Galileo Galilei - Italian scientist, philologist, mechanic, critic, poet, astronomer and physicist. He had a significant influence on the development of science of his time. He considered experience to be the basis of knowledge and fiercely fought against scholastic teachings. Now everyone knows his achievements: Galileo invented hydrostatic balances, the thermoscope and improved the telescope. The scientist is the founder of experimental physics. In this article we will tell you about the life and inventions of Galileo. So let's get started.

Childhood and youth

Galileo Galileo, whose brief biography will be presented below, was born in Pisa (Italy) in 1564. His father, who worked as a musician and mathematician, chose a medical profession for his son. After the boy graduated from the monastery school, he enrolled him in the Faculty of Medicine at the University of Pisa. But seventeen-year-old Galileo was not interested. He left the university and went to Florence, where he began studying the works of Archimedes and Euclid. Galileo's father, yielding to his son's requests, transferred him to the Faculty of Philosophy.

In his childhood, Galileo loved to design mechanical toys and working models of ships, mills, and cars. Galileo Viviani's student, who later wrote a biography of the scientist, mentioned that already in his youth Galileo was very observant. It was thanks to this quality that he was able to make an important discovery: after seeing a swinging chandelier in the Pisa Cathedral, the young man came up with the law of isochronism of pendulum oscillations (independence of the magnitude of the deviation from the period of oscillations). Many researchers disagree with Viviani and believe that this discovery did not belong to Galileo. But it is reliably known that Galileo tested this law experimentally many times. He also used it to determine periods of time. This experiment was enthusiastically received by doctors.

Hydrostatic balance Galileo

In 1586, the young scientist published his first scientific work of a practical nature. Galileo designed special hydrostatic balances and described them in detail in his work. We can say that this determined his future fate as a scientist.

They allow you to determine the density of precious stones and metals when weighing. The method itself was discovered by Archimedes. Galileo's work entitled “The Little Balances” came to the Florentine mathematician Guido del Monte. The scientist immediately recognized Galileo as a talented mechanic and wanted to get to know him.

It was on the recommendation of del Monte that in 1589 Galileo received a position as a professor at his university, which he was never able to graduate due to financial difficulties. True, he was hired on a minimum salary, but the scientist was still happy, because Galileo’s hydrostatic balances became famous in the scientific world. He was especially famous among Italian mathematicians.

Treatise “On Movement”

Having started teaching mathematics and philosophy at the university, Galileo faced a difficult choice. On the one hand, there are the inviolable dogmas of Aristotle’s views, on the other, one’s own reflections, supported by experience. According to Aristotle, the speed at which a body falls is proportional to its weight. Galileo refuted this statement when, in front of numerous witnesses, he dropped balls of the same size, but with different weights, from the Leaning Tower of Pisa. Aristotle taught that different bodies have different “properties of lightness,” which is why some fall much faster than others. For a body to move, it needs an air push, therefore, the movement of the body indicates the absence of emptiness. Galileo's experiments suggested the opposite.

In 1590, the researcher wrote a treatise “On Movement”. In it, he sharply criticized the views of the followers of Aristotle (Peripatetics). This caused a disapproving attitude towards the scientist on the part of representatives of official scholastic science. In addition, the salary received did not suit Galileo. He was very strapped for money. The aforementioned del Monte helped him by recommending Galileo to the University of Padua.

Paduan period

In 1592, the most fruitful period in the researcher’s life began. We have already talked about Galileo’s hydrostatic balances, which became his first discovery. So, over the years of teaching at the University of Padua, the scientist made two more. Galileo invented the thermoscope for research and improved the telescope into a telescope.

In fact, the thermoscope was the prototype of the thermometer. To invent it, Galileo had to radically rethink the existing principles of cold and heat at that time.

The invention of the spyglass was learned in Venice already in 1609. Interested in this discovery, Galileo improved the device and adapted it for observing the starry sky. In early 1610, this helped the researcher discover three satellites of the planet Jupiter. By observing the planet at different times, Galileo was able to understand that it was the satellites that revolved around it, and not vice versa. This confirmed the model of the Keplerian system, of which the scientist was a proponent.

In addition, Galileo discovered the principle of relativity in dynamics. It formed the basis of the current theory of relativity. Galileo recognized Aristotle's ideas about motion as erroneous. Empirically, the scientist found out that processes) are relative. That is, one cannot talk about movement without finding out in relation to which “body of reference” it occurs. The laws of motion themselves are irrelevant. Therefore, locked in a ship’s cabin, it is impossible to establish experimentally whether it is moving rectilinearly and uniformly or is at rest in place.

Astronomical discoveries

Thanks to the improved telescope, the scientist had new achievements. Galileo Galilei discovered and became convinced of the existence of a huge number of stars in the Milky Way. Observing the movement of sunspots, the researcher realized that this process occurs due to the rotation of the Sun. While studying the surface of the Moon, Galileo discovered craters and mountains. With all this, he undermined confidence in the cosmogonic dogma about the immutability of the universe, having carried out a revolutionary revolution in astronomy. Galileo described all his observations in his work “The Starry Messenger,” which was published in 1610. He dedicated this work to the Tuscan Duke named Cosimo de' Medici.

Return to Florence

Soon the Duke invited Galileo to work in Florence. The scientist took the position of court philosopher and first mathematician of the university, who was not obliged to lecture. By that time, Galileo's work had become known throughout Italy. They were admired by some, fiercely hated by others. True, at first there was no hostility. In 1611, the astronomer was even invited to Rome, where he was enthusiastically greeted by the top officials of the city and church. Galileo had no idea that he was under secret surveillance. The offensive of the opponents intensified in 1613, when the Inquisition raised the question of incompatibility with the discoveries of Galileo. The researcher gave a detailed answer to this accusation, in which he attempted to clearly distinguish between science and the church. In 1616 he went to Rome in order to defend his teaching.

First process

The circumstances were very fortunate. The reason for this was Galileo's brilliant oratorical abilities. In addition, the Duke of Tuscany helped the scientist by writing for the Inquisition. The charges brought against Galileo were found to be unfounded. However, now the scientist faces a rather difficult task: legalizing his scientific views.

The Copernican system could not be openly defended, but the form of dialogue-debate was not prohibited. Therefore, Galileo wrote the manuscript "Dialogue on the Ebb and Flow", in which three interlocutors discussed the two main systems of the world - Copernicus and Ptolemy. In 1630 he went with this book to Rome. It took the scientist two years to fight censorship to get permission to publish the manuscript. It was eventually published in Florence in August 1632.

Second process

The Inquisition immediately responded to the publication of the book, which was read throughout Europe. At the end of 1632, Galileo was ordered to come to Rome. The scientist asked for a postponement due to his illness and old age. But his request remained unheeded. At the beginning of 1633 he was taken to Rome on a stretcher. For a month he lived with the Tuscan envoy, and then Galileo was expelled to the Inquisition prison. Then there were threats of torture, demands for renunciation, interrogations and the worst thing for the researcher - the destruction of his works. Galileo failed to justify his “Dialogues” to the judges. After the trial, the scientist was brought to the monastery of St. Minerva was forced to sign a renunciation and publicly repent on his knees.

Recent years

In 1637, Galileo Galileo, whose brief biography was covered in this article, lost his sight. But before that, the scientist managed to finish a work dedicated to his achievements in the field of mechanics. The work was called “Mathematical Proofs and Conversations.” Unlike the “Dialogues,” in this book everything is presented as if the dispute with Aristotle’s supporters is no longer relevant and it is necessary to affirm new scientific views. Thanks to the efforts of Galileo’s friends, the book was published during the researcher’s lifetime. He was incredibly happy about this.

Galileo died early in 1642 at Villa Arcetri. In 1732, the scientist’s ashes were sent to Florence and buried next to Michelangelo.

This is the whole biography. Galileo Galilei forever inscribed his name in the history of science. Finally, here are a few facts about this researcher.

• In 1992, he described the scientist as a brilliant physicist and expressed regret about the verdict handed down to him in the past. This was the Vatican's first public acknowledgment of the Earth's rotation around the Sun.
• Galileo's hydrostatic balances are among the five most ingenious inventions used in our time.
• The phrase “And yet it spins!” the researcher never said. This myth was invented by an Italian journalist.

One of the most famous astronomers, physicists and philosophers in human history is Galileo Galilei. A short biography and his discoveries, which you will now learn about, will allow you to get a general idea of ​​​​this outstanding person.

First steps in the world of science

Galileo was born in Pisa (Italy), February 15, 1564. At the age of eighteen, the young man entered the University of Pisa to study medicine. His father pushed him to take this step, but due to lack of money, Galileo was soon forced to leave his studies. However, the time that the future scientist spent at the university was not in vain, because it was here that he began to take a keen interest in mathematics and physics. No longer a student, the gifted Galileo Galilei did not abandon his hobbies. A brief biography and his discoveries made during this period played an important role in the future fate of the scientist. He devotes some time to independent research into mechanics, and then returns to the University of Pisa, this time as a mathematics teacher. After some time, he was invited to continue teaching at the University of Padua, where he explained to students the basics of mechanics, geometry and astronomy. It was at this time that Galileo began to make discoveries significant for science.

In 1593, the first scientist was published - a book with the laconic title “Mechanics”, in which Galileo described his observations.

Astronomical research

After the book was published, a new Galileo Galilei was “born”. A short biography and his discoveries is a topic that cannot be discussed without mentioning the events of 1609. After all, it was then that Galileo independently built his first telescope with a concave eyepiece and a convex lens. The device gave an increase of approximately three times. However, Galileo did not stop there. Continuing to improve his telescope, he increased the magnification to 32 times. While using it to observe the Earth's satellite, the Moon, Galileo discovered that its surface, like the Earth's, was not flat, but covered with various mountains and numerous craters. Four stars were also discovered through the glass and changed their usual sizes, and for the first time the idea of ​​their global remoteness arose. turned out to be a huge accumulation of millions of new celestial bodies. In addition, the scientist began to observe the movement of the Sun and make notes about sunspots.

Conflict with the Church

The biography of Galileo Galilei is another round in the confrontation between the science of that time and church teaching. The scientist, based on his observations, soon comes to the conclusion that the heliocentric one, first proposed and substantiated by Copernicus, is the only correct one. This was contrary to the literal understanding of Psalms 93 and 104, as well as Ecclesiastes 1:5, which refers to the immobility of the Earth. Galileo was summoned to Rome, where they demanded that he stop promoting “heretical” views, and the scientist was forced to comply.

However, Galileo Galilei, whose discoveries at that time were already appreciated by some representatives of the scientific community, did not stop there. In 1632, he made a cunning move - he published a book entitled “Dialogue on the two most important systems of the world - Ptolemaic and Copernican.” This work was written in an unusual form of dialogue at that time, the participants of which were two supporters of the Copernican theory, as well as one follower of the teachings of Ptolemy and Aristotle. Pope Urban VIII, a good friend of Galileo, even gave permission for the book to be published. But this did not last long - after just a couple of months, the work was recognized as contrary to the tenets of the church and banned. The author was summoned to Rome for trial.

The investigation lasted quite a long time: from April 21 to June 21, 1633. On June 22, Galileo was forced to pronounce the text proposed to him, according to which he renounced his “false” beliefs.

The last years in the life of a scientist

I had to work in the most difficult conditions. Galileo was sent to his Villa Archertri in Florence. Here he was under constant supervision of the Inquisition and had no right to go to the city (Rome). In 1634, the scientist’s beloved daughter, who took care of him for a long time, died.

Death came to Galileo on January 8, 1642. He was buried on the territory of his villa, without any honors and even without a tombstone. However, in 1737, almost a hundred years later, the scientist’s last will was fulfilled - his ashes were transferred to the monastic chapel of the Florence Cathedral of Santa Croce. On the seventeenth of March he was finally buried there, not far from Michelangelo’s tomb.

Posthumous rehabilitation

Was Galileo Galilei right in his beliefs? A short biography and his discoveries have long been a topic of debate among clergy and luminaries of the scientific world; many conflicts and disputes have developed on this basis. However, only on December 31, 1992 (!) John Paul II officially admitted that the Inquisition in the 33rd year of the 17th century made a mistake, forcing the scientist to renounce the heliocentric theory of the universe formulated by Nicolaus Copernicus.

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.

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.

Prohibition of 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.

Renouncing your views

On June 22, 1633, in front of all the cardinals and members of the Inquisition, Galileo reads the text of his renunciation of his views. This event ostensibly signals the complete suppression of his resistance, but in reality it is the next big compromise he must make to continue his scientific work. The legendary phrase: “Eppur si muove” (and still it turns) is justified by his life and work after the trial. It is said that he uttered this phrase after his abdication, however, in fact, this fact is an artistic fiction of the 18th century.

Galileo is under house arrest near Florence, and, despite almost losing his sight, he is working hard on a new great work. The manuscript was smuggled out of Italy by her admirers, and in 1638 it was published in the Netherlands under the title Lectures and Mathematical Proofs of Two New Sciences.

Lectures and mathematical proofs of two new sciences

The lectures are the pinnacle of Galileo's work. They were written again as a conversation over six days between three interlocutors - Salviati, Sagredo and Simpliccio. As before, Salvati plays the leading role. Simplicio no longer argued, but asked questions only for more detailed explanations.

On the first, third and fourth days, the theory of the movement of falling and thrown bodies is revealed. The second day is devoted to the topic of materials and geometric balance. The fifth lecture gives mathematical theorems, and the last contains incomplete results and ideas about the theory of resistance. It has the least value among the six. Regarding material resistance, Galileo's work is pioneering in this field and plays an important role.

The most valuable results are contained in the first, third and fifth lectures. This is the highest point that Galileo reached in his understanding of motion. Considering the fall of bodies, he sums up:

"I think that if the resistance of the medium were completely removed, all bodies would fall at the same speed."

The theory of uniform rectilinear and equilibrium motion is further developed. The results of his numerous experiments on free fall, movement on an inclined plane and the movement of a body thrown at an angle to the horizon appear. The time dependence is clearly formulated and the parabolic trajectory is explored. Again, the principle of inertia is proven and used as fundamental in all considerations.

When the Lectures are published, Galileo is completely blind. But in the last years of his life he works. In 1636, he proposed a method for accurately determining longitude at sea using the satellites of Jupiter. His dream is to organize numerous astronomical observations from different points on the earth's surface. To this end, he negotiates with the Dutch commission to accept his method, but is refused and the church prohibits his further contacts. In his last letters to his followers, he continues to make important astronomical points.

Galileo Galilei died on January 8, 1642, surrounded by his students Viviani and Toricelli, his son and a representative of the Inquisition. Only 95 years later were his ashes allowed to be transported to Florence by the other two great sons of Italy, Michelangelo and Dante. His inventive scientific work, passing through the strict criteria of time, gives him immortality among the names of the brightest artists of physics and astronomy.

Galileo Galilei - biography of life and his discoveries

review 6 rating 4.3

Galileo Galilei (Italian: Galileo Galilei). Born February 15, 1564 in Pisa - died January 8, 1642 in Arcetri. Italian physicist, mechanic, astronomer, philosopher and mathematician, who had a significant influence on the science of his time. He was the first to use a telescope to observe celestial bodies and made a number of outstanding astronomical discoveries.

Galileo is the founder of experimental physics. With his experiments, he convincingly refuted speculative metaphysics and laid the foundation of classical mechanics.

During his lifetime, he was known as an active supporter of the heliocentric system of the world, which led Galileo to a serious conflict with the Catholic Church.

Galileo was born in 1564 in the Italian city of Pisa, in the family of a well-born but impoverished nobleman, Vincenzo Galilei, a prominent music theorist and lutenist. Galileo Galilei's full name: Galileo di Vincenzo Bonaiuti de Galilei (Italian: Galileo di Vincenzo Bonaiuti de "Galilei). Representatives of the Galilean family have been mentioned in documents since the 14th century. Several of his direct ancestors were priors (members of the ruling council) of the Florentine Republic, and Galileo's great-great-grandfather , a famous doctor who also bore the name Galileo, was elected head of the republic in 1445.

There were six children in the family of Vincenzo Galilei and Giulia Ammannati, but four managed to survive: Galileo (the eldest of the children), daughters Virginia, Livia and the youngest son Michelangelo, who later also gained fame as a composer-lutenist. In 1572, Vincenzo moved to Florence, the capital of the Duchy of Tuscany. The Medici dynasty that ruled there was known for its wide and constant patronage of the arts and sciences.

Little is known about Galileo's childhood. From an early age the boy was attracted to art; Throughout his life he carried with him a love of music and drawing, which he mastered to perfection. In his mature years, the best artists of Florence - Cigoli, Bronzino and others - consulted with him on issues of perspective and composition; Cigoli even claimed that it was to Galileo that he owed his fame. From Galileo's writings one can also conclude that he had remarkable literary talent.

Galileo received his primary education at the nearby Vallombrosa monastery. The boy loved to study and became one of the best students in the class. He weighed the possibility of becoming a priest, but his father was against it.

In 1581, 17-year-old Galileo, at the insistence of his father, entered the University of Pisa to study medicine. At the university, Galileo also attended lectures on geometry (previously he was completely unfamiliar with mathematics) and became so carried away by this science that his father began to fear that this would interfere with the study of medicine.

Galileo remained a student for less than three years; During this time, he managed to thoroughly familiarize himself with the works of ancient philosophers and mathematicians and earned a reputation among teachers as an indomitable debater. Even then, he considered himself entitled to have his own opinion on all scientific issues, regardless of traditional authorities.

It was probably during these years that he became acquainted with the theory. Astronomical problems were then actively discussed, especially in connection with the calendar reform that had just been carried out.

Soon, the father’s financial situation worsened, and he was unable to pay for his son’s further education. The request to exempt Galileo from paying fees (such an exception was made for the most capable students) was rejected. Galileo returned to Florence (1585) without receiving his degree. Fortunately, he managed to attract attention with several ingenious inventions (for example, hydrostatic balances), thanks to which he met the educated and wealthy lover of science, the Marquis Guidobaldo del Monte. The Marquis, unlike the Pisan professors, was able to correctly evaluate him. Even then, del Monte said that since time the world had not seen such a genius as Galileo. Admired by the young man’s extraordinary talent, the Marquis became his friend and patron; he introduced Galileo to the Tuscan Duke Ferdinand I de' Medici and petitioned for a paid scientific position for him.

In 1589, Galileo returned to the University of Pisa, now as a professor of mathematics. There he began to conduct independent research in mechanics and mathematics. True, he was given a minimum salary: 60 crowns a year (a professor of medicine received 2000 crowns). In 1590, Galileo wrote his treatise On Motion.

In 1591, the father died, and responsibility for the family passed to Galileo. First of all, he had to take care of raising his younger brother and the dowry of his two unmarried sisters.

In 1592, Galileo received a position at the prestigious and wealthy University of Padua (Venetian Republic), where he taught astronomy, mechanics and mathematics.

The years of his stay in Padua were the most fruitful period of Galileo's scientific activity. He soon became the most famous professor in Padua. Students flocked to his lectures, the Venetian government constantly entrusted Galileo with the development of various kinds of technical devices, and young Kepler and other scientific authorities of that time actively corresponded with him.

During these years he wrote a treatise called Mechanics, which aroused some interest and was republished in a French translation. In early works, as well as in correspondence, Galileo gave the first sketch of a new general theory of falling bodies and the motion of a pendulum.

The reason for a new stage in Galileo's scientific research was the appearance in 1604 of a new star, now called Kepler's Supernova. This awakens general interest in astronomy, and Galileo gives a series of private lectures. Having learned about the invention of the telescope in Holland, Galileo builds the first telescope with his own hands in 1609 and points it towards the sky.

What Galileo saw was so amazing that even many years later there were people who refused to believe in his discoveries and claimed that it was an illusion or delusion. Galileo discovered mountains on the Moon, the Milky Way broke up into individual stars, but his contemporaries were especially amazed by the 4 satellites of Jupiter he discovered (1610). In honor of the four sons of his late patron Ferdinand de' Medici (who died in 1609), Galileo named these satellites "Medician stars" (lat. Stellae Medicae). Now they have a more appropriate name "Galilean satellites".

Galileo described his first discoveries with a telescope in the work “The Starry Messenger” (Latin: Sidereus Nuncius), published in Florence in 1610. The book was a sensational success throughout Europe, even crowned heads rushed to order a telescope. Galileo donated several telescopes to the Venetian Senate, which, as a sign of gratitude, appointed him a professor for life with a salary of 1,000 florins. In September 1610, Kepler acquired a telescope, and in December, Galileo's discoveries were confirmed by the influential Roman astronomer Clavius. Universal recognition is coming. Galileo becomes the most famous scientist in Europe; odes are written in his honor, comparing him to Columbus. On April 20, 1610, shortly before his death, the French king Henry IV asked Galileo to discover a star for him.

There were, however, some dissatisfied people. Astronomer Francesco Sizzi (Italian: Sizzi) published a pamphlet in which he stated that seven is a perfect number, and even there are seven holes in the human head, so there can only be seven planets, and Galileo’s discoveries are an illusion. Astrologers and doctors also protested, complaining that the emergence of new celestial bodies was “disastrous for astrology and most of medicine,” since all the usual astrological methods “will be completely destroyed.”

During these years, Galileo entered into a civil marriage with the Venetian Marina Gamba (Italian: Marina Gamba). He never married Marina, but became the father of a son and two daughters. He named his son Vincenzo in memory of his father, and his daughters Virginia and Livia in honor of his sisters. Later, in 1619, Galileo officially legitimized his son; both daughters ended their lives in a monastery.

Pan-European fame and the need for money pushed Galileo to take a disastrous step, as it later turned out: in 1610 he left calm Venice, where he was inaccessible to the Inquisition, and moved to Florence. Duke Cosimo II de' Medici, son of Ferdinand, promised Galileo an honorable and profitable position as an adviser at the Tuscan court. He kept his promise, which allowed Galileo to solve the problem of huge debts that had accumulated after the marriage of his two sisters.

Galileo's duties at the court of Duke Cosimo II were not burdensome - teaching the sons of the Tuscan Duke and participating in some matters as an adviser and representative of the Duke. Formally, he is also enrolled as a professor at the University of Pisa, but is relieved of the tedious duty of lecturing.

Galileo continues scientific research and reveals the phases of Venus, spots on the Sun, and then the rotation of the Sun around its axis. Galileo often presented his achievements (and often his priorities) in a cocky polemical style, which earned him many new enemies (in particular, among the Jesuits).

The growing influence of Galileo, the independence of his thinking and his sharp opposition to the teachings of Aristotle contributed to the formation of an aggressive circle of his opponents, consisting of Peripatetic professors and some church leaders. Galileo's ill-wishers were especially outraged by his propaganda of the heliocentric system of the world, since, in their opinion, the rotation of the Earth contradicted the texts of the Psalms (Psalm 103:5), a verse from Ecclesiastes (Ecc. 1:5), as well as an episode from the Book of Joshua ( Joshua 10:12), which speaks of the motionlessness of the Earth and the movement of the Sun. In addition, a detailed substantiation of the concept of the immobility of the Earth and a refutation of hypotheses about its rotation was contained in Aristotle’s treatise “On Heaven” and in Ptolemy’s “Almagest”.

In 1611, Galileo, in the aura of his glory, decided to go to Rome, hoping to convince the Pope that Copernicanism was completely compatible with Catholicism. He was received well, elected the sixth member of the scientific “Academia dei Lincei”, and met Pope Paul V and influential cardinals. He showed them his telescope and gave explanations carefully and carefully. The cardinals created an entire commission to clarify the question of whether it was sinful to look at the sky through a pipe, but they came to the conclusion that this was permissible. It was also encouraging that Roman astronomers openly discussed the question of whether Venus was moving around the Earth or around the Sun (the changing phases of Venus clearly spoke in favor of the second option).

Emboldened, Galileo, in a letter to his student Abbot Castelli (1613), stated that Holy Scripture relates only to the salvation of the soul and is not authoritative in scientific matters: “not a single saying of Scripture has such a coercive force as any natural phenomenon.” Moreover, he published this letter, which caused denunciations to the Inquisition. Also in 1613, Galileo published the book “Letters on Sunspots,” in which he openly spoke out in favor of the Copernican system. On February 25, 1615, the Roman Inquisition began its first case against Galileo on charges of heresy. Galileo's last mistake was his call to Rome to express its final attitude towards Copernicanism (1615).

All this caused a reaction opposite to what was expected. Alarmed by the successes of the Reformation, the Catholic Church decided to strengthen its spiritual monopoly - in particular, by banning Copernicanism. The position of the Church is clarified by a letter from the influential Cardinal Bellarmino, sent on April 12, 1615 to the theologian Paolo Antonio Foscarini, a defender of Copernicanism. The cardinal explains that the Church does not object to the interpretation of Copernicanism as a convenient mathematical device, but accepting it as a reality would mean admitting that the previous, traditional interpretation of the biblical text was erroneous.

March 5, 1616 Rome officially defines heliocentrism as a dangerous heresy: “To assert that the Sun stands motionless in the center of the world is an absurd opinion, false from a philosophical point of view and formally heretical, since it directly contradicts Holy Scripture. To assert that the Earth is not in the center of the world, that it does not remain motionless and has even daily rotation, there is an opinion that is equally absurd, false from a philosophical point of view and sinful from a religious point of view."

The church prohibition of heliocentrism, the truth of which Galileo was convinced, was unacceptable for the scientist. He returned to Florence and began to think about how, without formally violating the ban, he could continue to defend the truth. He eventually decided to publish a book containing a neutral discussion of different points of view. He wrote this book for 16 years, collecting materials, honing his arguments and waiting for the right moment.

After the fatal decree of 1616, Galileo changed the direction of his struggle for several years - now he focuses his efforts primarily on criticizing Aristotle, whose writings also formed the basis of the medieval worldview. In 1623, Galileo’s book “The Assay Master” (Italian: Il Saggiatore) was published; This is a pamphlet directed against the Jesuits, in which Galileo sets out his erroneous theory of comets (he believed that comets are not cosmic bodies, but optical phenomena in the Earth's atmosphere). The position of the Jesuits (and Aristotle) ​​in this case was closer to the truth: comets are extraterrestrial objects. This mistake did not, however, prevent Galileo from presenting and wittily arguing his scientific method, from which grew the mechanistic worldview of subsequent centuries.

In the same 1623, Matteo Barberini, an old acquaintance and friend of Galileo, was elected as the new Pope, under the name Urban VIII. In April 1624, Galileo went to Rome, hoping to get the 1616 edict revoked. He was received with all honors, awarded with gifts and flattering words, but achieved nothing on the main issue. The edict was revoked only two centuries later, in 1818. Urban VIII especially praised the book “The Assay Master” and forbade the Jesuits to continue their polemics with Galileo.

In 1624, Galileo published Letters to Ingoli; it is a response to the anti-Copernican treatise of the theologian Francesco Ingoli. Galileo immediately stipulates that he is not going to defend Copernicanism, but only wants to show that it has solid scientific foundations. He used this technique later in his main book, “Dialogue on Two World Systems”; part of the text of “Letters to Ingoli” was simply transferred to “Dialogue”. In his consideration, Galileo equates the stars to the Sun, points out the colossal distance to them, and speaks of the infinity of the Universe. He even allowed himself a dangerous phrase: “If any point in the world can be called its [the world’s] center, then this is the center of revolutions of celestial bodies; and in it, as anyone who understands these matters knows, is the Sun, and not the Earth.” He also stated that the planets and the Moon, like the Earth, attract the bodies on them.

But the main scientific value of this work is laying the foundations of a new, non-Aristotelian mechanics, developed 12 years later in Galileo’s last work, “Conversations and Mathematical Proofs of Two New Sciences.”

In modern terminology, Galileo proclaimed the homogeneity of space (the absence of a center of the world) and the equality of inertial reference systems. An important anti-Aristotelian point should be noted: Galileo's argumentation implicitly assumes that the results of earthly experiments can be transferred to celestial bodies, that is, the laws on Earth and in heaven are the same.

At the end of his book, Galileo, with obvious irony, expresses the hope that his essay will help Ingoli replace his objections to Copernicanism with others that are more consistent with science.

In 1628, 18-year-old Ferdinand II, a pupil of Galileo, became Grand Duke of Tuscany; his father Cosimo II had died seven years earlier. The new duke maintained a warm relationship with the scientist, was proud of him and helped him in every possible way.

Valuable information about Galileo's life is contained in the surviving correspondence between Galileo and his eldest daughter Virginia, who took the name Maria Celeste as a monk. She lived in a Franciscan monastery in Arcetri, near Florence. The monastery, as befits the Franciscans, was poor, the father often sent his daughter food and flowers, in return the daughter prepared him jam, mended his clothes, and copied documents. Only letters from Maria Celeste have survived - letters from Galileo, most likely, the monastery was destroyed after the trial of 1633. The second daughter, Livia, lived in the same monastery, but at that time she was often ill and did not take part in the correspondence.

In 1629, Vincenzo, son of Galileo, married and settled with his father. The following year, Galileo had a grandson named after him. Soon, however, alarmed by another plague epidemic, Vincenzo and his family leave. Galileo is considering a plan to move to Arcetri, closer to his beloved daughter; this plan was realized in September 1631.

In March 1630, the book “Dialogue on the Two Chief Systems of the World - Ptolemaic and Copernican,” the result of almost 30 years of work, was basically completed, and Galileo, deciding that the moment for its release was favorable, provided the then version to his friend, the papal censor Riccardi . He waits for his decision for almost a year, then decides to use a trick. He adds a preface to the book, where he declares his goal to debunk Copernicanism and transfers the book to the Tuscan censorship, and, according to some information, in an incomplete and softened form. Having received a positive review, he forwards it to Rome. In the summer of 1631 he received the long-awaited permission.

At the beginning of 1632, the Dialogue was published. The book is written in the form of a dialogue between three lovers of science: the Copernican Salviati, the neutral Sagredo and Simplicio, an adherent of Aristotle and Ptolemy. Although the book does not contain the author's conclusions, the strength of the arguments in favor of the Copernican system speaks for itself. It is also important that the book was written not in learned Latin, but in “folk” Italian.

Galileo hoped that the Pope would treat his trick as leniently as he had previously treated the “Letters to Ingoli” with similar ideas, but he miscalculated. To top it all off, he himself recklessly sends out 30 copies of his book to influential clergy in Rome. As noted above, shortly before (1623) Galileo came into conflict with the Jesuits; He had few defenders left in Rome, and even those, assessing the danger of the situation, chose not to intervene.

Most biographers agree that in the simpleton Simplicio the Pope recognized himself, his arguments, and became furious. Historians note such characteristic features of Urban as despotism, stubbornness and incredible conceit. Galileo himself later believed that the initiative of the process belonged to the Jesuits, who presented the Pope with an extremely tendentious denunciation about Galileo’s book (see below Galileo’s letter to Diodati). Within a few months, the book was banned and withdrawn from sale, and Galileo was summoned to Rome (despite the plague epidemic) to be tried by the Inquisition on suspicion of heresy. After unsuccessful attempts to obtain a reprieve due to poor health and the ongoing plague epidemic (Urban threatened to deliver him forcibly in shackles), Galileo complied, served the required plague quarantine and arrived in Rome on February 13, 1633. Niccolini, the representative of Tuscany in Rome, at the direction of Duke Ferdinand II, settled Galileo in the embassy building. The investigation lasted from April 21 to June 21, 1633.

At the end of the first interrogation, the accused was taken into custody. Galileo spent only 18 days in prison (from April 12 to April 30, 1633) - this unusual leniency was probably caused by Galileo's agreement to repent, as well as the influence of the Tuscan Duke, who constantly worked to mitigate the fate of his old teacher. Taking into account his illness and advanced age, one of the service rooms in the building of the Inquisition Tribunal was used as a prison.

Historians have explored the question of whether Galileo was subjected to torture during his imprisonment. The documents of the trial were not published by the Vatican in full, and what was published may have been subject to preliminary editing. Nevertheless, the following words were found in the Inquisition verdict: “Noticing that when you answer, you do not quite frankly admit your intentions, we considered it necessary to resort to a strict test.”

After the “test,” Galileo, in a letter from prison (April 23), cautiously reports that he does not get out of bed, as he is tormented by “a terrible pain in his thigh.” Some biographers of Galileo suggest that torture actually took place, while others consider this assumption unproven; only the threat of torture, often accompanied by an imitation of the torture itself, was documented. In any case, if there was torture, it was on a moderate scale, since on April 30 the scientist was released back to the Tuscan embassy.

Judging by the surviving documents and letters, scientific topics were not discussed at the trial. The main questions were: whether Galileo deliberately violated the edict of 1616, and whether he repented of his deeds. Three Inquisition experts gave their conclusion: the book violates the ban on promoting the “Pythagorean” doctrine. As a result, the scientist was faced with a choice: either he would repent and renounce his “delusions,” or he would suffer the same fate.

“Having become acquainted with the whole course of the case and having listened to the testimony, His Holiness determined to interrogate Galileo under threat of torture and, if he resists, then after a preliminary renunciation as strongly suspected of heresy ... to be sentenced to imprisonment at the discretion of the Holy Congregation. He is ordered not to argue any more in writing or orally about what -image about the movement of the Earth and the immobility of the Sun... under pain of punishment as incorrigible."

Galileo's last interrogation took place on June 21. Galileo confirmed that he agreed to make the renunciation required of him; this time he was not allowed to go to the embassy and was again taken into custody. On June 22, the verdict was announced: Galileo was guilty of distributing a book with “false, heretical, contrary to Holy Scripture teaching” about the movement of the Earth:

“As a result of considering your guilt and your consciousness in it, we condemn and declare you, Galileo, for everything stated above and confessed by you under strong suspicion at this Holy Judgment of heresy, as possessed by a false and contrary to the Holy and Divine Scripture thought that the Sun is the center of the earth orbit and does not move from east to west, the Earth is mobile and is not the center of the Universe. We also recognize you as disobedient to the church authorities, who forbade you to expound, defend and present as probable a teaching recognized as false and contrary to Holy Scripture... So that such a grave and harmful sin. your disobedience would not have remained without any reward and you would not have subsequently become even more daring, but, on the contrary, would have served as an example and warning for others, we decided to ban the book entitled “Dialogue” by Galileo Galilei, and imprison you yourself in St. judgment for an indefinite period."

Galileo was sentenced to imprisonment for a term to be determined by the Pope. He was declared not a heretic, but “strongly suspected of heresy”; This formulation was also a grave accusation, but it saved him from the fire. After the verdict was announced, Galileo on his knees pronounced the text of the renunciation offered to him. Copies of the verdict, by personal order of Pope Urban, were sent to all universities in Catholic Europe.

The Pope did not keep Galileo in prison for long. After the verdict, Galileo was settled in one of the Medici villas, from where he was transferred to the palace of his friend, Archbishop Piccolomini in Siena. Five months later, Galileo was allowed to go home, and he settled in Arcetri, next to the monastery where his daughters were. Here he spent the rest of his life under house arrest and under constant surveillance by the Inquisition.

Galileo's detention regime was no different from prison, and he was constantly threatened with transfer to prison for the slightest violation of the regime. Galileo was not allowed to visit cities, although the seriously ill prisoner needed constant medical supervision. In the early years he was forbidden to receive guests on pain of being transferred to prison; Subsequently, the regime was somewhat softened, and friends were able to visit Galileo - however, no more than one at a time.

The Inquisition monitored the prisoner for the rest of his life; even at the death of Galileo, two of its representatives were present. All his printed works were subject to particularly careful censorship. Let us note that in Protestant Holland the publication of the Dialogue continued.

In 1634, the 33-year-old eldest daughter Virginia (Maria Celeste in monasticism), Galileo’s favorite, who devotedly cared for her sick father and keenly experienced his misadventures, died. Galileo writes that he is possessed by “boundless sadness and melancholy... I constantly hear my dear daughter calling me.” Galileo's health deteriorated, but he continued to work vigorously in the areas of science permitted to him.

A letter from Galileo to his friend Elia Diodati (1634) has been preserved, where he shares news of his misadventures, points to their culprits (the Jesuits) and shares plans for future research. The letter was sent through a proxy, and Galileo is quite frank in it: “In Rome, I was sentenced to imprisonment by the Holy Inquisition at the direction of His Holiness... the place of imprisonment for me was this small town one mile from Florence, with the strictest prohibition from going down into the city, meeting and talking with friends and inviting them... When I returned from the monastery Together with the doctor who visited my sick daughter before her death, and the doctor told me that the case was hopeless and that she would not survive the next day (as it happened), I found the vicar-inquisitor at home, he appeared to order me, by order. of the Holy Inquisition in Rome... that I should not have made a request to be allowed to return to Florence, otherwise I would be put in the real prison of the Holy Inquisition... This incident and others about which it would be too long to write show that my rage is very powerful persecutors are constantly increasing. And they finally wanted to reveal their faces: when one of my dear friends in Rome, about two months ago, in a conversation with Padre Christopher Greenberg, a Jesuit, mathematician of this college, touched on my affairs, this Jesuit told me. to a friend literally the following: “If Galileo had been able to retain the favor of the fathers of this college, he would have lived in freedom, enjoying fame, he would not have had any grief and he could have written at his own discretion about anything - even about the movement of the Earth,” etc. d. So, you see that they attacked me not because of this or that opinion of mine, but because I am out of favor with the Jesuits."

At the end of the letter, Galileo ridicules the ignorant who “declares the mobility of the Earth to be a heresy” and says that he intends to anonymously publish a new treatise in defense of his position, but first wants to finish a long-planned book on mechanics. Of these two plans, he managed to implement only the second - he wrote a book on mechanics, summarizing his earlier discoveries in this area.

Galileo's last book was Discourses and Mathematical Proofs of Two New Sciences, which sets out the fundamentals of kinematics and strength of materials. In fact, the content of the book is a demolition of Aristotelian dynamics; in return, Galileo puts forward his principles of motion, verified by experience. Challenging the Inquisition, Galileo brought out in his new book the same three characters as in the previously banned “Dialogue on the Two Chief Systems of the World.” In May 1636, the scientist negotiated the publication of his work in Holland, and then secretly sent the manuscript there. In a confidential letter to his friend, Comte de Noel (to whom he dedicated this book), Galileo writes that the new work “puts me again in the ranks of the fighters.” “Conversations...” was published in July 1638, and the book reached Arcetri almost a year later - in June 1639. This work became a reference book for Huygens and Newton, who completed the construction of the foundations of mechanics begun by Galileo.

Only once, shortly before his death (March 1638), the Inquisition allowed the blind and seriously ill Galileo to leave Arcetri and settle in Florence for treatment. At the same time, under pain of prison, he was forbidden to leave the house and discuss the “damned opinion” about the movement of the Earth. However, a few months later, after the appearance of the Dutch publication “Conversations...”, the permission was canceled and the scientist was ordered to return to Arcetri. Galileo was going to continue the “Conversations...” by writing two more chapters, but did not have time to complete his plan.

Galileo Galilei died on January 8, 1642, at the age of 78, in his bed. Pope Urban forbade Galileo to be buried in the family crypt of the Basilica of Santa Croce in Florence. He was buried in Arcetri without honors; the Pope also did not allow him to erect a monument.

The youngest daughter, Livia, died in the monastery. Later, Galileo’s only grandson also became a monk and burned the scientist’s priceless manuscripts that he kept as ungodly. He was the last representative of the Galilean family.

In 1737, Galileo's ashes, as he requested, were transferred to the Basilica of Santa Croce, where on March 17 he was solemnly buried next to Michelangelo. In 1758, Pope Benedict XIV ordered that works advocating heliocentrism be removed from the Index of Prohibited Books; however, this work was carried out slowly and was completed only in 1835.

From 1979 to 1981, on the initiative of Pope John Paul II, a commission worked to rehabilitate Galileo, and on October 31, 1992, Pope John Paul II officially admitted that the Inquisition in 1633 made a mistake by forcefully forcing the scientist to renounce the Copernican theory.

Scientific achievements of Galileo:

Galileo is rightfully considered the founder of not only experimental, but, to a large extent, theoretical physics. In his scientific method, he deliberately combined thoughtful experimentation with rational understanding and generalization, and he personally provided impressive examples of such research.

Galileo is considered one of the founders of mechanism. This scientific approach views the Universe as a gigantic mechanism, and complex natural processes as combinations of the simplest causes, the main of which is mechanical movement. The analysis of mechanical motion lies at the heart of Galileo's work.

Galileo formulated the correct laws of fall: speed increases in proportion to time, and distance increases in proportion to the square of time. In accordance with his scientific method, he immediately provided experimental data confirming the laws he discovered. Moreover, Galileo also considered (on the 4th day of the Conversations) a generalized problem: to study the behavior of a falling body with a non-zero horizontal initial velocity. He quite correctly assumed that the flight of such a body would be a superposition (superposition) of two “simple movements”: uniform horizontal motion by inertia and uniformly accelerated vertical fall.

Galileo proved that the indicated body, as well as any body thrown at an angle to the horizon, flies in a parabola. In the history of science, this is the first solved problem of dynamics. At the conclusion of the study, Galileo proved that the maximum flight range of an thrown body is achieved for a throw angle of 45° (previously this assumption was made by Tartaglia, who, however, could not strictly substantiate it). Based on his model, Galileo (still in Venice) compiled the first artillery tables.

Galileo also refuted the second of Aristotle’s laws given above, formulating the first law of mechanics (the law of inertia): in the absence of external forces, the body is either at rest or moving uniformly. What we call inertia, Galileo poetically called “indestructible imprinted motion.” True, he allowed free movement not only in a straight line, but also in a circle (apparently for astronomical reasons). The correct formulation of the law was later given by and; nevertheless, it is generally accepted that the very concept of “motion by inertia” was first introduced by Galileo, and the first law of mechanics rightly bears his name.

Galileo is one of the founders of the principle of relativity in classical mechanics, which in a slightly refined form became one of the cornerstones of the modern interpretation of this science and was later named in his honor.

The discoveries of Galileo listed above, among other things, allowed him to refute many of the arguments of opponents of the heliocentric system of the world, who argued that the rotation of the Earth would noticeably affect the phenomena occurring on its surface. For example, according to geocentrists, the surface of the rotating Earth during the fall of any body would move away from under this body, shifting by tens or even hundreds of meters. Galileo confidently predicted: “Any experiments that should indicate more against than for the rotation of the Earth will be inconclusive.”

Galileo published a study of pendulum oscillations and stated that the period of oscillations did not depend on their amplitude (this was approximately true for small amplitudes). He also discovered that the periods of a pendulum's oscillations correlate as the square roots of its length. Galileo's results attracted the attention of Huygens, who invented the pendulum regulator clock (1657); from this moment on, the possibility of precise measurements in experimental physics arose.

For the first time in the history of science, Galileo raised the question of the strength of rods and beams in bending and thereby laid the foundation for a new science - the strength of materials.

Many of Galileo's arguments are sketches of physical laws discovered much later. For example, in the Dialogue he reports that the vertical speed of a ball rolling over the surface of a complex terrain depends only on its current height, and illustrates this fact with several thought experiments; Now we would formulate this conclusion as the law of conservation of energy in a gravitational field. Similarly, he explains the (theoretically undamped) swing of a pendulum.

In statics, Galileo introduced the fundamental concept of moment of force.

In 1609, Galileo independently built his first telescope with a convex lens and a concave eyepiece. The tube provided approximately threefold magnification. Soon he managed to build a telescope that gave a magnification of 32 times. Let us note that it was Galileo who introduced the term telescope into science (the term itself was suggested to him by Federico Cesi, the founder of the Accademia dei Lincei). A number of Galileo's telescopic discoveries contributed to the establishment of the heliocentric system of the world, which Galileo actively promoted, and to the refutation of the views of the geocentrists Aristotle and Ptolemy.

Galileo made the first telescopic observations of celestial bodies on January 7, 1610. These observations showed that the Moon, like the Earth, has a complex topography - covered with mountains and craters. Galileo explained the ashen light of the Moon, known since ancient times, as a result of sunlight reflected by the Earth hitting our natural satellite. All this refuted Aristotle’s teaching about the opposition of “earthly” and “heavenly”: the Earth became a body of fundamentally the same nature as the celestial bodies, and this, in turn, served as an indirect argument in favor of the Copernican system: if other planets move, then naturally assume that the Earth is also moving. Galileo also discovered the libration of the Moon and quite accurately estimated the height of the lunar mountains.

Galileo also discovered (independently from Johann Fabricius and Herriot) sunspots. The existence of spots and their constant variability refuted Aristotle’s thesis about the perfection of the heavens (as opposed to the “sublunary world”). Based on the results of their observations, Galileo concluded that the Sun rotates around its axis, estimated the period of this rotation and the position of the Sun's axis.

Galileo discovered that Venus changes phases. On the one hand, this proved that it shines with reflected light from the Sun (about which there was no clarity in the astronomy of the previous period). On the other hand, the order of phase changes corresponded to the heliocentric system: in Ptolemy’s theory, Venus as the “lower” planet was always closer to the Earth than the Sun, and “full Venus” was impossible.

Galileo also noted the strange “appendages” of Saturn, but the discovery of the ring was prevented by the weakness of the telescope and the rotation of the ring, which hid it from an earthly observer. Half a century later, Saturn's ring was discovered and described by Huygens, who had a 92x telescope at his disposal.

Galileo showed that when observed through a telescope, the planets are visible as disks, the apparent sizes of which in different configurations change in the same ratio as follows from the Copernican theory. However, the diameter of stars does not increase when observed with a telescope. This refuted estimates of the apparent and actual size of stars, which were used by some astronomers as an argument against the heliocentric system.

The Milky Way, which to the naked eye looks like a continuous glow, broke up into individual stars (which confirmed Democritus’ guess), and a huge number of previously unknown stars became visible.

Galileo explained why the earth's axis does not rotate when the earth revolves around the sun; To explain this phenomenon, Copernicus introduced a special “third movement” of the Earth. Galileo showed experimentally that the axis of a freely moving top maintains its direction by itself.

His study of the outcomes of throwing dice belongs to the theory of probability. His “Discourse on the Game of Dice” (“Considerazione sopra il giuoco dei dadi”, date of writing unknown, published in 1718) provides a fairly complete analysis of this problem.

In “Conversations on Two New Sciences” he formulated the “Galileo's Paradox”: there are as many natural numbers as there are their squares, although most of the numbers are not squares. This prompted further research into the nature of infinite sets and their classification; the process of creating set theory.

Galileo created hydrostatic balances to determine the specific gravity of solids. Galileo described their design in his treatise La bilancetta (1586).

Galileo developed the first thermometer, still without scale (1592), proportional compass, used in drafting (1606), microscope, poor quality (1612); With its help, Galileo studied insects.

Disciples of Galileo:

Borelli, who continued the study of Jupiter's moons; he was one of the first to formulate the law of universal gravitation. Founder of biomechanics.
Viviani, Galileo's first biographer, was a talented physicist and mathematician.
Cavalieri, the forerunner of mathematical analysis, in whose fate Galileo's support played a huge role.
Castelli, creator of hydrometry.
Torricelli, who became an outstanding physicist and inventor.

Galileo Galilei was born on February 15, 1564 in Pisa to the musician Vincenzo Galilei and Giulia Ammannati. In 1572, he and his family moved to Florence. In 1581 he began to study medicine at the University of Pisa. One of Galileo's teachers, Ostilio Ricci, supported the young man in his passion for mathematics and physics, which affected the future fate of the scientist.

Galileo was unable to graduate from university due to financial difficulties encountered by his father and was forced to return to Florence, where he continued to study science. In 1586, he completed work on the treatise “Small Balances”, in which (following Archimedes) he described the device he had invented for hydrostatic weighing, and in the next work he gave a number of theorems regarding the center of gravity of paraboloids of revolution. Assessing the growth of the scientist's reputation, the Florentine Academy chose him as an arbiter in the dispute over how the topography of Dante's Inferno (1588) should be interpreted from a mathematical point of view. Thanks to the assistance of his friend Marquis Guidobaldo del Monte, Galileo received an honorary but poorly paid position as professor of mathematics at the University of Pisa.

The death of his father in 1591 and the extreme straits of his financial situation forced Galileo to look for a new place of work. In 1592, he received the chair of mathematics in Padua (in the possessions of the Venetian Republic). After spending eighteen years here, Galileo Galilei discovered the quadratic dependence of the falling path on time, established the parabolic trajectory of the projectile, and also made many other equally important discoveries.

In 1609, Galileo Galilei, based on the model of the first Dutch telescopes, made his telescope, capable of creating a three-fold zoom, and then designed a telescope with a thirty-fold zoom, magnifying one thousand times. Galileo became the first person to point a telescope at the sky; what he saw there meant a genuine revolution in the idea of ​​space: the Moon turned out to be covered with mountains and depressions (previously the surface of the Moon was considered smooth), the Milky Way - consisting of stars (according to Aristotle - this is fiery evaporation like the tail of comets), Jupiter - surrounded by four satellites (their rotation around Jupiter was an obvious analogy to the rotation of the planets around the Sun). Galileo later added to these observations the discovery of the phases of Venus and sunspots. He published the results in a book that was published in 1610 called “The Starry Messenger.” The book brought Galileo European fame. The famous mathematician and astronomer Johannes Kepler responded enthusiastically to it; monarchs and high clergy showed great interest in Galileo’s discoveries. With their help, he received a new, more honorable and secure position - the post of court mathematician to the Grand Duke of Tuscany. In 1611, Galileo visited Rome, where he was admitted to the scientific "Academia dei Lincei".

In 1613, he published an essay on sunspots, in which for the first time he clearly spoke out in favor of Copernicus' heliocentric theory.

However, to proclaim this in Italy at the beginning of the 17th century meant repeating the fate of Giordano Bruno, who was burned at the stake. The central point of the controversy that arose was the question of how to combine facts proven by science with contradictory passages from the Holy Scriptures. Galileo believed that in such cases the biblical story should be understood allegorically. The Church attacked the theory of Copernicus, whose book “On the Rotation of the Celestial Spheres” (1543), more than half a century after its publication, ended up on the list of prohibited publications. A decree on this appeared in March 1616, and a month earlier, the chief theologian of the Vatican, Cardinal Bellarmine, suggested that Galileo not further defend Copernicanism. In 1623, Maffeo Barberini, a friend of his youth and patron of Galileo, became Pope under the name of Urban VIII. At the same time, the scientist published his new work, “Assay Master,” which examines the nature of physical reality and methods of studying it. It was here that the famous saying of the scientist appeared: “The Book of Nature is written in the language of mathematics.”

In 1632, Galileo’s book “Dialogue on the Two Systems of the World, Ptolemaic and Copernican” was published, which was soon banned by the Inquisition, and the scientist himself was summoned to Rome, where his trial awaited him. In 1633, the scientist was sentenced to life imprisonment, which was replaced by house arrest; he spent the last years of his life on his estate Arcetri near Florence. The circumstances of the case still remain unclear. Galileo was accused not simply of defending the Copernican theory (such an accusation is legally untenable, since the book passed papal censorship), but of violating the previously given ban of 1616 “not to discuss in any form” this theory.

In 1638, Galileo published his new book “Conversations and Mathematical Proofs” in Holland, in the Elsevier publishing house, where he outlined his thoughts on the laws of mechanics in a more mathematical and academic form, and the range of problems considered was very wide - from statics and resistance of materials to laws of motion of a pendulum and laws of fall. Until his death, Galileo did not stop his active creative work: he tried to use the pendulum as the main element of the clock mechanism (followed by Christian Huygens), a few months before he became completely blind, he discovered the vibration of the Moon, and, already completely blind, dictated the last thoughts regarding the theory of impact to his students - Vincenzo Viviani and Evangelista Torricelli.

In addition to his great discoveries in astronomy and physics, Galileo went down in history as the creator of the modern method of experimentation. His idea was that in order to study a specific phenomenon, we must create some kind of ideal world (he called it al mondo di carta - “the world on paper”), in which this phenomenon would be extremely free from extraneous influences. This ideal world is subsequently the object of a mathematical description, and its conclusions are compared with the results of an experiment in which conditions are as close to ideal as possible.

Galileo died in Arcetri on January 8, 1642 after a debilitating fever. In his will, he asked to be buried in the family tomb in the Basilica of Santa Croce (Florence), but due to fears of opposition from the church, this was not done. The scientist’s last will was fulfilled only in 1737; his ashes were transported from Arcetri to Florence and buried with honors in the Church of Santa Croce next to Michelangelo.

In 1758, the Catholic Church lifted the ban on most works supporting the Copernican theory, and in 1835 it excluded On the Rotation of the Celestial Spheres from the index of prohibited books. In 1992, Pope John Paul II officially admitted that the church had made a mistake in condemning Galileo in 1633.

Galileo Galilei had three children born out of wedlock to the Venetian Marina Gamba. Only his son Vincenzo, who later became a musician, was recognized by the astronomer as his own in 1619. His daughters, Virginia and Livia, were sent to a monastery.

The material was prepared based on information from open sources