Want to learn how to make a super secret hide-out? Jessi shows you how a bedsheet, some books -- and a little bit of science -- can be used to make an awesome fort!

Paul Andersen explains how physical systems remain stable and unstable over time. The sum total of interactions acting on the system determine its stability. Feedback loops are used to maintain stability but require energy. If the...

Proteins, and by extension our bodies, depend on the fact that atoms are arranged, spaced, and linked to each other in specific ways. And thanks to June Sutor, we have a better understanding of how those atoms come together and interact...

Forces are pushes or pulls on an object. Forces can be determined by measuring the motion of an object. If an object accelerates then a force is present.

Paul Andersen introduces forces, motion, and Newton's three laws in this video. He begins by describing forces as pushes or pulls on objects that produce motion. A lack of motion results from a balanced set of forces. A teaching...

I'm sure you've heard of Isaac Newton and maybe of some of his laws. Like, that thing about "equal and opposite reactions" and such. But what do his laws mean? And how do they help us understand the world around us? In this episode of...

Jessi brought one of her favorite toys to the fort, a magnet! Let's see what it can stick to!

Go through the loop, Higgins!

Howcast - Pulling off the perfect ponytail is easy once you know a few tricks.

Howcast - Learn how to do a simple hip-hop routine from choreographer Randy Connor in this hip-hop dance video from Howcast.

Howcast - Let professional makeup artist Patricia Longo teach you how to put on pencil eyeliner in this eye makeup tutorial from Howcast.

Howcast - Learn how to dance like Ciara from choreographer Matt Steffanina in this Howcast dance video.

Howcast - Learn how to do a braid headband from professional hairstylist Joy La Rosa in this Howcast hair tutorial, part two of a two-part series.

Howcast - Learn how to do a braided updo with a big bow from professional hairstylist Joy La Rosa in this Howcast hair tutorial.

Howcast - Learn how to do the cobra from certified yoga instructor Chelsey Korus in this Howcast video.

Howcast - Learn how to do a cable crossover working the upper chest from personal trainer Max Tapper in this home chest workout for men video from Howcast.

Howcast - Learn how to do chainsaws from personal trainer Brett Azar in this Howcast home arm workout for men video.

Howcast - Learn how to remove a crankset from Silk Road Cycles' Brendon Nicholas in this Howcast bicycle repair and maintenance video.

Howcast - Learn how to maintain bike wheels from Silk Road Cycles' Brendon Nicholas in this Howcast bicycle repair and maintenance video.

Howcast - Learn how to do the walking tree pose from personal trainer Mindi Smith in this Howcast sexy legs workout video.

Howcast - Let musician Alex Skolnick teach you how to play two fret bends on strings 4 - 6 on guitar in this heavy metal guitar lesson from Howcast.

Howcast - Let musician Alex Skolnick teach you how to play hammer-ons and pull-offs on guitar in this heavy metal guitar lesson from Howcast.

Howcast - Learn how to draw a katana sword from Sensei Oliver Martin in this katana sword fighting video from Howcast.

Howcast - Learn how to do ombre or gradient tie dyeing in this Howcast video.