por Who was Johannes Kepler?
Johannes Kepler (1571-1630) was a German astronomer whose main contribution was the fundamental laws of the movement of the planets. He himself did not consider them laws, but part of a heavenly harmony that reflected the influence of God in the Universe.
Kepler’s discoveries made him go from the model of Nicolaus Copernicus (1473-1543) -with the Sun as the center of the Universe-, to a dynamic Universe, with planets revolving around the Sun in non-circular orbits.
In addition, he developed an explanation of the behavior of light, discovered new semiregular polyhedra, and proposed new principles for astronomy.
Biography of Johannes Kepler
Birth
Johannes Kepler was born in Weil der Stadt, Württemburg, Germany, on December 27, 1571 and died in Regensburg, a city located in German Bavaria, on November 15, 1630.
He grew up in a once renowned Lutheran Protestant family, but already in decline when Kepler was born.
His father, Heinrich Kepler, was a mercenary in the service of the Duke of Alba. Her mother, Katharina Guldenmann, was the daughter of an innkeeper and worked as a healer. She was accused of witchcraft because of her knowledge of herbalism.
Kepler was a sickly child and at the age of 3 nearly died from smallpox, which left him with impaired vision for the rest of his life. However, he overcame the consequences of an unfortunate childhood thanks to his tenacity and intelligence.
Studies
Motivated by his parents, from a very young age he was immersed in the study and observation of the stars and the universe.
Due to the family’s difficult economic situation, he had to drop out of school to work as a day laborer, but he was always studious. In 1584 he entered the Protestant seminary at Adelberg.
His intelligence and fascination for the Universe were so great that he won a scholarship to study at the University of Tübingen. There he studied philosophy, mathematics, ethics, astronomy and physics, among others. He time later he studied human sciences and theology.
In 1591 his teacher, the astronomer Michael Maestlin (1550-1631), taught him Nicholas Copernicus’s heliocentric system, which contradicted Ptolemy’s system.
In 1594 he interrupted his theological studies and traveled to Graz (Austria), where he served as a professor of mathematics at the Protestant school. During his stay as a teacher in Graz, he published a calendar with astrological predictions, which he wrote himself.
elliptical orbits
In July 1595, Kepler had an important revelation and developed a complex geometric hypothesis to explain the distances between planetary orbits, concluding that their orbits are elliptical.
He claimed that the Sun exerted a force that drives the planets to move around their orbits.
In 1596, he published a treatise entitled the cosmic mystery, who defends the Copernican system. In it he explains all his doctrines related to cosmology with his vision of the existence and wisdom of God in the cosmological model.
Marriage
On April 27, 1597, he married Bárbara Müller. Soon after, an edict of the Archduke Ferdinand against the Protestants forced him to leave Austria, and in October 1600 he moved to Prague, welcomed by the Danish astronomer Tycho Brahe.
Relationship with Tycho Brahe
Tycho Brahe was a mathematician who built the Prague observatory, where the best observations of the Solar System were made. When Kepler arrived in Prague, Tycho Brahe handed him the study of the orbit of Mars.
Brahe and Kepler had come to a perfect collaborative relationship that was sadly interrupted by Brahe’s unexpected death.
On Brahe’s death in 1602, Kepler replaced him as Rudolf II’s imperial mathematician and as astrological adviser, an occupation to which he frequently resorted to in order to survive.
Kepler’s laws
One of his most important works during this period was New Astronomy, published in Prague in 1609, where he explained the result of his studies for 5 years to calculate the orbit of Mars and the planetary movement. In this book the first two Kepler’s Laws are presented.
After carrying out several studies based on his first two laws, he related the trajectory of the planets to each other, also known as the law of planetary motion, and formulated his third law.
Second matrimony
In 1612 the Lutherans were expelled from Prague, so Kepler moved to Linz after the recent death of his wife and two children. He subsequently remarried but had many personal and financial problems.
In 1617, his mother Katharina was accused of being a witch. Thanks in part to the extensive legal defense that Kepler prepared for her, she was released in October 1621.
That year, Kepler completed the last of seven volumes of his textbook on astronomy, bringing together and expanding his work on the Copernican system.
Linz
When King Rudolf II died and his brother Matthias of Habsburg came to the throne, Kepler was appointed professor of mathematics in Linz, where he lived until 1626.
In 1627 he completed the Rudolphine Tables which provided accurate calculations of the future positions of the planets and enabled the prediction of rare astronomical events.
Haunted by debts, in 1628 he went into the service of a Czech military nobleman, Albrecht von Wallenstein, in Sagan, Silesia, who promised to help him pay off his debts.
Death
Days before he died, he had left Silesia looking for a new job. Johannes Kepler died in Regensburg on November 15, 1630, at the age of 58. His tomb was demolished – two years after it was buried – by the Swedish army in the Thirty Years’ War.
Kepler’s three laws
It took Kepler almost eight years to understand the retrograde motion of the planet Mars. Using Brahe’s detailed observations, he realized that the planets traveled in «stretched out» circles, known as ellipses.
The Sun is not located exactly in the center of its orbit, but moves to one side, at one of two points known as the focus.
Some planets, like Earth, have an orbit very close to a circle, but the orbit of Mars is one of the most elliptical. The fact that the planets travel along elliptical paths is known as Kepler’s First Law.
Kepler also noticed that a planet moved more slowly when it was farther from the Sun than when it was close.
Understanding that planets traveled in ellipses, he determined that an invisible line connecting the Sun to a planet covered an equal amount of area for the same amount of time, this being Kepler’s Second Law.
Kepler’s Third Law was published a decade later, and it recognized that the relationship between the period of two planets—the time they take to orbit the Sun—corresponds to their distance from the Sun.
While Kepler’s first two laws focus on the details of a single planet’s motion, the third law is a comparison between the orbits of two planets.
Other contributions of Kepler
Although Kepler is best known for the laws that define planetary motion, he also made other notable contributions to science:
-Determined that refraction drives vision in the eye, and that the use of two eyes allows depth perception.
-Created glasses for myopia and hyperopia.
-Explained the operation of the telescope.
-Described the properties of reflection.
-He affirmed that gravity depends on two bodies instead of one, claiming that the Moon is the cause of the movement of the tides on Earth.
-He mentioned the rotation of the Sun and created the word “satellite”.
-He tried to use his knowledge to measure the distance to the stars.
-Made several contributions to mathematics, including the creation of faster calculation methods.
-Investigated the volume of many solid bodies.
-He calculated the year of Christ’s birth.
-He was the first to explain the principles of telescope operation.
-Your book Stereometrica Doliorum provided the basis of integral calculus.
Mathematics, astronomy and astrology
In addition to teaching mathematics in Graz, Kepler became a district mathematician. In this position he elaborated the calendars of his time that had to include useful information for the daily life of the people.
The information included advice to farmers on when to plant crops, advice to leaders on military campaigns, advice on matters of romance, etc.
In Kepler’s day there was considerable confusion both in the general community and in universities as to the distinction between astronomy and astrology.
As part of this process, Kepler published a book in 1601 that «rejected the superstitious view that the stars guide the lives of human beings» and progressively rejected other aspects of astrology.
Recognition
In recognition of Johannes Kepler’s contributions to understanding the motion of the planets, NASA named in his honor to the planet-finding telescope.
kepler and god
Many of Kepler’s writings reflect his deep desire to bear witness to the glory of God. On one occasion, he wrote:
“He simply thought of God’s thoughts after Him. PSince we astronomers are priests of the Most High God in regard to the book of nature, it benefits us to be thoughtful, not of the glory of our minds, but rather, above all, of the glory of God.”.
Showing the humility that characterized him, and eager to develop a personal relationship with God, Kepler reflected:
“Can I find God, who in the contemplation of the entire universe I can almost feel in my hands, also in myself?
References
Bellis M. Johannes Kepler – Astronomy. Retrieved from thoughtco.com.
DeVore E. Kepler and Mars – Understanding How Planets Move. Retrieved from space.com.
Fowler M. Johannes Kepler. Retrieved from galileoandeinstein.physics.virginia.edu.
Lamont A. Johannes Kepler (1571-1630). Outstanding scientist and committed Christian. Recovered from creation.com.
Rabin S. Johannes Kepler. Retrieved from oxfordbibliographies.com.
Sobel D. Searching Heaven and Earth for the Real Johannes Kepler. Retrieved from Discover Magazine; Nov 2008.
Taylor N. Johannes Kepler: Biography. Retrieved from space.com.