1975 in science

Astronomy and space exploration

• April 19 – Aryabhata, India's first satellite, is launched using Soviet boosters.
• July 17 – Apollo–Soyuz Test Project: An American Apollo and a Soviet Soyuz spacecraft dock with each other in orbit marking the first such link-up between spacecraft from the two nations.
• August 20 – Viking program: NASA launches the Viking 1 planetary probe toward Mars.

Biology

• August 7 – César Milstein and Georges Köhler report their discovery of how to use hybridoma cells to isolate monoclonal antibodies, effectively beginning the history of monoclonal antibody use in science.
• Living specimens of the Chacoan Peccary, previously known only from fossils, are identified in Paraguay.

Climatology

• August 8 – The term global warming is probably first used in its modern sense by Wallace Smith Broecker.

Computer science

• January – Altair 8800 is released, sparking the era of the microcomputer.
• March 5 – Hackers in Silicon Valley hold the first meeting of the Homebrew Computer Club.
• April 4 – Bill Gates and Paul Allen form a company at this time called Micro-Soft in Albuquerque, New Mexico, to develop and sell their Altair BASIC interpreter software for the Altair 8800.
• The MOS Technology 6502 is introduced. An 8-bit microprocessor designed by a small team led by Chuck Peddle for MOS Technology, it is, by a considerable margin, the least expensive full-featured microprocessor on the market.

Mathematics

• Benoit Mandelbrot coins the term fractal.
• The Harada–Norton group is discovered.
• John N. Mather and Richard McGehee prove that for the Newtonian collinear four-body problem there exist solutions which become unbounded in a finite time interval.
• The Monty Hall problem in probability is first posed, by Steve Selvin.

Medicine

• October 16 – The last naturally occurring case of smallpox is diagnosed and treated, the victim being two-year-old Rahima Banu in Bangladesh.
• Lyme disease first recognised at Lyme, Connecticut.
• Mini–mental state examination or Folstein test introduced to screen for dementia or other cognitive dysfunction.

Technology

• Steven Sasson of Eastman Kodak in the United States produces the first self-contained digital camera.

Awards

• Nobel Prizes
• * Physics – Aage Bohr, Ben Roy Mottelson, James Rainwater
• * Chemistry – John Warcup Cornforth, Vladimir Prelog
• * Medicine – David Baltimore, Renato Dulbecco, Howard Martin Temin
• Turing Award – Allen Newell, Herbert A. Simon

Births

• July 11 – Naomi McClure-Griffiths, American-born astrophysicist.
• July 17 – Terence Tao, Australian-born mathematician.
• November 14 – Martin Hairer, Swiss-born Austrian-British mathematician.
• Catherine A. Lozupone, American microbiologist.

Deaths

• February 8 – Sir Robert Robinson b. 1886), British chemist, Nobel Prize laureate
• February 10 – Elizabeth Kozlova, Russian ornithologist
• February 14 – Sir Julian Huxley, English biologist and author.
• April 19 – Percy Lavon Julian, African American research chemist.
• May 14 – Ernst Alexanderson, Swedish American television pioneer.
• May 18 – Christopher Strachey, English computer scientist.
• June 8 – Douglas Guthrie, Scottish otolaryngologist and medical historian.
• June 27 – Sir Geoffrey Taylor, English physicist.
• September 5 – Alice Catherine Evans, American microbiologist.
• October 10 – August Dvorak, American educational psychologist.
• October 23 – Gordon Hamilton Fairley, British oncologist.
• November – Priscilla Fairfield Bok, American astronomer.
• November 19 – Tokushichi Mishima, Japanese inventor and metallurgist.
• December 13 – Mary Locke Petermann, American cellular biochemist.
• December 28 – Frances McConnell-Mills, American toxicologist.