1675 - February 18 - Newton attends his first meeting of Royal Society.
March - At later meetings Newton meets Robert Boyle.
December 9 - 16 - Newton's Hypothesis explaining the Properties of Light is read before Royal Society.
1676 - January 20 - February 10 - Discourse of Observations read to Royal Society.
June 13 - Newton sends his Epistola prior to Oldenburg.
October 20 - Newton sends his Epistola posterior to Oldenburg.
1677 - September - Henry Oldenburg, first Secretary of the Royal Society, dies.
1679 - June 4 - Newton's mother, Hannah, is buried at Woolsthorpe, where Newton spends much of the year.
November 24 - first of a series of letters exchanged with Robert Hooke, a philosophical correspondence on the problem of planetary motion.
1680 - January 17 - Newton severs exchange with Hooke.
December 12 - Newton begins to observe the Comet of 1680-81; he writes Geometria curvilinea.
1681 - Newton observes the Comet until March and corresponds with John Flamsteed (1646-1719) on the topic.
1682 - December - Newton observes 'Halley's' comet.
1683 - November 10 - John Collins dies.