescience - 1926 to 1950

1926 to 1950

Setting the scene

Flying develops at a rapid rate after the use of aircraft in the First World War is so successful. In 1927 Charles Lindbergh makes the first nonstop solo flight across the Atlantic Ocean in 33.5 hours.

The late 1920s sees the beginning of the Great Depression, a worldwide economic slump that continues into the early 1930s. The slump leads to massive unemployment, and about 20% of the British population is estimated to be on a very poor diet.

In Germany Adolf Hitler's National Socialist party come to power, promising to solve Germany's economic and political problems. After re-arming Germany, Hitler is increasingly daring, until the invasion of Poland leads to a declaration of war between Britain and Germany in 1939. For the next six years all the efforts of Britain and her allies go into providing weapons, aircraft and munitions for the fight against the Nazis in Europe and against Japan in the Far East..

After the war there is a tremendous feeling of optimism, but in those countries most involved in the fighting, society has undergone a fundamental change. In the UK, women have worked throughout the war in the munitions factories, and on the land - doing jobs traditionally done by men. As a result, women do not want to return to the old days when they were regarded almost as their husband's property.

By the end of the 1940s scientific developments are being turned into new technologies which will change the workplace, health care and the home for ever.

The science

1926	Working with fruit flies, the American Hermann Muller discovers that X-rays cause genetic mutation. The Austrian physicist Erwin Schrödinger publishes his first paper on wave mechanics, in which the orbiting electron in Bohr's model is replaced by a wave.
1927	Philip Drinker and Louis Straw develop an "iron lung", a machine for mechanical artificial respiration in people who are paralysed and unable to breathe for themselves. The German physicist Werner Heisenberg puts forward his uncertainty principle in which he shows how it is impossible to determine accurately two variables, such as position and momentum.
1928	The Hungarian-American biochemist Albert Szent-Györgyi von Nagyrapolt and the American Charles Glen King discover vitamin C independently of each other. King has priority for the discovery by two weeks, although von Nagyrapolt will win the 1937 Nobel Prize for his work on vitamin C. In England, Alexander Fleming discovers penicillin in mould. Indian physicist Chandrasekhara Venkata Raman discovers that the change in frequency caused when molecules scatter light can provide information about the molecules causing the scattering.
1929	The American chemist William Giauque discovers that oxygen is a mixture of 3 isotopes - ¹⁶O, ¹⁷O and ¹⁸O - this will result in a change from the use of the ¹⁶O standard for atomic mass in 1961. It will be replaced with the ¹²C standard still used at the start of the 21st century..
1930	Karl Landsteiner from America wins the Nobel Prize for discovering the 4 human blood groups A, B, AB, O. American biochemist John Howard Northrop crystallises the enzyme pepsin which is a major step on the road to understanding the chemical nature of enzymes and how they work. The Austrian-American physicist Wolfgang Pauli proposes the existence of the neutrino to explain the process of beta decay of the nucleus. Conclusive evidence for the existence of the neutrino will not be obtained until 1955.
1931	In Germany, Ernest Ruska discovers that a magnetic coil can be used to focus an electron beam and uses this to develop the first electron microscope, although he only achieves a magnification of 400x. Rheinhold Ruedenberg also invents an electron microscope at almost exactly the same time.
1932	The American Charles King isolates vitamin C from lemon juice. In America, Harold Urey discovers deuterium. James Chadwick obtains experimental evidence for the existence of the neutron, an uncharged particle in the nucleus of atoms whose existence was first predicted as a result of work by Marie and Pierre Curie. Chadwick's work will lead to the development of artificial nuclear fission, a necessary process for nuclear power to be harnessed, both as a weapon of war and as a means of producing electricity.
1933	Ernest Ruska builds the first electron microscope which is more powerful than a light microscope, achieving a magnification of x 12,000. Hubert James and Albert Sprague Coolidge use the new theories of quantum mechanics to calculate the strength of a chemical bond. The results agree well with experimental measurements.
1934	Wernher von Braun, a German engineer, develops a rocket powered by liquid fuel. It reaches a height of 2.4km.
1935	Wallace Carothers patents nylon, which he invented in 1934. The sulphonamide drug called prontosil is used on a person for the first time. Its discoverer, the German bacteriologist Gerhard Domagk, gives it to his youngest daughter who is dying from a bacterial infection. She lives!
1936	Catalytic cracking is developed for refining petroleum.
1937	Having left Germany for England in 1933, Hans Adolf Krebs discovers the citric acid cycle (or Krebs cycle as it comes to be called), and explains how food is oxidised to produce energy in cells.
1938	Captain Hendrik Goosen catches a coelacanth in the Indian Ocean. This is a species of fish which had been thought to be extinct for 60 million years. Together the German physical chemist, Otto Hahn, and the Austrian-Swedish physicist Lise Meitner split an atom of uranium. Hahn is very cautious when he publishes his results and does not describe this as nuclear fission. Lise Meitner is forced to flee from German-controlled Austria to neutral Sweden because she is Jewish. She takes the work she had been doing with Hahn with her and her further work starts the drive towards the atomic bomb.
1939	Meitner and Austrian-British physicist Otto Frisch use the term fission to describe the splitting of uranium atoms when bombarded by neutrons. ICI begin to manufacture polyethene (polythene). Swiss chemist Paul Muller discovers that DDT is a powerful insecticide. Marguerite Perey of the Curie Laboratory of the Radium Institute of Paris discovers the element Francium. Gerhard Domagk is awarded the Nobel Prize, but will be unable to accept it until 1947 - Hitler has forbidden German citizens to accept Nobel Prizes.
1940	In the USSR Nikolay Vavilov is sentenced to death for opposing the idea that acquired characteristics are inherited, put forward by Trofim Denisovich Lysenko, Stalin's favourite geneticist. The unstable, radioactive isotope of carbon, ¹⁴C, is discovered.
1941	In America, George Beadle and Edward Tatum develop the idea that each gene controls the development of one enzyme. Small-scale production of penicillin begins.
1942	The yellow fever vaccine used to inoculate thousands of US soldiers causes hepatitis B in many of them, and leads to the development of a new vaccine which is not grown on human blood products. Scientists working under the Italian physicist Enrico Fermi at the University of Chicago create the world's first atomic chain reaction in an atomic reactor in December.
1943	The first kidney dialysis machine is developed by the Dutch doctor Wilhelm Kolff. Jacques Yves Cousteau invents the aqualung and opens up the exploration of life under the sea.
1944	In America, Oswald Avery, Colin Macleod and Maclyn McCarthy show that DNA is the hereditary material for most living organisms. Paper chromatography is developed by two British biochemists, Archer Martin and Richard Synge. Howard Aiken and his team at IBM produce their Mark I computer, which uses punched paper tape for programming. Unfortunately it breaks down with monotonous regularity.
1945	The Japanese city of Hiroshima is bombed with a uranium-based nuclear fission bomb on August 6. A plutonium-based nuclear fission bomb is exploded over Nagasaki on August 9. This uses up the entire American supply of atomic weapons, although few people realise this at the time. The Japanese surrender on August 14. In America Melvin Calvin starts using the ¹⁴C isotope to find out the sequence of events in photosynthesis.
1946	The Americans John Mauchly and John Eckert complete ENIAC (Electronic Numerical Integrator And Computer), the first all-purpose electronic computer. It draws so much power that lights in a nearby town dim each time it is used.
1947	In America, Willard Frank Libby introduces the radioactive carbon-14 method of dating ancient objects. Scottish biochemist Baron Alexander Todd synthesises the main energy-supplying molecules in the cell - ATP and ADP. The Hungarian-born British physicist Dennis Gaber invented holography.
1948	In America, George Gamow, Ralph Adler and Robert Herman develop the Big Bang theory of the origin of the universe. Three American Researchers - John Enders, Thomas Weller and Frederick Robbins, learn how to grow mumps and polio viruses in chick tissue without bacterial contamination, opening the way for increasingly effective vaccine production.
1949	In England, Dorothy Hodgkin uses an electronic computer to help her X-ray crystallography analysis of penicillin.
1950	The Dutch astronomer Jan Hendrik Oort proposes that a great cloud of cometary material and dust surrounds the solar system outside the orbit of Pluto. From this Oort cloud (as it becomes known) materials falls towards the Sun from time to time, and we see it as a comet.