Galileo Galilei ( gal ih LAY oh gal ih LAY ee) was born in Pisa, Italy on February 15, 1564. His father, Vencenzio, was a musician and a mathematician. He was Galileo's teacher until he was ten years old. At that time the family moved to Florence. The boy was tutored for a while and then attended a monastery* where he studied Latin, Greek, logic, music, and religion.
The Lamp of Galileo
While he was a student at the University of Pisa he began to study the pendulum by watching a suspended lamp swing back and forth in the cathedral. From these first observations came his theory for the pendulum clock. Near the end of his life he would design the first pendulum clock.
Galileo is called the Father of Modern Science. He was the first to develop a scientific theory in which he would observe an event, develop a theory and then experiment to test his theory.
He studied motion and performed experiments by dropping objects from heights such as the Leaning Tower of Pisa. He wanted to disprove Aristotle's idea that heavier objects fall faster than lighter ones. According to legend he dropped two objects of different weights and proved that two falling objects of different weights reach the ground at the same time. You can view a photograph of a falling objects demonstration.
In this video astronaut David Scott demonstrates Galileo's theory of falling objects by showing how they behave in a weightless environment.
Before Galileo's time many people believed the earth was the center of the universe and the sun and the planets moved in an orbit around the earth. This theory was described by a Roman astronomer named Ptolemy (TAH luh me) and was called the Ptolemaic (tah luh MA ik) Theory. Aristotle also believed the sun moved around the earth. To believe otherwise was considered heresy by the Roman Catholic Church, and people were persecuted who believed the earth was not central.
Nicolaus Copernicus (nik uh LA us ko PUR nih kus) about twenty years before Galileo was born published a theory that the earth revolved around the sun. It was called the Copernican (ko PER nih kuhn) Theory, but he died before he could prove it.
Galileo decided he would either prove Copernicus' theory or else show it was false. In 1609 he heard about an invention which enabled people to see things far away. It was the telescope . He reproduced it and studied the moon and the planets. He discovered four bright "stars" revolving around Jupiter and concluded they must be planets near Jupiter. He called them Medician (med uh CHEE un) Stars to honor his patron in the influential Medici (MED ih chee) family. These moons of Jupiter are now named Io, Europa, Ganymede, and Callisto. Shortly after his discovery he was appointed Chief Mathematician of the University of Pisa. He would hold the title for life.
Galileo concluded that if "planets", as he called them, could revolve around another planet, then the planets could also revolve around another body such as the sun. His view of the cosmos* is known as heliocentrism * . This model is shown at the bottom of the illustration with the sun in the center. The upper part of the illustration shows a geocentric * model with the earth at the center.
Galileo went to Rome and appeared before the Roman Church to defend his views, but the Church considered them heresy* since his ideas were contrary to the Ptolemaic view that the sun revolved around the earth, which they considered the Biblical view. He was forbidden to discuss or write about his theory.
When a new pope was appointed Galileo had new hope that he would be heard. In April 1624 he traveled to Rome and had six audiences with Pope Urban VIII. As a result of his visit he was permitted to discuss his theory as long as he treated it as a mathematical hypothesis* .
However, after the printing of Galileo's book Dialogue* he was summoned to appear before the Inquisition* . Galileo replied that he was too ill to go to Rome. He was told he would be arrested and brought in chains if he did not come. He went to Rome where he was questioned for 18 days.
At an Inquisition the accused person had to testify, but could not ask questions nor be represented by counsel. Sometimes a person was tortured to get them to "confess", and the sentence could not be appealed.
They condemned him for heresy and put him under house arrest. He was released for a while, but there would be further hearings and he would remain under arrest the remainder of his life. Five years after his sentencing he became totally blind. He asked to be released from his imprisonment, but his plea was denied.
During his lifetime Galileo had three children; two girls and a boy. His girls were Virginia and Livia who were both raised in convents and his son, Vencenzio, was named after his grandfather, Galileo's father.
Galileo respected people. He is quoted as saying "he never met a man so ignorant but that something might be learnt from him." He did not have unkind words even for those with whom he totally disagreed.
Galileo died on January 8, 1642 while still under house arrest at his home in Arcetri near Florence.
This biography by Patsy Stevens, a retired teacher, was written in 2008.
A frequent question:
"Who wrote this biography and when was it written?"
Look on this Reference Citations Chart.
The Galileo Project
easy biography at Hero History
Institute and Museum of the History of Science
article by J.J. O'Connor and E.F. Robertson
Catholic Encyclopedia edu
Galileo's Observation of the Moon, Jupiter, Venus, and the Sun
The Internet Encyclopedia of Science BBC
Galileo's Battle for the Heavens
The Discovery of the Galilean Satellites (NASA)
Galileo: the Telescope & the Laws of Dynamics
Linda Hall Library
Student Projects and Experiments
my physics lab
Color Me Physics - Coloring Book
What's a Pendulum Anyway?
California Academy of Sciences
The Pendulum (audio)
Sixteenth - Century Pneumatics (audio)
Galileo's Experiment (audio)
Artists and the Moon (audio)
Galileo, the Church, and the Vatican Library (audio)
Engines of Our Ingenuity.
From Word Central's Student Dictionary
by Merriam - Webster
(Pronunciation note: the schwa sound is shown by ə)
MAHN uh ster e
a place where a community of monks or nuns live and work
KAHZ mus or KAHZ mohs
1 : the orderly universe
2 : a complex harmonious system
he le oh SEN trik
1 : referred to or measured from the sun's center or appearing as if seen from it
2 : having or relating to the sun as a center
HEHR uh se
1 : religious opinion that is opposed to the doctrines of a church
2 : opinion that is opposed to a generally accepted belief
hi PAHTH uh sus
something not proved but assumed to be true for purposes of
argument or further study or investigation
DI uh log
1 : a conversation between two or more persons
2 : conversation given in a written story or play
in kwuh ZISH uhn
capitalized : a. former Roman Catholic court for the discovery and punishment of heresy
b. : an investigation conducted with little concern for individual rights
c. : a severe questioning
je oh SEN trik
1 : relating to or measured from the earth's center
2 : having or relating to the earth as a center
Galileo DVD Genius Series
By Kultur International Films
This is the story of the brilliant Italian astronomer and mathematician who dared to challenge the accepted teachings of his day. Galileo's work brought him to the attention of the Inquisition and one of history's greatest minds was forced to work his last years under house arrest. Featuring specially-filmed dramatized depictions and rare contemporary images, this program vividly recreates Galileo's life and work. It also includes expert commentary and analyses by eminent historians.
This DVD features:
Running time: 50 minutes.
- Exact Mathematical Measurement
- Gravity and Flotation
- The Principle of Inertia
- The Telescope
- Controversy with the Church
- Motion and Acceleration
A LIBRARY OF
ONLINE BOOKS and BOOK PREVIEWS
The Private Life of Galileo
by Galileo Galilei, Maria Celeste Galilei, Mary Allan-Olney (public domain, full view) Order here
The Sidereal Messenger (English Version) by Galileo
Linda Hall Library
The great physicists from Galileo to Einstein
by George Gamow (selected pages) Order here
Great Scientists and Discoveries
by Ron Shaw (selected pages) Order here
Inventors and Inventions
by Doris Simonis (selected pages)
The Story of Galileo: the astronomer of Pisa
(public domain 1886, full view)
Preview some of the Amazon books using the links below.
Renaissance Genius: Galileo Galilei & His Legacy to Modern Science
by David Whitehouse (selected pages)
Galileo Galilei: father of modern science
by Rachel Hilliam (selected pages)
Galileo for Kids: His Life and Ideas, 25 Activities
by Richard Panchyk, Buzz Aldrin (selected pages)
Galileo: astronomer and physicis
by Robin Santos Doak (selected pages)
Galileo: The Genius Who Faced the Inquisition
by Philip Steele (selected pages)
Letters to Father: Suor Maria Celeste to Galileo
by Maria Celeste Galilei, Dava Sobel (selected pages)
Most Recent Comments ( See more comments on this page ) 2012-12-19
terribel, just terrible, it didnt help me at all
joe the foe
this is soooooooooo coool
the story was really interesting and has a lot of facts.
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