1933 in science

Astronomy

• October 13 – The British Interplanetary Society is founded.
• Walter Baade and Fritz Zwicky invent the concept of the neutron star, a new type of celestial object, suggesting that supernovae might be created by the collapse of a normal star to form a neutron star.
• Sir Arthur Eddington publishes The Expanding Universe: Astronomy's 'Great Debate', 1900–1931 in Cambridge.
• Comedian Will Hay observes the periodic Great White Spot on Saturn from his private observatory in London.
• Fritz Zwicky postulates the existence of dark matter.

  Chemistry

• Gilbert N. Lewis isolates the first sample of pure heavy water by electrolysis.
• Morris S. Kharasch and Frank R. Mayo propose that free radicals are responsible for anti-Markovnikov addition of hydrogen bromide to allyl bromide.

  Earth sciences

• March 10 – Long Beach earthquake in Southern California: First recording of earthquake strong ground motions by an accelerograph network, installed in 1932 by the United States Coast and Geodetic Survey.

  Mathematics

• Andrey Kolmogorov publishes Foundations of the Theory of Probability, laying the modern axiomatic foundations of probability theory.
• David Champernowne, while still a Cambridge undergraduate, publishes his work on the Champernowne constant in real numbers.
• Alfréd Haar introduces Haar measure.
• Jerzy Neyman and Egon Pearson publish the Neyman–Pearson lemma.
• Stanley Skewes discovers Skewes' number.

  Medicine

• April 3 – First attempted human kidney transplant, by Dr :ru:Вороной, Юрий Юрьевич|Yuri Voronoy in the Soviet city of Kherson; the recipient dies 2 days later due to incompatibility of blood type with the donor.
• July 14 – Law for the Prevention of Hereditarily Diseased Offspring enacted in Nazi Germany allowing compulsory sterilization of citizens suffering from a list of alleged genetic disorders.
• Manfred Sakel begins to practice insulin shock therapy on psychiatric patients in Vienna.

  Physics

• September 12 – Leó Szilárd, waiting for a red light on Southampton Row in Bloomsbury, conceives the idea of the nuclear chain reaction.

  Technology

• June – A research group at RCA headed by Vladimir K. Zworykin publicly launches the iconoscope, the first practical cathode ray tube television camera.
• June 26 – American Totalisator unveils its first tote board, the electronic pari-mutuel betting machine, at the Arlington Park race track near Chicago.

  Organizations

• Museum of Science and Industry first opens to the public, as part of the Century of Progress Exposition.
• The Institute for Advanced Study opens at Princeton, New Jersey, attracting Albert Einstein, John von Neumann and Kurt Gödel.
• Sheffield Trades Historical Society established in England.

  Awards

• Nobel Prizes
• * Physics – Erwin Schrödinger and Paul Dirac
• * Chemistry – not awarded
• * Physiology or Medicine – Thomas Hunt Morgan

  Births

• January 6 – Oleg Makarov, Soviet cosmonaut.
• January 18 – David Bellamy, English botanist.
• March 9 – Sir David Weatherall, English molecular geneticist.
• March 10 – Patricia Bergquist, New Zealand scientist specializing in anatomy and taxonomy.
• March 23 – Philip Zimbardo, American social psychologist.
• April 14 – Yuri Oganessian, Russian nuclear physicist.
• May 22 – Chen Jingrun, Chinese mathematician.
• July 9 – Oliver Sacks, English-born neurologist.
• July 12 – Max Birnstiel, Swiss molecular biologist.
• August 10 – Ed Posner, American mathematician.
• August 15
• * Stanley Milgram, American social psychologist.
• * Michael Rutter, English child psychiatrist.
• September 6 – Juliet Clutton-Brock, English zooarchaeologist.
• September 10 – Yevgeny Khrunov, Soviet cosmonaut.
• September 26 – Charles C. Conley, American mathematician specializing in dynamical systems.
• October 2 – Sir John Gurdon, English developmental biologist, recipient of the Nobel Prize in Physiology or Medicine.
• October 9 – Sir Peter Mansfield, English physicist, recipient of the Nobel Prize in Physiology or Medicine.
• November 1 – Dijen K. Ray-Chaudhuri, Bengali-born mathematician.
• November 4 – Sir Charles K. Kao, Chinese electrical engineer and physicist, recipient of the Nobel Prize in Physics.
• December 22 – Thomas Stockham, American electrical engineer and inventor
• December 23 – Akihito, ichthyologist and Emperor of Japan.

  Deaths

• January 14 – Sir Robert Jones, 1st Baronet, Welsh orthopaedic surgeon.
• May 22 – Sándor Ferenczi, Hungarian psychoanalyst.
• June 14 – Ernest William Moir, British civil engineer.
• September 25 – Paul Ehrenfest, Austrian physicist and mathematician.
• December 8 – John Joly, Irish physicist.