Italian Philosopher, physicist, mathematician and most importantly astronomer, Galileo Galilei is one of the the most influential scientific figures of the renaissance era, and is still a household name. His questioning on already formed theories in physics and astronomy, his improvements of the telescope, and his books and journals have shaped the world for what it is today. This essay will go through the eventful life of Galileo, going through his various discoveries, theories, inventions and controversy as he became the “The Father of Modern Science”.Galileo was born on February 15th, 1564 in Pisa Italy, as the oldest son in his family 2. His father was a musician and taught Galileo a very important lesson that would shape his life; “the value of well-measured or quantified experimentation”. Galileo began his academic journey in medical school at The University of Pisa but soon realized his passion for Mathematics, and eventually switched to Mathematics and philosophy, though he never graduated 6. In 1592, he moved to become a mathematics professor at the University of Padua, a position he held until 1610, during this time he worked on a variety of experiments. One of these experiments was the careful observation of the sky through his telescope which led to him quitting his job as a professor. His observations led him to believe in the Copernican system3. His support for said system landed him in trouble with the catholic church, which accused him of heresy twice, the second occasion left him under permanent house arrest to the end of his life. At age 72, Galileo had gone blind. Many believe that Galileo had gone blind due to his extensive observation of the sun using his telescopes, but this is actually false. Galileo became visually impaired through a combination of cataracts and glaucoma1. He passed away on January 8, 1642 in Arcretri near Florence, Italy as the result of his suffering from a fever and heart palpitations, leaving behind two illegitimate daughters and one son from his relationship with Marina Gamba and a great legacy as the “The Father of Modern Science” 3. .Galileo wrote many books during his career The Operations of the Geometrical and Military Compass which covers how to conduct an experiment, The Starry Messenger (1610) showed the earth was spherical and not flat, Discourse on Bodies in Water, Dialogue Concerning the Two Chief World Systems (1632) his most controversial publication that brought turmoil with the church and Two New Sciences (1638) which summarized his life’s work.Galileo is respected as one of the most, if not most influential astronomer in history, but his work also changed science as a whole. Galileo did his best to separate science from philosophy by focusing on pure observation8. He also understood the importance of variables and mathematics in order to produce scientific theories. This scientific method is still used today by all scientists conducting experiments to build theories. One of Galileo’s early experiments involved in what today has become basic physics. His first experiment debunked Aristotle’s theory that heavy objects fall faster compared to lighter objects. Galileo conducted an experiment by setting up a series of trials determining at what rate of acceleration balls of different weight rolled down an incline, determining the position of the balls after a set time. He noting that the rate of acceleration was not related to the weight of the ball8. This was the start of the law of acceleration used in physics today. The shape of the parabola was also developed by Galileo, which was discovered by an experiment using a pendulum. During this time there was no accurate way to tell time. He determined that the time it takes a pendulum to swing back and forth does not depend on the arc of the swing. Near the end of his lifetime, Galileo designed the first pendulum clock, that was actually made by his son3.As stated earlier, Galileo’s impact on astronomy was substantial. The way we observe space and the universe is derived from his inventions and methods. While, Galileo is a well known name, there are many misconceptions on his work and personal life3. Most notably, many believe he invented the telescope but he actually improved the telescope, which was invented by Hans Lippershey as a toy, by producing lenses that increased the magnification by up to 20 times, when others could only increase magnification up to 3 times8. Originally designed for spotting ships from the coast, he then started looking into the sky. With his powerful telescope, Galileo was able to observe the universe like no one before him. He discovered craters on the moon, Jupiter and its moons, that saturn had a ring and that venus had phases just like the moon 3. In 1616, Galileo decided to publish his new findings, which would be the first of many in his career2. His innovation in telescopes are beneficial to the evolution of the telescope today; now seen in the Hubble and Herschel. Aristotelian philosophy suggested Earth was the centre of the universe. The observation that venus had phases just like the moon was ultimately what made him shift from the Aristotelian to the Copernican heliocentrism. Copernican suggested the Sun was the centre of the universe while earth was a planet like venus that orbited around the sun. This did not sit well with the catholic church who supported aristotelian philosophy6. Later that year he was summoned by Rome on the accounts of heresy and was warned to not not teach nor write on the subject2. Galileo initially followed the orders because he was a devoted catholic. Seven years later he released a book that again promoted Copernicanism.The church responded accusing him of heresy and in a final attempt to break him, Galileo was threatened with torture which led him to publicly deny the Copernican theory, but privately held that his statements were correct. He was convicted of heresy and spent his remaining years under house arrest. Galileo wrote his book “Two New Sciences” during that time and it was published in Holland in 1638. By this time, Galileo had become blind and in ill health. In time, however, the Church couldn’t deny the truth in science. In 1758, it lifted the ban on most works supporting Copernican theory and heliocentrism.The heliocentric model was just a theory, but it was proved true by Galileo’s findings 9. Thus, Galileo helped solidify the heliocentric model as the correct model, and that has resulted in significant knowledge gained by astronomers.There is little doubt that Galileo Galilei was one of the most influential scientists of modern times and deserves the nickname “The Father of Modern Science”. Not just because of his use of the telescope and finding the existence of gravity, which although was not discovered and named until Isaac Newton, and the overall study of astronomy, but to science as a whole. His contribution to the scientific method laid the foundations of modern science, and his perseverance to strive for what he believes in will never be forgotten.