If you don't already know why a helium balloon tethered to the floor of a minivan has the power to make your jaw drop, you're going to want to see this. Seriously – set aside five minutes of your time, have a seat and watch. You won't regret it.
This is just excellent. ISS Commander Chris Hadfield was recently asked by high school students Kendra Lemke and Meredith Faulkner to demonstrate what happens when you wring out a waterlogged washcloth in space.