all one's life
Galileo was born in Pisa, on the west coast of Italy, on February 1564. He was originally from Florence and came from a noble family. Galileo's father was a frustrated musician, proficient in Greek and Latin, and quite accomplished in mathematics. So Galileo received a good family education from an early age.
At the age of twelve, Galileo entered the monastery of Varosha near Florence and received a classical education. At the age of seventeen, he entered the University of Pisa to study medicine and devoted himself to studying physics and mathematics. Due to the financial difficulties of his family, Galileo left the University of Pisa without a diploma. In a difficult environment, he still insisted on scientific research, studied many works of Euclid and Archimedes, made many experiments and published many influential papers, which attracted great attention from the academic circles at that time and was called "the contemporary Archimedes".
Galileo studied mathematics at the University of Pisa at the age of 25. Two years later, Galileo angered the church and lost his job because of the famous experiment on the leaning tower of Pisa. After leaving the University of Pisa, Galileo went to teach at the University of Padua in Venice in 1592 until 16 10. This period was the golden age of Galileo's scientific research. Here, he has made fruitful achievements in mechanics and astronomy.
16 10, Galileo published his book in the form of popular reading, named "Star Messenger". This book was published in Venice, which caused a sensation in Europe at that time and won a high honor for Galileo. Galileo was hired as "court philosopher" and "court chief mathematician", and he returned to his hometown of Florence.
Galileo continued his scientific research in the court of Florence, but his astronomical discoveries and works clearly reflected the views of Copernicus and Heliocentrism. Therefore, Galileo began to attract the attention of the church. From 16 16, Galileo began to be brutally persecuted by the Roman Inquisition for more than 20 years.
Galileo lived a miserable life in his later years, and celeste, who took care of his daughter, died before him. The grief of losing his beloved daughter blinded Galileo. Even under such conditions, he still didn't give up his scientific research work.
1642 65438+1At 4 o'clock on the morning of October 8, the great Galileo, a lifelong fighter for science and truth, and a giant of science, died at the age of 78. On the eve of his death, he repeated this sentence: "It takes special courage to pursue science."
1564 February 15, Galileo was born in a humble aristocratic family in Pisa, Italy. It is said that his ancestors were famous doctors in Florence, but that was his father Galileo? In Fan Sandu's generation, the family fortune is declining. Van Sandu is a talented composer. He published several pastoral poems and instrumental works before his death. He is also good at mathematics and proficient in Greek and Latin. However, wonderful music can't fill a family's stomach, and his mathematical talent can't get him a good position. Shortly after Galileo was born, Van Sandu opened a small shop selling woolen goods in Florence, not far from Pisa, which was a last resort. But in order to support his family, Fan Sandu had to go into business against his will.
Galileo Jr. is the eldest son of Fan Sandu, and his father placed great hopes on his son. He found that Galileo Jr. was very clever and had a strong curiosity about everything since he was a child. Not only that, the child is ingenious, and it seems that he has never been idle, either painting or playing the piano. He often makes many clever motor toys for his brothers and sisters and has a good time.
Galileo junior first entered the school of Frenborosa Monastery. In this school, he concentrates on philosophy and religion. For a time, Galileo hoped to be a missionary dedicated to the church in the future. But when Fan Sandu heard this, he immediately took his son home. He persuaded Galileo to study medicine, which he had already designed for his son's future.
/kloc-At the age of 0/7, Galileo entered the famous University of Pisa. According to his father's wishes, he became a medical student. The University of Pisa is an ancient university, and its library is rich in books, just to Galileo's taste. However, Galileo was not very interested in medicine. He seldom attends class, and as soon as he attends class, he puts forward such and such questions about what the professor teaches, which makes it difficult for the professor to answer. In the eyes of the professor, Galileo was a very unpopular bad student. However, Galileo was not interested in medicine. He studied mathematics, physics and other natural sciences tirelessly, and looked at those theories that have been regarded as classics since ancient times with suspicion.
You know, Galileo lived in a famous Renaissance era in European history, and Italy was the birthplace of the Renaissance. At that time, many big cities in Italy, such as Florence, Genoa and Venice, developed into the centers of East-West trade, established firms, workshops and the earliest banks, and the capitalist relations of production sprouted. Coupled with the development of trade and the invention of printing, new ideas spread faster than ever before. As a result, people began to shake the religious theology and traditional dogma that had bound their thoughts for thousands of years.
By chance, Galileo listened to the court mathematician Matteo? Leach's lecture. Galileo was deeply fascinated by the young mathematician's profound knowledge and strict logic, especially his verification method in proving mathematical problems. His eyes lit up, as if he had discovered a magical world, which was his dream mathematics kingdom! He was so excited that he immediately found the court mathematician Matteo? Leach asked him many puzzling questions.
Matthew. Leach came to Pisa with the Grand Duke of Tuscany from Florence. He taught mathematics to court attendants, but he didn't expect an enthusiastic audience. And his questions are very interesting, which fully shows his extraordinary wisdom and profound knowledge.
When madou? When Leach heard that Galileo was a medical student at the University of Pisa, he couldn't help but blurt out, "Ah, Galileo, you are a genius, and you will become an outstanding mathematician."
Galileo blushed. He talked about his boredom with medicine, his father's expectation of him, and his distress that he could not study according to his own wishes.
"Don't be discouraged." Matthew. Leach said kindly, "Study hard by yourself. If you have any difficulties, I will always be your loyal friend. "
Did you listen to Matthew? Encouraged by Leach, Galileo studied math and physics harder and harder. He carefully read every book borrowed from the court mathematician and absorbed it like a sponge. However, he is not the kind of person who is superstitious about books. Those authoritative conclusions that people think are true often bring unexpected problems in Galileo's mind. He often feels distressed and falls into deep thinking.
On one occasion, Galileo strolled to his familiar Pisa Cathedral. He sat on a bench and stared at the beautifully carved altar and arched colonnade. Suddenly, the giant lamp in the center of the church hall shook, and it was the house repairman who installed the chandelier there.
This was originally a very common thing. The chandelier swings like a pendulum, drawing an invisible arc in the air. However, Galileo followed the swaying chandelier as if he had been touched by electricity. At the same time, he used his right hand to count the number of times the chandelier swings and the number of times the pulse beats according to the pulse of his left wrist, thus calculating the swinging time of the chandelier.
As a result of this calculation, Galileo discovered a secret, that is, the time for the chandelier to swing once is always the same, regardless of the radian. At first, the chandelier swung badly, and gradually, it slowed down, but every time it was swung, the number of pulse beats was the same.
Galileo's mind churned, and he thought, it is clear in the book that it is faster to pass through a short arc than a long one. This is what the ancient Greek philosopher Aristotle said, and no one doubts it. Is there something wrong with your eyes or something?
He ran back to the university dormitory like a madman and repeated the experiment behind closed doors. He found ropes and chains of different lengths, as well as iron balls and wooden balls from somewhere. On the roof, on the branches outside the window, I repeated over and over again, recording the time of swinging with an hourglass. Finally, Galileo had to boldly come to the conclusion that Aristotle's conclusion was wrong. It is the length of the rope that determines the swing period, which has nothing to do with the weight of the object at the end of the rope. In addition, the vibration period is the same for the pendulum rope with the same length. This is the law of pendulum motion discovered by Galileo.
It was 1609 in June, and Galileo heard a news that Lippach, a Dutch optician, saw something invisible to the naked eye in the distance with a kind of lens in an accidental discovery. "Isn't this just what I need?" Galileo was very happy. Soon, one of Galileo's students wrote from Paris, further confirming the accuracy of the news. The letter said that although I don't know how Lipski made it, the optician must have made a lens barrel, which can magnify the object many times.
"lens barrel!" Galileo read the letter several times, and then hurried into his laboratory. He found paper and a gooseneck pen and began to draw a schematic diagram of lens imaging one by one. Galileo was inspired by the hint of the lens barrel. It seems that the secret of lens barrel magnifying objects lies in the choice of lenses, especially how to match convex lenses and concave lenses. He found the information about the lens and kept calculating, forgetting that he climbed the window at dusk and how dawn entered the room.
After a whole night, Galileo finally understood that if the convex lens and concave lens are placed at a proper distance, as the Dutch saw, distant objects invisible to the naked eye can be seen clearly after magnification.
Galileo was very happy. He forgot to rest and immediately began to grind his glasses, which was a time-consuming and meticulous job. He worked for several days, grinding out a pair of convex lenses and concave lenses, and then made an exquisite sliding double-layer metal tube. Now, it is time to test his invention.
Galileo carefully placed a large convex lens at one end of the tube and a smaller concave lens at the other end, and then pointed the tube out of the window. When he looked at one end of the concave lens, a miracle appeared. The church in the distance seems to be close at hand. He can clearly see the cross on the bell tower, and even a pigeon resting on the cross is very realistic.
The news that Galileo had built a telescope spread at once. "The news that I made a telescope spread to Venice." In a letter to my brother-in-law, Galileo wrote: "A week later, I was asked to show this telescope to the Speaker and Members of Parliament. They were very surprised. Gentlemen and members of parliament, although very old, all boarded the tallest bell tower in Venice in order and looked at the ships in the distance of the port, all of them could see clearly; Without my telescope, I can't see for two hours. The utility of this instrument can make objects 50 miles away look like they are within 5 miles. "
The telescope invented by Galileo, after continuous improvement, has a magnification of more than 30 times, which can enlarge the object by 1000 times. Now, he seems to have clairvoyance, and can spy on the secrets of the universe.
This is an epoch-making revolution in astronomical research. For thousands of years, the era when astronomers only observed the sun, moon and stars with naked eyes has ended, and optical telescopes have been replaced. With this powerful weapon, the door of modern astronomy was opened.
Now, whenever the stars shine or the bright moon is in the sky, Galileo will aim his telescope at the deep and distant sky and observe it day and night, regardless of fatigue and cold.
In the past, people always thought that the moon was a smooth celestial body, which shone by itself like the sun. But Galileo discovered through a telescope that the moon, like the earth where we live, has high mountains and low depressions (Galileo called it "ocean" at that time). He also found from the movement of the bright and dark parts of the moon that the moon itself cannot shine, and the light of the moon comes from the sun.
Galileo aimed his telescope at the Milky Way in the sky. People used to think that the Milky Way was a white fog formed by the condensation of water vapor on the earth, and Aristotle also thought so. Galileo decided to use a telescope to test whether this statement was correct. He was surprised when he pointed his telescope at the blurred band of light in the night sky. It turned out that it was not a cloud at all, but a gathering of thousands of stars in Qian Qian. Galileo also observed the mottled clouds in the sky-the so-called clusters, and found that clusters are also gathered by many stars, such as Orion cluster, Orion cluster and honeycomb cluster.
Galileo's telescope revealed the secrets of one universe after another. He discovered the satellites orbiting Jupiter and calculated their operating periods. Now we know that Jupiter has 14 satellites, and Galileo discovered the largest four of them. In addition, Galileo also observed sunspots through a telescope. He inferred from the movement of sunspots that the sun was also spinning.
One exciting discovery after another is enough for Galileo to write a book about the latest astronomical discoveries, and he wants to announce his observations to the world. 19 10 In March, Galileo's Star Messenger was published in Venice, which immediately caused a sensation in Europe.
However, he didn't expect that the secret of the universe uncovered by the telescope greatly angered many people, and a terrible doom was about to befall this outstanding scientist.
Miserable encounter
16 15 One winter day, the weather was extremely cold and the sky was covered with clouds. Galileo came to Rome alone. Five years ago, in 16 10, Galileo bid farewell to the University of Padua and returned to Florence to become a court mathematician and philosopher in Tuscany and a professor of mathematics at the University of Pisa. It was also in this year that he visited Rome and was warmly received and treated with high standards. His series of new discoveries in astronomy and the invention of telescopes were valued by Pope Paul V, and Roman nobles and scientists were honored to know him. However, only five years later, the face of Rome has completely changed. There are no flowers and smiling faces, and there are cold expressionless faces everywhere. Even familiar people stay away from him like the plague.
What happened? It turned out that this time, Galileo's name was blacklisted by the Roman Inquisition, and he was summoned to Rome for trial by the notorious Inquisition.
What crime did Galileo commit? Let's start from the beginning.
15 and 16 century Europe is a crucial period for the transformation from feudal society to capitalist society. For a long time, in order to consolidate the feudal ruling order, Europe ruled by theocracy replaced science with theology and freedom with barbarism. Theologians absurdly claim that the universe is full of "angels of all levels and each other's crystal balls", and the stationary earth is in the center of these crystal balls. They admire the ancient Greek astronomer Ptolemy's theory that the earth is the center of the universe, because in the eyes of theologians, the sun revolves around the earth, because God created the sun to illuminate the earth and treat mankind well. This is an eternal and irrefutable truth.
In order to maintain this absurd theory, the inquisition of the Catholic Church does not hesitate to use horrible violence against all those who dare to raise objections. 1327, Italian astronomer Tseko? Daskol was burned alive. His crime is that the earth is spherical and there are people living in another hemisphere, but he was persecuted for violating the teachings of the Bible. 1600, 17 In February, the Italian philosopher Bruno was burned alive in the Hundred Flowers Square in Rome, because he propagated Copernicus everywhere and shook the geocentric theory.
Galileo was Bruno's contemporary. As early as when he was teaching at the University of Padua, he had read Copernicus's book On the Hypothesis of Celestial Motion (aka:>). In this book, the outstanding Polish astronomer boldly put forward the theory that the sun is the center of the solar system and the earth and other planets revolve around the sun, that is, the sun-centric theory, which aroused Galileo's great interest from the beginning. But Galileo was a scholar with a very serious scientific attitude. He thought that in the past, it was said that the sun revolved around the earth, but Copernicus put forward the opposite view. Which one is correct? Instead of jumping to conclusions, Galileo decided to use his telescope to prove who was right and who was wrong.
When Galileo's book Star Messenger was published, he was already a staunch supporter of Copernicus. Through his own observation and research, Galileo gradually realized that Copernicus' theory was correct, while Ptolemy's geocentric theory was wrong, and many of Aristotle's views were untenable. Galileo not only published a paper criticizing Aristotle, but also supported Copernicus' theory unabashedly through letters, and even sent a copy of the letter directly to the Roman church. In Galileo's view, the conscience of scientists is to follow the truth.
However, the Vatican will never let Galileo go. First, they issued a severe warning to Galileo, and then called him to Rome for trial. 16 16 February, the Inquisition announced that Galileo was not allowed to publicize Copernicus' theory, and he was not allowed to speak Copernicus' theory as truth in his lectures or writing.
Galileo will never forget that Bruno was burned alive by these respectable black-robed guards 16 years ago. If he dares to resist, he will never end up better than Bruno.
Under the threat of the church, Galileo was forced to give up Copernicus. He returned to Florence with great pain and spent many years in silence.
However, Galileo did not give up Copernicus' theory in his heart. On the contrary, his constant observation and in-depth study made him more convinced that Copernicus' theory was completely correct. Galileo lived an isolated life in a Sydney villa on the outskirts of Florence. His health is not as good as before, and the disease is torturing him cruelly, but he still persists in propagating Copernicus' theory. After a long period of deliberation, it took almost five years to finally produce a great book, Dialogue between Two World Systems.
On the surface, Dialogue between Two World Systems objectively discusses Ptolemy's geocentric theory and Copernicus' Heliocentrism in the form of a three-person dialogue, and makes an impartial discussion on who is right and who is wrong. However, when this book was published in February 1632, it is not difficult for careful readers to see that this book strongly criticized the wrong theories of Aristotle and Ptolemy, scientifically demonstrated Copernicus' theory of earth movement, and declared the complete bankruptcy of religious theology with sufficient arguments and a large number of indisputable facts.
Soon, the church with a more sensitive sense of smell than hunting dogs sniffed out the terrible thoughts contained in this book, and the bold conclusions revealed between the lines made theologians feel great panic. Those academic swindlers who had been dissatisfied with Galileo for a long time immediately colluded with the church, accused Luo Zhi, and plotted to create public opinion for persecuting Galileo.
The irreconcilable struggle between science and theology broke out. 1632 In August, the Roman Inquisition banned the sale of this book, and the Pope appointed a special committee to examine the book. Galileo had a premonition of disaster, and sure enough, in June 5438+10, he received a document from the Inquisition, asking him to go to Rome for trial.
At this time, Galileo was 69 years old, suffering from illness and inconvenient to move. Many people who care about him plead for him everywhere, but the Pope said angrily, "Unless he is proved unable to move, he will be handcuffed and taken to Rome if necessary!" "
In this way, at the beginning of 1633, Galileo came to Rome with illness. As soon as he arrived in Rome, he lost his freedom and was put in the prison of the Inquisition. No one was allowed to contact him.
In this way, an appalling persecution in human history began. In the bloody and horrible court of the Roman Inquisition, truth was rejected by falsehood and science was judged by theocracy. Those hideous church judges threatened Galileo to give up his faith with the stake, or he would be executed.
Galileo, who was old and sick, was desperate. He knows that truth cannot be destroyed by violence. Although he can sever ties with Copernicus, no one can change the order of the celestial bodies in the universe.
Under the interrogation and torture of criminal law, Galileo was forced to publicly express his remorse in court, agreed to give up Copernicus theory and sign the verdict.
"In order to punish you for this serious and harmful mistake and sin, to be more cautious, and to set an example and warning for future people," the presiding judge in black robes read out Galileo's verdict in public. "We announced that Galileo's book Dialogue between Two World Systems was banned by public order; Sentenced to temporarily officially put you in prison, according to our opinion, and saved your confession, read seven confession hymns every week for three years ... "
Galileo's later years were very miserable. The scientist who opened the human horizon and revealed the secrets of the universe was completely blind in 1637 and fell into boundless darkness. His only relative, his youngest daughter Maria, died before him, which was a great blow to him. However, even so, Galileo did not lose the courage to explore the truth. 1638, one of his "Discussions on Two New Sciences" was published in the Netherlands with the help of friends. This book is a systematic summary of Galileo's long-term research on physics and the first masterpiece of modern physics. Later, the inquisition relaxed its surveillance on him, and several of his students, including the famous physicist and discoverer of atmospheric pressure Torricelli, came to the old man's side to take care of him and ask him for advice. They can discuss scientific inventions happily together again.
1642 65438+1On October 8th, 78-year-old Galileo stopped breathing. But the truth he defended all his life is immortal. Ironically, today, more than 300 years later, 1979, 165438+ 10, at the meeting of bishops, the Pope proposed to reopen the Galileo case. To this end, world-renowned scientists formed a review Committee to review this unjust case. In fact, where is it necessary to try anything? Spaceships fly in space, humans leave deep footprints on the surface of the moon, satellites fly in the sky, and radio waves sent back by space probes fly out of the solar system ... These advances in modern science and technology have declared the complete bankruptcy of religious theology, and mankind will always remember the dazzling name Galileo.
Main contribution
It can be divided into the following three aspects:
① mechanics
Galileo was the first scientist to introduce experiments into mechanics. He determined some important mechanical laws through the combination of experiment and mathematics. 1582, after long-term experimental observation and mathematical calculation, he got the isochronous law of pendulum. Later, he dropped out of school on 1585 due to family financial difficulties. When he left the University of Pisa, he deeply studied the works of ancient Greek scholars Euclid and Archimedes. He wrote his first paper entitled "Balance" based on the principle of lever and buoyancy. Soon after, he wrote a paper on gravity, which revealed the essence of gravity and center of gravity for the first time and gave an accurate mathematical expression, so he became famous at one fell swoop. At the same time, he questioned many viewpoints of Aristotle.
During the period of 1589 ~ 159 1, Galileo made a detailed observation on the motion of falling objects. Theoretically and experimentally, it is denied that Aristotle, who has ruled for thousands of years, established the correct "law of free fall" on the "law of falling body motion", that is, under the condition of ignoring air resistance, balls with different weights fall to the ground at the same time, and the falling speed has nothing to do with the weight. According to V. viviani, a student in Galileo's later years, the falling experiment was conducted in public on the leaning tower of Pisa: 1589, one day, Galileo dropped an iron ball weighing 10 pounds and landed almost at the same time, and all the competitors present were dumbfounded and shrugged their shoulders in laughter. However, Galileo's works did not clearly indicate that the experiment was carried out on the leaning tower of Pisa. So it has been controversial for several years.
Galileo made a detailed study on the basic concepts of motion, including center of gravity, speed and acceleration, and gave a strict mathematical expression. Especially the concept of acceleration is a milestone in the history of mechanics. With the concept of acceleration, the dynamic part of mechanics can have scientific basis, while before Galileo, only the static part was described quantitatively.
Galileo informally put forward the law of inertia (see Newton's law of motion) and the law of motion of objects under the action of external forces, which laid the foundation for Newton to formally put forward the first and second laws of motion. Galileo was the pioneer of Newton's creation of classical mechanics.
Galileo also put forward the law of resultant force and projectile motion's law, and established Galileo's relativity principle. Galileo's contribution to mechanics is various. This is described in detail in his mechanical book Dialogue between Two New Sciences and Mathematical Proof written in his later years. In this immortal book, besides dynamics, there are many contents about mechanics of materials. For example, he expounded the bending test and theoretical analysis of beams, and correctly summarized the mechanical similarity relationship between the bending capacity and geometric dimensions of beams. He pointed out that for cylindrical beams of similar length, the bending moment is proportional to the cube of radius. He also analyzed the simply supported beam under concentrated load and correctly pointed out that the maximum bending moment is under load and is proportional to the product of its distance to two points. Galileo also analyzed the problems that should be paid attention to when applying the beam bending theory to practice, and pointed out that the size of engineering structures should not be too large, because they would be destroyed under their own weight. According to his experiments, he came to the conclusion that when the body size of animals decreases, the strength of their bodies does not decrease proportionally. He said, "A puppy may be able to carry two or three dogs of the same size, but I believe a horse may not be able to carry a horse of the same size."
② Astronomy
He was the first scientist who made great achievements in observing celestial bodies with a telescope. These achievements include: the discovery that the surface of the moon is uneven, Jupiter has four satellites (now called Galileo satellites), the rotation of sunspots and the sun, the profit and loss of Venus and Jupiter, and the Milky Way is composed of countless stars. He confirmed Copernicus's "theory of earth movement" with experiments, and completely denied Aristotle and Ptolemy's "theory of earth movement" which ruled for more than 1000 years.
③ Philosophy
Throughout his life, he insisted on fighting against idealism and scholasticism, advocated understanding the laws of nature with concrete experiments, and believed that experience was the source of theoretical knowledge. He denied the existence of absolute truth and absolute authority to master the truth in the world, and opposed blind superstition. He acknowledged the objectivity, diversity and infinity of matter, which is of great significance to the development of materialist philosophy. However, due to historical limitations, he emphasized that only material attributes that can be summarized as quantitative characteristics exist objectively.
Galileo "abandoned" Heliocentrism because he supported Heliocentrism's imprisonment. He said, "Considering various obstacles, the shortest line between two points is not necessarily a straight line". It is precisely because of this idea that he temporarily gave up for eternal support, instead of being as brave as Bruno, he could continue to contribute his strength to science.
Galileo and his scientific discoveries
In ancient Greece, there were two schools of physics, one represented by the philosopher Aristotle and the other by the natural scientist Archimedes. Both of them are famous scholars in ancient Greece, but their scientific conclusions are different because of their different viewpoints and methods, forming a sharp opposition. Aristotle's view is basically idealistic, and he draws conclusions by subjective thinking and pure reasoning, so it is full of fallacies. Archimedes' view is basically materialistic, and he relies entirely on scientific practice to draw conclusions.
However, since 1 1 century, with the support of the Christian church, Aristotle's works have attracted the attention of scholastic philosophers, who rejected Archimedes' physics and regarded Aristotle's physics as a classic, and all scholars who violated Aristotle's physics were regarded as "heresies". But Galileo was skeptical about Aristotle's physics. On the contrary, he paid special attention to the study of Archimedes physics. He attaches importance to integrating theory with practice, observes various natural phenomena and thinks about various problems. When Galileo was eighteen, he once went to the church in Pisa. He noticed that the ever-burning lamp hanging in the church was regularly swung from left to right by the wind. He timed them according to the pulse and found that the reciprocating time was always equal. In this way, he discovered the synchronicity of pendulum. Later, the Dutch physicist Huygens made a hanging pendulum clock according to this principle, which was called "Galileo clock".
According to Archimedes' theory, Galileo studied the hydrostatic balance for rapid determination of alloy composition, invented the "small balance" for measuring material density, and wrote a paper called "small balance". Later, he devoted himself to studying the geometry of the center of gravity of objects, and published the article "Center of Gravity of Solids" in 1588, which attracted the attention of academic circles. The following year, on the recommendation of a friend, he was hired as a professor of mathematics by the University of Pisa.
Aristotle believes that two objects fall at the same height, and the heavier object falls first than the lighter one. But after repeated research and experiments, Galileo came to the opposite conclusion: the falling speed has nothing to do with the weight. 1590, Galileo made a falling experiment on the leaning tower of Pisa, which proved that Aristotle's statement was wrong, which shook Aristotle's theory that ruled people's thoughts for more than 2000 years for the first time. However, some famous scholars invited to watch denied what they saw with their own eyes, and they attacked Galileo. Galileo was expelled from Pisa in 159 1 year.
Just ... see the link.