Johannes Kepler lived from 1571 to 1630. Kepler was a German astronomer who worked closely with Galileo and Tycho Brahe. Kepler came up with the three laws of planetary motion, which he is most famous for. Kepler calculated some of the most well known mathematical calculations to this day as well as gave the first proof as to how logarithms worked. He also did a large amount of work with optics as well. The following is an interview with the famous astronomer.

WM Times: What type of lifestyle were you born into?

J. Kepler: I was born into a poor family, where there were problems. My parents had a very unhappy marriage and I, unfortunately, was subjected to there constant bickering. When I was five years old my father left and died most likely in a war with the Netherlands.

WM Times: What was your first college or university?

J. Kepler: At the time period nobody called a school a college but the university which I did attend was the University of Tubingen where I got a scholarship from the Dukes of Wurttemberg.

WM Times: How did you get to know Tycho Brahe and what accomplishments did you share?

J. Kepler: In the year 1600 AD Tycho Brahe invited me to join his research team. After his death I was appointed to be his successor as the Imperial Mathematician.

WM Times: What were the books that you published and what were they on?

J. Kepler: My first book was *Ad
Vitellionem Parapolemna, Quibus stronomicaal Pars optica Traditur*
(Supplement to Witelo, concerning optical astronomy). Then in
1609 I wrote *Astronomia Nova* (New Astronomy). *Dissertatio
cum Nuncio Siderio Nuper co mortal's missoa Galilaeo Galilaeo*
(conversation with Galileo's sidereal revenge) was written
including Galileo's information. Ten years later I published a
book, *Harmonices Mundi *(Harmonies of the world) on the
harmonic law.

WM Times: What was your Harmonic Law?

J. Kepler: My Harmonic Law was the third law of planetary motion which states “The squares of the sidereal periods of the planets are proportionate to the cubes of the semi major axes (mean radii) of their orbit”.

WM Times: How would you explain this law?

J. Kepler: This can simply be stated as the time that it takes a planet to revolve around the sun squared is equivalent to the cube of the distance between the planet and the sun.

WM Times: What was your first law?

J. Kepler: The path of a planet around the sun is an ellipse, with the sun at one focal point.

WM Times: How would you explain this law?

J. Kepler: My first law generally states that the path of all planets is an ellipse centered around two foci. An ellipse is generally the shape of an oblate spheroid meaning that it is close to an oval that is slightly squashed.

WM. Times: What is your second law?

J. Kepler: The radius vector to a planet sweeps over equal areas in equal intervals of time.

WM. Times: How would you explain this law?

J. Kepler: Angular momentum is the constant time for all central forces and when the mass and angular momentum are combined it causes the planet when moving closer to the sun to move faster than when it is at a farther distance from the sun. The gravitational pull would also cause it to move faster while being closer to the sun.

Through this interview we can see how much
just a bit of Kepler's work has helped society in the long run
and if we had talked about everything that he did we would run
out of room and would have a never ending article. Kepler was
also said to have been an amazing student from a very young age.
He conveyed his knowledge through math and sciences, with the
laws of planetary motion and optics, and his great works.

Works Cited

Kepler, Johannes. Charles Glenn Wallis,
trans. *Epitome of Copernican Astronomy: 7 Harmonies of the
World. *Prometheus Books, 1995.

Strong primary sources for the paper but vary difficult to understand for the ordinary mind.

Land, Barbara. Sam Wisnom, ill. *The
Quest of Johannes Kepler, Astronomer.* Garden City: Doubleday
& Company, Inc., 1963.

Provided excellent background info on him and his family and explained the three laws of planetary motion.

Mitton, Jacqueline. *Astronomy: an
Introduction for the Amateur Astronomer. *The Berne
Convention, 1978.

This work was decent but slightly difficult to understand in the sense of the mathematics but useful as well as it is very similar to Introductory Astronomy and Astrophysics.

Moore, Patrick.* The Amateur Astronomer:
A completely new version of Moore's classic work. *W.W.
Norton & Company, Inc., 1990.

Slightly easy to understand but also depends on the reader fully in this area.

Zeilik, Michael and Elske v.P. Smith. *Introductory
Astronomy and Astrophysics, *2nd ed. CBS College Publishing,
1987.

This book is a little more challenging for the reader to understand then Astronomy an Introduction for an Amateur Astronomer which is also less factual as the other book.