Born 1564, Galileo Galilei is credited with establishing the modern experimental method. Before Galileo, knowledge of the physical world that was advanced by scientists and thinkers was for the most part a matter of hypothesis and conjecture. In contrast, Galileo introduced the practice of proving or disproving a scientific theory by conducting tests and observing the results. His desire to increase the precision of his observations led him to develop a number of inventions and discovery, particularly in the fields of physics and astronomy. Galileo is with us today at age 70 and is willing to share with us some of his past achievements and discoveries as well as the many challenges he faced throughout his astonishing career. I will be conducting a simple interview with him and hopefully, we'll gain a better understanding of this ordinary person with an extraordinary mind.

Dennis: I am very glad you could make it, I'm sure many of us are dying to find out exactly what you've accomplished throughout your life.

Galileo: Thank you, I am honored to be here and cherish the chance to help answer any questions you may have.

Dennis: Ok so let's start with your early education, can you describe your life when you were an adolescent?

Galileo: When I was young, I received an education at a monastery near Florence. Later, I entered the University of Pisa to study medicine. I wasn't exactly interested in science and mathematics back then as I am now, but that would soon change in a matter of years.

Dennis: I've heard that you've received inspiration from a hanging lamp? What exactly is the story behind that?

Galileo: Haha, ah yes the lamp…while I was a student at Pisa, I observed a hanging lamp at one of the chapels that was quite peculiar. I noticed that when the lamp was swinging back and forth, the amount of time it took the lamp to complete an oscillation remained constant, even as the arc of the swing steadily decreased. I didn't think much of it at first, but I soon realized that this was something new and intriguing and before I knew it, I was studying the physics behind the pendulum.

Dennis: That is certainly interesting, can you perhaps give us a brief summary on what you've discovered about the pendulum?

Galileo: Well, I've observed many things about pendulums some of which I'll mention here. First off, I've noticed that pendulums always return close to their released heights. I believe that friction in the air slow the pendulum down slightly, otherwise, a pendulum's arc height would remain constant.

Secondly, I've observed that pendulums with less mass usually come to rest faster then those with a heavier mass when the length of the string is the same. I believe this is because it takes less opposing forces to slow a light pendulum then a heavier pendulum causing the light one to stop sooner despite the two having the same oscillation time.

Finally, perhaps the discovery that took the most thinking and agonizing is why the oscillation time remains the same despite weight and angle differences when the string length is constant. The answer is easier then many have realized. When a pendulum's release height is increased, it gains a lot more potential energy because of its higher elevation, which is then transformed into kinetic energy upon release. This causes the pendulum to swing considerably faster then another pendulum released at a lower elevation. One oscillation of the first pendulum is therefore equal to one oscillation of the second pendulum because even though there's more distance in each swing, the pendulum has a greater velocity, which makes up for the distance. For example, if you have two balls of the same weight dropped from different elevations, in order for the balls to both hit the ground at the same time, the ball at the higher elevation has to fall much faster then the ball at the lower elevation. That is exactly what happens with a pendulum and why every oscillation takes the same amount of time. I hope that clarified some things for you.

Dennis: Yes that definitely explained a lot, so how has this pendulum helped the scientific community?

Galileo: Well, since the pendulum's oscillation time was so predictable and remained fairly constant, I was able to incorporate that into an instrument that measured specific increments of time. Later, it was used to measure pulse rates and I've also heard that there have been plans to build some type of clock using the pendulum.

Dennis: That is certainly amazing, however, that is just the tip of the iceberg with you right? So what other inventions have you created?

Galileo: Well, I've made a hydrostatic balance that measures the density of objects when placed in water. This was about the same time I decided to focus my life on mathematics and science instead of medicine.

Dennis: You've done so many things in your life I couldn't even begin listing them all, could you perhaps give us a brief run through of your many experiments and your results or findings?

Galileo: Certainly. At Padua, I conducted many experiments with falling objects. Aristotle had stated that heavier objects should fall faster than a lighter one. I tested his assertion by climbing the leaning tower of Pisa and dropping various weights to the ground. This proved conclusively that all objects, regardless of weight, fall at the same rate.

Dennis: Aristotle! Ha what does he know right?

Galileo: Agreed! Anyways, after that test, I proceeded to test a few more things such as the speed of light, which kind of failed. I also invented a few small gadgets here and there such as the thermometer and telescope, but nothing major really.

Dennis: Haha, you invented the telescope? I thought a person named Hans Lippershey invented the telescope.

Galileo: Well…umm….yah he made the “first” telescope but I mean c'mon, we all know that I am the Real creator of the telescope.

Dennis: But…

Galileo: No, buts…I am the inventor of the telescope and that's final!

(Please note: Many people believed Galileo invented the telescope, however, that is not the case for he merely stole the design from someone else and improved upon it)

Dennis: Anyways moving on. So tell us about your astronomy career? What discoveries did you make?

Galileo: Well, using the telescope that I invented, I was able to observe our various neighboring planets and their satellites or moons. I discovered the four moons of Jupiter and was able to discern mountain ranges and canyons on the surface of our own moon. I also studied our own Milky Way galaxy as well as observing and recording the paths of sunspots on our sun. After studying the paths and orbits of moons, stars and planets, I was able to conclude that our solar system was based on the heliocentric model instead of the geocentric model which so many had previously believed.

Dennis: Ah yes, the heliocentric model…didn't that get you into a lot of trouble?

Galileo: Trouble was just the beginning, my life was in danger soon after. I published many books on my discoveries and supported the Copernican Theory, which was the first to believe in the heliocentric model. The Roman Catholic Church and their many stubborn officials had me arrested and put on trial. Basically, I was given too choices, withdraw my beliefs in the heliocentric model or face death. Lovely choices aren't they?

Dennis: Well seeing as you're still alive, I'm guessing you took the latter choice?

Galileo: Well, yah! It was that or the guillotine.

Dennis: Well, I'm glad you're still alive and kickin' well not quite kickin' but alive at least. It's been a pleasure talking to you and I wish you luck and happiness for the remainder of your days.

Galileo: Thank you, it was my pleasure, if you have any more questions, come back and visit anytime.

Dennis: Thanks, Good Bye and take care.

Galileo died at age 78, with a life full of achievements behind him. He will always be remembered as a person who accomplished so much when so many things were against him. He stood up against the church even when facing death, he fought for what he believed in and refused to give in until faced with no other option. In the end, he proved to be right about so many things. He brought to the world so much and we are forever in debt to his accomplishments.

Works Cited

Fermi, Laura. Galileo and the Scientific Revolution. New York: Basic Books Inc, 1961 (good source)

Sharratt, Michael. Galileo: Decisive Innovator. Cambridge: Blackwell, 1994 (good source)

Thomas, George. Galileo: Math and Astronomy Explained. London: Wiley, 1986 (ok source)

Galileo GALILEI. (ok source)

Fowler, Michael. “Life of Galileo” (ok source)