Isaac Newton of the Principia

Sir Isaac Newton (1642/3--1727)

Newton's birth year is confused by the fact that England still used the Julian calendar until 1752sep while most of Europe had switched to the Gregorian calendar that had been introduced first only in Roman Catholic countries starting 1582oct. By the Julian calendar Newton was born 1642dec25: he was lucky not to be named Christmas Newton: babies born on Christmas day occasionally received that moniker: nowadays we usually settle for Noel. By the Gregorian calendar the day was 1643jan04. We use Gregorian and Newton used Julian, and so it seems fair to comprise and give 1642/3 as his birth year.


  1. Hall, A. R. 1992, Isaac Newton: Adventurer in Thought (Oxford: Blackwell Publishers)


  1. Isaac Newton The University of St. Andrews MacTutor History of Mathematicians Archive.
  2. Isaac Newton The Wikipedia Isaac Newton page.
  3. The Virtual Museum of Newton Temporarily (?) a dead link.


Some of the images are now broken links. I've come to the conclusion that without some clear statement of permission to use or of public domain status, I've no clear right to show those images. Historical originals are uncopyrighted, of course, but reproduced images may be copyrighted and even if not, someone might feel agrieved that they circulate on the web. The images linked by thumbnails are legitimate to use for personal educational purposes with credit or are public domain. The thumbnail link gives the credit and link to the source if needed.

  1. Newton of the Principia

    Based on the 1689 portrait of Newton by Godfrey Kneller. This is the Newton of the Principia. He is dressed in doctoral robes I assume.

  2. Isaac Alien discovers gravity. Isaac Alien discovers gravity.

  3. Credit: Digital Imaging Project of Mary Ann Sullivan, Bluffton College; download site Digital Imaging Project's chronological Index site. The download site gives more information.

    1. Wren's Trinity College Library Christopher Wren's Library at Trinity College Cambridge

    2. Wren's St. Paul's Cathedral (south Transept), London Christopher Wren's St. Paul's Cathedral (south Transept), London.

  4. Credit: Willliam R. Shepherd, 1926 Historical Atlas (now public domain). Download site Perry-Casta~neda Library Map Collection. An excellent site for public domain maps.

    1. Newton's England Newton's England.

    2. Chaucer's London Chaucer's London.

  5. The Newton of the Principia (1687) Painting by Geoffrey Kneller in 1689: the year of the Glorious Revolution.
  6. The Newton of the Principia (1687) Detail in color.
  7. Newton's Trinity College, Cambridge 1690