In this episode of the "Once Upon a Time" animated series on world explorers, we begin to learn the history of Cairo and the Nile River in Egypt.

Galileo is in prison. He tries one more time to prove his theories to his inquisitor. But he finally recants during the trial saying the famous sentence: "and yet... it turns"

Galileo faces an uncertain future. Behind the scenes are political and religious intrigues and enemies plotting his downfall. The Pope, until now sympathetic to Galileo, has a change of heart. Under pressure from all sides and insulted by his latest works, The Dialogue Concerning the Two Chief World Systems, portraying the Church's view through the character Simplicio (Simpleton), the pope finally sends Galileo to the Inquisition Tribunal.

Galileo is under close scrutiny because of his Copernican views. Unfazed, he carries on his research and his teachings. Will the Inquisition bring his demise or will his powerful friends, Pope Urban VIII among them, protect him?

Galileo is about to throw caution to the wind and reveal his startling discoveries about planet Earth.

In part five of this episode on "The Discoverers," Galileo is warned. His belief that the Earth revolves around the sun is sacrilegious. Giordano Bruno, who claimed this fact, was burned as a heretic by the Inquisition Tribunal.

In part four of this episode on "The Discoverers," Galileo, now a reputable scholar at the University of Padua, proceeds to make a telescope out of lenses with the help of his instrument maker, Marc'Antonio. In this cartoon, an attempt is made to explain Galileo's discoveries.

Episode nine of this series focuses on Galileo, a prolific inventor and scientist. He discovered the principle of the simple pendulum motion, very useful in the measure of time and later in the making of clocks.

In this video, a young Galileo gets one of his first revolutionary ideas on how to measure time. Pretty impressive for a fourteen-year-old, huh?

The Maestro explains how the revolutionary ideas of the early discoverers, which we now take for granted, were not always well received. Before Galileo, for example, everyone believed that the sun and all the other planets revolved around the earth!

In the last segment of this Il était une fois... episode on technology, we learn more about what vertical farms can do to help the planet thrive. The first commercial vertical farm recently opened in Singapore.

The students present the Maestro with various solutions for eliminating pollution on our planet, including vertical farms and biotechnology.

A group of smart young people found revolutionary ways to solve our planet's woes. Electronic books, Internet mail and much more...

Modern technology comes to the rescue! Planet Earth has a chance of recovering from man-made pollution.

Technology not only helps clean up our planet, but also allows us to explore the entire universe. According to the astrophysicist Alfred Vidal-Madjar, in five hundred years, we will have visited all the planets in the solar system.