Johannes Kepler (born December 27, 1571 - death November 15, 1630) - the great German astronomer and mathematician, was the discoverer of the laws of motion of the planets of the solar system.
Johannes Kepler was one of the creators of modern astronomy. He discovered three main motions of planets relative to the Sun, he invented an optical system, which is used, in particular, in modern refractors, prepared the creation of the differential, integral and variational calculus in mathematics.
Early years. Training
Johannes Kepler was born in 1571 in Weilder Stadt, southern Germany, to a poor Protestant family. After completing his studies at the monastery school in 1589, he entered the theological seminary at the Tübingen Academy. In those years, he became acquainted with the heliocentric system of N. Copernicus and immediately became its staunch supporter. Kepler developed an interest in astronomy as a child, when his mother showed an impressionable child a bright comet in 1577, and later, a lunar eclipse that occurred in 1580.
Kepler was born a very weak child. At the age of four, he contracted smallpox and nearly died. He had liver and stomach problems, and often had a headache. In addition, he had congenital visual impairments - severe myopia and a defect in which one object appears to be multiple (looking at the Moon, Kepler saw several Moons). Diseases followed him throughout his life. All the more worthy of respect are his courage and fortitude, thanks to which he was able to achieve amazing scientific success and become one of the creators of modern astronomy and physics.
1591 - Kepler enters the university in Tübingen - first at the Faculty of Arts, which then included mathematics and astronomy, then moved to the theological faculty. After graduating from the academy in 1593, Kepler, accused of free thought, was not allowed to pursue a theological career and was given the position of a school teacher of mathematics.
Initially, Kepler planned to become a Protestant priest, but due to his outstanding mathematical abilities he was invited in 1594 to lecture in mathematics at the University of Graz.
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Scientific activity
Kepler was in Graz for 6 years. There, in 1596, his first book, The Mystery of the World, was published. In it, Kepler tried to find the secret harmony of the Universe, for which he compared the orbits of 5 planets known at that time (he singled out the Earth's sphere especially) different "Platonic bodies" (regular polyhedrons). He presented the orbit of Saturn as a circle (not yet an ellipse) on the surface of a sphere, described around a cube. In turn, a ball was inscribed in the cube, which was supposed to represent the orbit of Jupiter. In this ball was inscribed a tetrahedron, described around the ball, representing the orbit of Mars, etc.
This work, after further discoveries by Kepler, lost its original significance (if only because the orbits of the planets were not circular); nevertheless, Kepler believed in the presence of a hidden mathematical harmony of the Universe until the end of his days, and in 1621 he republished "The Secret of the World", making many changes and additions to it.
1597 Kepler marries the widow Barbara Müller von Mulek. Their first two children died in infancy, and their wife fell ill with epilepsy. In addition, persecution of Protestants began in Catholic Graz. Kepler, included in the list of expelled "heretics", was forced to leave the city.
Kepler's Cup: a model of the solar system of five Platonic solids.
Kepler in Prague. Heritage
1600 - he went to Prague to the famous astronomer Tycho Brahe, after whose death he received the materials of his many years and numerous observations. Kepler wrote many scientific papers and articles. 1601 - after the death of Brahe, Kepler became his successor in office, and after litigation with his family, Brahe was able to inherit the results of astronomical observations. Being an excellent observer, Tycho Brahe for many years compiled a voluminous work on the observation of planets and hundreds of stars, while the accuracy of his measurements was significantly higher than that of all his predecessors.
At the end of the 16th century in astronomy, there was still a struggle between the geocentric system of Ptolemy (when the center of the universe is assumed to be the Earth) and the heliocentric system of Copernicus (in which the sun is at the center of the universe). In Copernicus' model, the planets move uniformly in circular orbits: which was not consistent with the apparent unevenness of the planetary motion. Although the astronomical tables of Copernicus were originally more accurate than the Ptolemaic tables, they soon diverged significantly from observations, which puzzled and chilled the enthusiastic Copernicans a lot.
Mechanics and Physics
Kepler's most important work is his work "New Astronomy" (1609), dedicated to the study of the motion of Mars according to Brahe's observations and containing the first two laws of attraction of planets. Based on the Copernican system, over the course of several years, Kepler carefully studied the data of Brahe and, as a result of careful analysis, came to the conclusion that the trajectory of Mars is not a circle, but an ellipse, in one of the focuses of which the Sun is located - the position known today as Kepler's first law.
Further analysis led to the second law: the radius vector connecting the planet and the Sun describes equal areas at the same time. This meant that the further the planet is from the Sun, the slower it moves.
When searching for orbits, Kepler had to use the matching method. He calculated and calculated, but there were no coincidences with observations. First, the oval was discarded - a curve made up of four circular arcs. For about a year, the scientist fiddled with the "ovoid" - an egg-shaped figure. In the end, he came to the conclusion: the truth lies between the circle and the oval, as if the orbit of Mars was an exact ellipse. But the ellipse did not fit until Kepler placed the sun in its focus.
Then at the beginning of 1605, everything came together and fell into place. All points of the orbit, calculated from observations, lay on the ellipse; it also converged with the area law. The new model of movement generated great interest among Copernican scholars, although not all of them accepted it. Galileo strongly rejected Keplerian ellipses.
1619 - in the essay "Harmony of the World", the scientist formulated the third law, uniting the theory of the motion of all planets into a harmonious whole. The sun, occupying one of the focuses of the elliptical orbit, is, according to Kepler, the source of the force that drives the planet. He made a fair guess about the existence of gravity between the celestial bodies and explained the ebb and flow of the earth's oceans by the influence of the moon.
Kepler's second law: the shaded areas are equal and traversed in the same time.
Astronomy
The three laws of planetary motion discovered by Kepler fully and with excellent accuracy explained the apparent unevenness of these motions. Instead of the convoluted models of Ptolemy and Copernicus, containing contrived elements, Kepler's model includes only one curve - an ellipse. The second law established how the speed of the planet changes when moving away or approaching the Sun, and the third makes it possible to calculate this speed and the period of revolution around the Sun.
1627, summer - Johannes Kepler, after 22 years of work, published (for his own money) astronomical tables, which he named "Rudolphs" in honor of the emperor. These tables made it possible to calculate, for any moment in time, the position of the planets with high accuracy for that epoch. The demand for them was huge, since all the previous tables had long diverged from observations. Kepler's tables served astronomers and sailors until the early 19th century.
In addition to Kepler's three laws, the scientist owns a number of important discoveries. In the work "Reduction of Copernicus Astronomy" (1618–1622) Kepler outlined the theory and methods of predicting solar and lunar eclipses. His research in optics (problems of light refraction, astronomical refraction, development of the theory of telescopes) are presented in the works "Supplement to Vittelo" (1604) and "Dioptrics" (1611)
Maths
The scientist's remarkable mathematical abilities were manifested, in particular, in the derivation of formulas for determining the volumes of many bodies of revolution.
Last years. Death
The last years of his life, the scientist spent in constant travel, partly due to political turmoil … Thirty Years War … (at one time he was in Wallenstein's service as an astrologer), partly as a result of the trial of his mother, who was accused of witchcraft. Johannes Kepler died on November 15, 1630, in Regensburg, where he was buried in the cemetery of St. Peter. An inscription is made over his grave: “Mensus eram coelos nune terrae metior umbras; Mens coelestis erat, corporis umbra jacet. " This epitaph, written by Johannes Kepler himself, means: “Before I measured the heavens, now I measure the underground darkness; my mind was a gift from heaven - and my body, transformed into a shadow, rests. " In Regensburg, in 1808, a monument was erected to him.
A. Mudrova