Parkour is a free-style method of exercise and exploration, in which an individual propels him- or herself through a urban landscape using only their surroundings and their own body—it requires agility and good form in order to prevent injury. In this lesson from Zoic Nation, learn how to do a parkour cat grab. Andy starts by outlining baby steps to get started with, as well as the often-injurious mistakes that people often make, before demonstrating a perfect cat grab.

Both a “punch” and a “plyo” are two-footed jumps in the sport of parkour. But a plyo is not a punch. In this lesson from Zoic Nation, learn how to do a plyometric jump, safely. Andy demonstrates how to step into a plyo (instead of hopping or hurdling into it) for a quiet landing on the balls of your feet, as well as how to swing your arms forward into your jump for momentum. Finally, he illustrates common mistakes that people make and shows what a well-executed plyo should look like.

Ready to learn how to do a side flip? In this lesson, teacher Christopher Tung uses stop-action footage to show you exactly how to take off and jump higher. You'll see how to position your arms to generate torque when spinning, control your tuck, and spot the ground for a smooth landing. With some practice, you'll be able to add this trick to your free running and parkour moves!

How can we know if what we perceive is real? What's the difference between true belief and knowledge? Socrates tackles these philosophical questions and more in Plato’s cave allegory. This lesson offers an illustrated explanation of the allegory - in which a prisoner is kept facing a wall, seeing only shadow puppets and hearing only echoes. It’s all he has ever known, until he is dragged from the cave and sees the sun. Learn what happens when he returns to explain to his fellow prisoners...

They can huff and puff, they won't be able to blow down this wall! In this lesson, stonemason Mike Haduck teaches you to cut a brick design into a wall made of cement and stucco. Learn to create a frame for your cement and apply each layer of cement and stucco. See how to rub your stucco with a sponge for a nice sandy finish, then create a cutting tool using an old wall tie and slice in your brick pattern.

Get a forehand tennis swing like just the pros! In this lesson, Rachael from Full Swing Tennis teaches you all about the modern forehand in four easy steps. Learn about the semi-western grip, which can allow for extra topspin. The lesson also covers dropping your racket for the backswing, rotating your waist and shoulders, and swinging through with your non-hitting hand. Be sure to keep your weight on your inside foot as you step out for the swing.

Do you love Greek mythology and the art of ancient Greece? Learn about a mythic monster from the Classical World, the original femme-fatale, the Gorgon Medusa. Through Greek sculpture, painting and poetry, this lesson explores Medusa’s lineage, background, and tragic curse. In this lesson, Lucas Livingston, a historian at the Art Institute of Chicago, discusses the possible origins of this haunting myth. As Lucas tells the tale of Medusa, he will also cover the Clash of the Titans, Perseus, Poseidon, and Athena.

One of the most difficult and most common applications of derivatives is the related rates problem. But related rates don’t have to be hard! In this lesson from integralCALC, Krista gives you the tools to conquer these problems. Implicit differentiation is the key to learning how to deal with an equation when there is no clean separation of the unknown variables—once you’ve got that down, you’ll be able to solve any related rates problem in just four easy steps.

New to homebrewing beer or curious about the chemistry and cooking process behind the delicious brew you already know how to make? In this video James teaches you the tricks and techniques of home brewing your own beer while making a Nut Brown Ale from a malt extract recipe. Learn how each ingredient and process contributes to the flavor profile and appearance of your homemade brew.

When it comes to screen printing, standard flood and stroke methods are not ergonomically designed, and can stress your back, arms, wrists, and fingers. But there is a better way, and Jonathan from Catspit Productions is here to tell you about it. Jonathan uses a “pull flood” and “push stroke” method that puts less tension on your muscles that applies more force to your transfer and gives you more control of the ink. Because this method is so efficient, just be careful to not use too much force.

Mix up your style with this flirtatious play on the traditional braid. Learn how to part, braid, and pin your hair for a look so easy that you might surprise even yourself! As versatile as it is fun, this look can be paired with lace for sophisticated bridal hair - or with summer flowers for a casual style worthy of a day in the park. Keep this updo in your back pocket as a perfect fix for those bed-head bad-hair days!

For more beauty and style tips, check out the [Milkmaid Braid](http://www.pinkpistachio.com/the-milkmaid-braid) post on Pink Pistachio's blog.

Javascript is not only one of the main languages used in contemporary web development, but it also has many non-web based applications, from.pdf files to desktop widgets. Thus, Javascript is an extremely versatile and valuable language to have command of. In this lesson, Mark from LearnToProgram.tv demonstrates how to begin coding with Javascript, as well as how to test your code using a text editor (Mark recommends Komodo Edit). Finally, learn how to use Javascript to manipulate HTML pages.

Want to store your stuff with style? Crafty Gemini teaches you how to stitch your very own quilted zipper pouch with boxy corners. All that you'll need is two kinds of fabric, batting, a lapel stick, a zipper, and a sewing machine. These bags are easy to make and perfect to use as pencil cases, make-up bags, travel dop kits, or what you will. This video offers handy tips for sewing zippers onto fabric using a zipper foot.

A thesis statement is the first and most important piece of any essay—whether you call it a controlling idea or a unifying concept, your paper must have one. But a thesis doesn’t just state your position on whatever matter you are writing about; it also provides a road map for constructing the body of your essay, an outline for you to follow. In this lesson from David Taylor, learn a simple formula to create a thesis; once you have a solid thesis, your paper will be a delight to write.

Get ready for the rainy season by installing new gutters. In this DIY home improvement lesson, Ron will teach you how to install gutters to promote proper drainage around your property. Learn how to find the slope of the eaves, how to cut and and hang your gutters and downspout, and how to ensure that your new gutter system doesn’t leak.

Wish you had more shade in your backyard? Put the finishing touches on your home and garden by building a freestanding pergola with Ron Hazelton. For this DIY project, learn to build a trellis and canopy to cover an outdoor patio or accent your landscaping - perfect for providing a bit of shade on sunny days.

Interested in making over your old furniture? Give your chairs new life by reupholstering them with the O'Neil Sisters! Jennifer and Kitty will teach you how to refinish your chair with spray paint, how to choose the right upholstery fabric, and how to recover the cushion to give your outdated or vintage chair an updated look.

Have you mastered the double crochet and slip stitch? Are your friends and family always complimenting your handmade crochet scarves and accessories? If you want to start selling your crochet for profit, this is the course for you! You’ll learn how to create a business plan to make your dream into a reality. Begin by thinking about your audience, inventory, pricing, and advertising strategy.