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Edmond Halley: 2 ideas worth knowing

2 ideas from Edmond Halley, each explained in a minute and credited to the original work. Free on Savvy.

• A comet's return in 1758 proved Newton's laws worked beyond the planets

  In 1705, Edmond Halley noticed that comets seen in 1531, 1607 and 1682 shared the same orbit and guessed they were one object, returning roughly every 76 years. Using Newton's grav…

  — Edmond Halley, A Synopsis of the Astronomy of Comets

• A comet astronomer also invented the math behind your life insurance

  In 1693, Edmond Halley analyzed birth and death records from Breslau to build one of the first rigorous life tables, showing how to calculate the probability of surviving to any gi…

  — Edmond Halley, An Estimate of the Degrees of the Mortality of Mankind

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