His academic career can be divided into the following three periods.
1. Early active period
1583, Galileo noticed the swing of a chandelier in Pisa church, and then made a simulation experiment with a copper ball suspended by a wire, which confirmed the synchronization of small swing and the influence of swing length on the period, and thus created a pulse meter to measure short time intervals. From 65438 to 0585, he dropped out of school because of family poverty and became a tutor, but he still worked hard to teach himself. 1586, he invented the buoyancy balance and wrote the paper "Small Balance".
1587, he took a paper on the calculation of solid center of gravity to the University of Rome and called on Professor C. Clavius, a famous mathematician and historian, who was greatly praised and encouraged. Clavius brought back his lectures on logic and natural philosophy from P Vara, a professor at the University of Rome, which was of great help to his future work.
From 65438 to 0588, he gave an academic lecture on the graphic conception of purgatory in Dante's Divine Comedy at Florence College, and his literary and mathematical talents were greatly praised. The following year, he published several papers on the calculation of solid center of gravity, including some new statics theorems. Because of these achievements, the University of Pisa hired him to teach geometry and astronomy. The next year he discovered the cycloid.
At that time, the textbooks of Pisa University were all written by Aristotelian scholars, and the books were full of theological and metaphysical dogmas. Galileo often expressed sharp objections and was discriminated and rejected by the school. 159 1 year, his father died of illness and the family burden increased, so he decided to leave Pisa.
2. During the Padua period, Galileo transferred to the University of Padua to teach at 1592. Padua belongs to the principality of Venice, far from Rome, not directly controlled by the Vatican, and his academic thoughts are relatively free. In this good atmosphere, he often participates in various academic and cultural activities inside and outside the school, arguing with colleagues with various ideas and opinions. At this time, while absorbing the research results of mathematics and mechanics of N.F. tartaglia, G.B. Benedetti, F. Comentino and others, he often inspected factories, workshops, mines and various military and civil projects, made extensive friends with technicians in various industries, helped them solve technical problems, and learned production technical knowledge and various new experiences from them, which was inspired.
During this period, he deeply and systematically studied the falling body, projectile motion, statics, hydraulics and some civil and military buildings. Discovered the principle of inertia, invented the thermometer and telescope.
1597, he received a book "The Mysterious Universe" by J Kepler, and began to believe in Heliocentrism, acknowledging that the earth has two movements: revolution and rotation. But at this time, he was deeply impressed by Plato's most natural and perfect circular motion thought, and was not interested in Kepler's theory of planetary elliptical orbit.
1604 A supernova appeared in the sky, and the light lasted for 18 months. He took the opportunity to make several popular science speeches in Venice to promote Copernicus' theory. Because of the wonderful speech, the audience gradually increased and finally reached more than 1000 people.
1609 In July, it was rumored that a Dutch glasses worker invented a telescope for people to enjoy. He didn't see the real thing, so he thought of making a telescope with organ tube and convex-concave lens in the future. The magnification was 3, and then it was raised to 9. He invited Senator Venice to the top floor of the tower and looked at the distant view through a telescope, which surprised all the spectators. The Senate then decided that he was a tenured professor at the University of Padua. At the beginning of 16 10, he increased the magnification of the telescope to 33 times to observe the moon, the sun and the stars, and found many new discoveries, such as the uneven surface of the moon, the light emitted by the moon and other planets is the reflection of the sun, Mercury has four satellites, the Milky Way was originally a confluence of countless luminous bodies, Saturn has a changeable ellipse and so on, which opened up a new world of astronomy. In March of that year, he published the book Star Messenger, which shocked all of Europe. Later, it was discovered that Venus changed in profit and loss and size, which was a strong support for Heliocentrism.
Galileo later looked back on his 18 years in Padua and thought it was the most productive and spiritual period in his life. In fact, this is also the greatest academic achievement in his life.
Galileo's fruitful achievements in physics and astronomy during his 20 years in Tuscany aroused his greater academic ambition. In order to get enough time to devote himself to scientific research, in the spring of 16 10, he resigned from the university and accepted the appointment of the Grand Duke of Tuscany as the chief mathematician and philosopher of the court and the honorary position of the chief professor of mathematics at the University of Pisa.
In order to protect science from church interference, Galileo went to Rome many times. 16 1 1 year, in order to win the recognition of his discoveries in astronomy from religious, political and academic circles, he went to Rome for the second time. In Rome, he was warmly received by elites including Pope Paul V and some senior bishops, and was accepted as an academician by the Lindsay Institute. At that time, the Jesuit priest acknowledged his observation, but disagreed with his explanation. In May this year, at the meeting of the University of Rome, several senior priests publicly announced Galileo's astronomical achievements.
In the same year, he observed sunspots and their movements, compared the movement law of sunspots with the projection principle of circular motion, and proved that sunspots are on the surface of the sun; He also found that the sun rotates. 16 13 published three communication articles about sunspots. In addition, in 16 12, the book "floating body dialogue in water" was published.
16 15 A perfidious cleric group and many people in the church who were hostile to Galileo jointly attacked Galileo's argument of defending Copernicus and accused him of violating Christianity. After learning the news, he went to Rome for the third time in the winter of, trying to save his reputation, pleading with the Vatican not to be punished for keeping Copernicus' views, and not to publicly suppress him and publicize Copernicus' theory. The Vatican acquiesced in the former request, but rejected the latter. In 16 16, Pope Paul V issued the famous "16 16 ban", forbidding him to reserve, teach or defend Heliocentrism orally or in writing.
1624, he went to Rome for the fourth time, hoping that his old friend, the new Pope urban VIII, would sympathize with and understand his wishes in order to maintain the vitality of emerging science. He had six audiences, trying to explain that Heliocentrism could be in harmony with Christian teachings, saying that "the Bible teaches people how to enter the kingdom of heaven, not how celestial bodies work"; And tried to convince some archbishops, but to no avail. Urbon VIII insists on "16 16 ban" unchanged; He is only allowed to write a book introducing Heliocentrism and geocentric theory at the same time, but his attitude towards these two theories must not be biased, and both should be written as mathematical hypotheses. In this year's efforts, he developed a microscope, "which can enlarge flies into hens."
In the following six years, he wrote a book "Dialogue between Ptolemy and Copernicus". 1630, he went to Rome for the fifth time and obtained the "publishing license" of this book. The book was finally published in 1632. This book is neutral on the surface, but actually defends the Copernican system, and in many places implicitly ridicules the Pope and the Bishop, which goes far beyond the scope of discussing only mathematical assumptions. The book has a humorous style and is listed as a literary masterpiece in the history of Italian literature.
4. The persecution of the Holy See and the later life. Half a year after the publication of Dialogue, the Holy See ordered it to stop selling, arguing that the author had blatantly violated the "prohibition of 16 16", which was a serious problem and needed urgent review. It turns out that before Pope urban VIII, Galileo was provoked to say that in the Dialogue, he made some absurd and wrong remarks with the Simpleqiu and conservative mouth, which made him furious. The group that once supported him as pope strongly advocated severely punishing Galileo, while the Holy Roman Empire and the Kingdom of Spain believed that conniving Galileo would have a great impact on heresy in various countries and put forward a joint warning. Under these internal and external pressures and provocations, the Pope ignored his old friends and issued an order this autumn to have Galileo tried by the Roman Inquisition.
Galileo, who was nearly seventy years old and sickly, was forced to go to Rome in the cold winter. He was interrogated three times under the threat of torture and was not allowed to stand trial at all. After several tortures, on June 22nd, 1633, 10 cardinals jointly pronounced the sentence, mainly for violating the "16 16 prohibition" and biblical teachings. Galileo was forced to kneel on the cold slate and sign the "repentance book" written by the Vatican. The presiding judge announced that Galileo was sentenced to life imprisonment; The dialogue must be burned and it is forbidden to publish or reprint his other works. This judgment immediately informed the whole Catholic world that all cities with universities must gather to read it, so as to set an example for others.
Galileo is both a diligent scientist and a devout Catholic, convinced that the task of scientists is to explore the laws of nature, while the function of the church is to manage people's souls and should not infringe upon each other. Therefore, he didn't want to escape before his trial, and he didn't openly resist when he was tried, but he always obeyed the Vatican's disposal. He believes that it is extremely unwise for the Vatican to exercise its power outside the scope of theology, and it can only be privately dissatisfied. Obviously, G Bruno was burned to death at the stake, and T campanella was put on death row for a long time. What happened to these two outstanding Italian philosophers cast a terrible shadow on his spirit.
The inquisition's decision was later changed to house arrest, and his student and old friend Archbishop A. Picolomini was appointed to take care of him in a private house in Siena. The regulations prohibit visitors and hand in writing materials every day. Under the careful care and encouragement of Piclomini, Galileo was resurrected, and he accepted Piclomini's suggestion and continued to study uncontroversial physical problems. So he still wrote his most mature scientific thoughts and research results into Dialogues on Two New Sciences and Dialogues on Mathematical Proving, using three dialogists in Dialogues, with simple style and writing style. Two new sciences refer to mechanics and dynamics of materials. This manuscript was completed on 1636. Because the church banned the publication of any of his works, he had to entrust a Venetian friend to smuggle them out of the country and publish them in Leiden, the Netherlands on 1638.
Galileo had just stayed in Piccolomini's house for five months when someone wrote an anonymous letter accusing Piccolomini of being too kind to Galileo. The Vatican ordered Galileo to move to his former residence in Chetri near Florence in June 5438+February of that year, and the ban remained. She took good care of her father, but died before him four months later.
Galileo repeatedly asked to go out for medical treatment, but was not allowed. 1637 is blind. It was not until the next year that he was allowed to live in his son's house. During this period, in addition to the Grand Duke of Tuscany, there were J Milton, a famous British poet and political commentator, and P Gasandi, a French scientist and philosopher. His student and old friend B. Castay also discussed with him the calculation of ground longitude by using wooden satellites. At this time, the Vatican's restrictions and surveillance on him have been obviously relaxed.
1in the summer of 639, Galileo was allowed to accept the smart and studious 18-year-old youth V. viviani as his last student, and he could take care of him. The young man made him very satisfied. 164 1 10 in June, Casta introduced his student and former secretary e torricelli to accompany him. They discussed with the blind old scientist how to design a mechanical clock by using the isochronism of pendulum, and also discussed the collision theory, the libration of the moon, the height of water column in the mine under atmospheric pressure and other issues, so he was still engaged in scientific research until his death.
Galileo died on1642 65438+1October 8, and the funeral was sloppy. It was not until the next century that his bones were moved to the cathedral in his hometown.
The continuous development of science forced the Holy See to announce the lifting of Copernicus' theory of celestial movement in 1757. 1882, the Pope reluctantly recognized Heliocentrism. June1979165438+1October 10 On behalf of the Holy See, Pope Paul II publicly rehabilitated Galileo, thinking that the persecution of him by the Holy See more than 300 years ago was a serious mistake. This shows that the court finally admitted Galileo's claim that religion should not interfere with science.
Second, scientific achievements.
1. New scientific ideas and scientific research methods
Before Galileo's research results were recognized, physics and even the whole natural science was only a branch of philosophy and did not gain its own independent status. Philosophers at that time were bound by theology and Aristotle's dogma, thinking hard, and could not get objective laws in line with reality. Galileo dared to challenge the traditional authoritative thought, not by speculating on the causes of things, but by observing natural phenomena and discovering natural laws. He abandoned the theological view of the universe and thought that the world was an orderly whole that obeyed simple laws. To understand nature, it is necessary to carry out systematic experimental quantitative observation and find out its accurate quantitative relationship.
Based on this new scientific idea, Galileo advocated the research method of combining mathematics with experiment; This research method is the source of his great achievements in science and his most important contribution to modern science. The study of physical problems by mathematical methods was not initiated by Galileo, and can be traced back to Galileo in the 3rd century BC, the oxford school and Parisian School in14th century and the Italian academic circles in 15 and16th century. They have made some achievements in this respect, but they have not put experimental methods in the first place, so they have not made a breakthrough in their thinking. Galileo's idea of attaching importance to experiments can be seen in a letter he wrote to Duchess Christina in 16 15: "I want to ask these clever and careful priests to seriously consider the difference between speculative principles and principles confirmed by experiments. You know, the opinions of professors who do experimental work are not determined by subjective will alone. "
Generally speaking, Galileo divided the research method of combining mathematics with experiment into three steps: ① Firstly, the main part of intuitive knowledge obtained from phenomena was extracted and expressed in the simplest mathematical form, and the concept of quantity was established; Secondly, another quantitative relationship that is easy to be verified by experiments is derived from this formula by mathematical method. (3) Then, this quantitative relationship is confirmed by experiments. His research on the law of uniform acceleration of falling objects is the best explanation.
2. Innovation of physical concepts and principles
Inertia principle and new concepts of force and acceleration require large force when pushing heavy objects and small force when pushing light objects, which is the intuitive feeling of people. Aristotle came to a general conclusion that all objects have the nature of keeping still or looking for their "natural position", and that "everything that moves must have a promoter" and connected power with speed by the law of proportion. Galileo put forward a new concept. He observed that when an object slides upward along a smooth inclined plane, the speed will be slowed down to different degrees due to the different inclination angles of the inclined plane. The smaller the inclination angle, the smaller the deceleration. If you slide on a level surface without resistance, keep the original speed and slide forever. It is concluded that "if a moving object has a certain speed, as long as there is no external reason to increase or decrease its speed, it will always maintain this speed-this condition is only possible on the horizontal plane, because in the case of inclined plane, the downward inclined plane provides the reason for acceleration, while the upward inclined plane provides the reason for deceleration;" Therefore, only the motion on the horizontal plane is constant "(dialogue between two new sciences, the third day, question 9, hypothesis 23). In this way, Galileo put forward the concept of inertia for the first time, and for the first time linked the external force with the "external cause of acceleration or deceleration", that is, the change of motion. Galileo put forward new concepts of inertia and acceleration and new laws of uniform acceleration motion of objects under the action of gravity, which laid the foundation for the establishment of Newton's theoretical system of mechanics. There are the following aspects.
(1) The principle of independence of motion and the law of composition and decomposition of motion In the study of trajectory, Galileo found that horizontal motion and vertical motion are independent and do not interfere with each other, but the actual trajectory can be synthesized by parallelogram law. He completely explained the parabolic nature of trajectory from the uniform acceleration motion perpendicular to the ground and the uniform acceleration motion in the horizontal direction, which is a great gain in the research of motion synthesis and has practical significance.
(2) The concept of inertial frame of reference When Galileo defended Copernicus's theory of ground motion with physical principles, he applied the principle of motion independence to explain that the stone fell from the top of the mast to the bottom of the mast without deviating from the stern. He further put forward the concept of inertial frame of reference for the first time with the famous assertion that the motion law of the objects in the cabin is constant in uniform linear motion. This principle is called Galileo's principle of relativity by an Einstein, and it is the predecessor of special relativity.
(3) The discovery of the periodic nature of the simple pendulum Galileo made an experimental study on the simple pendulum by observing the swing of the hanging lamp in the church, and found that the period of the simple pendulum is proportional to the square root of the pendulum length, but has nothing to do with the amplitude and weight of the pendulum. The discovery of this law laid a foundation for the vibration theory and the design scheme of mechanical timing device.
(4) The finite speed of light and its measurement predecessors never had a clear understanding of whether the speed of light is limited. Galileo observed the lightning phenomenon, thought that the speed of light was limited, and designed a scheme of shielding the light to measure the speed of light. However, limited by the experimental conditions at that time, this measurement method actually measured the reaction of the experimenter and the action time of the human hand, rather than the propagation time of light. However, if there is a light source with regular light and dark changes, or a device controlled by high-speed machinery instead of human hands, the true speed of light can be measured. Later, the methods of measuring the speed of light, such as satellite food method, rotating gear method, rotating mirror method, Kerr box method and frequency conversion flash method, were all used for reference.
3. Development of several basic physics experimental instruments.
Galileo not only personally designed and demonstrated many experiments, but also personally developed many experimental instruments. He is rich in craft knowledge and exquisite in production technology. Many experimental instruments he created were very influential at that time and later generations. Here are some examples:
(1) Buoyancy Balance This is a direct reading instrument that uses buoyancy principle to quickly determine the proportion of gold and silver in gold and silver utensils and jewelry. This tool has been used in the trading of gold, silver and jewelry ships.
(2) Thermometer The thermometer pioneered by Galileo is an open liquid thermometer. The glass tube is filled with colored water and alcohol, and the liquid level is communicated with the atmosphere. This is actually a mixture of thermometer and barometer, because he didn't have a clear understanding of the change of atmospheric pressure at that time. Nevertheless, its academic value is still great, and temperature has since become an objective physical quantity, rather than an uncertain subjective feeling.
(3) Telescope The telescope made by Galileo can observe the positive image of an object. After improvement, its magnification is gradually increased from 3 times to 33 times; It not only points to the starry sky, but also can be applied to ship fortresses, and has made unprecedented rich discoveries. This telescope is simple in structure, but its magnification and resolution are greatly limited by spherical aberration and chromatic aberration.
4. Thoroughly overthrow Aristotle's material view.
The view of nature, which was absolutely dominant in medieval Europe, was an Aristotle's view of nature after theological transformation, and it became a tool for feudal theocracy rulers to control people's thoughts. Aristotle believes that the earth and everything on it are composed of four elements: air, fire, water and earth. They are ugly, unclean and imperfect, with changes and birth and death. Fire and gas make up light things that flow upward, and water and soil make up heavy things that fall upward. Celestial bodies are pure, perfect and eternal objects composed of "ether". And because "God hates vacuum", vacuum cannot exist. But Galileo found from the telescope that the surface of the moon has peaks and depressions, uneven and imperfect, and Venus also has profit and loss changes; There are still active sunspots on the surface of the sun; The naked eye can directly see the explosion of supernovae and its gradual darkening and disappearance. All these have broken Aristotle's thought that the sky is higher than the earth, and the nature of the celestial bodies in the sky is very different from that on the earth. Galileo learned from the study of floating bodies through hydrostatics that all objects are heavy and not absolutely light. Celestial bodies are unified with the earth and everything on the ground in material structure. Vacuum may also exist and produce, and only in vacuum can we study the real properties of objects. This completely overthrew Aristotle's material view based on subjective speculation, thus fundamentally shaking the ideological rule of feudal theocracy.
5. Pioneer of scientific revolution and father of modern science.
Galileo was a great Italian physicist and astronomer and a pioneer of the scientific revolution. He made epoch-making contributions in the process of human ideological emancipation and the development of civilization. Under the social conditions at that time, in order to strive for academic freedom that was not suppressed by power and old traditions, and for the growth of modern science, he waged unremitting struggles and made a loud voice to the whole world. Therefore, he is a pioneer of the scientific revolution. In history, he first integrated mathematics, physics and astronomy on the basis of scientific experiments, expanding, deepening and changing human understanding of material movement and the universe. Galileo devoted his life to proving and spreading Copernicus' Heliocentrism. As a result, he was persecuted by the church in his later years and imprisoned for life. He overthrew the traditional speculative view of nature represented by Aristotle with systematic experiments and observations, and founded a modern science based on experimental facts and with a strict logical system. Therefore, he is called "the father of modern science". His work laid the foundation for the establishment of Newton's theoretical system. Although he was finally deprived of his personal freedom in his later years, his will to create new science did not waver. His spirit and achievements in pursuing scientific truth will always be admired by future generations.
Third, anecdotes
1. Love mathematics but not medicine
158 1 year, Galileo 17 years old, was admitted to the University of Pisa where Galileo was born. His father insisted that he study medicine, because in Italy in the16th century, medicine was regarded as the most effective first step for college students to succeed and eventually become rich.
Galileo reluctantly fulfilled his father's wish, but a few months later, bigger differences began to appear. Galileo is a versatile young man. He is not only a talented musician and an excellent painter, but also a talented writer. But in the first year of Galileo's arrival in Pisa, he was not interested in medicine and found his real hobby, which changed his life track.
In the first semester of Pisa University, Galileo spent his spare time listening to mathematics lectures, and he began to be fascinated by the rigorous beauty of this subject. In particular, the subject of Euclidean geometry, taught by the court mathematician Austi Lo Leech, which was named after the Greek Euclid, the father of geometry, deeply attracted him.
Galileo listened to Leach's lectures every week. Soon after, the court mathematician began to notice that a handsome young man always sat at the back of the lecture hall, listening attentively to everything he said. At the end of each lecture, Galileo always asked Leach many questions. The mathematician realized that there was a very clever student in his subject, so he suggested Galileo give up studying medical reform and mathematics in this university.
Although his father was angry, Galileo continued his hobby and changed his theme. He insisted that he was no longer a child, and this time he didn't do as his father asked. Before the end of the first semester, Galileo was already an undergraduate majoring in mathematics.
2. Nickname of "debater"
When Galileo was still studying at the University of Pisa, he did not like the philosopher's attitude towards science, so he expressed his views bluntly in both argument and private discussion. On many occasions, he will become very excited, raise his voice and argue loudly with colleagues and speakers.
Galileo was indeed born a little naughty, but fundamentally, he was a polite and disciplined student. He is very popular with some classmates and has won a good reputation for his wit and enthusiasm. However, on the issues of mathematics and physics, he is not afraid to express his views clearly. The fact is that Galileo argued so much in college that he got the nickname "debater".
The focus of his argument is that it is impossible to promote scientific progress just by sitting there and thinking like a Greek. Aristotle never did an experiment in his life. He just reached a conclusion by logical method. Galileo thought it was not enough. Aristotle's whole philosophical system is interrelated. One principle leads to another principle, and one viewpoint supports another. If there is something wrong with his philosophical system, it is tantamount to declaring that all his philosophical contents are problematic.
Galileo dealt with problems in the opposite way to Aristotle. At the University of Pisa, he insisted that science can only be based on experiments. An idea can be based on inspiration at first, but it can only be proved and accepted through experiments-this is a view that is taken for granted today.
Most of Galileo's colleagues at the university disagreed with him. Galileo knew the attitude of the church, and he was very clever to demonstrate his point of view as one of many suggestions, so as not to make people pay more attention to his anti-Aristotle thought. This is at least the way Galileo used it in public. ...
3. The story of the Leaning Tower of Pisa
During Galileo's long life, many famous events were commemorated and recorded by later generations. Perhaps the most popular story is that he is said to have conducted an experiment on the top of the leaning tower of Pisa in 159 1 year.
The leaning tower is located in Pisa. This unusual building was built in 1 174, and has been tilted by about 17 feet since its initial tilt. By the16th century, the leaning tower of Pisa had become a historic building, attracting the attention of tourists from all over Italy.
Galileo was very angry with his colleagues because they resolutely refused to consider his anti-Aristotle views. He decided to prove the mistake of the Greek philosopher with a special kind of evidence.
One of Aristotle's main points in physics is that if two objects with different weights are allowed to fall under the action of gravity, the heavier one will fall to the ground. However, like all his arguments, Aristotle did not try this argument, but admitted it as an indisputable fact.
To prove his point. Galileo climbed to the top of the leaning tower with two assistants and two shot puts with different weights.
Climbing this tower is very thrilling. He had to climb hundreds of old and slippery steps. The stairs are inside the stone fence, spiraling up, very steep. When he reached the top of the tower, Galileo was sweating and exhausted. But he will do well. Inspired by anger and frustration, he climbed the bell tower on the top platform. The heavy building leans to one side at a terrible angle. He tried his best to overcome his dizziness and hold on to the highest point. He has never climbed such a tall building before.
He stood on the edge of the bell tower, shot twice, off the ground 179 feet. He can overlook the whole pizza. He saw his colleagues who were persuaded by him in the university under the tower. He stretched out a hand to test whether there was wind. There happened to be no wind that day.
Two assistants stood against the edge of the bell tower, each holding a shot put. At the right time, Galileo sent a signal to his assistant. At the same time, the two assistants released the shot put in their hands and let them fall to the grass below under the action of gravity.
Sure enough, people clearly saw that the two shots landed almost at the same time, which really proved that Aristotle's argument about falling objects was completely wrong.
Although there is ample evidence that Galileo didn't do the falling body experiment, and in fact this experiment is not convincing, people still prefer to believe it. Because it is full of drama, it has brought pizza a worldwide reputation.
4. Life as a teacher at Padua University
Galileo was satisfied with the life in Padua University, but although he could earn a large salary, it was very difficult to support his family. He had to accept students in private, as he did at Pisa University.
Through long-term teaching work, Galileo gradually became busy. He not only teaches local astronomy and mathematics enthusiasts, but also teaches machine manufacturing technology courses to military mechanics stationed in the city.
A few years later, Galileo's financial situation gradually improved, and he was able to buy a small house in the city. He started dating a Venetian woman named Marina Gamba. They are not married, but they have lived together for 10 years, 16 10 years. When Galileo moved again, Marina stayed in Padua and they separated. During these years of living together, they have two daughters and a son.
As he grew older, Galileo showed no interest in marrying Marina, and seemed to concentrate more and more on his academic research. He will never forget all the people who depend on him, but he is definitely not a lovely father or a loyal husband. In his life, he really has only one real hobby-natural science.
Padua's 18 is the happiest period of Galileo's life, that is, in these years, he made some most important discoveries.
References:
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References:
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