1686 in science

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The year 1686 in science and technology involved some significant events.

Astronomy

John Ray begins publication of his Historia Plantarum, including the first biological definition of the term species;^[1] also his edition of Francis Willughby's Historia Piscum.^[2]

Edmund Halley establishes the relationship between barometric pressure and height above sea level.

Edmund Halley presents a systematic study of the trade winds and monsoons and identifies solar heating as the cause of atmospheric motions.^[3]

Isaac Newton uses a fixed length pendulum with weights of varying composition to test the weak equivalence principle to 1 part in 1000.

May 11 – Otto von Guericke, German physicist (born 1602)
November 25 (NS December 5) – Nicolas Steno, Danish pioneer geologist (born 1638)