Destin Sandlin, an Alabama engineer and YouTube star, shows us how very difficult it is to learn to ride a backwards bike. You think it's going to be a piece of cake, but it's not!

Judging by the 26 billion views on over 2 million YouTube videos of them, one thing is certain: cats are very entertaining. But their strange feline behaviors, both amusing and baffling, leave many of us asking: Why do cats do that? Tony Buffington explains the evolutionary history behind some of your cat’s strangest behaviors.

Physicists, philosophers, and UFO enthusiasts all have ideas on how many universes there may be or if there is extraterrestrial life. Chris Anderson summarizes the theories and expects that in the coming years physicists will arrive at more answers.

In the first of a new TED-Ed series designed to catalyze curiosity, TED Curator Chris Anderson shares his boyhood obsession with quirky questions that seem to have no answers.

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.

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.

You've made it to the final round of a game show, and get to pick between 3 doors, one of which has a car behind it! You make your choice, and then the host decides to show you one of the wrong answers. He then offers you the opportunity to change your choice. Should you do it? Find out just how wrong human intuition can be in this classic Monty Hall Problem.

On stage at Cannes Lions, game designer and author Jane McGonigal showcased research demonstrating the power that gaming can have in the real world.

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.

In this episode of SciShow Kids, Jessi talks about how solar eclipses occur, and why they can only be seen from certain locations.

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

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.

Within a deep and narrow cave in South Africa, paleoanthropologist Lee Berger and his team found fossil remains belonging to the newest member of our human family. The Homo naledi discovery adds another exciting chapter to the human evolution story by introducing an ancestor that was primitive, but shared physical characteristics with modern humans.

In this final installment of the series, a white Kermode bear encounters a black bear while fishing. Observe their behavior. Look and see for yourself what ensues!