Many of Kepler's writings reflect his deep desire to testify to God's glory.
Kepler went back to Graz to learn that he and his family would be expelled.
On October 17, 1604, Kepler observed that an exceptionally bright star had suddenly appeared in the constellation Ophiuchus.
To understand the orbit of Mars, Kepler needed to know the orbit of the Earth accurately.
The political backdrop to all that was going on for Kepler was one of great turmoil.
Kepler also made fundamental investigations into combinatorics (a branch of mathematics), geometrical optimization, and natural phenomena such as snowflakes, always with an emphasis on form and design.
Based on his open mind and painstaking analysis of astronomical data, Kepler came to the realization that the planets move in elliptical—not circular—orbits.
Much to Kepler's delight, the orbital motions of the planets appeared to verify his theoretical postulate that there is a "planet moving force" flowing from the Sun.
At least 800 horoscopes and natal charts drawn up by Kepler are still extant, several of himself and his family, accompanied by some unflattering remarks.
Kepler inherited from Tycho Brahe a wealth of the most accurate raw data ever collected on the positions of the planets.
Kepler discovered the laws of planetary motion while trying to achieve the Pythagorean purpose of finding harmony of the celestial spheres.
Kepler, however, never discovered the underlying reasons for the laws, despite many years of what would now be considered non-scientific, mystical speculation.
To escape the carnage and turmoil his family had witnessed in Prague, Kepler took the post of provincial mathematician in Linz, a city in Upper Austria.
After Tycho's death, Kepler was appointed to take his place as Imperial Mathematician for Rudolf II.
Kepler incorporated this understanding in his now-famous laws of planetary motion.
Kepler believed in astrology in the sense that he was convinced that astrological aspects physically and really affected humans as well as the weather on Earth.
Kepler's equal-area law: The line connecting a planet to the Sun sweeps out equal areas in equal amounts of time.
Kepler's attempts to fix the orbits of the planets within spheres separated by polyhedra never worked out.
According to historian of science James R. Voelkel (Johannes Kepler and the New Astronomy), he asked a unique question: "Why did God choose to construct the solar system in this way and not another?"
Throughout the trial, Kepler postponed his other work (on the Rudolphine Tables and a multi-volume astronomy textbook) to focus on his "harmonic theory."
Kepler hoped that this data would assist him in his quest to unravel the mystery of the harmony of the universe, and he joined Tycho in 1600.
Under the instruction of Michael Maestlin, Kepler learned both the geocentric (Earth-centered) and heliocentric (Sun-centered) cosmological models.
Two children she had with Kepler and one by an earlier marriage outlived her.
Inspired by Copernicus' work, Tycho Brahe's findings, and some of Plato's ideas, Kepler became convinced of the correctness of the heliocentric model.
Finally losing her temper, Athena destroyed Arachne's tapestry and loom, striking it with her shuttle.
Johannes Kepler (December 27, 1571 – November 15, 1630), a key figure in the scientific revolution, was a German Lutheran, a mathematician, astrologer, astronomer, and a professionally trained theologian.
Working with Tycho's extensive collection of highly accurate observational data, Kepler also set out to refine his earlier ideas about planetary orbits.
Second, the protection and financial security afforded by the new post at Prague must have seemed like a God-given opportunity to the Kepler family.
Kepler also took important steps in trying to describe the motion of the planets by appealing to a force that resembled magnetism, which he believed emanated from the Sun.
Despite his desire to become a minister, Kepler was recommended, near the end of his studies, for a position as teacher of mathematics and astronomy at the Protestant school in Graz, Austria.
In 1592, an outer earth rampart with 50 towers was erected around the city, including an area on the right bank of the Moscow River.
Applying this law rigorously to the orbits of the other planets led him to what we now refer to as Kepler's First Law of Planetary Motion.
Thanks largely to the Ocean Spray cooperative, Massachusetts is the second largest cranberry producing state in the union after Wisconsin.
Kepler's elliptical orbit law: The planets orbit the sun in elliptical orbits, with the Sun at one focus.
The atmosphere of free inquiry and expression of opinion required for Kepler's scientific approach was no longer present in Graz.
Kepler completed the last of seven volumes of his textbook Epitome of Copernican Astronomy in 1621.
Kepler was a Pythagorean mystic who incorporated religious arguments and reasoning into his work.
Introduced to astronomy/astrology at an early age, Kepler developed a love for that discipline that spanned his entire life.
Kepler's laws were the first clear evidence in favor of the heliocentric model of the solar system, because they only came out to be so simple under the heliocentric assumption.
The Kepler family made a hasty exit to Prague, where Johannes rejoined Tycho.
To make matters worse, the Protestant leaders fought among themselves and Kepler, with his independent streak, was ultimately excommunicated.
In 1615, Kepler married Susanna Ruettinger, with whom he had several children.
Kepler wrote to Maestlin, his old astromony professor, expressing his intention to publish this model for the glorification of God.
Kepler's law of periods: The time required for a planet to orbit the Sun, called its period, is proportional to the long axis of the ellipse raised to the power of 3/2.
In 1617, Kepler's mother, Katharina, was accused of being a witch in Leonberg.
After five years of painstaking study of the Mars orbit, Kepler began to question his own belief that the orbits must be circular.
At first, Tycho assigned Kepler to study the motion of Mars—a seemingly minor responsibility.
Kepler's willingness to abandon his highly cherished theory in the face of precise observational evidence indicates that he had a very modern attitude to scientific research.
Kepler expounded these two laws in his book Astronomia Nova (New Astronomy), which was completed in 1606 and published in 1609.
Developing his ideas from the time he taught geometry in Graz, Kepler began to think it was not a coincidence that the number of perfect polyhedra was one less than the number of known planets.