The English Calendar in the 17th Century

Most recent answer: 10/22/2007

Q:
how come u say that isaac newton died on the 31st of march and everybody else says that he died on the 20th of march and where did he live? and did aristotle ever marry, have children and where did he live?
- lizzy
australia
A:
I’m no historian, so you’re going to have to ask another web site about Aristotle’s family life or lack thereof.

But I did recently read James Glieck’s fine biography of Sir Isaac, and he explains the first puzzle in the beginning of his "notes" at the end. To paraphrase:

In Newton’s time, the English calendar ran at first ten and then eleven days behind the calendar in most of Europe. Furthermore, the year in England was considered to start March 25, not January 1, and so when Newton died on England’s March 20, it was 1726 in England and 1727 in Europe.

You would think that this sorry state of affairs would be a great starting point to question the nature of absolute time and of simultenaity. But one of Newton’s great achievements was to think of idealized systems which were not affected by things like friction or air resistance, in which the laws of physics are simple. Cutting through the clutter of the definition of time is a more obvious improvement and it probably didn’t occur to anyone that the idea of simultenaity would have to be though about more carefully later on.

One of my favorite quotes from Misner, Thorne and Wheeler’s book on general relativity: "Time is defined so motion looks simple." (not according to 17th century European calendars!)

Tom

(published on 10/22/2007)