Galileo+by+MusicLover6991

Introduction: Who was Galileo Galilei?
Galileo was a scientist and mathematician, born on February 15, 1564, who made many discoveries, like that the length of the string of a pendulum does not change the length of the swing. He also discovered that the weight of the bob also doesn't change the length of the swing. He used this information to make clocks with pendulums.

Galileo wrote a book called __The Dialogue...__ which got him in trouble for saying that the sun is in the center of the universe. Back then, people believed that the Earth was in the center of the universe since that was what the bible said. Galileo disagreed, so he was guilty of heresy (called a "heretic").

He studied at the University of Pisa, where not many people were open to new ideas. Later in his life, he worked there, but was fired after an experiment he did that proved that Aristotle (a philosopher who agreed with the church) had a theory that was wrong. Aristotle's theory was that objects of different weights fell at different speeds. Galileo climbed the leaning tower of Pisa (in the picture to the left) and dropped two balls of different weights, which both landed at the same time, proving that Aristotle was wrong. After this, his father died and he left Pisa to move to Padua.

In Padua, he became a teacher again, but this time people accepted his new ideas and he also got paid more. He met a woman named Marina while he was there and he soon fell in love with her. Of course, they could not marry so Galileo settled for living with her and having two daughters and a son with her. However, they parted ways when Galileo decided to continue experimenting and making discoveries away from home. He died on January 8,1642. Keep reading to learn about the discoveries he made.

Moon Observations: What did Galileo discover about the moon?
Galileo discovered that the moon had craters and mountains. This discovery disproved Aristotle's ideas because Aristotle thought that the moon had no imperfections because God had made everything perfect. Basically, Aristotle had the church on his side and Galileo didn't, so this was another disagreement that got Galileo in trouble.





**Jupiter and Its Moons: What did Galileo discover about Jupiter?** In 1610, Galileo observed four objects around Jupiter. He got the idea that they orbited Jupiter, so he was the first one to discover the four moons of Jupiter. This meant that not everything orbited Earth like Aristotle had believed. It also meant that maybe the Earth wasn't the center of the universe and maybe the Sun was like Aristarchus, Copernicus and Galileo said. Galileo named these moons after Grand Duke Cosimo II, who was his boss.

[[image:sat width="148" height="109" align="right"]]
Galileo spent long days and nights observing the skies with his telescope pointed at Saturn. He saw something unusual around it. Then around 1614, he discovered that they were Saturn's rings.

Sunspots on the Sun: What did Galileo discover about the Sun?


Galileo discovered that the sun had spots by looking through his telescope. They appeared as blotches that were darker than the rest of the sun. He eventually went blind from looking at the sun, but he was able to disprove Aristotle who thought that the Sun was perfect and unchanging. The pictures to the left and right are edited so that they have color so you can see what the sunspots would look like.

Venus has Phases: What did Galileo discover about Venus? [[image:http://nssdc.gsfc.nasa.gov/image/planetary/venus/pvo_uv_790205.jpg width="184" height="185" align="right"]]
Galileo used his telescope to discover that Venus had phases, just like the Moon. If Venus had phases, that meant that it revolved around the Sun (not the Earth) like in Copernicus' geocentric model of our solar system. This was something that once again disproved Aristotle who thought that the Earth was the center of the solar system. Now it was clear that it was not possible for the Earth to be in the center.

BIBLIOGRAPHY:
(Pictures) http://www.crystalinks.com/galileo.jpg //http://www.nhn.ou.edu/~jeffery/astro/italy/leaning_tower.jpg// http://nssdc.gsfc.nasa.gov/planetary/image/jupiter_cassini.jpg http://nssdc.gsfc.nasa.gov/image/planetary/venus/pvo_uv_790205.jpg // White, Michael. Galileo Galilei: Inventor, Astronomer and Rebel //. Woodbridge, CT: Blackbirch, 1999. Print.