Global warming is threatening the ski industry in the French Alps. Many operators have to resort to snow guns to keep the slopes open as snowfall has halved in the last fifty years.

Parisians can thank Fulgence Bienvenüe for their metro system, which is so efficient that many people use the names of the metro stations in favor of street names when giving directions. Some of the most interesting stations are Bir-Hakeim, overlooking the Eiffel Tower, and Arts et Métiers, with its old-fashioned industrial design. Some metro stations are a destination in themselves!

Lionel tells us about the Seine's recent flooding, caused by severe weather conditions in Paris and surrounding areas. A statue of a French soldier below the Pont de l'Alma acts as an indicator of the river's water level.

The Underwater Museum of Lorient might be a little hard to get to, given that it's literally underwater. Dedicated to shipwrecks and other sunken objects, the museum is made possible by a team of volunteers with a passion for documenting these lost treasures at the bottom of the ocean.

In an effort to promote ecotourism, the town of Echelles has constructed one of the largest natural bathing areas in France. Its filtration system is 100% natural, powered by thousands of plant seedlings.

Meet Sheldon, the friendly robot with friendly eyes that flash little hearts when it interacts with people. Sheldon is a huge attraction at tech fairs, where it is used to entertain and delight the crowds. It certainly lives up to the task.

This next part of the Il était une fois series on George Stephenson deals with the Rainhill Trials, a competition that determined what kind of trains (steam engines or locomotives) would be used on the Liverpool and Manchester Railway.

The future of the railroad depends on whether George Stephenson's locomotive, 38 cars long, will run or not. The local townspeople debate whether it will go full speed ahead or not budge at all due to its size.

George Stephenson tries out his invention, a steam locomotive. He allows his son, Robert, to ride on it as long as he stays on the edge of the carriage and gets ready to jump off if the rails buckle under the weight of the locomotive... which they do. Luckily his son followed his instructions!

Years of research and trial and error culminated in the invention of the first locomotive on rails. Not bad for a father-and-son experiment. That's what Murdoch and his son George achieved in 1797.

In part two of this series, "Once upon a Time... the Discoverers," Maestro talks about Cugnot, the inventor of the steam traction engine.

In the series "Once Upon a Time... the Discoverers," the Maestro lets off some steam. Some two thousand years ago, Heron invented the steam machine in Alexandria, but it took two millenia to perfect the invention and put it to practical use.

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?