Henrietta Swan Leavitt, a 'computer' at the Harvard College Observatory, studied photographic plates of the Small Magellanic Cloud and catalogued thousands of variable stars. In 1912 she showed that for the Cepheids the longer the pulsation period, the brighter the star. Since all stars in the Cloud are at nearly the same distance, the relation gave astronomers a way to calibrate distances across the universe. Edwin Hubble used it to prove that other galaxies exist, and it still underlies the cosmic distance ladder. Leavitt died in 1921, before receiving wide recognition.
Before and after
- 1912Founding of Swansea City A.F.C.
- 1912Founding of Russia men's national football team
- 1912Construction of Atatürk Airport
- 1912Rise of vorticism
- 1912Henrietta Leavitt finds the period-luminosity law
- 1912The Piltdown Man is announced
- 6 January 1912Alfred Wegener proposes continental drift
- 28 January 1912Birth of Jackson Pollock
- 1 March 1912Founding of World Tennis
More in Science & technology
- 1766Discovery of hydrogen
- 1771Discovery of oxygen
- 1789Discovery of carbon
- 18 August 1868Discovery of helium
- 1875Discovery of gallium
- 1898Discovery of krypton
The era
This moment belongs to the Industrial era (1760 CE to 1914 CE), steam, factories and revolutions. You can also browse everything in the 20th century.