Science experiment in space

What do you think will happen if you wring out a wet cloth in space? Astronaut Chris Hadfield performed a simple science experiment designed by high school students to find out.

Instructions

Do the preparation task first. Then watch the video and do the exercises. Remember you can read the transcript at any time.

Transcript

CSA Astronaut Chris Hadfield: The question is: if you get a cloth dripping wet without gravity and you wring it out, what's going to happen? What will happen to a wrung-out cloth?

So, I had to use equipment that was here on board the space station. We may have the coolest washcloths ever here on the space station. I'm going to show you. Here's one of our washcloths. And it's compacted. It's put down into this little tiny hockey puck so that, uh, it saves space. But when you open up a hockey puck and you pull out your washcloth … This is the one I'm going to use for the experiment today … And so when you open up your hockey puck and turn it into a washcloth. It was compressed in a great big vice somewhere. OK, so here's my washcloth. Like a magic trick. And now I'm going to get this soaking wet and then we're going to see what'll happen when we wring it out. Meredith and Kendra suggested that I dip this in a bag, but bags don't hold water in space so instead I filled a water bag – this has drinking water in it – and I'm going to, uh, squirt a bunch of water into this washcloth. OK, so here's a soaking wet washcloth. Get the microphone so you can hear me while I'm talking. And now let's, let's start wringing it out. It's really wet. It's becoming a tube of water. The water's all over my hands, in fact. It wrings out of the cloth into my hands. And if I let go of the cloth carefully, the water sort of has it stick to my hand.

OK, so the, uh, experiment worked beautifully. And the answer to the question is, the water squeezes out of the cloth and then because of the surface tension of the water, it, um, it actually runs along the surface of the cloth and then up into my hand, almost like you had Jell-O on your hands or gel on your hand. And it'll just stay there. Wonderful moisturiser on my hands. And the cloth doesn't really unravel itself. It just stays there, floating, like a, uh, like a dog's chew toy, soaking wet. Great experiment. Worked perfectly. Meredith and Kendra, congratulations! Great idea.