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.
GALILEO GALILEI
Galileo was born in 1564 in Pisa and belonged to a ruined Florentine family. From an early age, the boy was attracted to art; all his life he was interested in music and drawing – he mastered them perfectly. In 1581, 17-year-old Galileo, at the insistence of his father, entered the University of Pisa to study medicine, but was passionately interested in geometry, and in 1592, Galileo received a place at the prestigious and rich University of Padua, where he taught astronomy, mechanics and mathematics. After learning about the invention of the telescope in Holland, Galileo decided to build his own telescope. In 1609. he assembled the first telescope and pointed it at the sky. Soon he was able to build a telescope that gives a magnification of 32 times. It is also important to note that the term “telescope” was introduced into science by Galileo. Using the telescope, which became the main instrument of all astronomers, Galileo Galilei saw the surface of the moon and discovered mountains and craters on the moon, and the milky Way broke up into separate clusters of stars. But even more surprisingly, Galileo was able to see as many as four moons of Jupiter. In Florence, Galileo continued his scientific research, discovering the phases of Venus, spots on the Sun, and then the rotation of the Sun around its axis.
Galileo was a very versatile man, who invented hydraulic scales, studied probability theory, created a prototype microscope with which he studied insects; also worked on the theory of color and magnetism, the resistance of materials, optics and acoustics. He was the first to experimentally measure the density of air. Galileo was a gifted writer and philosopher, and he was certainly the founder of both experimental and theoretical physics, and even Einstein called Galileo “the father of modern science”. He can be considered one of the founders of mechanism, because it is the analysis of mechanical movement that underlies his work. This scientific approach considers the Universe as a large mechanism, and complex natural processes as combinations of the simplest causes, the main of which is mechanical movement.
As you know, Galileo studied inertia and free fall, and in his last book formulated the laws of fall: “The speed increases in proportion to time, and the path increases in proportion to the square of time.” This contradicted the famous statements of Aristotle that the speed of falling is greater the greater the weight of the body. However, with the Catholic Church, things did not go so smoothly for Galileo. The fact is that the absolute majority of his works contained a variety of different statements and hypotheses that completely contradicted Aristotle, namely, the works of Aristotle built the medieval worldview. Seeing the obvious refutations of the geocentric system of the world and its fallacy, he decides to fight for the truth with the Catholic Church. His books violated the prohibition on promoting the “Pythagorean” doctrine, and Galileo was faced with a choice: either he would repent and renounce his “errors”, or he would suffer the fate of Giordano Bruno. Galileo confirmed that he agreed to recite the required recantation, and then was sentenced to prison. He spent the rest of his life under house arrest and the constant supervision of inquisitors. Galileo Galilei died on January 8, 1642, at the age of 78, in his bed. Pope Urban forbade the burial of Galileo in the family crypt in Florence. The greatest scientist of the middle Ages was buried without honors, and the head of the Catholic Church also did not allow to erect a monument. Officially, the Vatican rehabilitated Galileo Galilei only in 1992.
Among the most famous students of Galileo are Torricelli, who became a physicist and inventor, Castelli, the Creator of hydrometry, and Borelli, the founder of biomechanics. Craters, satellites, asteroids, and a NASA space probe were named in memory of the great scientist of the middle Ages.
ISAAC NEWTON
On Christmas night, 1642, a weak and quiet baby was born in the village of Woolsthorpe, named Isaac. Relatives did not baptize the baby at first, because they were afraid that the premature baby would not recover. Isaac’s mother was a widow, and he grew up without friends, and did not participate in noisy games that required skill and physical strength. Even as a child, he built a kind of water clock that measured time so accurately that soon the whole family began to use it. In 1655, 12-year-old Newton was sent to study at a nearby school in Grantham, where he lived in the house of an Apothecary. From the first lessons, the boy showed outstanding abilities. Isaac preferred all other pursuits to writing poetry, reading books, and constructing various mechanisms. In his youth, Isaac passionately devoted himself to writing poetry. After completing his education at school, Newton was able to continue his education at the University of Cambridge. More than 30 years of Newton’s life are associated with this educational institution. The basics of many Sciences were given to Newton without much difficulty, but despite the discoveries of Galileo, natural science and philosophy, Cambridge still taught according to Aristotle. After passing the exams, Isaac received a scholarship, but according to the memoirs of a roommate, Newton completely devoted himself to learning and science, forgetting food and sleep, and probably this is the way of life the young scientist desired for himself. By the age of 23, Isaac Newton was already considered a brilliant mathematician who made a number of discoveries.
In 1664, the plague began in England, and Isaac went to Woolsthorpe, taking with him all the tools and medicines. For three years, according to official data, about 30 thousand people died in London alone. But Isaac was able to find profit in this solitude, and in two plague years Newton made three of his major discoveries: the law of universal gravitation, an explanation of the nature of light, and methods of differential and integral calculus.
We can not help but say, perhaps, about the most famous Apple that fell next to the great scientist, prompting him to study the laws of falling. All his life, Newton was inspired by the great minds of the past – Descartes, Galileo and Kepler, and many of his works are based on their work. Conducting optical experiments, Newton built a mixed telescope-reflector, which in addition to its large size gave a 40-fold magnification. Rumors of the new instrument reached London, and after demonstrating his invention to the king, Newton became famous and in January 1672 was elected a fellow of the Royal society. Later, it was with an improved model of the Newtonian telescope that other galaxies, the planet Uranus, and redshifts were discovered. By 1687, Newton’s main work was published – “Mathematical principles of natural philosophy”, in which