Imagine that you discovered something very important.
Imagine that your discovery was so important that it would change the way people think and live.
I'm sure that you would run out and tell everyone about your new discovery.
You might write a book about it and talk to many people.
Now imagine that no one believes you, and they even get angry with you.
They accuse you of being a liar and tell you that you are evil.
Finally, because you keep insisting that you are right, they throw you into prison for the rest of your life.
That is exactly what happened to Galileo Galilei.
Galileo was born in Pisa, which is a city in Italy, in 1564.
Galileo came from a well-respected family, and his parents expected him to become a doctor.
However, much to his father's disappointment, Galileo decided not to be a doctor.
He was more interested in mathematics and philosophy.
During his early years as a professor of mathematics, Galileo made some very important discoveries.
For instance, if you dropped a heavy ball and a light ball, which would hit the ground first?
Scientists used to think that the heavy ball would land first.
But Galileo believed they would hit the ground at the same time, and he wrote a mathematical formula to explain his idea.
To prove his theory, he climbed to the top of the famous Leaning Tower of Pisa and dropped two balls of the same size, one heavy and one light.
He proved his theory was correct. The two balls landed at the exact same time.
Because of this experiment, most people believed Galileo and accepted his new theory.
However, some people were not happy because Galileo's new ideas contradicted the old ones.
Sometimes new ideas make people feel uncomfortable and afraid.
Galileo's life took a drastic turn in 1609, when he heard about a new and incredible invention from the Netherlands.
It was a tool that made distant objects look near.
It was the telescope, and Galileo thought it was a fantastic invention.
Galileo began working on the telescope to make it more powerful.
He taught himself how to grind glass in order to make lenses for his telescope.
After many years and a lot of hard work, he made a telescope so powerful that it could magnify the stars and planets.
Before this, people could only view stars with their eyes.
Galileo's telescope impressed many people, and he became the highest-paid professor at his university.
Over the next few months, he made even more powerful telescopes.
This was when Galileo's real problems started.
At first he discovered some very interesting and wonderful things that no one questioned.
For example, he found that the moon was very bumpy instead of smooth.
He also discovered that Jupiter had four moons and that there were many more stars than people could see with the naked eye.
However, Galileo soon discovered something that made many people very angry.
By looking into space and observing the planets, the sun, and the stars,
he discovered that Earth was a ball that revolved around the sun like the other planets.
Many religious leaders thought that Galileo didn't believe in God and was questioning how the world was created.
They accused Galileo of doubting God's Word.
This was a big problem for Galileo because at that time, the Catholic Church was the most powerful organization in the world.
The religious leaders brought Galileo before the Inquisition.
The Inquisition was a religious court that decided if a person was saying things against the Christian faith.
If the judges decided that a person was speaking against God, they decided how to punish him.
The Inquisition decided that Galileo was against God, and his punishment was that he should not speak or write about his discoveries anymore.
But Galileo was a true scientist, and he did not want to be quiet.
So he continued to argue that his discoveries were not against the Bible and not against God.
He wanted people to hear what he was saying.
Once again Galileo was called before the Inquisition.
Now he was in very big trouble because this time he had disobeyed the Inquisition.
In order to stop Galileo from spreading his lies to other people, the Inquisition arrested him and imprisoned him for the rest of his life.
Of course, today we know that Galileo was right about many of his theories, and he has become one of the most respected thinkers of all time.
But at that time, he was the great man who no one believed.