The focus of this segment is on animals of the African savanna. We get to see giraffes and elephants, the largest of the land creatures, as well as cheetahs, the fastest.

Rhinoceroses, or rhinos for short, are the largest land animals after elephants. Five species remain (two in Africa and three in Asia) and all are endangered as a consequence of the illicit trade of their horns. The importance of rivers is another focus of this segment.

The series draws to a close with footage of apes, the most direct ancestors of humans. The narrator nicely sums up the meaning of evolution and man's place in nature.

This dazzling short film references the Rosetta mission of the European Space Agency, which intends unlock the mysteries of the comets and, in doing so, the origins of our Solar System.

Rosetta revisits the exciting scientific discoveries she has made during her time at Comet 67P/Churyumov-Gerasimenko, including the successful search to find Philae. Now it's time to start preparing to descend to the comet for the end of her extraordinary mission.

Have you ever wondered what an escalator looks like on the inside, or how it works? Here's a brief demonstration.

With help from Fuse School, learn the basics about global warming, particularly how burning fossil fuels adds extra carbon dioxide to the atmosphere, and how this then leads to climate change.

Fuse School: To better understand the science behind global warming, it is important to first understand how the Earth's atmosphere functions. This informative video shows the role of gravity and how the electromagnetic spectrum is involved.

Fuse School: Learn the basics about the effects of global warming on the environment. Some of the problems global warming may cause are changing climate, extremes of weather, problems for ecosystems, rising sea levels, and ocean acidification.

Learn about the states of matter, solids, liquids and gases, how they're different and where they're found in everyday life.

By following honeyguides, a species of bird, people in Africa are able to locate bees’ nests to harvest honey. Research now reveals that humans use special calls to solicit the help of honeyguides and that honeyguides actively recruit appropriate human partners. This relationship is a rare example of cooperation between humans and free-living animals.

The BBC looks at a new and innovative renewable energy invention, Kite Power Solutions. It is estimated that 30 kites could provide electricity for 75,000 homes.

Douglas Adams was a writer and author best known for The Hitchhiker’s Guide to the Galaxy. Sadly, he died of a massive heart attack in 2001 at the young age of 49. Each year, fans of his work celebrate the 25th of May (or “Towel Day”) as a tribute to the author.

The philosopher Friedrich Nietzsche questioned the ability of science to explain and give meaning to our world, daring us to think critically not only about religion, but science, and knowledge itself. Learn all about his ideas in this fun video inspired by vintage video games.

The more you think about it, the more complex time travel seems! This video explains a key paradox that is one of the main reasons for this.