Date: July 1st, 2012

Title: Encore: Don’t Forget Kepler

Podcaster: David Powell

Organization: None

This podcast originally aired on April 22, 2009

Description: I will give biographical information on Kepler and Galileo telling stories about each of their lives, foibles and major contributions. I will focus on how Kepler’s contributions are not always recognized, as being just as important as Galileo’s. I will then tie things up, talking about the many ways people can get involved with astronomy. One might take the path of Galileo and become an avid observer or you might be more inclined to teaching and mathematics, as Kepler. Sign off with, there are many books about both Kepler and Galileo and that when you read history, its always a good idea to get information from a couple of different sources.

Bio: I am a 57 year old retired Police Officer originally from Portland, Oregon. I have been married for 35 years and have 2 grown children. I graduated from Portland State University with a BS in Psychology. My time is currently being filled with volneetering at OMSI-both at the museum proper and at their dark sky camp in Eastern Oregon, being a member of the Rose City Astronomers, I sit on the Oregon Star Party Committee and I also do astronomy outreach and go fishing. I current own 2 telescopes, both of which I made myself; an 8″ Dob and a 12 1/2″ “String Telescope.” I currently live in Longview, Washington, about 50 miles north of Portland, Oregon.

Today’s Sponsor: “This episode of 365 days of astronomy was sponsored by – Expanding your horizons in astronomy today. The premier on-demand telescope network, at dark sky sites in Spain, New Mexico and Siding Spring, Australia.”


Hi, I’m Dave Powell and I want to thank you for taking the time to listen to this podcast, I’m an amateur astronomer in the Portland, Oregon area and I volunteer at Harry C. Kendall Planetarium. The planetarium is part of the Oregon Museum of Science and Industry and if you’re ever in the Portland area, I want to invite you to stop by for one of our presentations.

You probably already know that 2009 has been designated as the International Year of Astronomy or as most people call it, “The I-Y-A.” One of the reasons it was selected as The I-Y-A, is because 400 years ago, Galileo Galilei first turned his telescope toward the night sky and recorded his observations. In 1609 Galileo’s observations were not the only important thing happening in astronomy; Johannes Kepler had just published his first two laws of planetary motion.

Most people would recognize the name Galileo and most would be able to tell you a few of his accomplishments, whether it be the discovery of the moons of Jupiter, the phases of Venus or the craters on the Moon or perhaps the small problem he had with the Catholic Church.

On the other hand, mention the name of Johannes Kepler and you will probably get a blank stare. Only a few people will be able to tell you any of his major contributions to science. Well, I’m here to change that. Let’s take a look at the lives of Galileo and Kepler and see how they compare.

Galileo was born in northern Italy in 1564, the same year as William Shakespeare, to an upper middle class family. He had a comfortable life and was sent off to a Jesuit monastery for his education, when he was about 10 years old. After learning Greek, Latin, philosophy and logic, he thought a career path of becoming a monk, might be a good option. His Father thought otherwise and immediately removed him from the monastery. His Father thought the young Galileo should become a physician. Galileo agreed to study medicine, but his true love was Geometry and Mathematics. He ended up as a Lecturer of Mathematics at the University of Pisa.

Taking a look at Johannes Kepler’s early life, it is the complete opposite of Galileo’s. Kepler was born into the lowest social class of Germany in 1571. His family was penniless and his parents were rarely around. Johannes’s Father was a mercenary and his mother was a “camp follower,” selling her charms to the soldiers in the evening. Johannes was raised by his extended family. He was the oldest of 7 children and grew up sharing the family home with 10 to 12 other relatives. Besides these problems, Kepler was a sickly child, being extremely nearsighted, having skin problems and nearly dying of Smallpox when he was just four years old. Despite these hardships, his Mother was able to show him a beautiful comet in 1577, which apparently sparked his interest in astronomy.

Kepler also benefited from the Lutheran school system in Germany. Like Galileo he studied to become a minister, but unlike Galileo, Kepler’s Father had no objections, as he had abandoned the family when Johannes was sixteen. Kepler never did become a minister and ended up as a school teacher in what is now Austria. He was apparently not a very good teacher, as during his second year of teaching, not a single student wanted to take his classes, but the school continued to have faith in him, as he was obviously a brilliant man.

Both Galileo and Kepler were in jobs they really did not want and each had greater ambitions. Galileo did not like the little town of Pisa and wanted to move to the big time of Florence. Kepler also wanted more. Johannes got married in 1597 and despite his continuing health problems they did manage to have several children together. Galileo, on the other hand, always remained a bachelor, although he did manage to father a son and two daughters with the same woman.

As is the case with many great people, an opportunity comes along and both Kepler and Galileo answered the knock at the door. Galileo was able to make improvements to the newly invented telescope and was trying to curry favor with the Grand Duke of Tuscany, Cosmo II de’ Medici. Galileo named the moons of Jupiter he discovered, the Medician stars, in Cosmos honor. His ploy worked and he received an appointment as the Court Mathematician in Florence.

Kepler’s opportunity came thru the back door, when he got kicked out of Austria for failing to convert to Roman Catholicism. This gave him the chance to get a job with Tyco Brahe in Prague. Tyco was known for the precession of his observations, while Kepler had a more theoretical mind. Tyco and Kepler did not get along, but both seemed to realize they needed each other. Johannes had bragged that he would be able to compute the orbit of Mars in just 8 days, if Tyco would give him all of his records. Tyco wanted to keep his data private… Unfortunately for Tyco, he died in 1601 and Kepler got all the data he needed. It only takes Johannes 8 years to figure out the orbit of Mars and his first two laws of planetary motion. The first law, that planets go around the Sun in elliptical orbits and his second law, that a planets speed various as it travels around the Sun. This may not seem like a great feat, but it was revolutionary. To be fair to Kepler, you should realize that he did not have a Texas Instruments Graphing Calculator and he had to do all of his calculations by hand. His health problems made his calculations more difficult, as most were made while he was standing up, as he suffered from a severe case of hemorrhoids.

Galileo and Kepler continued on with their work and made important contributions to astronomy and science. Both of these great men’s lives, took a turn for the worse. We all know that Galileo was put on trial by the Roman Catholic Church and ended up confined to his home for the rest of his life. In his last years, Galileo went blind and passed in 1642. To be fair to the Catholic Church, they did apologize to Galileo shortly after his death; I think it was in 1992. Kepler did not have it much better. In 1611 his first wife died along with one of their children. Kepler remarried and went on to discover his third law of planetary motion. It states the square of a planets orbital period and the cube of its distance, are always the same proportion to each other. Kepler spent the last years of his life defending his mother against charges of witchcraft and he had an uneventful death in 1630, while on a trip, trying to collect some overdue salary.

Kepler and Galileo each made important and lasting contributions to science. Galileo was able to prove that Aristotle was wrong in claiming that heavier objects fell faster than lighter ones. He made improvements to the telescope, increasing its magnification and using it to observe the heavens. His work with pendulums and making a useful thermometer are also important.

Kepler also worked with optics and improved the telescope by giving it a much wider field of view, at the cost of making the image appear upside down. As an expert mathematician, he formed the basis of Integral Calculus, was the first to derive Logarithms based on mathematics, He coined the word satellite and of course, discovered the three laws of planetary motion; the third law also helped Isaac Newton figure out his Universal Law of Gravity.

As a final comparison, NASA has also chosen to honor these two great astronomers, with their own namesake missions. The Galileo mission to Jupiter, which revealed secrets of the gas giant that Galileo Galilei could never have guessed at. The recent successful launch of the Kepler Mission, whose purpose is to discover Earth sized planets around other stars, is also appropriately named.

During this short podcast, I’ve only been able to touch briefly on these two great men. If you would like to learn more about the life and times of Johannes Kepler or Galileo Galilei, there are numerous resources on the web and at any library. When you are reading history, it’s always a good idea to get your information from more than one source. You might learn some quirky little fact about your subject, like Keplers extreme fear of taking a bath. It was his first wife who finally forced him into taking one, in 1605, 8 years into their marriage; Kepler thought it a very unpleasant experience.

I hope you’ve enjoyed this podcast and thanks for listening, and remember, when you’re thinking of or talking about the great astronomers, “Don’t Forget Kepler.”

End of podcast:

365 Days of Astronomy
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