The Harvard Women Who Measured Starlight by Hand
In the early 1900s, Henrietta Leavitt cataloged thousands of pulsing stars on glass photographic plates for 30 cents an hour, and found a pattern that let astronomers finally measure the distance to other galaxies. Her overlooked law became the yardstick Hubble used to prove the universe was expanding. This is the story of the discovery that gave the cosmos its scale.
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Harvard hired women for twenty-five cents an hour to analyze massive surpluses of glass plate photography.
Henrietta Swan Leavitt cataloged one thousand seven hundred seventy-seven variable stars by stacking glass plates.
Leavitt discovered that longer pulse cycles in Cepheid stars indicate higher intrinsic brightness.
Pulsing stars serve as standard candles to measure the universe's third dimension beyond the parallax method.
Edwin Hubble used Leavitt’s Law to prove that Andromeda is a separate galaxy from the Milky Way.
Institutional culture originally credited Leavitt’s groundbreaking manual data analysis to director Edward Pickering.
- 01Intro1 min
- 02The Glass Universe2 min
- 03The Pattern in the Clouds2 min
- 04Leavitt's Law2 min
- 05The Shadow of the Giant2 min
- 06Outro1 min
- Henrietta Swan Leavitt | Biography & Facts | Britannica
- Henrietta Swan Leavitt - Wikipedia
- Henrietta Swan Leavitt - Biography - University of St Andrews
- Henrietta Swan Leavitt | National Women's History Museum
- Henrietta Swan Leavitt | The Harvard Plate Stacks
- This Month in Astronomical History
- Harvard Computers - Wikipedia
- "Harvard Computers": Women Who Analyzed the Night Sky | AMNH
- Harvard's 'Computers': The Women Who Measured the Stars
- Before circuit boards, female 'computers' set the standard
- Unearthing the legacy of Harvard's female 'computers'
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