Galileo Galilei

Pre 1900

About Galileo

Galileo Galilei was a Tuscan (Italian) astronomer, physicist, mathematician, inventor and philosopher. He was born in Pisa and was the eldest of six children. When Galileo was a young man, his father sent him to the University of Pisa so he could study medicine, but instead of studying medicine Galileo studied mathematics. Later in his life Galileo became professor and chair of mathematics at the university. Until about 1906 Galileo taught mathematics and had already made several discoveries in physics.

Galileo's Discoveries

Galileo then became interested in optics and astronomy. In 1609 Hans Lippershey (a spectacle-maker from Holland) put two spectacle lenses into a tube and discovered that when you look through the tube objects that were miles away appeared to be close. Galileo then stole that idea, invented his own and called it a telescope. Galileo's telescope would allow you to see objects sixty times closer and using this telescope Galileo had a theory that the moon wasn't round but that it was more in fact like a dry, dirty stone with mountains and valleys. He later improved his telescope to see four hundred times further which allowed him to do more accurate sketches to prove what he had seen. Galileo then profected his telescope and could see a thousand times further.

After a year Galileo published his first results, where he discovered the phases or the moon, Jupiter's four largest moons and some newly discovered stars. Galileo also discovered Venus's phases and sunspots, which confirmed that the sun rotates and that the planets orbit the sun instead of orbiting the Earth. Although Galileo discovered that the planets orbit the sun he thought they did it in a circular shape although they orbit the sun in an oval shape which was later shown by Johannes Kepler.


Timeline of Galileo's Discoveries

-1569- Galileo was born on the 15th of February in Pisa, Italy.

-1583- Galileo invented the pendulum.

-1589- Galileo dropped balls of different weights and sizes from the Leaning Tower of Pisa and proved that everything falls at the same speed.

-1593- Galileo invented the thermometer.

-1596- Galileo invented a gun sight to find the angle a gun needs to be set at to hit its target.

-1597- Improved his gun sight which was used for map-making and surveying. He also invented the theodolite.

-1609- Made his first telescope.

-1610- His book "The Starry Messenger" was published.

-1631- Another book was published "A Dialogue Concerning the Two Chief World Systems."

-1633- Was imprisoned for heresy.

-1642- Galileo died on the 8th of January at 77 years old in Arcetri, Italy.


Galileo in Prision

In 1632 Galileo angered the Pope as he had a book published which clearly stated that the Earth moved around the sun. Because of this Galileo was put on trial by the Inquisition in Rome, where he was found a suspect of heresy and was made to admit that his findings were wrong. He was then imprisoned and later confined to his house near Florence.


Technologies Used

Galileo used the telescope he made and just kept improving it.


Did You Know ????

  • Galileo actually became completely blind by the age of 74.
  • In 1612 Galileo observed Neptune but thought that it was a distant star. He also observed Saturn's rings but they appeared to be two separate bodies attached to the one planet, that was according to Galileo.
  • Galileo also attempted to measure then speed of light as he placed observers with lanterns about a mile apart but was unsuccessful.
  • Galileo was the first person to make a working thermometer although it wasn't very accurate.
  • Galileo's father, Vincenzo Galilei helped to invent a new style of music as he was a musician and music theorist


Contributions to our Knowledge or the Solar System

Galileo has made many contributions towards our knowledge of the solar system as he discovered the phases of the moon and that it wasn't round, Jupiter's four largest moons, some stars, Venus's phases and sunspots and that the planets orbit the sun. Galileo has also contributed to discoveries since his time and will also contribute to future discoveries as he invented and improved the telescope which we use for many of our observations.