Galileo Galilei: Father of Modern Science

Galileo Galilei was a truth seeker. His quest for truth, though, was to bring him into conflict with the most powerful institution of his day, the Roman Catholic Church. Through such inventions as the telescope, he revealed truths that landed him in front of the Holy Roman Inquisition, fighting for his very survival. Condemned during his life, he is now revered as a true genius. In today's Biographics, we're getting the full story on Galileo Galilei. Galileo Galilei was born on February 15, 1564, in Pisa, Italy. He was the first of six children to Vincenzo de' Bonaggiuti di Galilei and Ghila Galilei. The Galileis were from an ancient and respected family who originated in Florence. Vincenzo was a wool trader who had an abiding interest in philosophy, science, and music. At the age of four days, young Galileo was baptized Catholic. He was raised according to the strict tenets of the faith, as was everybody else in the region. From an early age, Galileo showed an intense interest in making things. He was constantly making small little gadgets that would amuse his friends and teachers. These would include wooden animals with moving arms and legs. He was fascinated by how machines worked, and he'd be constantly pulling things apart and putting them back together again. If he was making a machine himself, and he didn't have a part, he'd simply improvise. When Galileo was ten years of age, his father decided to move the family to Florence. By now, Vincenzo had developed a reputation as a learned and wise man. Despite the demands of business, he managed to write several books, the most popular of which was The Dialogue of Ancient and Modern Music. Wealthy people streamed to him to benefit from his knowledge of Greek and Roman literature and to hear his musical theories. He was invited to spend some time with Duke Albrecht of Bavaria, who lived in Munich, Germany, some 300 miles from Florence. Vincenzo was also an active member of the Florentine Camerata, a group of musicians who were experimenting with musical drama, and that was the genesis of what would become opera. Galileo and his siblings were therefore raised in an intellectually stimulating environment. Vincenzo taught his oldest son how to play a number of musical instruments, the favorite of which, for both, was the lute. Galileo also experimented with drawing and painting, and showed great promise in both of these areas. His teenage years coincided with the High Renaissance period, when Italy was being filled with the works of the great painters, sculptors, and architects. He considered devoting his life to that of an artist, but his father was keen for his son to follow him into the wool trade. Vincenzo had a great passion for the arts, but he knew that nothing but a solid business career would secure a stable financial future for his son. By the time that Galileo had reached his mid-teens, it was apparent to everyone, including his father, that his keen mind was destined for greater things than life as a wool trader. Vincenzo saw it his duty to encourage Galileo to use his God-given intellectual talents to the fullest extent. Through his studies of the works of Aristotle, Vincenzo had instilled in his son the discipline of independent study, observation, and experimentation. Rather than being swayed by what others had already concluded on a matter, he would independently study the subject for himself, and reach his own conclusions based on those observations. When he was fifteen years of age, Galileo attended the Benedictine Monastery of Santa Maria de Vallambrosa. From the monks, he learned religion and logic. After a few months, however, he had to return home because he got an eye infection. When he was seventeen, Galileo passed the bachelor's exam, which permitted him entry to the University of Pisa. Universities in the 16th century were places attended by members of only the wealthiest families, and were generally reserved for those with the ambition of becoming a priest, a doctor, or a professor. Although Galileo seriously considered the priesthood as a young man, Galileo, or more likely Galileo's father, had decided on a career in medicine for him. In order to achieve it, he first had to obtain a master's degree. Galileo applied himself to his studies, and made excellent progress. However, several months into the first year of his medical degree, he happened to overhear a geometry lecture being delivered by a friend of his father, Austilio Ricci. He was immediately attracted to the logic and beauty of the math being applied. When Ricci heard from Galileo's father that the boy was fascinated with his lecture, he invited him to take his course. Vincenzo had first made Ricci promise not to let Galileo know that he had consented to him taking the geometry paper, in case he saw it as permission to abandon his medical studies. In addition to attending geometry lectures, Galileo worked one-on-one with Ricci as he studied the works of the Greek mathematician Euclid. As he became more deeply immersed in the subject, Galileo became less interested in medicine. Finally, he confronted his father and asked him not to stand in the way of his focus on geometry. Vincenzo was a realist. He knew that his son would not prosper as a doctor if his heart wasn't in it. He agreed to support Galileo in his mathematical pursuits. After switching to mathematics, Galileo brought his full intellectual rigor to bear on the subject. He was an excellent student, but he still managed to frustrate his professors. The inclination to question everything that his father had instilled in him meant that he would not accept anything as fact. Established theories were meaningless unless he had personally pulled them apart, studied them, and reached his own conclusions. It was the Aristotelian scientific method in action, but it even caused the teenager to question the theories of Aristotle himself. One day, when he was 19, Galileo happened to be in the Pisa Cathedral for a mass observance. After the service, he was wandering around the building when his attention happened to be caught by a sculpted bronze lamp located in the dome of the cathedral. The lamp was swinging back and forth like a pendulum. He observed that, regardless of the lessening arc of the swing, the time it took for each swing remained the same. To check this observation, he timed the swings with his pulse. This led him to the realization that the rhythmic swings of a pendulum were an excellent way to measure the human pulse. This was the inspiration for the later invention of Galileo's machine that was designed to take pulses, or a harmonic oscillator. This was the first example of Galileo not only observing and testing phenomena, but also finding practical applications of his findings. By 1585, the financial strain of supporting his son's university studies was too much for Vincenzo, and Galileo had to withdraw from the University of Pisa. He hadn't yet completed his doctoral degree, but the budding genius was not to be deterred. He embarked upon his own studies by examining the works of the great minds of Ancient Rome and Ancient Greece. After dissecting the works of Archimedes, he wrote his first scientific dissertation in which he described an invention he called the Little Balance. This was a hydrostatic scale to measure the air-water balance. He also developed a horse-powered pump for crop irrigation that was inspired by the famous Archimedes' screw. Just as his father had a decade earlier with his muscle talent, Galileo began to impress important people with his practical application of science. He gained a reputation as an up-and-coming scientist. One person who was particularly interested in Galileo's work was the Marquis Guidobaldo de Monte, a wealthy patron with an abiding interest in astronomy, mathematics, and architecture. The Marquis began writing to Galileo, and the two maintained a vigorous correspondence during which Galileo would explain his latest observations and applications. de Monte encouraged the 22-year-old Galileo to study the center of gravity in solid bodies, which ultimately led to the publication of a treatise on the subject. It was through de Monte that Galileo came to the attention of the Grand Duke of Tuscany, Ferdinand I de Medici. In 1589, the Grand Duke appointed him as a Professor of Mathematics at the University of Pisa. This was the position that Galileo had been hoping to secure ever since he had been forced to quit his studies. At the time, mathematics was a minor subject of study at university that wasn't even seen as worthy of study by many people. Galileo's salary was only 60 florins a year, while philosophy professors earned 600 or more. In addition, he was looked down on by them as a young upstart who dared to question the teachings of the great Aristotle. To them, this was akin to blasphemy, with the writings of Aristotle being considered the final word on all things. Ironically, Galileo was simply following through on the teachings of Aristotle himself, who championed independent study and observation, well aware that his own theories could well be overturned as new knowledge was observed. The most famous example of Galileo not simply accepting one of Aristotle's theories because it was written down on paper had to do with the speed of falling objects. Aristotle had contended that two objects of different weights would fall to the ground at different speeds, with the heaviest object falling faster. As the story goes, Galileo climbed to the top of the leaning Tower of Pisa, although the building thought to have been used may have been the church tower in Delft, and then he dropped two spheres of different masses to the ground below. They both hit the ground at the same time, disproving Aristotle's theory. Galileo's experiment at the Tower of Pisa was believed to have been observed by many of his students and fellow professors of the university. Still, some of the professors refused to acknowledge that the young man had just overturned one of Aristotle's theories. This stubborn refusal to accept empirical evidence that overturned long-entrenched views is something that Galileo was going to contend with for the rest of his life. specific scientific concept, and then you're asked to solve a problem based on that information. It's an incredibly effective way to learn, and right now Brilliant have something relatively new on their platform called Daily Problems. These are problems you can do for five minutes a day. They exercise your brain, and they teach you something new. If you're into learning new things, which you probably are because you're watching this channel, Brilliant is great for you. With each problem, it provides you the context and the framework you need to tackle it. That means you can learn concepts by applying them. That's that active learning stuff. This sort of short daily practice can lead you from curiosity to mastery in far less time than you would think. So go to brilliant.org forward slash biographics and finish your day a little smarter. The first 200 of you to do so will get 20% off your annual subscription, and you'll be able to view all of the problems in the archives. Let's get back to Galileo, because he's about to make some enemies. Not long after the tower experiment, Galileo was approached by a member of the powerful Medici family, Giovanni de' Medici, and asked to evaluate a machine he had invented. The machine was designed to dredge the harbour bottoms of Lacon to remove the mucky layer and make them safer for ships to come into. Galileo carefully studied the machine, only to conclude that it was badly designed and not fit for purpose. This presented a bit of a problem. Should he be honest and tell the man that the machine wouldn't work, or should he placate him with false praise? The Medicis were the most powerful clan in Italy, and Galileo was very wary of getting on the wrong side of any of them. Still, his loyalty to scientific truth would not allow him to deceive the inventor. In a public forum, he spelled out what was wrong with the machine, and assured everyone present that it would not work. His opinion was borne out when the machine proved to be a dismal failure. Galileo's honesty had created a powerful enemy. The humiliated Medici man was determined to bring Galileo down, and he set about getting him fired from his professorship at the University. Under the advice of Marquis Guidobaldo de Monte, Galileo resigned his position. De Monte had opened the door to a new posting as the Chairman of Mathematics at the University of Padua, 130 miles northeast of Pisa. This was a big step up for Galileo. He was now making 180 florins, which was three times his previous income. Also, he no longer had to contend with the ridicule of his fellow professors. He soon became a very popular lecturer, with his classes almost overflowing. At Padua, he also found the time to work on his inventions and writings. He became an expert at applying science to military fortifications, designing reinforced walls for forts, and mechanically superior siege engines. In 1593, he was invited to Venice to give advice on the ideal positioning of a rowing ship's oars to generate maximum use of manpower. In 1593, Galileo developed an undiagnosed illness which kept him in pain, affected his appetite and robbed him of sleep. These symptoms would affect him for the rest of his life. Despite his sickness, he managed to meet his university obligations. At the end of his first six-year term at Padua, he was appointed for a further six years. By the end of the 1590s, Galileo had invented a range of products which were in demand all over the country. These included an irrigation pump that required only a single horse to power it, and the sector, which was used to measure precise angles. Lacking the time to produce each piece himself, he hired a craftsman named Marcantonio Mazzaleni to make his inventions. It wasn't until the mid-1590s that Galileo took any serious interest in astronomy. Without studying the issue, he believed in the Ptolemaic theory that the Sun and other planets revolve around the Earth. When a visiting lecturer spoke on the Copernican theory which contended that the Earth and other planets actually revolve around the Sun, Galileo did not attend, considering the theory to be ridiculous. Some time later, he was talking with some of his students who had attended the lecture. Most of them didn't accept the new theory, but there was one person who did. It was then that Galileo had a simple but profound realization. Every person who had abandoned the Ptolemaic theory in favor of the Copernican theory would be subjected to ridicule. They would, therefore, only do so on the basis of overwhelming evidence. He was now obsessed with finding out what that evidence was. The question of whether the Sun or the Earth was at the center of the universe would consume him for the rest of his life. Even though he continued to teach the theories of Ptolemy in his classes, he became more convinced that Copernicus was right. In 1597, he established written communication with the German astronomer Johannes Kepler, who was also an advocate of the Copernican theory. Kepler had published a work supporting Copernicus, and encouraged Galileo to do the same. However, the Italian was worried that doing so would bring upon him the anger of the Catholic Church, which held that the Earth was undoubtedly at the center of the universe. On a visit to Venice, Galileo met a woman by the name of Marina Gamba. A relationship developed, with Marina moving in with him. Before long, a child was born to the unwed couple, the first of three, two girls and a boy. In 1610, Galileo left Padua, taking his two daughters, both given to the convent eventually due to their illegitimate births, but he left behind his son, Vincenzo, with Marina. Years later, Marina married another man, but Galileo remained friendly with her throughout his lifetime. In the first decade of the 1600s, Galileo continued to invent new technologies. In 1604, he observed and discussed Kepler's supernova. His talk was so popular that he had to move from the overcrowded lecture theatre to an outside forum so that everyone could hear him. In 1609, Galileo began working on a machine that would magnify the night sky. He used two eyeglass lenses, one concave and the other convex, placing them at opposite ends of a long metal tube. When looking through this Venetian glass, later called a telescope, the stars were magnified several times. The invention was a hit and prominent people from all over Italy clambered to get a look at this amazing machine which allowed you to see things that were far away. His telescopes were also a profitable sideline for Galileo, who sold them to merchants who found them useful both at sea and as items of trade. The invention reflected positively on the University of Padua, prompting the board to offer Galileo a lifetime professorship and increase his salary to 1,000 florins. Before long, Galileo had improved his telescope until it was able to magnify up to 30 times. This enabled him to look through it at the moon. He discovered that, rather than being perfectly round and smooth as Aristotle had written, it was rough and filled with craters and valleys. His telescope also enabled Galileo to identify and observe the moons of other planets. During the period between January 8th and 14th, 1610, he discovered that Jupiter had four moons. Then, in July of that same year, he became the first person to identify the rings around Saturn, though he didn't quite realize what they were at the time. Later that year, he identified that Jupiter and Mars had phases which were similar to the moon. Through his telescope, Galileo was able to identify that there were many, many more stars than had originally been thought and that, therefore, the universe was simply much larger than previously thought. This upset many people who thought that, through his telescope, Galileo was using some form of trickery to make new discoveries. In 1609, he was invited to move to the palace of the Grand Duke in Florence. He accepted, moving back to his home region of Tuscany. His job now involved giving lectures to princes and other members of the royal family. No longer having to lecture, he now had the freedom to study and write books. By 1615, there was a rising tide of opposition to Galileo. Many of his discoveries had flown in the face of accepted church doctrine, which was closely aligned with the teachings of Aristotle. People began asserting that his findings were at odds with the scriptures, which were the revealed word of God. Galileo responded by writing that the Bible was not a scientific textbook, but where it touched on science, it was actually in harmony with his findings. He thought that people had simply interpreted the scriptures incorrectly. The letter that Galileo wrote soon found its way into the hands of his enemies, particularly the Dominicans of St. Mark. They viewed what he had written as heresy, and they made sure that a copy of the letter got in front of the Pope in Rome. The Pope called for the leading Dominican to come and give testimony about Galileo. This man made the most of the opportunity, telling lies to paint Galileo and his followers as blasphemous. Galileo was not a coward. He considered those who spoke against him as ignorant fools, and he set out to defend himself. To do so, he travelled to the center of the cauldron itself, Rome. He appeared before the Holy Office on February 26, 1616, and was ordered to never again teach that the sun was the center of the universe. His reasoned argument in his defense fell on deaf ears. Galileo remained in Rome to argue with his detractors. This was not pleasing to his patron back in the court of Tuscany, who felt that the conflict could cause a rift between them and Rome. In June, Galileo finally complied, returning to Florence. The stress of defending his reputation had taken a toll on Galileo. He was constantly plagued with physical pain, and spent increasing amounts of time bedridden. In 1617, he moved to a hilltop villa just outside of Florence in order to benefit from the rural air. He continued to study the heavens, but was now far more guarded about what he wrote. Then, in 1618, his ailments worsened. He was confined to bed for several weeks, and he became extremely weak. By 1624, there was a new pope, Urban VIII. As a cardinal, he had expressed admiration for Galileo, but he had never agreed with the Copernican theory. A slightly recovered Galileo was convinced to make a pilgrimage to Rome in order to meet with the pope in order to assess his standing with the pontiff. Urban received him well, even presenting a medal and promising a pension. Galileo also noticed that the church officials around Rome were far less hostile to him than they had been before. He felt confident, believing that the new pope had eased the pressure on him. In 1629, Galileo wrote a masterful work, Dialogue Concerning the Two Chief World Systems, which presented a dialogue between three men on the merits of the Ptolemaic and Copernican theories. Before it could be published, he had to present it to the chief censor of the press in Rome. He was forced to make changes that presented the Ptolemaic theory in a far more favorable light, and to state clearly that the ideas expressed were not facts, but opinions. Galileo made the changes, but a series of delays prevented the book's publication until 1632. The new book brought out the ire of the enemies of the now 68-year-old Galileo. When Pope Urban got to read it, he became enraged. He became convinced that one of the three debaters in the book was based on himself, and he considered this to be an insult of the highest level. In August 1632, all copies of the book sold in bookstores were seized, and the printer was ordered to cease publication. Then, in September, Galileo was ordered to appear before the Holy Roman Inquisition. After stalling due to ill health, he finally headed to Rome to face his inquisitors on January 20, 1633. He had to wait until April 12 to appear before the vice commissioner of the Holy Office and two other examiners for preliminary questioning. It was stated that his book was in direct violation of the 1616 oath he had taken not to publicly discuss the teachings of Copernicus. In his defense, Galileo contended that the book was simply a dialogue between the two theories and did not favor the view that the sun was at the center of the universe. A second interview was held on April 30. This time, Galileo was more conciliatory, agreeing that the arguments in favor of the Copernican theory come to the ear of the reader with far greater force and power than should have been imparted to them by someone who regarded them as inconclusive. The interview concluded with the examiners agreeing to give Galileo time to prepare his full defense. That hearing was held on June 21. Before he could fully develop his defense, he was asked point blank whether he had ever held to the Copernican theory. He answered that he had initially been indifferent to both theories, but after careful study, now believed in the wisdom of the Ptolemaic theory. This was clearly not true, and none of the examiners believed him. The following day, he was sentenced to prison with the term to be decided later, and his book was banned. He was then made to read a statement of apology on bended knee. Pope Urban seemed satisfied with this outcome. Galileo had been both condemned and humiliated. The Pope decided that the imprisonment for which Galileo had been sentenced could be carried out by way of home detention at the Grand Duke of Tuscany's villa near Rome. However, Galileo was desperate to live out his last years in Florence, where his family were located. He wrote to the Pope, begging his indulgence, which he was granted. He would be confined to the villa of a powerful friend. After five months, he was permitted to return to his own villa. Galileo's final years were marked by ill health. By 1637, he was nearly totally blind. Before his sight was gone completely, he managed to complete his last and, in his view, his most outstanding work, entitled Discourses and Mathematical Demonstrations of Two New Sciences. Under the rules of his sentence, he could not publish it in Italy, and so the manuscript was smuggled to Amsterdam and published there. During his last days, the blind genius received many visitors to his villa. He died on January 8, 1642, at the age of 77. He had been fighting fever and heart problems for months. Nearly a hundred years later, with his brilliance having finally been recognized, his remains were removed from the chapel at Santa Croce and relocated to a much more elaborate mausoleum inside the church. During this move, three fingers and a tooth were removed from his remains. One of these fingers, the middle finger from Galileo's right hand, is currently on exhibition at the Museo Galileo in Florence, Italy. A monument was also erected with a bust of Galileo and two figures, representing his monumental achievements in the worlds of astronomy and geometry.