Galileo was born in Pisa, Italy where he grew up during the Renaissance. His father was a music teacher and a famous musician.
Galileo was an accomplished musician and an excellent student. At first he wanted to become a doctor, so he went to the University of Pisa to study medicine in 1581. While at university, Galileo became interested in physics and mathematics. In 1585, Galileo left the university and landed a job as a math teacher.
He began to experiment with pendulums, levers, balls, and other objects. He tried to describe how they moved using mathematic equations. He even invented an advanced measuring device called the hydrostatic balance.
In 1609, Galileo heard of an invention from Holland called the telescope that could make far away items appear much closer. He decided to build his own telescope. He made great improvements to the telescope and began to use it to view the planets. Soon Galileo’s version of the telescope was used throughout Europe. Galileo made many discoveries using his telescope including the four large moons around Jupiter and the phases of the planet Venus. He also discovered sunspots and learned that the Moon was not smooth.
As Galileo studied the planets and the Sun, he became convinced that the Earth and the other planets orbited the Sun. In 1632, he wrote a book called the Dialogue Concerning the Two Chief World Systems. In this book he described why he thought the Earth orbited the Sun. However, the misguided Catholic Church considered Galileo’s ideas threatening to their beliefs. At first they sentenced him to life in prison, but later allowed him to live at his home in Tuscany under house arrest.