Conversations and mathematical proofs of two new sciences. Biography of Galileo Galilei. Scientific achievements of Galileo

Galileo Galilei - the greatest thinker of the Renaissance, the founder of modern mechanics, physics and astronomy, a follower of ideas, a predecessor.

The future scientist was born in Italy, the city of Pisa on February 15, 1564. Father Vincenzo Galilei, who belonged to an impoverished family of aristocrats, played the lute and wrote treatises on music theory. Vincenzo was a member of the Florentine Camerata society, whose members sought to revive the ancient Greek tragedy. The result of the activities of musicians, poets and singers was the creation of a new genre of opera at the turn of the 16th-17th centuries.

Mother Giulia Ammannati ran the household and raised four children: the eldest Galileo, Virginia, Livia and Michelangelo. The youngest son followed in the footsteps of his father and subsequently became famous for his composing art. When Galileo was 8 years old, the family moved to the capital of Tuscany, the city of Florence, where the Medici dynasty flourished, known for its patronage of artists, musicians, poets and scientists.

At an early age, Galileo was sent to school at the Benedictine monastery of Vallombrosa. The boy showed the ability to draw, study languages ​​and the exact sciences. From his father, Galileo inherited an ear for music and the ability to compose, but only science really attracted the young man.

Studies

At 17, Galileo travels to Pisa to study medicine at the university. The young man, in addition to the basic subjects and medical practice, became interested in attending mathematical classes. The young man discovered the world of geometry and algebraic formulas, which influenced Galileo's worldview. During the three years that the young man studied at the university, he thoroughly studied the works of ancient Greek thinkers and scientists, and also got acquainted with the heliocentric theory of Copernicus.

After a three-year stay in educational institution Galileo was forced to return to Florence due to the lack of funds for further education from his parents. The management of the university did not make any concessions to the talented young man, did not give him the opportunity to complete the course and receive a degree. But Galileo already had an influential patron, the Marquis Guidobaldo del Monte, who admired Galileo's talents in the field of invention. The aristocrat took care of the ward before the Tuscan Duke Ferdinand I of Medici and provided the young man with a salary at the court of the ruler.

Work at the university

The Marquis del Monte helped the talented scientist get a teaching position at the University of Bologna. In addition to lectures, Galileo leads a fruitful scientific activity. The scientist deals with issues of mechanics and mathematics. In 1689, the thinker returned to the University of Pisa for three years, but now as a teacher of mathematics. In 1692, for 18 years, he moved to the Venetian Republic, the city of Padua.

Combining teaching work at a local university with scientific experiments, Galileo publishes the books "On Motion", "Mechanics", where he refutes ideas. During these years one of the important events- A scientist invents a telescope, which made it possible to observe the life of heavenly bodies. The discoveries made by Galileo with the help of a new device, the astronomer described in the treatise "Star Messenger".

Returning to Florence in 1610, under the care of the Duke of Tuscany Cosimo de' Medici II, Galileo published the essay "Letters on Sunspots", which was critically received by the Catholic Church. At the beginning of the XVII century, the Inquisition acted on a large scale. And the followers of Copernicus were among the zealots of the Christian faith in a special account.

In 1600, he was already executed at the stake, who never renounced his own views. Therefore, the works of Galileo Galilei were considered provocative by Catholics. The scientist himself considered himself an exemplary Catholic and did not see a contradiction between his work and the Christocentric picture of the world. The astronomer and mathematician considered the Bible to be a book that contributes to the salvation of the soul, and not at all a scientific cognitive treatise.

In 1611, Galileo went to Rome to demonstrate the telescope to Pope Paul V. The presentation of the device was carried out by the scientist as correctly as possible and even received the approval of the metropolitan astronomers. But the request of the scientist to make a final decision on the issue of the heliocentric system of the world decided his fate in the eyes of the Catholic Church. The papists declared Galileo a heretic, and the indictment process was launched in 1615. The concept of heliocentrism was officially recognized as false by the Roman Commission in 1616.

Philosophy

The main postulate of Galileo's worldview is the recognition of the objectivity of the world, regardless of subjective perception by a person. The universe is eternal and infinite, initiated by the divine first impulse. Nothing in space disappears without a trace, only a change in the form of matter occurs. The basis of the material world is the mechanical movement of particles, by studying which you can learn the laws of the universe. Therefore, scientific activity should be based on experience and sensory knowledge of the world. According to Galileo, nature is the true subject of philosophy, comprehending which you can get closer to the truth and the fundamental principle of all things.

Galileo was an adherent of two methods of natural science - experimental and deductive. With the help of the first method, the scientist sought to prove the hypotheses, the second assumed a consistent movement from one experience to another, in order to achieve the completeness of knowledge. In his work, the thinker relied primarily on teaching. Criticizing the views, Galileo did not reject the analytical method used by the philosopher of antiquity.

Astronomy

Thanks to the telescope invented in 1609, which was created using a convex lens and a concave eyepiece, Galileo began observing the heavenly bodies. But a three-fold increase in the first device was not enough for a scientist for full-fledged experiments, and soon the astronomer creates a telescope with a 32-fold increase in objects.

Inventions of Galileo Galilei: telescope and first compass

The first luminary, which Galileo studied in detail with the help of a new device, was the Moon. The scientist discovered many mountains and craters on the surface of the Earth's satellite. The first discovery confirmed that the Earth physical properties does not differ from other celestial bodies. This was the first refutation of Aristotle's statement about the difference between earthly and heavenly nature.

The second major discovery in the field of astronomy concerned the discovery of the four satellites of Jupiter, which in the 20th century was already confirmed by numerous space photos. Thus, he refuted the arguments of the opponents of Copernicus that if the Moon revolves around the Earth, then the Earth cannot revolve around the Sun. Galileo, due to the imperfection of the first telescopes, could not establish the period of rotation of these satellites. The final proof of the rotation of the moons of Jupiter was put forward 70 years later by the astronomer Cassini.

Galileo discovered the presence of sunspots, which he observed for a long time. Having studied the luminary, Galileo concluded that the Sun rotates around its own axis. Observing Venus and Mercury, the astronomer determined that the orbits of the planets are closer to the Sun than the earth. Galileo discovered the rings of Saturn and even described the planet Neptune, but he was not able to advance in these discoveries to the end, due to the imperfection of technology. Watching the stars of the Milky Way through a telescope, the scientist was convinced of their immense number.

By experience and empirical way, Galileo proves that the Earth revolves not only around the Sun, but also around its axis, which further strengthened the astronomer in the correctness of the Copernican hypothesis. In Rome, after a hospitable reception in the Vatican, Galileo becomes a member of the Accademia dei Lincei, which was founded by Prince Cesi.

Mechanics

According to Galileo, the basis of the physical process in nature is mechanical motion. The scientist considered the universe as a complex mechanism consisting of the simplest causes. Therefore, mechanics became the cornerstone in the scientific activity of Galileo. Galileo made many discoveries in the field of mechanics itself, and also determined the direction of future discoveries in physics.

The scientist was the first to establish the law of falling and confirmed it empirically. Galileo discovered the physical formula for the flight of a body moving at an angle to a horizontal surface. The parabolic motion of a thrown object was essential to the calculation of artillery tables.

Galileo formulated the law of inertia, which became the fundamental axiom of mechanics. Another discovery was the substantiation of the principle of relativity for classical mechanics, as well as the calculation of the formula for the oscillation of pendulums. Based on the latest research, the first pendulum clock was invented in 1657 by the physicist Huygens.

Galileo was the first to pay attention to the resistance of the material, which gave impetus to the development of an independent science. The reasoning of the scientist later formed the basis of the laws of physics on the conservation of energy in the field of gravity, the moment of force.

Mathematics

Galileo in mathematical judgments approached the idea of ​​the theory of probability. The scientist outlined his own research on this subject in the treatise “Discourses on the game of dice”, which was published 76 years after the death of the author. Galileo became the author of the famous mathematical paradox about natural numbers and their squares. Galileo recorded the calculations in the work "Conversations about two new sciences". Developments formed the basis of the theory of sets and their classification.

Conflict with the Church

After 1616, a turning point in Galileo's scientific biography, he was forced to go into the shadows. The scientist was afraid to express own ideas obviously, therefore, the only book Galileo published after Copernicus was declared a heretic was the 1623 essay "The Assayer". After the change of power in the Vatican, Galileo perked up, he believed that the new Pope Urban VIII would react more favorably to Copernican ideas than his predecessor.

But after the appearance in print in 1632 of the polemical treatise "Dialogue Concerning the Two Chief Systems of the World," the Inquisition again brought proceedings against the scientist. The story of the accusation repeated itself, but this time for Galileo everything ended much worse.

Personal life

While living in Padua, young Gallileo met Marina Gamba, a citizen of the Venetian Republic, who became the civil wife of the scientist. Three children were born in the family of Galileo - the son of Vincenzo and the daughters of Virginia and Livia. Since the children appeared outside of a married marriage, the girls subsequently had to become nuns. At the age of 55, Galileo managed to legitimize only his son, so the young man was able to marry and give his father a grandson, who later, like his aunts, became a monk.

Galileo Galilei was outlawed

After the Inquisition outlawed Galileo, he moved to a villa in Arcetri, which was not far from the daughters' monastery. Therefore, quite often, Galileo could see his favorite, the eldest daughter Virginia, until her death in 1634. The younger Livia did not visit her father due to illness.

Death

As a result of a short-term imprisonment in 1633, Galileo renounced the idea of ​​heliocentrism and was placed under indefinite arrest. The scientist was placed under home guard in the city of Arcetri with limited communication. Galileo stayed at the Tuscan villa without a break until last days life. The heart of a genius stopped on January 8, 1642. At the time of death, two students, Viviani and Torricelli, were next to the scientist. During the 30s, the last works of the thinker, Dialogues and Conversations and Mathematical Proofs Concerning Two New Branches of Science, were published in Protestant Holland.

Tomb of Galileo Galilei

After his death, the Catholics forbade the burial of the ashes of Galileo in the crypt of the Basilica of Santa Croce, where the scientist wanted to rest. Justice prevailed in 1737. From now on, the grave of Galileo is located next to. After another 20 years, the church rehabilitated the idea of ​​heliocentrism. Galileo's acquittal had to wait much longer. The error of the Inquisition was only recognized in 1992 by Pope John Paul II.

Big soviet encyclopedia: Galileo (Galilei) Galileo (February 15, 1564, Pisa, - January 8, 1642, Arcetri, near Florence), Italian physicist, mechanic and astronomer, one of the founders of natural science, poet, philologist and critic.
G. belonged to a noble, but impoverished Florentine family. His father, Vincenzo, a famous musician, had a great influence on the development and formation of G.'s abilities. Until the age of 11, G. lived in Pisa, attended school there, then the family moved to Florence. G. received further education in the monastery of Vallombrosa, where he was accepted as a novice in a monastic order. Here he got acquainted with the works of Latin and Greek writers. Under the pretext of a serious eye disease, the father took his son from the monastery. At the insistence of his father in 1581, Mr.. entered the University of Pisa, where he studied medicine. Here he first became acquainted with the physics of Aristotle, which from the very beginning seemed unconvincing to him. G. turned to reading the ancient mathematicians - Euclid and Archimedes. Archimedes became his real teacher. Fascinated by geometry and mechanics, G. gave up medicine and returned to Florence, where he spent 4 years studying mathematics. The result of this period of G.'s life was a small essay "Little Scales" (1586, ed. 1655), which describes the hydrostatic balance built by G. to quickly determine the composition of metal alloys, and a geometric study on the centers of gravity of bodily figures. These works brought G. first fame among Italian mathematicians. In 1589 he received the chair of mathematics in Pisa, continuing his scientific work. His “Dialogue on Motion”, written in Pisa and directed against Aristotle, has been preserved in manuscripts. Some of the conclusions and arguments in this work are erroneous, and G. subsequently abandoned them. But already here, without naming Copernicus, G. gives arguments refuting Aristotle's objections to the daily rotation of the Earth.
In 1592 G. took the chair of mathematics in Padua. The Padua period of G.'s life (1592-1610) is the time of the highest flowering of his activity. During these years, his static research on machines arose, where he proceeds from general principle equilibrium coinciding with the principle of possible displacements (see the principle of possible displacements), his main dynamic works on the laws of free fall of bodies, on falling along an inclined plane, on the motion of a body thrown at an angle to the horizon, and on the isochronism of pendulum oscillations, have matured. The same period includes research on the strength of materials, on the mechanics of animal bodies; finally, in Padua, G. became quite a convinced follower of Copernicus. However, the scientific work of Mr.. remained hidden from everyone, except for friends. Lectures G. read according to the traditional program, they expounded the teachings of Ptolemy. In Padua, G. published only a description of the proportional compass, allowing you to quickly make various calculations and constructions.
In 1609, on the basis of information that had come down to him about the spotting scope invented in Holland, G. built his first telescope, giving approximately 3-fold magnification. The work of the telescope was demonstrated from the tower of St. Mark in Venice and made a huge impression. Soon G. built a telescope with a magnification of 32 times. The observations made with its help destroyed Aristotle's "ideal spheres" and the dogma of the perfection of celestial bodies: the surface of the Moon turned out to be covered with mountains and pitted with craters, the stars lost their apparent size, and for the first time their colossal remoteness was comprehended. Jupiter discovered 4 satellites, a huge number of new stars became visible in the sky. The Milky Way has broken up into individual stars. G. described his observations in the essay "The Starry Messenger" (1610-11), which made a stunning impression. At the same time, a fierce controversy began. G. was accused of the fact that everything he saw was an optical illusion, they argued simply that his observations contradict Aristotle, and therefore are erroneous.
Astronomical discoveries served as a turning point in G.'s life: he freed himself from teaching and, at the invitation of Duke Cosimo II de Medici, moved to Florence. Here he becomes the court "philosopher" and the "first mathematician" of the university, without the obligation to lecture.
Continuing telescopic observations, G. discovered the phases of Venus, sunspots and the rotation of the Sun, studied the movement of Jupiter's satellites, and observed Saturn. In 1611, G. went to Rome, where he was given an enthusiastic reception at the papal court and where he struck up a friendship with Prince Cesi, the founder of the Academy dei Lincei ("Academy of the Lynx-eyed"), of which he became a member. At the insistence of the duke G. published his first anti-Aristotelian essay - "Discourse on the bodies that are in the water, and those that move in it" (1612), where he applied the principle of equal moments to the derivation of equilibrium conditions in liquid bodies.
However, in 1613 it became known letter G. to the abbot Castelli, in which he defended the views of Copernicus. The letter served as a pretext for a direct denunciation of G. to the Inquisition. In 1616, the Jesuit congregation declared the teachings of Copernicus heretical, the book of Copernicus was included in the list of banned books. The name of G. was not named in the resolution, but he was privately ordered to refuse to defend this doctrine. G. formally obeyed the decree. For several years he was forced to remain silent about the Copernican system or to speak of it in allusions. the only big essay During this period, G. was The Assayer (1623), a polemical treatise on three comets that appeared in 1618. In terms of literary form, wit, and sophistication of style, this is one of the most remarkable works of G.
In 1623, G.'s friend, Cardinal Maffeo Barberini, assumed the papacy under the name of Urban VIII. For G. this event seemed tantamount to liberation from the bonds of the interdict (decree). In 1630, he arrived in Rome with the finished manuscript of the Dialogue on the Ebb and Flow (the first title of the Dialogue on the Two Chief Systems of the World), in which the systems of Copernicus and Ptolemy are presented in the conversations of three interlocutors: Sagredo, Salviati and Simplicio.
Pope Urban VIII agreed to the publication of a book in which the teachings of Copernicus would be presented as one of the possible hypotheses. After lengthy censorship ordeals, G. received the long-awaited permission to print Dialogue with some changes; the book appeared in Florence in Italian in January 1632. A few months after the publication of the book, G. received an order from Rome to stop further sales of the publication. At the request of the Inquisition, G. was forced in February 1633 to come to Rome. Proceedings were initiated against G.. During four interrogations - from April 12 to June 21, 1633 - G. renounced the teachings of Copernicus and on June 22 brought public repentance on his knees in the church of Maria Sopra Minerva. "Dialogue" was banned, and G. was officially considered a "prisoner of the Inquisition" for 9 years. At first he lived in Rome, in the ducal palace, then in his villa Arcetri, near Florence. He was forbidden to talk with anyone about the movement of the Earth and to print works. Despite the papal interdict, a Latin translation of the Dialogue appeared in Protestant countries, and G.'s discourse on the relationship between the Bible and natural science was printed in Holland. Finally, in 1638 in Holland, one of G.'s most important works was published, summing up his physical research and containing a substantiation of dynamics - "Conversations and mathematical proofs concerning two new branches of science ...".
In 1637 G. went blind. He died on January 8, 1642. In 1737, the last will of Galileo was fulfilled - his ashes were transferred to Florence in the church of Santa Croce, where he was buried next to Michelangelo.
G.'s influence on the development of mechanics, optics, and astronomy in the 17th century. invaluable. His scientific activity, the great importance of the discovery, scientific courage were of decisive importance for the victory of the heliocentric system of the world. Particularly significant work G. to create the basic principles of mechanics. If the basic laws of motion were not expressed by G. with the clarity with which I. Newton did, then in essence the law of inertia and the law of addition of motions were fully realized by him and applied to the solution of practical problems. The history of statics begins with Archimedes; the history of dynamics is opened by G. He was the first to put forward the idea of ​​the relativity of motion (Galilean's principle of relativity), he solved a number of basic mechanical problems. These include, first of all, the study of the laws of free fall of bodies and their fall along an inclined plane; the laws of motion of a body thrown at an angle to the horizon; establishing conservation mechanical energy when the pendulum swings. G. dealt a blow to the Aristotelian dogmatic ideas about absolutely light bodies (fire, air); in a series of witty experiments, he showed that air is a heavy body and even determined its specific gravity in relation to water.
The basis of G.'s worldview is the recognition of the objective existence of the world, i.e. its existence outside and independent of human consciousness. The world is infinite, he believed, matter is eternal. In all processes occurring in nature, nothing is destroyed or generated - there is only a change in the relative position of bodies or their parts. Matter consists of absolutely indivisible atoms, its movement is the only universal mechanical movement. The heavenly bodies are similar to the Earth and obey the same laws of mechanics. Everything in nature is subject to strict mechanical causality. G. saw the true purpose of science in finding the causes of phenomena. According to G., knowledge of the inner necessity of phenomena is the highest level of knowledge. G. considered observation as the starting point for the knowledge of nature, and experience as the basis of science. Rejecting the attempts of the scholastics to extract the truth from a comparison of the texts of recognized authorities and through abstract reasoning, G. argued that the scientist’s task is “... to study the great book of nature, which is the real subject of philosophy” (“Dialogue on the two main systems of the world, Ptolemaic and Copernicus”, M.-L., 1948, p. 21). Those who blindly adhere to the opinion of authorities, not wanting to independently study the phenomena of nature, G. called "servile minds", considered them unworthy of the title of philosopher and branded them as "doctors of cramming." However, limited by the conditions of his time, G. was not consistent; he shared the theory of dual truth and allowed for a divine first impulse.
Gifted G. was not limited to the field of science: he was a musician, artist, art lover and a brilliant writer. His scientific treatises, most of which were written in vernacular Italian, although G. was fluent in Latin, can also be classified as works of art in terms of simplicity and clarity of presentation and the brilliance of the literary style. G. translated from Greek into Latin, studied the ancient classics and poets of the Renaissance (the works Notes on Ariosto, Criticism of Tasso), spoke at the Florence Academy on the study of Dante, wrote the burlesque poem Satire on Toga Wearers. G. - co-author of the canzone A. Salvadori "On the stars of the Medici" - satellites of Jupiter, discovered by G. in 1610.

ital. Galileo Galilei

Italian physicist, mechanic, astronomer, philosopher, mathematician

short biography

Galileo Galileo- an outstanding Italian scientist, author of a large number of important astronomical discoveries, founder of experimental physics, creator of the foundations of classical mechanics, a literary gifted person - was born into the family of a famous musician, an impoverished nobleman on February 15, 1564 in Pisa. His full name is Galileo di Vincenzo Bonaiuti de Galilei. Art in its most diverse manifestations interested the young Galileo since childhood, he not only fell in love with painting and music for life, but was also a real master in these areas.

Having been educated in a monastery, Galileo thought about a career as a clergyman, but his father insisted that his son study to be a doctor, and in 1581 the 17-year-old boy began to study medicine at the University of Pisa. During his studies, Galileo showed great interest in mathematics and physics, had his own point of view on many issues, different from the opinion of the luminaries, and was known as a great lover of discussions. Due to the financial difficulties of the family, Galileo did not study for even three years, and in 1585 he was forced to return to Florence without a degree.

In 1586, Galileo published the first scientific work entitled "Small hydrostatic balance". Seeing remarkable potential in the young man, he was taken under his wing by the wealthy Marquis Guidobaldo del Monte, who was interested in science, thanks to whose efforts Galileo received a paid scientific position. In 1589 he returned to the University of Pisa, but already as a professor of mathematics - there he began to work on his own research in the field of mathematics and mechanics. In 1590, his work "On the Movement" was published, which criticized the Aristotelian doctrine.

In 1592, a new, extremely fruitful stage began in the biography of Galileo, associated with his moving to the Venetian Republic and teaching at the University of Padua, a rich educational institution with an excellent reputation. The scientific authority of the scientist grew rapidly, in Padua he quickly became the most famous and popular professor, respected not only by the scientific community, but also by the government.

Galileo's scientific research received a new impetus in connection with the discovery in 1604 of a star known today as Kepler's supernova and the increased general interest in astronomy in connection with this. At the end of 1609, he invented and created the first telescope, with the help of which he made a number of discoveries described in the work The Starry Messenger (1610) - for example, the presence of mountains and craters on the Moon, satellites of Jupiter, etc. The book produced a real sensation and brought Galileo pan-European glory. His personal life was also arranged during this period: a civil marriage with Marina Gamba subsequently gave him three beloved children.

The glory of the great scientist did not save Galileo from material problems, which served as an impetus for moving to Florence in 1610, where, thanks to Duke Cosimo II of Medici, he managed to get a prestigious and well-paid position as a court adviser with easy duties. Galileo keeps doing scientific discoveries, among which were, in particular, the presence of spots on the Sun, its rotation around its axis. The camp of the ill-wishers of the scientist was constantly replenished, not in last turn because of his habit of expressing his views in a harsh, polemical manner, because of his growing influence.

In 1613, the book "Letters on Sunspots" was published with an open defense of the views of Copernicus on the structure of the solar system, which undermined the authority of the church, because. did not coincide with the postulates of the sacred scriptures. In February 1615, the Inquisition initiated a case against Galileo for the first time. Already in March of the same year, heliocentrism was officially declared a dangerous heresy, in connection with which the scientist's book was banned - with the author's warning about the inadmissibility of further support for Copernicanism. Returning to Florence, Galileo changed tactics, making the teachings of Aristotle the main object of his critical mind.

In the spring of 1630, the scientist summarizes many years of work in the "Dialogue on the two main systems of the world - Ptolemaic and Copernican." The book, published by hook or by crook, attracted the attention of the Inquisition, as a result of which, a couple of months later, it was withdrawn from sale, and its author was summoned to Rome on February 13, 1633, where an investigation was conducted on the case of accusing him of heresy until June 21. Faced with a difficult choice, Galileo, in order to avoid the fate of Giordano Bruno, renounced his views and spent the rest of his life under house arrest in his villa near Florence, under the strict control of the Inquisition.

But even in such conditions, he did not stop his scientific activity, although everything that came out of his pen was subject to censorship. In 1638, his work Conversations and Mathematical Proofs, secretly sent to Holland, was published, on the basis of which Huygens and Newton subsequently continued to develop the postulates of mechanics. The last five years of his biography were overshadowed by illness: Galileo worked, being almost blind, with the help of his students.

The greatest scientist, who died on January 8, 1642, was buried as a mere mortal, the Pope did not give permission to erect a monument. In 1737, his ashes were solemnly reburied, according to the dying will of the deceased, in the Basilica of Santa Croce. In 1835, work was completed to remove the works of Galileo from the list of banned literature, initiated by Pope Benedict XIV in 1758, and in October 1992, Pope John Paul II, following the work of a special rehabilitation commission, officially recognized the erroneous actions of the Inquisition regarding Galileo Galilei.

Biography from Wikipedia

Galileo Galilei(Italian Galileo Galilei; February 15, 1564, Pisa - January 8, 1642, Arcetri) - Italian physicist, mechanic, astronomer, philosopher, mathematician, who had a significant impact 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 the speculative metaphysics of Aristotle and laid the foundation for 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.

early years

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 lute player. Full name Galileo Galilei: 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 ruling council) of the Florentine Republic, and the great-great-grandfather of Galileo, a famous doctor who also bore the name Galileo, in 1445 he was elected head of the republic.

The family of Vincenzo Galilei and Giulia Ammannati had six children, but four managed to survive: Galileo (the eldest of the children), the daughters of Virginia, Livia and the youngest son of Michelangelo, who later also gained fame as a lute composer. In 1572 Vincenzo moved to Florence, the capital of the Duchy of Tuscany. The Medici dynasty ruling 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 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. Based on the writings of Galileo, one can also conclude that he had a remarkable literary talent.

Galileo received his primary education at the nearby monastery of Vallombrosa, where he was accepted as a novice into a monastic order. The boy was very fond of learning and became one of the best students in the class. He considered becoming a priest, but his father was against it.

The old building of the University of Pisa (today - the Higher Normal School)

In 1581, the 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 was a student for less than three years; during this time he managed to thoroughly familiarize himself with the writings 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.

Probably during these years he became acquainted with the theory of Copernicus. Astronomical problems were then lively discussed, especially in connection with the just carried out calendar reform.

Soon the father's financial situation worsened, and he was unable to pay for his son's further education. The request to release Galileo from payment (such an exception was made for the most capable students) was rejected. Galileo returned to Florence (1585) without receiving a degree. Fortunately, he managed to attract attention with several ingenious inventions (for example, hydrostatic balances), thanks to which he met the educated and wealthy science lover, the Marquis Guidobaldo del Monte. The Marquis, unlike the Pisan professors, was able to correctly evaluate him. Even then del Monte said that since the time of Archimedes 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 Duke of Tuscany, Ferdinand I de' Medici, and petitioned for a paid scientific position for him.

In 1589 Galileo returned to the University of Pisa, now a professor of mathematics. There he began to independent research in mechanics and mathematics. True, he was given a minimum salary: 60 skudos a year (a professor of medicine received 2,000 skudos). In 1590, Galileo wrote a treatise On Motion.

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

In 1592, Galileo received a position at the prestigious and wealthy University of Padua (Republic of Venice), where he taught astronomy, mechanics, and mathematics. According to the letter of recommendation from the Doge of Venice to the university, one can judge that the scientific authority of Galileo was already extremely high in these years:

Realizing the importance of mathematical knowledge and its usefulness for other major sciences, we hesitated with the appointment, not finding a worthy candidate. Signor Galileo, a former professor at Pisa, who is very famous and rightly recognized as the most knowledgeable in the mathematical sciences, has now declared a desire to take this place. Therefore, we gladly give him the chair of mathematics for four years with a salary of 180 florins a year.

Padua, 1592-1610

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

During these years he wrote the treatise Mechanics, which aroused some interest and was republished in a French translation. In early writings, as well as in correspondence, Galileo gave the first draft of a new general theory of the fall of bodies and the motion of a pendulum. In 1604, Galileo received a denunciation to the Inquisition - he was accused of practicing astrology and reading forbidden literature. The Padua inquisitor Cesare Lippi, who sympathized with Galileo, left the denunciation without consequences.

The reason for a new stage in the scientific research of Galileo was the appearance in 1604 of a new star, now called Kepler's Supernova. This awakens a general interest in astronomy, and Galileo delivers a series of private lectures. Having learned about the invention of the telescope in Holland, Galileo in 1609 constructs the first telescope with his own hands and directs it to 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 an illusion. Galileo discovered mountains on the Moon, the Milky Way broke up into separate stars, but the four satellites of Jupiter discovered by him (1610) were especially striking to his contemporaries. 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 are more appropriately called "Galilean satellites", the modern names of the satellites were proposed by Simon Marius in the treatise "The World of Jupiter" (lat. Mundus Iovialis, 1614).

Galileo described his first discoveries with a telescope in the Starry Herald (lat. Sidereus Nuncius), published in Florence in 1610. The book was a sensational success throughout Europe, even the crowned persons were in a hurry to order a telescope. Galileo presented several telescopes to the Venetian Senate, which, in gratitude, appointed him professor for life with a salary of 1,000 florins. In September 1610, Kepler acquired a telescope, and in December, Galileo's discovery was confirmed by the influential Roman astronomer Clavius. There is general acceptance. Galileo becomes the most famous scientist in Europe, odes are composed in his honor, where he is compared with Columbus. The French king Henry IV on April 20, 1610, shortly before his death, asked Galileo to open some star for him. However, there were also those who were dissatisfied. Astronomer Francesco Sizzi (Italian Sizzi) published a pamphlet where 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. The discoveries of Galileo were declared illusory by the Padua professor Cesare Cremonini, and the Czech astronomer Martin Horki ( Martin Horky) told Kepler that the Bolognese scientists did not trust the telescope: “On the ground it works amazingly; deceives in heaven, for some single stars appear to be double. Astrologers and doctors also protested, complaining that the appearance of new celestial bodies "is fatal to 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 di Andrea Gamba, 1570-1612). 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, in honor of his sisters, Virginia and Livia. Later, in 1619, Galileo officially legitimized his son; both daughters ended their lives in the monastery.

Pan-European fame and the need for money pushed Galileo to a disastrous step, as it turned out later: in 1610 he left quiet Venice, where he was inaccessible to the Inquisition, and moved to Florence. Duke Cosimo II of Medici, son of Ferdinand I, promised Galileo an honorary 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.

Florence, 1610-1632

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 discovers the phases of Venus, spots on the Sun, and then the rotation of the Sun around its axis. Galileo often set out his achievements (as well as his priority) in a cocky-polemical style, which made him many new enemies (in particular, among the Jesuits).

Defense of Copernicanism

The growth of Galileo's influence, 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 104:5), a verse from Ecclesiastes (Ecclesiastes 1:5), as well as an episode from the Book of Joshua ( Joshua 10:12), which refers to the immobility of the Earth and the movement of the Sun. In addition, a detailed substantiation of the concept of the Earth's immobility and refutation of the hypotheses about its rotation was contained in Aristotle's treatise "On the Sky" and in Ptolemy's "Almagest".

In 1611, Galileo, in the halo of his glory, decided to go to Rome, hoping to convince the Pope that Copernicanism was quite compatible with Catholicism. He was well received, elected the sixth member of the scientific "Academia dei Lincei", met Pope Paul V, influential cardinals. I showed them my telescope, gave explanations carefully and prudently. The cardinals created a whole commission to find out whether it was a sin to look at the sky through a trumpet, but they came to the conclusion that it was permissible. It was also encouraging that Roman astronomers openly discussed the question of whether Venus moves around the Earth or around the Sun (the change in the phases of Venus clearly spoke in favor of the second option).

Emboldened, Galileo, in a letter to his student Abbot Castelli (1613), stated that the Holy Scripture refers 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 has.” Moreover, he published this letter, which caused the appearance of denunciations to the Inquisition. In the same 1613, Galileo published the book Letters on Sunspots, in which he openly spoke in favor of the Copernican system. On February 25, 1615, the Roman Inquisition opened its first case against Galileo on charges of heresy. The last mistake of Galileo was the call to Rome to express its final attitude towards Copernicanism (1615).

All this caused a reaction that was the opposite of what was expected. Alarmed by the success 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 Inquisitor Bellarmino, sent on April 12, 1615, to the theologian Paolo Antonio Foscarini, a defender of Copernicanism. In this letter, the cardinal explained 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. And this, in turn, will shake the authority of the church:

Firstly, it seems to me that your priesthood and Mr. Galileo act wisely, being content with what they say presumably, and not absolutely; I always assumed that Copernicus said the same thing. Because if one says that the assumption of the motion of the Earth and the immobility of the Sun allows one to represent all phenomena better than the assumption of eccentrics and epicycles, then this will be said beautifully and does not entail any danger. For a mathematician, this is quite enough. But to assert that the Sun is in fact the center of the world and revolves only around itself, without moving from east to west, that the Earth stands in the third heaven and revolves around the Sun with great speed, is very dangerous to assert, not only because it means to excite irritation of all philosophers and scholastic theologians; it would be to harm the holy faith by presenting the provisions of Holy Scripture as false...

Secondly, as you know, the Council of Trent forbade the interpretation of Holy Scripture contrary to the general opinion of the Holy Fathers. And if your priesthood wants to read not only the Holy Fathers, but also new commentaries on the book of Exodus, Psalms, Ecclesiastes and the book of Jesus, then you will find that everyone agrees that this must be taken literally - that the Sun is in the sky and rotates around the Earth with great speed, and the Earth is the most distant from the sky and stands motionless in the center of the world. Judge for yourselves, with all your prudence, whether the Church can allow Scripture to be given a meaning contrary to everything that the Holy Fathers and all Greek and Latin interpreters wrote?

On February 24, 1616, eleven qualifiers (experts of the Inquisition) officially identified 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 at the center of the world, that it does not remain motionless and even has a daily rotation, is an opinion that is equally absurd, false from a philosophical point of view and sinful from a religious point of view.

On March 5, Pope Paul V approved this decision. It should be noted that the expression "formally heretical" in the text of the conclusion meant that this opinion contradicted the most important, fundamental provisions of the Catholic faith. On the same day, the Pope approved the decree of the congregation, which included the book of Copernicus in the Index of Forbidden Books "until it is corrected." At the same time, the works of Foscarini and several other Copernicans got into the Index. The Letters on Sunspots and other books by Galileo that defended heliocentrism were not mentioned. The decree prescribed:

... So that from now on no one, whatever his rank and whatever his position, dares to print them or contribute to the printing, keep them or read them, and everyone who has or will continue to have them, is charged with the obligation immediately upon publication of this decree to submit them to local authorities or inquisitors.

All this time (from December 1615 to March 1616) Galileo spent in Rome, unsuccessfully trying to turn things around. On February 26, on behalf of the Pope, Bellarmino summoned him and assured him that nothing threatened him personally, but henceforth all support for the "Copernican heresy" should be stopped. As a sign of reconciliation, on March 11, Galileo was honored with a 45-minute walk with the Pope.

The church ban on heliocentrism, in the truth of which Galileo was convinced, was unacceptable to the scientist. He returned to Florence and began to think about how, without formally violating the ban, to continue the defense of the truth. In the end, he 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.

Creation of new mechanics

After the fateful decree of 1616, Galileo changed the direction of the struggle for several years - now he focuses his efforts mainly on the criticism of 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, however, did not prevent Galileo from expounding and wittily arguing his scientific method, out of 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 traveled to Rome, hoping to get the edict of 1616 repealed. He was received with all honors, awarded with gifts and flattering words, but achieved nothing on the main issue. The edict was rescinded only two centuries later, in 1818. Urban VIII especially praised the book "The Assayer" and forbade the Jesuits to continue polemics with Galileo.

In 1624 Galileo published Letters to Ingoli; it is a response to an anti-Copernican treatise by theologian Francesco Ingoli. Galileo immediately stipulates that he is not going to defend Copernicanism, but only wants to show that he has solid scientific foundations. He used this technique later in his main book, Dialogue Concerning the Two Systems of the World; part of the text of the "Letters to Ingoli" was simply transferred to the "Dialogue". In his consideration, Galileo equates the stars to the Sun, points to the colossal distance to them, and speaks of the infinity of the Universe. He even allowed himself a dangerous phrase: “If any point of the world can be called its [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 that are on them.

But the main scientific value of this work is the laying of the foundations of a new, non-Aristotelian mechanics, deployed 12 years later in Galileo's last work, Conversations and Mathematical Proofs of Two New Sciences. Already in the Letters to Ingoli, Galileo clearly formulates the principle of relativity for uniform motion:

The results of the shooting will always be the same, no matter which country of the world it is directed to ... this will happen because it should also turn out whether the Earth is in motion or standing still ... Give the ship movement, and moreover, at any speed; then (if only its movement is uniform, and not oscillating back and forth) you will not notice the slightest difference [in what happens].

In modern terminology, Galileo proclaimed the homogeneity of space (the absence of the center of the world) and the equality of inertial frames of reference. An important anti-Aristotelian point should be noted: Galileo's argument 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 to replace his objections to Copernicanism with others more appropriate to 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 warm relations with the scientist, was proud of him and helped in every possible way.

Valuable information about the life of Galileo is contained in the surviving correspondence between Galileo and his eldest daughter Virginia, who in monasticism took the name Maria Celesta. She lived in a Franciscan monastery in Arcetri, near Florence. The monastery, as it should be with the Franciscans, was poor, the father often sent food and flowers to his daughter, in return the daughter made jam for him, mended his clothes, copied documents. Only letters from Mary Celeste have survived - letters from Galileo, most likely, the monastery destroyed after the process of 1633. The second daughter, Livia, in the monasticism of Archangel, lived in the same monastery, but was often ill and did not take part in correspondence.

In 1629, Vincenzo, the 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, Vincenzo and his family leave. Galileo considers a plan to move to Arcetri, closer to his beloved daughter; this plan was realized in September 1631.

Conflict with the Catholic Church

In March 1630, the book "Dialogue on the two main 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, papal censor Riccardi . For almost a year, he waits for his decision, then decides to go for a trick. He adds a preface to the book, where he declares his goal to debunk Copernicanism and gives the book to Tuscan censorship, and, according to some sources, in an incomplete and softened form. Having received a positive response, he forwards it to Rome. In the summer of 1631, he receives a long-awaited permit.

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 participant in the Sagredo and Simplicio, the adherent of Aristotle and Ptolemy. Although there are no authorial conclusions in the book, 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.

Pope Urban VIII. Portrait by Giovanni Lorenzo Bernini, circa 1625

Galileo hoped that the Pope would treat his trick as condescendingly as he had previously treated his Letters to Ingoli, similar in ideas, but he miscalculated. To top it off, he himself recklessly mails 30 copies of his book to influential clerics 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, preferred not to intervene.

Most biographers agree that in the simpleton Simplicio, the Pope recognized himself, his arguments, and was furious. Historians note such character traits Urbana, 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 the book of Galileo. A few months later, the book was banned and withdrawn from sale, and Galileo was summoned to Rome (despite the plague epidemic) to be judged by the Inquisition on suspicion of heresy. After unsuccessful attempts to obtain a reprieve due to ill health and the ongoing plague (Urban threatened to deliver him by force in shackles), Galileo complied, wrote a will, served the 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 dragged on from April 21 to June 21, 1633.

Galileo before the court of the Inquisition Joseph Nicolas Robert Fleury, 1847, Louvre

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 indulgence was probably caused by Galileo's consent to repent, as well as the influence of the Tuscan duke, who was constantly fussing about mitigating 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 investigated whether Galileo was subjected to torture during his imprisonment. The documents of the trial have not been published in full by the Vatican, and what has been published may have undergone preliminary editing. Nevertheless, the following words were found in the verdict of the Inquisition:

Noticing that you do not honestly confess your intentions in your answers, we considered it necessary to resort to a strict test.

Galileo's sentence (lat.)

Galileo in prison Jean Antoine Laurent

After the “test”, Galileo, in a letter from prison (April 23), carefully reports that he does not get out of bed, as he is tormented by “terrible pain in his thigh”. Some biographers of Galileo suggest that torture really took place, while others consider this assumption unproven, only the threat of torture, often accompanied by an imitation of the torture itself, is documented. In any case, if there was torture, it was on a moderate scale, since already 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. There were two main questions: did Galileo deliberately violate the edict of 1616, and whether he repented of his deed. Three experts of the Inquisition gave a conclusion: the book violates the ban on the promotion of 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 fate of Giordano Bruno.

Having familiarized himself with the whole course of the case and having listened to the evidence, His Holiness determined that Galileo be interrogated under threat of torture and, if he resisted, then after a preliminary renunciation as strongly suspected of heresy ... sentenced to imprisonment at the discretion of the Holy Congregation. He is ordered not to talk more in writing or orally in any way about the movement of the Earth and the immobility of the Sun ... under pain of punishment as irreparable.

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

As a result of consideration of your guilt and your consciousness in it, we condemn and declare you, Galileo, for all of the above and confessed by you under strong suspicion at this Holy Judgment Seat of heresy, as being possessed by a false and contrary to Sacred and Divine Scripture thought that the Sun is the center of the earth's 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 a disobedient church authority, which forbade you to expound, defend and pass off as a probable teaching, recognized as false and contrary to Holy Scripture ... So that such a grave and harmful sin and disobedience of yours would not be left without any recompense and you would not subsequently become even more daring, but , on the contrary, would serve as an example and a warning to others, we decided to ban the book entitled "Dialogue" by Galileo Galilei, and imprison you yourself at the Holy Judgment Seat for an indefinite time.

Galileo was sentenced to imprisonment for a term set by the Pope. He was declared not a heretic, but "strongly suspected of heresy"; such a wording was also a grave accusation, but saved from the fire. After the announcement of the verdict, 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.

Galileo Galilei, around 1630 Peter Paul Rubens

Last years

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 the constant supervision of the Inquisition.

The detention regime for Galileo did not differ from the prison regime, and he was constantly threatened with transfer to prison for the slightest violation of the regime. Galileo was not allowed to visit cities, although a seriously ill prisoner needed constant medical supervision. In the early years, he was forbidden to receive guests under pain of transfer to prison; subsequently, the regime was somewhat relaxed, and friends were able to visit Galileo - however, no more than one at a time.

The Inquisition followed the captive 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 especially careful censorship. Note that in Protestant Holland the publication of the Dialogue continued (first publication: 1635, translated into Latin).

In 1634, the 33-year-old eldest daughter Virginia (in monasticism Maria Celesta), Galileo's favorite, who devotedly looked after her sick father and acutely 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 has deteriorated, but he continues to work vigorously in the areas of science allowed for him.

A letter from Galileo to his friend Elia Diodati (1634) has been preserved, where he shares news of his misadventures, points to their perpetrators (Jesuits) and shares plans for future research. The letter was sent through a confidant, and Galileo is quite frank in it:

In Rome, I was sentenced by the Holy Inquisition to imprisonment at the direction of His Holiness ... the place of imprisonment for me was this small town one mile from Florence, with the strictest prohibition to go down to the city, meet and talk with friends and invite them ...
When I returned from the monastery with a 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 came to order me, by order of the Holy Inquisition in Rome ... that I should not apply for permission to return to Florence, otherwise they would put me in a real prison of the Holy Inquisition ...
This incident, and others that it would take too long to write about, shows that the fury of my very powerful persecutors is constantly increasing. And in the end they wanted to reveal their faces: when one of my dear friends in Rome, about two months old, in a conversation with Padre Christopher Greenberg, a Jesuit, a mathematician of this college, touched on my affairs, this Jesuit said to my friend literally the following: “ If Galileo had managed to keep 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 write at his own discretion about anything - even about the movement of the Earth, etc. So, You see that I was attacked not because of this or that opinion of mine, but because I am in disfavour with the Jesuits.

At the end of the letter, Galileo ridicules the ignoramuses who "declare the mobility of the Earth a heresy" and announces 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 carry out only the second - he wrote a book on mechanics, summing up his earlier discoveries in this area.

Soon after the death of his daughter, Galileo completely lost his sight, but continued his scientific research, relying on faithful students: Castelli, Torricelli and Viviani (the author of the first biography of Galileo). In a letter on January 30, 1638, Galileo stated:

I do not stop, even in the darkness that has enveloped me, to build reasoning about one or another natural phenomenon, and I could not rest my restless mind, even if I wanted to.

Galileo's last book was Conversations and Mathematical Proofs of Two New Sciences, which outlines the basics of kinematics and strength of materials. In fact, the content of the book is a debacle of Aristotelian dynamics; in return, Galileo puts forward his principles of motion, proven by experience. Defying the Inquisition, Galileo brought out in the 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 a friend, the Comte de Noel (to whom he dedicated this book), Galileo declared that the new work “puts me back in the ranks of the fighters.” "Conversations ..." was published in July 1638, and the book came to 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 edition of "Conversations ...", the permission was canceled, and the scientist was ordered to return to Arcetri. Galileo was going to continue "Conversations ...", 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 the burial of Galileo in the family crypt of the Basilica of Santa Croce in Florence. They buried him in Archetri without honors, the Pope also did not allow him to erect a monument.

The youngest daughter, Livia, died in the convent. Later, the only grandson of Galileo also took the monastic vows and burned the priceless manuscripts of the scientist that he kept as ungodly. He was the last representative of the Galilean family.

In 1737, the ashes of Galileo, 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 struck out of the Index of Forbidden Books; however, this work was carried out slowly and was completed only in 1835.

From 1979 to 1981, at the initiative of Pope John Paul II, a commission for the rehabilitation of Galileo worked, and on October 31, 1992, Pope John Paul II officially recognized that the Inquisition had made a mistake in 1633, forcing the scientist to renounce the theory of Copernicus by force.

Scientific achievements

Galileo is rightfully considered the founder of not only experimental, but - to a large extent - theoretical physics. In his scientific method, he consciously combined thoughtful experiment with its rational reflection and generalization, and personally gave impressive examples of such studies. Sometimes, due to a lack of scientific data, Galileo was wrong (for example, in questions about the shape of planetary orbits, the nature of comets, or the causes of tides), but in the overwhelming majority of cases, his method led to the goal. Characteristically, Kepler, who had more complete and accurate data than Galileo, drew correct conclusions when Galileo was wrong.

Philosophy and scientific method

Although in ancient greece there were remarkable engineers (Archimedes, Heron and others), the very idea of ​​an experimental method of cognition, which should complement and confirm deductive-speculative constructions, was alien to the aristocratic spirit of ancient physics. In Europe, back in the 13th century, Robert Grosseteste and Roger Bacon called for the creation of an experimental science that could describe natural phenomena in mathematical language, but before Galileo there was no significant progress in implementing this idea: scientific methods differed little from theological ones, and answers to scientific questions still looked for in the books of ancient authorities. The scientific revolution in physics begins with Galileo.

With regard to the philosophy of nature, Galileo was a staunch rationalist. Galileo noted that the human mind, no matter how far it goes, will always embrace only an infinitesimal part of the truth. But at the same time, according to the level of reliability, the mind is quite capable of comprehending the laws of nature. In Dialogue Concerning the Two Systems of the World, he wrote:

Extensively, in relation to the set of cognizable objects, and this set is infinite, the knowledge of a person is, as it were, nothing, although he knows thousands of truths, since a thousand, compared with infinity, is, as it were, zero; but if knowledge is taken intensively, since the term "intensive" means the knowledge of some truth, then I maintain that the human mind knows certain truths as perfectly and with such absolute certainty as nature itself has; such are the pure mathematical sciences, geometry and arithmetic; although the Divine mind knows infinitely more truths in them ... but in those few that the human mind has comprehended, I think that its knowledge is equal in objective certainty to the Divine, for it comes to an understanding of their necessity, and the highest degree of certainty does not exist.

The mind of Galileo is its own judge; in case of conflict with any other authority, even religious, he must not yield:

It seems to me that when discussing natural problems, we should start not from the authority of the texts of Holy Scripture, but from sensory experiences and the necessary evidence ... I believe that everything related to the actions of nature, which is accessible to our eyes or can be understood by logical evidence, should not excite doubts, much less be condemned on the basis of the texts of Holy Scripture, perhaps even misunderstood.
God is no less revealed to us in the phenomena of nature than in the sayings of the Holy Scriptures... It would be dangerous to attribute to the Holy Scriptures any judgment, at least once challenged by experience.

Ancient and medieval philosophers offered various "metaphysical entities" (substances) to explain natural phenomena, to which far-fetched properties were attributed. Galileo did not like this approach:

I consider the search for essence to be a vain and impossible occupation, and the efforts expended are equally futile both in the case of distant celestial substances, and with the nearest and elementary ones; and it seems to me that both the substance of the Moon and the Earth, both sunspots and ordinary clouds are equally unknown ... [But] if it is in vain to look for the substance of sunspots, this does not mean that we cannot investigate some of their characteristics, for example, place, movement, form, size, opacity, ability to change, their formation and disappearance.

Descartes rejected such a position (in his physics, the main attention was paid precisely to finding the “main causes”), however, starting from Newton, the Galilean approach becomes predominant.

Galileo is considered one of the founders of mechanism. This scientific approach considers 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 is at the heart of Galileo's work. He wrote in The Assay Master:

I will never demand from external bodies anything other than size, figure, quantity, and more or less rapid movements in order to explain the occurrence of sensations of taste, smell and sound; I think that if we eliminated ears, tongues, noses, then only figures, numbers, movements would remain, but not smells, tastes and sounds, which, in my opinion, outside a living being are nothing but empty names .

To design an experiment and to comprehend its results, some preliminary theoretical model of the phenomenon under study is needed, and Galileo considered mathematics to be its basis, the conclusions of which he considered as the most reliable knowledge: the book of nature is “written in the language of mathematics”; “He who wants to solve the problems of the natural sciences without the help of mathematics poses an unsolvable problem. Measure what is measurable and make measurable what is not.

Galileo considered the experience not as a simple observation, but as a meaningful and thoughtful question posed to nature. He also allowed thought experiments, if their results are not in doubt. At the same time, he clearly understood that experience in itself does not give reliable knowledge, and the answer received from nature must be analyzed, the result of which can lead to a reworking of the original model or even to replacing it with another one. Thus, an effective way of cognition, according to Galileo, consists in a combination of synthetic (in his terminology, composite method) and analytical ( resolutive method), sensual and abstract. This position, supported by Descartes, has been established in science since that moment. Thus, science received its own method, its own criterion of truth and a secular character.

Mechanics

Physics and mechanics in those years were studied according to the writings of Aristotle, which contained metaphysical reasoning about the "original causes" of natural processes. In particular, Aristotle stated:

• The rate of fall is proportional to the weight of the body.
• Movement occurs while the "motivating cause" (force) is in effect, and in the absence of force it stops.

While at the University of Padua, Galileo studied inertia and the free fall of bodies. In particular, he noticed that the acceleration of free fall does not depend on the weight of the body, thus disproving Aristotle's first statement.

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

Galileo proved that the indicated body, as well as any body thrown at an angle to the horizon, flies along a parabola. In the history of science, this is the first solved problem of dynamics. In conclusion of the study, Galileo proved that the maximum flight range of a thrown body is achieved for a throw angle of 45 ° (this assumption was previously 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 the above laws of Aristotle, formulating the first law of mechanics (the law of inertia): in the absence of external forces, the body either rests or moves uniformly. What we call inertia, Galileo poetically called "indestructibly imprinted movement." 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 Descartes and Newton; 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 after him. In the Dialogue Concerning the Two Systems of the World, Galileo formulated the principle of relativity as follows:

For objects caught in a uniform motion, this latter, as it were, does not exist and manifests its effect only on things that do not take part in it.

Explaining the principle of relativity, Galileo puts into the mouth of Salviati a detailed and colorful (very typical for the style of scientific prose of the great Italian) description of an imaginary "experiment" carried out in the hold of a ship:

… Stock up on flies, butterflies and other similar small flying insects; let you have there also a large vessel with water and small fish swimming in it; hang, further, a pail at the top, from which water will fall drop by drop into another vessel with a narrow neck, substituted below. While the ship is stationary, observe diligently how small flying animals move with the same speed in all directions of the room; fish, as you will see, will swim indifferently in all directions; all falling drops will fall into the substituted vessel ... Now make the ship move at low speed and then (if only the movement is uniform and without rolling in one direction or the other) in all the phenomena named you will not find the slightest change and in none of them will you be able to determine whether the ship is moving or standing still.

Strictly speaking, Galileo's ship does not move in a straight line, but along an arc of a great circle of the surface of the globe. Within the framework of the modern understanding of the principle of relativity, the frame of reference associated with this ship will be only approximately inertial, so it is still possible to reveal the fact of its movement without referring to external landmarks (although measuring instruments suitable for this appeared only in the 20th century ...) .

The discoveries of Galileo listed above, among other things, allowed him to refute many arguments of the 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 leave from under this body, shifting by tens or even hundreds of meters. Galileo confidently predicted: “Any experiments that should indicate more than against, how behind rotation of the earth.

Galileo published a study of the oscillations of a pendulum and stated that the period of oscillations does not depend on their amplitude (this is approximately true for small amplitudes). He also found that the periods of a pendulum are related as the square roots of its length. Galileo's results attracted the attention of Huygens, who used the pendulum regulator (1657) to improve the escapement of clocks; from that moment on, it became possible to make accurate measurements in experimental physics.

For the first time in the history of science, Galileo raised the question of the strength of rods and beams in bending, and thus 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 on 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 the gravitational field. Similarly, he explains the (theoretically undamped) swings of the pendulum.

In statics, Galileo introduced the fundamental concept moment of force(ital. momento).

Astronomy

In 1609, Galileo independently built his first telescope with a convex lens and a concave eyepiece. The tube gave approximately a threefold increase. Soon he managed to build a telescope giving a magnification of 32 times. Note that the term telescope it was Galileo who introduced science 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 relief - covered with mountains and craters. Galileo explained the ashen light of the moon, known since ancient times, as the 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 the same nature as the heavenly 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 moving. Galileo also discovered the libration of the moon and fairly accurately estimated the height of the lunar mountains.

Jupiter has its own moons - four satellites. Thus, Galileo refuted one of the arguments of the opponents of heliocentrism: the Earth cannot revolve around the Sun, since the Moon revolves around it. After all, Jupiter obviously had to revolve either around the Earth (as in the geocentric system) or around the Sun (as in the heliocentric system). A year and a half of observations allowed Galileo to estimate the orbital period of these satellites (1612), although an acceptable accuracy of the estimate was achieved only in Newton's epoch. Galileo suggested using observations of the eclipses of Jupiter's satellites to solve the most important problem of determining longitude at sea. He himself was unable to develop an implementation of this approach, although he worked on it until the end of his life; Cassini (1681) was the first to succeed, but due to the difficulties of observing at sea, Galileo's method was used mainly by land expeditions, and after the invention of the marine chronometer (mid-18th century), the problem was closed.

Galileo also discovered (independently of Johann Fabricius and Harriot) sunspots. The existence of spots and their constant variability disproved Aristotle's thesis about the perfection of the heavens (as opposed to the "sublunar 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 found that Venus changes phases. On the one hand, this proved that it shines with the reflected light of the Sun (about which there was no clarity in the astronomy of the previous period). On the other hand, the order of phase change 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 opening of the ring was prevented by the weakness of the telescope and the rotation of the ring, which hid it from the earthly observer. Half a century later, the ring of Saturn was discovered and described by Huygens, who had at his disposal a 92-fold telescope.

Historians of science have discovered that on December 28, 1612, Galileo observed the then-undiscovered planet Neptune and sketched its position among the stars, and on January 29, 1613, observed it in conjunction with Jupiter. However, Galileo did not identify Neptune as a planet.

Galileo showed that when viewed through a telescope, the planets are seen as disks, the apparent dimensions of which in various configurations change in such a ratio as follows from the theory of Copernicus. However, the diameter of the stars during observations with a telescope does not increase. This disproved the estimates of the apparent and real size of the stars, which were used by some astronomers as an argument against the heliocentric system.

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

In the Dialogue on Two Systems of the World, Galileo explained in detail (through the character of Salviati) why he prefers the system of Copernicus over Ptolemy:

• Venus and Mercury never find themselves in opposition, that is, in the side of the sky opposite the Sun. This means that they revolve around the Sun, and their orbit passes between the Sun and the Earth.
• Mars has opposition. In addition, Galileo did not reveal phases in Mars that are noticeably different from the total illumination of the visible disk. From here and from the analysis of changes in brightness during the movement of Mars, Galileo concluded that this planet also revolves around the Sun, but in this case the Earth is located inside its orbits. He made similar conclusions for Jupiter and Saturn.

Thus, it remains to choose between two systems of the world: the Sun (with planets) revolves around the Earth or the Earth revolves around the Sun. The observed picture of the motions of the planets in both cases is the same, this is guaranteed by the principle of relativity, formulated by Galileo himself. Therefore, for the choice, additional arguments are needed, among which Galileo cites greater simplicity and naturalness of the Copernican model.

Being an ardent supporter of Copernicus, Galileo, however, rejected Kepler's system with elliptical planetary orbits. Note that it was Kepler's laws, together with Galileo's dynamics, that led Newton to the law gravity. Galileo was not yet aware of the idea of ​​the force interaction of celestial bodies, considering the movement of the planets around the Sun as if their natural property; in this he involuntarily found himself closer to Aristotle than perhaps he wanted.

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 motion" of the Earth. Galileo showed by experience that the axis of a freely moving top retains its direction by itself (“Letters to Ingoli”):

A similar phenomenon is evidently found in every body in a freely suspended state, as I have shown to many; yes, and you yourself can verify this by placing a floating wooden ball in a vessel with water, which you will take in your hands, and then, stretching them out, begin to rotate around yourself; you will see how this ball will rotate around itself in the opposite direction to your rotation; it will complete its full rotation at the same time as you complete yours.

However, Galileo made a serious mistake, believing that the phenomenon of tides proves the rotation of the Earth around its axis. However, he gives other serious arguments in favor of the daily rotation of the Earth:

• It is difficult to agree that the entire Universe makes a daily revolution around the Earth (especially given the enormous distances to the stars); it is more natural to explain the observed picture by the rotation of one Earth. The synchronous participation of the planets in the daily rotation would also violate the observed pattern, according to which the farther the planet is from the Sun, the slower it moves.
• Even the huge Sun has axial rotation.

Galileo describes here a thought experiment that could prove the rotation of the Earth: a cannon projectile or a falling body deviates slightly from the vertical during the fall; however, his calculation shows that this deviation is negligible. He made the correct observation that the rotation of the Earth should affect the dynamics of the winds. All these effects were discovered much later.

Mathematics

Probability theory includes his research on outcomes when throwing dice. His Discourse on Dice (Considerazione sopra il giuoco dei dadi, date unknown, published 1718) provides a fairly complete analysis of this problem.

In Conversations on Two New Sciences, he formulated the "Galilean paradox": there are as many natural numbers as 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 ended with the creation of set theory.

Other achievements

Galileo invented:

• Hydrostatic balance for determining specific gravity solids. Galileo described their construction in a treatise "La Bilancetta" (1586).
• The first thermometer, still without a scale (1592).
• Proportional compass used in drafting (1606).
• Microscope, poor quality (1612); with it, Galileo studied insects.

-- Some of Galileo's Inventions --

Telescope of Galileo (modern copy)

Galileo's thermometer (modern copy)

proportional compass

"Lens of Galileo", Museum of Galileo (Florence)

He also dealt with optics, acoustics, the theory of color and magnetism, hydrostatics, strength of materials, problems of fortification. He conducted an experiment to measure the speed of light, which he considered finite (without success). He was the first to experimentally measure the density of air, which Aristotle considered equal to 1/10 of the density of water; Galileo's experiment gave a value of 1/400, which is much closer to the true value (about 1/770). Clearly formulated the law of indestructibility of matter.

Students

Galileo's students included:

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

Memory

Named after Galileo:

• The "Galilean satellites" of Jupiter discovered by him.
• Impact crater on the Moon (-63º, +10º).
• Crater on Mars (6º N, 27º W)
• A 3200 km diameter region on Ganymede.
• Asteroid (697) Galilee.
• The principle of relativity and the transformation of coordinates in classical mechanics.
• NASA's Galileo space probe (1989-2003).
• European project "Galileo" satellite navigation system.
• Unit of acceleration "Gal" (Gal) in the cgs system, equal to 1 cm / s².
• Scientific entertainment and educational TV program Galileo shown in several countries. In Russia, it has been running since 2007 on STS.
• Airport in Pisa.

To commemorate the 400th anniversary of Galileo's first observations, the UN General Assembly declared 2009 the Year of Astronomy.

Personality scores

Lagrange assessed Galileo's contribution to theoretical physics as follows:

Exceptional fortitude was required to extract the laws of nature from concrete phenomena that were always before everyone's eyes, but whose explanation nevertheless eluded the inquisitive gaze of philosophers.

Einstein called Galileo "the father of modern science" and gave him the following characterization:

Before us appears a man of extraordinary will, intelligence and courage, capable of standing up as a representative of rational thinking against those who, relying on the ignorance of the people and the idleness of teachers in church vestments and university robes, are trying to strengthen and protect their position. An extraordinary literary talent allows him to address the educated people of his time in such a clear and expressive language that he manages to overcome the anthropocentric and mythical thinking of his contemporaries and restore to them the objective and causal perception of the cosmos, lost with the decline of Greek culture.

The eminent physicist Stephen Hawking, born on the 300th anniversary of Galileo's death, wrote:

Galileo, perhaps more than any other individual, is responsible for the birth of modern science. The famous controversy with the Catholic Church was central to Galileo's philosophy, for he was one of the first to declare that man has the hope of understanding how the world works, and, moreover, that this can be achieved by observing our real world.
Remaining a devoted Catholic, Galileo did not waver in his belief in the independence of science. Four years before his death, in 1642, while still under house arrest, he secretly sent the manuscript of his second major book, Two New Sciences, to a Dutch publishing house. It was this work, more than his support for Copernicus, that gave birth to modern science.

In literature and art

• Bertolt Brecht. Life of Galileo. Play. - In the book: Bertolt Brecht. Theater. Plays. Articles. Statements. In five volumes. - M.: Art, 1963. - T. 2.
• Liliana Cavani (director) Galileo (movie) (English) (1968). Retrieved March 2, 2009. Archived from the original on August 13, 2011.
• Joseph Losey (director) Galileo (film adaptation of Brecht's play) (English) (1975). Retrieved March 2, 2009. Archived from the original on August 13, 2011.
• Philip Glass(composer), opera Galileo.

On bonds and postage stamps

Italy, banknote 2000 lire,
1973

USSR, 1964

Ukraine, 2009

Kazakhstan, 2009

On coins

In 2005, the Republic of San Marino issued a commemorative €2 coin to celebrate the World Year of Physics.

San Marino, 2005

Myths and alternative versions

Date of death of Galileo and date of birth of Newton

Some popular books claim that Isaac Newton was born exactly on the day of Galileo's death, as if taking over the scientific baton from him. This statement is the result of an erroneous confusion of two different calendars - the Gregorian in Italy and the Julian, which was in force in England until 1752. Based on the modern Gregorian calendar, Galileo died on January 8, 1642, and Newton was born almost a year later, on January 4, 1643.

"And yet she turns"

There is a well-known legend according to which, after an ostentatious renunciation, Galileo said: “And yet it is spinning!” However, there is no evidence for this. As historians have discovered, this myth was put into circulation in 1757 by the journalist Giuseppe Baretti and became widely known in 1761 after the translation of Baretti's book into French.

Galileo and the Leaning Tower of Pisa

According to the biography of Galileo, written by his student and secretary Vincenzo Viviani, Galileo, in the presence of other teachers, simultaneously dropped bodies of different masses from the top of the Leaning Tower of Pisa. The description of this famous experience was included in many books, but in the 20th century a number of authors came to the conclusion that this was a legend, based primarily on the fact that Galileo himself did not claim in his books that he had conducted this public experiment. Some historians, however, are inclined to believe that this experiment really took place.

It is documented that Galileo measured the time of the balls' descent down an inclined plane (1609). It should be taken into account that there were no accurate clocks at that time (Galileo used an imperfect water clock and his own pulse to measure time), so rolling balls was more convenient for measurements than falling. At the same time, Galileo checked that the laws of rolling obtained by him are qualitatively independent of the angle of inclination of the plane, and, therefore, they can be extended to the case of a fall.

The principle of relativity and the movement of the Sun around the Earth

IN late XIX century, the Newtonian concept of absolute space was subjected to annihilating criticism, and at the beginning of the 20th century, Henri Poincaré and Albert Einstein proclaimed the universal principle of relativity: it makes no sense to say that a body is at rest or moves, unless it is additionally clarified with respect to what it is at rest or moves. In substantiating this fundamental proposition, both authors used polemically sharp formulations. So, Poincare in the book "Science and Hypothesis" (1900) wrote that the statement "The Earth rotates" does not make any sense, and Einstein and Infeld in the book "The Evolution of Physics" indicated that the systems of Ptolemy and Copernicus are just two different agreements about coordinate systems, and their struggle is meaningless.

In connection with these new views, the mass press repeatedly discussed the question: was Galileo right in his persistent struggle? For example, in 1908, an article appeared in the French newspaper Matin, where the author stated: “Poincaré, the greatest mathematician of the century, considers Galileo’s stubbornness erroneous.” Poincare, however, back in 1904 wrote a special article "Does the Earth Rotate?" with a refutation of the opinion attributed to him about the equivalence of the systems of Ptolemy and Copernicus, and in the book "The Value of Science" (1905) he stated: "The truth for which Galileo suffered remains the truth."

As for the above remark of Infeld and Einstein, it refers to the general theory of relativity and means the fundamental admissibility of any reference systems. However, their physical (and even mathematical) equivalence does not follow from this. From the point of view of a distant observer in a reference frame close to inertial, the planets solar system still move "according to Copernicus", and the geocentric coordinate system, although often convenient for an earthly observer, has a limited scope. Infeld later admitted that the above phrase from the book "The Evolution of Physics" does not belong to Einstein and is generally poorly worded, therefore "to conclude from this that the theory of relativity underestimates the Copernican case to some extent means to make an accusation that is not even worth refuting" .

In addition, in the system of Ptolemy it would be impossible to derive the laws of Kepler and the law of universal gravitation, therefore, from the point of view of the progress of science, Galileo's struggle was not in vain.

Accusation of atomism

In June 1982, the Italian historian Pietro Redondi ( Pietro Redondi) discovered in the Vatican archives an anonymous denunciation (undated) accusing Galileo of defending atomism. Based on this document, he constructed and published the following hypothesis. According to Redondi, the Council of Trent branded atomism as a heresy, and Galileo's defense of it in the book "Assay Master" threatened the death penalty, so Pope Urban, in an effort to save his friend Galileo, replaced the accusation with a safer one - heliocentrism.

Redondi's version, which removed the blame from the Pope and the Inquisition, aroused great interest among journalists, but professional historians quickly and unanimously rejected it. Their refutation is based on the following facts.

• There is not a word about atomism in the decisions of the Council of Trent. It is possible to interpret the interpretation of the Eucharist adopted by the Council as conflicting with atomism, and such opinions were indeed expressed, but they remained the private opinion of their authors. There was no official church ban on atomism (unlike heliocentrism), and there were no legal grounds to judge Galileo for atomism. Therefore, if the Pope really wanted to save Galileo, then he should have done the opposite - replace the accusation of heliocentrism with the accusation of supporting atomism, then instead of abdication, Galileo would have got off with an exhortation, as in 1616. It should be noted that just during these years Gassendi freely published books with the propaganda of atomism, and there were no objections from the church.
• Galileo's The Assayer, which Redondi considers a defense of atomism, dates from 1623, while Galileo's trial took place 10 years later. Moreover, statements in favor of atomism are found in the book of Galileo "Discourse on bodies immersed in water" (1612). They did not arouse any interest in the Inquisition, and none of these books was banned. Finally, after the trial, under the supervision of the Inquisition, Galileo in his last book again talks about atoms - and the Inquisition, which promised to return him to prison for the slightest violation of the regime, does not pay attention to this.
• No evidence was found that the denunciation found by Redondi had any consequences.

Currently, the Redondi hypothesis among historians is considered unproven and is not discussed. Historian I. S. Dmitriev regards this hypothesis as nothing more than a "historical detective story in the spirit of Dan Brown." Nevertheless, in Russia this version is still vigorously defended by Protodeacon Andrey Kuraev.

Scientific works

In the original language

• Le Opera di Galileo Galilei. - Firenze: G. Barbero Editore, 1929-1939. This is a classic annotated edition of the works of Galileo in the original language in 20 volumes (reprint of an earlier collection of 1890-1909), called the "National Edition" (Italian: Edizione Nazionale). The main works of Galileo are contained in the first 8 volumes of the publication.
  • Volume 1. About the movement ( De Motu), around 1590.
  • Volume 2. Mechanics ( Le Meccaniche), about 1593.
  • Volume 3. Star Herald ( sidereus nuncius), 1610.
  • Volume 4. Discourse on bodies immersed in water ( Discorso intorno alle cose, che stanno in su l'aqua), 1612.
  • Volume 5. Letters on Sunspots ( Historia e dimostrazioni intorno alle Macchie Solari), 1613.
  • Volume 6. Assay master ( Il Saggiatore), 1623.
  • Volume 7. Dialogue about two systems of the world ( Dialogo sopra i due massimi sistemi del mondo, tolemaico e copernicano), 1632.
  • Volume 8. Conversations and mathematical proofs of two new sciences ( Discorsi e dimostrazioni matematiche intorno a due nuove scienze), 1638.
• Lettera al Padre Benedetto Castelli(correspondence with Castelli), 1613.

Translations into Russian

• Selected works in two volumes. - M.: Nauka, 1964.
  • Volume 1: Star Herald. Message to Ingoli. Dialogue about two systems of the world. 645 pp.
  • Volume 2: Mechanics. About bodies in water. Conversations and mathematical proofs concerning two new branches of science. 574 pages
  • Applications and bibliography:
    • B. G. Kuznetsov. Galileo Galilei (Essay on life and scientific creativity).
    • L. E. Maistrov. Galileo and the theory of probability.
    • Galileo and Descartes.
    • I. B. Pogrebyssky, W. I. Frankfurt. Galileo and Huygens.
    • L. V. Zhigalova. The first mention of Galilee in Russian scientific literature.
• Dialogue about two systems of the world. - M.-L.: GITTL, 1948.
• Mathematical proofs concerning two new branches of science related to mechanics and local motion. - M.-L.: GITTL, 1934.

  Popular biographies

Galileo Galilei was born on February 15, 1564 in Pisa to the musician Vincenzo Galilei and Giulia Ammannati. In 1572 he moved with his family 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 further fate of the scientist.

Galileo was unable to graduate from the university due to his father's financial difficulties and was forced to return to Florence, where he continued to study science. In 1586, he completed work on the treatise "Little Scales", in which (following Archimedes) he described the device he 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 arbitrator in a dispute about how the topography of Dante's Hell (1588) should be interpreted from a mathematical point of view. Thanks to the assistance of his friend the Marquis Guidobaldo del Monte, Galileo received an honorary but meagerly paid position as professor of mathematics at the University of Pisa.

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

In 1609, Galileo Galilei, modeled on the first Dutch telescopes, made his own telescope, capable of creating a threefold zoom, and then designed a telescope with a thirtyfold zoom, magnifying one thousand times. Galileo was the first person to point a telescope at the sky; what was seen there meant a genuine revolution in the concept 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 a fiery evaporation like a 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 under the title The Starry Herald. The book brought Galileo European fame. The well-known mathematician and astronomer Johannes Kepler enthusiastically responded to it, the monarchs and the higher clergy showed great interest in the discoveries of Galileo. With their help, he received a new, more honorable and secure position - the post of court mathematician of the Grand Duke of Tuscany. In 1611, Galileo visited Rome, where he was admitted to the scientific "Academy dei Lincei".

In 1613, he published a work on sunspots, in which he spoke for the first time quite definitely in favor of the heliocentric theory of Copernicus.

However, to proclaim this in Italy at the beginning of the 17th century meant to repeat 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 passages from the Holy Scriptures that contradict them. Galileo believed that in such cases the biblical story should be understood allegorically. The church attacked the theory of Copernicus, whose book On the Revolutions of the Celestial Spheres (1543), more than half a century after its publication, was on the list of banned publications. A decree to this effect appeared in March 1616, and a month earlier, the chief theologian of the Vatican, Cardinal Bellarmine, suggested to Galileo that he no longer defend Copernicanism. In 1623, Galileo's friend and patron Maffeo Barberini 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 for 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 he was awaited by the court. In 1633, the scientist was sentenced to life imprisonment, which was replaced by house arrest, last years he spent his life without a break in his estate Arcetri near Florence. The circumstances of the case are still unclear. Galileo was accused not just of defending the theory of Copernicus (such an accusation is legally untenable, since the book passed papal censorship), but of violating an earlier ban from 1616 "not to discuss" this theory in any form.

In 1638, Galileo published in Holland, in the Elsevier publishing house, his new book"Conversations and Mathematical Proofs", where in a more mathematical and academic form he expressed his thoughts on the laws of mechanics, and the range of problems considered was very wide - from statics and resistance of materials to the laws of motion of a pendulum and the laws of fall. Until his death, Galileo did not stop active creative activity: he tried to use the pendulum as the main element of the clock mechanism (Christian Huygens soon followed him), a few months before he became completely blind, he discovered the vibration of the moon, and, already completely blind, dictated the latest thoughts on 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 particular 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 maximally freed from extraneous influences. This ideal world is further the object of a mathematical description, and its conclusions are compared with the results of an experiment in which the conditions are as close as possible to ideal ones.

Galileo died at 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 last will of the scientist 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 theory of Copernicus, and in 1835 excluded On the Revolutions of the Celestial Spheres from the index of banned books. In 1992, Pope John Paul II officially acknowledged that the church had made a mistake by condemning Galileo in 1633.

Galileo Galilei had three children born out of wedlock to the Venetian Marina Gamba. Only the son of 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 convent.

The material was prepared on the basis of information from open sources

Galileo Galileo (02/15/1564 - 01/08/1642) was an Italian physicist, astronomer, mathematician and philosopher who made a great contribution to the development of science. He discovered experimental physics, laid the foundation for the development of classical mechanics, made major discoveries in astronomy.

Young years

Galileo - a native of the city of Pisa, had a noble origin, but his family was not rich. Galileo was the eldest child of four (a total of six children were born in the family, but two died). From childhood, the boy was drawn to creativity: like his father, a musician, he was seriously fond of music, he drew well and understood questions visual arts. He also had a literary gift, which later allowed him to express his scientific research in his writings.

He was an outstanding student at the school at the monastery. He wanted to become a clergyman, but changed his mind due to the rejection of this idea by his father, who insisted that his son receive a medical education. So at the age of 17, Galileo went to the University of Pisa, where, in addition to medicine, he studied geometry, which greatly fascinated him.

Already at that time, the young man was characterized by the desire to defend his own position, not being afraid of established authoritative opinions. Constantly argued with teachers on science issues. I studied at the university for three years. It is assumed that at that time Galileo learned the teachings of Copernicus. He was forced to drop out of school when his father could no longer pay for it.

Due to the fact that the young man managed to make several inventions, he was noticed. He was especially admired by the Marquis del Monte, who was very fond of science and had good capital. So Galileo found a patron who also introduced him to the Duke of Medici and placed him as a professor at the same university. This time Galileo focused on mathematics and mechanics. In 1590 he published his work - the treatise "On the Movement".

Professor in Venice

From 1592 to 1610, Galileo taught at the University of Padua, became the head of the mathematical department, and was famous in scientific circles. The most active activity of Galileo fell on this time. He was very popular with students who dreamed of getting into his classes. Eminent scientists corresponded with him, and the authorities constantly set new technical tasks for Galileo. At the same time, the treatise "Mechanics" was published.

When a new star was discovered in 1604, his scientific research fell on astronomy. In 1609, he assembles the first telescope, with the help of which he seriously advanced the development of astronomical science. Galileo described the surface of the Moon, the Milky Way, discovered the satellites of Jupiter. His book The Starry Messenger, published in 1610, was a huge success and made the telescope a popular acquisition in Europe. But along with recognition and reverence, the scientist is also accused of the illusory nature of his discoveries, as well as in an effort to harm the medical and astrological sciences.

Soon, Professor Galileo enters into an unofficial marriage with Marina Gamba, who bore him three children. Responding to an offer of a high position in Florence from the Duke of Medici, he moves and becomes an adviser at court. This decision allowed Galileo to pay off large debts, but partly played a disastrous role in his fate.

Life in Florence

At the new location, the scientist continued his astronomical research. It was characteristic of him to present his discoveries in a bullying style, which greatly annoyed other figures, as well as the Jesuits. This led to the formation of an anti-Galilean society. The main claim on the part of the church was the heliocentric system, which contradicted religious texts.

In 1611, the scientist went to Rome to meet with the head of the Catholic Church, where he was received rather warmly. There he introduced the cardinals to the telescope and tried, with care, to give some explanations. Later, encouraged by a successful visit, he published his letter to the abbot that Scripture could not have authority in matters of science, which attracted the attention of the Inquisition.

Galileo demonstrates the laws of gravity (fresco by D. Bezzoli, 1841)

His 1613 book "Letters on Sunspots" contained open support for the teachings of N. Copernicus. In 1615, the first case was opened against Galileo by the Inquisition. And after he called on the Pope to express his final point of view on Copernicanism, the situation only worsened. In 1616, the Church declares heliocentrism a heresy and bans the book of Galileo. Galileo's attempts to rectify the situation did not lead to anything, but he was promised not to be persecuted if he stopped supporting the teachings of Copernicus. But for a scientist convinced of his rightness, this was impossible.

Nevertheless, for a while, he decided to turn his energy in a different direction, engaging in criticism of the teachings of Aristotle. The result was his book The Assay Master, written in 1623. At the same time, a longtime friend Galileo Barberini was elected Pope. In the hope of lifting the ban on the church, the scientist went to Rome, where he was well received, but did not get what he wanted. Further, Galileo decided in his writings to continue to defend the truth, considering several scientific points of view from a position of neutrality. His Dialogue on Two Systems of the World lays the groundwork for the new mechanics.

Galileo's conflict with the church

Having handed over his Dialogue to the Catholic censor in 1630, Galileo waits a year, after which he resorts to a trick: he writes a preface about the rejection of Copernicanism as a doctrine. As a result, permission was obtained. Published in 1632, the book did not contain specific conclusions of the author, although it clearly made sense in the argumentation of the Copernican system. The work was written in accessible Italian, and the author also independently sent copies to the highest ministers of the church.

A few months later, the book was banned and Galileo was called to trial. He was arrested and spent 18 days in captivity. Thanks to the troubles of his pupil, the duke, the scientist was shown leniency, although he was presumably still tortured. The investigation went on for two months, after which Galileo was found guilty and sentenced to life imprisonment as a punishment, he also had to renounce his own "delusions". The catchphrase “But nevertheless it turns”, which is attributed to Galileo, he did not actually utter. This legend was invented by the Italian literary figure D. Baretti.

Galileo before the Judgment (K. Bunty, 1857)

Old age

The scientist did not stay in prison for a long time, he was allowed to live on the Medici estate, and five months later he returned home, where they continued to follow him. Galileo settled in Arcetri near the monastery where his daughters served, and spent his last years under house arrest. toppled a large number prohibitions that hindered his treatment and communication with friends. Later, they were allowed to visit the scientist one at a time.

Despite the difficulties, Galileo continued to work in non-prohibited scientific directions. He published a book on mechanics, planned to anonymously publish a book in defense of his views, but did not have time. After the death of his beloved daughter, he went blind, but continued to work, wrote a work on kinematics, published in Holland and which became the basis for the research of Huygens and Newton.

Galileo died and was buried in Arcetri, the church forbade burial in the family crypt and the erection of monuments to the scientist. His grandson, the last representative of the family, having become a monk, destroyed valuable manuscripts. In 1737, the remains of the scientist were transferred to the family tomb. The Catholic Church only rehabilitated Galileo in the late 70s of the last century, in 1992 the mistake of the Inquisition was officially recognized.