Wednesday, April 27, 2011

Happy Birthday, Universe!

Or, at least, happy birthday according to seventeenth century astronomer Johannes Kepler.
Make a wish!
Kepler, born Dec. 27, 1571, was a German mathematician, astronomer, and astrologer, and became a key figure in the 17th century scientific revolution.  Perhaps best known for his laws of planetary motion, Kepler's work laid the foundation for Isaac Newton's theory of universal gravitation.

While at the University of Tubingen, Kepler studied both the Ptolemaic system (geocentric) and the Copernican system (heliocentric) of planetary motion, becoming a Copernican.  As a student, Kepler defended heliocentrism from both a theoretical and theological perspective, maintaining that the Sun was the principal source of motive power in the universe.
That is one powerful beard!
Following his studies, Kepler became a professor of mathematics and astronomy at the University of Graz, in Austria, at the age of 23.  He later went on to work with Danish astronomer Tycho Brahe, and although Tycho guarded his data closely, he was impressed by Kepler's theoretical ideas, and eventually allowed him more access to his data and his observatory.  When Tycho unexpectedly died the next year, Kepler inherited Tycho's extensive collection of astronomy data, as well as the post of imperial mathematician for Holy Roman emperor Rudolph II. 

While at this post, Kepler became exceedingly productive.  Kepler learned of the work of Italian physicist and astronomer Galileo Galilei, who had discovered mountains and craters on the moon as well as four moons of Jupiter with a telescope he had invented.  Kepler later corresponded with Galileo, obtaining a telescope of his own and improving upon the design.  Somewhere along the way, Kepler found the time to publish his three laws of planetary motion, as well as several scientific works and validation of Galileo's works.  Among his studies and calculations, Kepler came up with a calculation for the beginning of the universe: April 27, 4977 BC.

I honestly have no idea what was taken into consideration for this computation, but Kepler did not employ any calculating assistants (back then, you hired your calculators, rather than buying them from Texas Instruments), so for having to do the math all by himself, he didn't do too badly.  Granted, the universe really is something like 13.75 billion years old, but he's only off by 214,843,750%!

So sit right back, universe, and grab yourself a slice of cake.  You've got to have a birthday sometime, why not today?


  1. Kepler! One of my favorite astronomers, and a bit of a crazy guy too, nothing on Tycho, but out there. I don't know where he got that date from either, in his later days, Kepler was known for his long rambling nonsensical theories. Galileo often made fun of his letters for being incomprehensible.

  2. I used to always get those calendars that have famous people's birthdays in the margin. I never saw "the universe" on any of the days. If I were born on April 27th I would want to know I share a birthday with the universe.

  3. Considering how eccentric Tycho Brahe was, Kepler being his "heir", so to speak, is no small feat.

  4. Galileo was thee man in those days. Thanks for a great post.