Richard Feynman was obviously famous for his work as a physicist, but he's also widely regarded as one of the most lucid and effective lecturers to ever address an audience. So renowned, so readily accessible were his presentations, that his introductory physics lectures (which he delivered to undergraduates at…

Back in August, we told you about a free course on artificial intelligence being offered by Stanford University, and co-taught by two world-renowned AI experts. The class officially started today, so if you managed to register for it on time, then good on you.

If you've ever wanted a world-class introduction to the basics of artificial intelligence, here's your chance. Every fall, engineering students at Stanford University can enroll in a class titled "Introduction to Artificial Intelligence." And now you can, too.

In this simple demonstration of how waves work, a Harvard instructor shows how a group of pendulums can move through a complicated dance together — due entirely to the way each pendulum oscillates at a different rate.

The Euhaplorchis californiensis is a little parasite who lives in Southern California. And in this movie, released last year by researchers with the USGS, we learn why its lifecycle is the stuff of nightmares.

In this film, taken a couple of years ago from a rocket booster on the space shuttle Discovery, you can see what it's like to blast into space, shooting fire and whirling back into the upper atmosphere.

If you haven't heard of Mavericks, that's because it's a tiny beach on the Northern California coast. But scientists and surfers know it well, because it delivers some of the most spectacularly huge waves in the world. Find out why.

Watch as Earth becomes a mega-snowball, just like it did 650 million years ago! To watch this video properly, you have to yell "dude!" every time a scientific fact is followed by a dramatic reenactment where the WORLD IS DESTROYED.

For thousands of years, a fist-sized octopus called the argonaut has baffled scientists. Even Aristotle wondered why this creature wraps its body in a thin "paper nautilus" to swim. Now, video evidence suggests these creatures have a highly-sophisticated ballast system.

Now that we know octopi like to play with cameras, it's time to investigate other forms of animal play. Did you know that rats laugh when you tickle them? This scientist has proof - and it's pretty damn cute.