The man who changed the world of science. Galileo Galilei. Brief biography and his discoveries. Galileo Galilei - short biography and his discoveries What Galileo Galilei created
1. The first person to point a “spotting scope” into the sky, turning it into a telescope, and obtain new scientific data was Galileo Galilei. He invented his telescope in 1609. With its help, he discovered mountains on the Moon, and then compiled the world's first map of the lunar surface. With the help of his invention, he also discovered the four satellites of Jupiter, discovered that the Milky Way consists of many stars, discovered the sunspot and its rotation, the phases of Venus. These astronomical discoveries brought Galileo and his telescope such wide popularity that he even started producing telescopes.
2. In 1586, Galileo designed special hydrostatic balances to determine the density of bodies. The scientist described their design in the treatise “La bilancetta”
3. It is generally accepted that Galileo Galilei invented the thermometer. This happened in 1592. The design of the thermoscope, which is what the thermometer was called then, was primitive: a thin glass tube was soldered to a glass ball of small diameter and placed in a liquid. The air in the glass ball was heated by means of a burner or by simply rubbing it with the palms, as a result of which it began to displace the liquid in the glass tube, thereby showing the degree of temperature increase: the higher the air temperature in the glass ball became, the lower the water level in the tube dropped. An important role was played by the ratio of the volume of the ball to the diameter of the tube: by creating a thinner tube, it was possible to monitor minor changes in temperature in the ball. Subsequently, the design of Galileo's thermoscope was modified by one of his students, Fernando Medici.
4. Galileo Galilei is also considered one of the contenders for the invention of the microscope. In 1609 he developed the "occhiolino" - "little eye", or compound microscope with a convex and concave lens. Galileo presented his microscope to the public at the Accademia dei Lincei. With his help, Galileo studied insects.
5. In 1606, Galileo Galilei published a scientific article where he outlined the idea and drawings of the proportional compass he invented. A proportional compass is a simple, ingenious tool that allows you to change the scale of the dimensions you take. This is achieved by the fact that the axis of rotation of the legs of the compass relative to each other is movable (set in accordance with the desired change in scale and fixed), and the measurement of the size and its application on a changed scale are carried out by the opposite ends of the legs of the compass. If the axis of rotation of the legs of the compass is exactly in the middle position, that is, the length of all four parts of the legs of the compass is the same, there will be no change in scale. If you move the center of rotation, for example, so that two parts of the legs of the compass are 3 times longer than the other two, then the scale ratio will be 1:3.
The Italian scientist Galileo Galilei (1564-1642) is rightly considered the true founder of the method of studying nature. His scientific activity was combined with a deep awareness of the philosophical foundations of the new natural science: the ideas expressed by Galileo in this regard make him the first representative mechanistic materialism. An astronomer, mechanic and philosopher, Galileo gave in his writings a detailed and coherent presentation of the experimental-mathematical method and clearly formulated the essence of the corresponding understanding of the world.
For the triumph of the Copernican theory and the ideas expressed by Giordano Bruno, the discoveries made in the sky by Galileo with the help of a telescope, which he was one of the first to build, were of great importance. Using a telescope, the scientist discovered craters and ridges on the Moon (in his mind, “mountains” and “sea”), saw countless clusters of stars forming the Milky Way, and saw the satellites of Jupiter. Galileo told the world about all this in his work “The Starry Messenger” (1610), which brought the scientist the fame of “Columbus of Heaven.” Then he clearly saw spots on the Sun and discovered the phases of Venus.
Galileo's astronomical discoveries - primarily the moons of Jupiter and the phases of Venus - became clear evidence of the truth of Copernicus's heliocentric theory; observations of the Moon, which seemed to be a planet quite similar to the Earth, and spots on the Sun, played the same role in relation to Giordano Bruno’s idea of the physical homogeneity of the Earth and the sky. The shift of sunspots showed that the Sun rotates on its axis. The discovery of the stellar composition of the Milky Way (many scholastics considered it a “fusion” of two celestial hemispheres) was indirect evidence of the countless worlds in the Universe.
All these discoveries of Galileo marked the beginning of his fierce polemics with the scholastics and churchmen. Until now, the Catholic Church was forced to tolerate the views of those scientists who recognized the Copernican theory as one of the hypotheses, and its ideologists believed that it was impossible to prove this hypothesis as a theory. Now that this evidence has appeared, the Roman Curia makes a decision prohibiting any propaganda of Copernicus’s views, even as a hypothesis, and Copernicus’ book “On the Revolution of the Celestial Spheres” itself is included in the “List of Forbidden Books.”
Galileo's work was thereby jeopardized, but the scientist continued to work to improve the evidence for the truth of Copernicus' theory. In this regard, Galileo’s work in the field played a huge role, even more important than observing the sky through a telescope. mechanics.
Galileo, through a series of experiments, created an important branch of mechanics - dynamics, i.e. the doctrine of the movement of bodies. While dealing with various issues of mechanics (uniform motion of bodies, free motion of bodies, motion of bodies on an inclined plane, motion of a body thrown at an angle to the horizon, etc.), Galileo discovered a number of fundamental laws of mechanics: the same speed of falling of bodies of different weights in an airless environment , the indestructibility of rectilinear uniform motion imparted to any body until any external influence stops it (what later became known as the law of inertia), etc.
The philosophical significance of the laws of mechanics formulated by Galileo was that these laws, which could be formulated mathematically, applied to all of nature and placed the concept of nature on a strictly scientific basis.
These same laws were applied by Galileo to prove the physical reality of Copernicus' theory, which was incomprehensible to most people unfamiliar with the laws of mechanics.
The strength of the arguments, based on the principles of mechanics discovered by Galileo and expressed in the “Dialogue on the Two Chief Systems of the World, Ptolemaic and Copernican,” published in 1632, was such that it left no doubt about the overwhelming persuasiveness of Copernicus’ theory. Galileo’s “guilt” in the face of the Catholic Church was that the “Dialogue” was written and published in the vernacular Italian language and, thus, the audience capable of perceiving and appreciating the Copernican theory, already dangerous for the church, significantly increased.
He receives a very good musical education. When he was ten years old, his family moved to his father's hometown of Florence, and then Galileo was sent to school in a Benedictine monastery. There, for four years, he studied the usual medieval disciplines with the scholastics.
Vincenzo Galilei chooses an honorable and profitable profession as a doctor for his son. In 1581, seventeen-year-old Galileo was enrolled as a student at the University of Piraeus in the Faculty of Medicine and Philosophy. But the state of medical science at that time filled him with dissatisfaction and pushed him away from a medical career. At that time, he happened to attend a lecture on mathematics by Ostillo Ricci, a friend of his family, and was amazed at the logic and beauty of Euclid's geometry.
He immediately studied the works of Euclid and Archimedes. His stay at the university becomes more and more unbearable. After spending four years there, Galileo left it shortly before completion and returned to Florence. There he continued his studies under the guidance of Ritchie, who appreciated the extraordinary abilities of the young Galileo. In addition to purely mathematical questions, he became acquainted with technical achievements. He studies ancient philosophers and modern writers and in a short time acquires the knowledge of a serious scientist.
Discoveries of Galileo Galilei
Law of motion of a pendulum
Studying in Pisa with his powers of observation and keen intelligence, he discovers the law of motion of the pendulum (the period depends only on the length, not on the amplitude or weight of the pendulum). Later he proposes the design of a device with a pendulum for measuring at regular intervals. In 1586, Galileo completed his first solo study of hydrostatic equilibrium and constructed a new type of hydrostatic balance. The following year he wrote a purely geometric work, Theorems of a Rigid Body.
Galileo's first treatises were not published, but quickly spread and came to the fore. In 1588, commissioned by the Florentine Academy, he gave two lectures on the form, position and extent of Dante's Hell. They are filled with mechanical theorems and numerous geometric proofs, and are used as a pretext for the development of geography and ideas for the whole world. In 1589, the Grand Duke of Tuscany appointed Galileo as professor in the Faculty of Mathematics at the University of Pisa.
In Pisa, a young scientist again encounters educational medieval science. Galileo must learn the geocentric system of Ptolemy, which, along with the philosophy of Aristotle, adapted to the needs of the church, is accepted. He does not interact with his colleagues, argues with them, and initially doubts many of Aristotle's claims about physics.
The first scientific experiment in physics
According to him, the movement of the Earth's bodies is divided into “natural”, when they tend to their “natural places” (for example, downward movement for heavy bodies and “upward” movement) and “violent” movement. The movement stops when the cause disappears. “Perfect celestial bodies” are eternal motion in perfect circles around the center of the Earth (and the center of the world). To refute Aristotle's assertions that bodies fall at a speed proportional to their weights, Galileo made his famous experiments with bodies falling from the leaning tower at Pisa.
This is actually the first scientific experiment in physics and with it Galileo introduces a new method of acquiring knowledge - from experience and observation. The result of these studies is the treatise “Falling Bodies,” which sets out the main conclusion about the independence of speed from the weight of a falling body. It is written in a new style for scientific literature - in the form of a dialogue, which reveals the main conclusion about the speed that does not depend on the weight of the falling body.
The lack of a scientific base and low pay force Galie to leave the University of Pisa before the expiration of his three-year contract. At that time, after his father died, he had to take over the family. Galileo is invited to take up the chair of mathematics at the University of Padua. The University of Padua was one of the oldest in Europe and was renowned for its spirit of freedom of thought and independence from the clergy. Here Galileo worked and quickly made a name for himself as an excellent physicist and a very good engineer. In 1593, his first two works were completed, as well as “Mechanics”, in which he outlined his views on the theory of simple machines, invented proportions with which it is easy to perform various geometric operations - enlargement of a drawing, etc. His patents for hydraulic equipment also preserved.
Galileo's lectures at the university voiced official views, he taught geometry, Ptolemy's geocentric system and Aristotle's physics.
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Introduction to the teachings of Copernicus
At the same time, at home, among friends and students, he talks about various problems and expounds his own new views. This duality of life Galileo is forced to lead for a long time until he becomes convinced of his ideas in the public space. It is believed that while still in Pisa, Galileo became acquainted with the teachings of Copernicus. In Padua he is already a convinced supporter of the heliocentric system and has as his main goal the collection of evidence in its favor. In a letter to Kepler in 1597 he wrote:
“Many years ago I turned to the ideas of Copernicus and with my theory I was able to completely explain a number of phenomena that generally could not be explained by opposing theories. I have come up with many arguments that refute opposing ideas."
Galilean pipe
At the end of 1608, news reaches Galilee that an optical device has been discovered in the Netherlands that allows one to see distant objects. Galileo, after hard work and processing hundreds of pieces of optical glass, built his first telescope with triple magnification. This is a system of lenses (eyepieces) now called the Galilean tube. His third telescope, with 32x magnification, looks at the sky.
Only after several months of observation, he published amazing discoveries in a book:
The Moon is not perfectly spherical and smooth, its surface is covered with hills and depressions similar to the Earth.
The Milky Way is a collection of numerous stars.
The planet Jupiter has four satellites that orbit around it like the Moon around the Earth.
Despite the fact that the book is allowed to be printed, this book actually contains a serious blow to Christian dogmas - the principle of the difference between “imperfect” earthly bodies and “perfect, eternal and unchangeable” celestial bodies is destroyed.
The motion of Jupiter's moons has been used as an argument for the Copernican system. Galileo's first bold astronomical achievements did not attract the attention of the Inquisition; on the contrary, they brought him enormous popularity and influence as a renowned scientist throughout Italy, including among the clergy.
In 1610, Galileo was appointed "first mathematician and philosopher" in the court of the ruler of Tuscany and his former student Cosimo II de' Medici. He leaves the University of Padua after 18 years of residence there and moves to Florence, where he is freed from any academic work and can concentrate only on his research.
The arguments in favor of the Copernican system were soon supplemented by the discovery of the phases of Venus, the observation of Saturn's rings and sunspots. He visited Rome, where he was greeted by the cardinals and the pope. Galileo hopes that the logical perfection and experimental justification of the new science will force the church to recognize this. In 1612, his important work “Reflections on Floating Bodies” was published. In it, he gives new evidence for Archimedes' law and opposes many aspects of scholastic philosophy, asserting the right of reason not to obey authorities. In 1613, he wrote a treatise on sunspots in Italian with great literary talent. At that time he also almost discovered the rotation of the Sun.
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Ban on the teachings of Copernicus
Since the first attacks had already been made on Galileo and his students, he felt the need to speak and write his famous letter to Castelli. He proclaimed the independence of science from theology and the uselessness of Scripture in the research of scientists: “... in mathematical disputes, it seems to me that the Bible belongs to the last place.” But the spread of opinions about the heliocentric system seriously worried theologians and in March 1616, with a decree of the Holy Congregation, the teachings of Copernicus were prohibited.
For the entire active community of Copernicus supporters, many years of silence begin. But the system becomes obvious only when in 1610-1616. The main weapon against the geocentric system was astronomical discoveries. Now Galileo strikes at the very foundations of the old, unscientific worldview, affecting the deepest physical roots of the world. The struggle resumed with the appearance in 1624 of two works, including “Letter to Ingoli.” In this work, Galileo expounds the principle of relativity. The traditional argument against the Earth's motion is discussed, namely that if the Earth were rotating, a stone thrown from a tower would lag behind the Earth's surface.
Dialogue on the two main systems of the world – Ptolemy and Copernicus
In the following years, Galileo was immersed in work on a major book that reflected the results of his 30 years of research and reflection, the experience gained in applied mechanics and astronomy, and his general philosophical views on the world. In 1630, an extensive manuscript entitled “Dialogue on the two main systems of the world - Ptolemy and Copernicus” was completed.
The exposition of the book was structured in the form of a conversation between three people: Salviatti, a convinced supporter of Copernicus and the new philosophy; Sagredo, who is a wise man and agrees with all of Salviatti's arguments, but is initially neutral; and Simplicchio, a defender of the traditional Aristotelian concept. The names Salviatti and Sagredo were given to two of Galileo's friends, while Simplicio was named after Aristotle's famous 6th-century commentator Simplicius, meaning "simple" in Italian.
The dialogue provides insight into almost all of Galileo's scientific discoveries, as well as his understanding of nature and the possibilities of studying it. He takes a materialistic position; believes that the world exists independently of human consciousness and introduces new methods of research - observation, experiment, thought experiment and quantitative mathematical analysis instead of offensive reasoning and references to authority and dogma.
Galileo considers the world to be one and changeable, without dividing it into “eternal” and “variable” substance; denies absolute motion around a fixed center of the world: "May I reasonably ask you the question whether there is any center of the world at all, because neither you nor anyone else has proven that the world is finite and has a definite shape, and not infinite and unlimited." Galileo made great efforts to have his work published. He makes a number of compromises and writes to readers that he does not adhere to the teachings of Copernicus and provides a hypothetical possibility that is not true and should be rejected.
Ban on "Dialogue"
For two years he collected permission from the highest spiritual authorities and the censors of the Inquisition, and at the beginning of 1632 the book was published. But very soon there is a strong reaction from theologians. The Roman Pontiff was convinced that he was depicted under the image of Simplicio. A special commission of theologians was appointed, which declared the work heretical, and the seventy-year-old Galileo was summoned to trial in Rome. The process launched by the Inquisition against him lasts a year and a half and ends with a verdict according to which “Dialogue” is prohibited.
