Theme 8. The birth of modern science

The revival also touched astronomy, in 1543 the Polish priest Nicolaus Copernicus, who was studying in Italy, published a book in which he resurrected the idea of ​​Aristarch of Samos that the earth revolves around the sun. However, as in ancient times, this theory was not consistent with the observations of astronomers, in particular with the observations of the Danish astronomer Tycho Brahe, who created extensive and accurate astronomical tables. In 1609, Johann Kepler, an astronomer and astrologer at the court of the German emperor, analyzed the tables of Tycho Brahe and, through painstaking calculations, showed that the Earth revolves around the Sun - not in a circle, but in an ellipse. Thus, the scientists of New Age for the first time surpassed the scientists of the Ancient World.

Experimental confirmation of Kepler’s theory was given by the great Italian scientist Galileo Galilei. For a long time, the main objection against the heliocentric theory was that the moon revolves around the earth - by analogy it was thought that other celestial bodies should revolve around the earth. In 1609, Galileo was one of the first to create a telescope and, with her help, made many sensational discoveries for that time. He discovered many new stars and discovered four satellites revolving around Jupiter - now it became clear that the Moon is not a planet, but a satellite similar to Jupiter’s satellites, and planets, unlike satellites, revolve around the Sun. Galileo energetically came out in support of the teachings of Copernicus and was brought to justice by the Inquisition; he was forced, on his knees, to publicly renounce his delusions. Galileo was then 70 years old, and he spent the rest of his life under house arrest — but continued to work and set experiments. He established that Aristotle was wrong, arguing that heavy bodies fall faster than the lungs, that the cannonball flies in a parabola and that the time of the pendulum oscillations does not depend on amplitude. Galileo discovered the law of inertia, the law of uniformly accelerated motion, and established the principle of addition (superposition) of motions. These discoveries were the beginning of modern mechanics.

The experiments of Galileo were continued by his pupil Torricelli (1608-1647), who discovered the vacuum, the atmospheric pressure, and created the first barometer. The study of vacuum interested scientists in many countries. The Frenchman Blaise Pascal made an ascent to one of the mountains with this barometer and found that as the pressure rises, the atmospheric pressure drops. The German Otto Guernica and the Englishman Robert Boyle almost simultaneously invented the air pump. Boyle also found that the volume occupied by gas is inversely proportional to pressure (the famous Boyle-Mariotte law). The study of the pendulum started by Galileo was continued by the Dutchman Christian Huygens (1629-95), who in 1657 created the first pendulum clock.

As science developed, the problem of correct substantiation of scientific truths and theorems was solved. The English philosopher Francis Bacon in his work “The New Organon” (1620) defined inductive and deductive methods of proof. The French philosopher Rene Descartes (1596–1650) introduced the rules of mathematical proof into the new science; he insisted on the need to prove any statement. When Descartes was asked to prove that he exists, he replied: "I think - therefore, I exist." Descartes first began to depict curves in the form of graphs of functions and created analytical geometry; he introduced the concept of “momentum” (this is the product of mass and velocity, mv) and established the law of conservation of momentum in the absence of external forces.

Descartes' ideas were received by Isaac Newton (1643-1727). Newton's greatest discovery was his "second law of mechanics," which claimed that "the change in the amount of motion is proportional to the force applied." The “change in momentum” is the mass multiplied by the derivative of speed, so the second law gave rise to differential calculus. Another great discovery of Newton was the law of world wideness, in proving this Newton used the formula of centrifugal force, previously obtained by Huygens.

The honor of creating differential calculus was challenged in Newton by the famous German scientist Gottfried Leibniz (1646-1716). Leibniz, in particular, established the law of conservation of kinetic energy. The works of Leibniz and Newton in the field of mechanics and differential calculus continued the Swiss scientist Johann Bernoulli (1667-1748).

The success of scientists attracted the attention of kings and ministers. In 1666, the famous minister of Louis XIV, Jean-Baptiste Colbert, persuaded the king to release funds to create the French Academy of Sciences. It was the restoration of the traditions of the Alexandria Museya, an observatory, library and research laboratories were created at the Academy, a scientific journal was published. Academics were paid a great salary; Among the academicians were such celebrities as Huygens and Leibniz. Colbert set practical tasks for the Academy, under the direction of Picard the degree of the meridian was precisely measured and an accurate map of France was drawn up - and it turned out that the size of the country was smaller than previously thought. Louis XIV jokingly said that "gentlemen, academicians have stolen part of the kingdom from him." The student of Huygens Denis Papen was the creator of the steam cylinder and worked on the creation of the steam engine. Huygens and Papen were Protestants; when in France after the abolition of the Edict of Nantes the persecution of Protestants began, they were forced to leave the country. Papen went to Germany, where he built the first steam engine, installed it on a boat, and in 1709 arrived on this “steamer” to London. He asked for money to continue his work with the Royal Society of London. The royal society was created at about the same time as the French Academy, and Isaac Newton was president of the society at the time. However, the British government practically did not give the public money, and it was forced to refuse Papen. Papen died in poverty and it is not known what became of the first ship.

Following the example of Louis XIV, many European kings were quick to acquire their Academies. In 1710, on the initiative of Leibniz, the Berlin Academy was established. In 1724, shortly before his death, Peter I signed a decree establishing the Russian Academy of Sciences. The main celebrity of the Russian Academy was a student of Bernoulli, the famous Swiss mathematician Leonard Euler. Euler continued to develop the theory of differential equations, begun in the works of Leibniz and Bernoulli. The theory of differential equations was the greatest discovery of the eighteenth century; it turned out that all the processes associated with the movement of bodies are described by differential equations, and having solved them, one can find the trajectory of motion. In 1758, the French mathematician and astronomer Clareau calculated the trajectory of Comet Halley, taking into account the influence of the attraction of Jupiter and Saturn - it was a brilliant demonstration of the possibilities of the new theory. This theory was completed in the famous book “Analytical Mechanics” by Joseph Lagrange, which was published in Paris in 1788.