Читать книгу Astronomy in your pocket - Vladimir Vladimirovich Bereznyakovsky - Страница 10

Johann Kepler was born in the German state of Stuttgart on December 27, 1571 in a poor Protestant family. At the age of six in 1577 Kepler first saw a comet, the same comet was observed and described by the Danish astronomer Tycho Brahe. In 1589 Kepler graduated from the school at the Maulbronn monastery, and for his outstanding abilities in almost all Sciences, the city authorities awarded him a scholarship to help him further his studies, but Johann was very sickly, ailments followed him all his life.

At the end of the XVI century in many cities of Europe, there was an open confrontation between groups of people who had different ideas about the structure of the Universe. And in 1600, both exiles – Kepler and Brahe – met in Prague, but it soon became clear that the way Kepler represented astronomy, Tycho Brahe shared only partially. To preserve the already relatively outdated model of the universe, according to which the Central position in the Universe is occupied by the stationary Earth, Brahe proposed a compromise model: all the planets, except the Earth, rotate around the Sun, and the Sun rotates around the stationary Earth (geo-heliocentric system of the world).

The three laws of planetary motion formed by Kepler gave answers to many questions related to the shape of the orbit and the speed of the planets.

Kepler’s first law (the law of ellipses): “Every planet’s orbit is an ellipse with the Sun at a focus.”

Kepler’s second law (law of squares): “Each planet moves in a plane passing through the center of the Sun, and for equal periods of time, the radius vector connecting the Sun and the planet covers equal areas.” In simple words, the Sun is not in the center of the ellipse that the planets move along, so the closer the planet is to the sun, the faster it moves in its orbit. For example, the speed of the Earth as it orbits the Sun changes every six months by about 4,000 km/h.

Kepler’s third law (harmonic law): “The Squares of the periods of the planets’ rotation around the Sun are referred to as cubes of the large semi-axes of the planets’ orbits”. In other words, when a planet approaches the Sun, the radius (half – axis) of its orbit decreases, but the speed, and therefore the time of movement (period) – increases.

Only in 1609, with great agony, Kepler managed to publish his works, in which the scientist explained not only the new astronomy and physics of the sky, but also for the first time found out what is the cause of ocean tides. Kepler absolutely proved that the Moon is the cause of tides. It was also Kepler who introduced the term “inertia” into physics as the innate property of bodies to resist an applied external force, forming in a clear form the first law of mechanics: “Any body that is not affected by other bodies is at rest or performs a uniform rectilinear motion.”

The works of Johannes Kepler on optical phenomena can be considered the beginning of optics as a science. In his works, he outlined geometric and physiological optics, described the General theory of lenses, light refraction, refraction, and the concept of an optical image. Kepler also discovered the role of the human lens for the first time, describing the causes of myopia and farsightedness, and an in-depth study of optical laws led Kepler to the scheme of a telescopic telescope (Kepler telescope).

Craters on the moon and Mars, a supernova, an orbiting Observatory, and a spacecraft were named in memory of the great scientist.