Friday, May 3, 2013

Surface Tension - on earth & in space

Water is strong. If you want to know just how strong, fill a small juice glass up to the brim. Now grab a pile of pennies - a hundred might be enough...
Slip a penny into the glass. Does the water spill? Probably not, because a penny isn't very big and doesn't displace much water.
How many pennies do you think it will take before the water starts to spill over the lip of the glass? Ten? Fifty? Somewhere in between? Something higher?
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Test out your answer by putting pennies into the cup one by one. At some point get your eyes level to the top of the glass and look at where the water is!

Water molecules hold onto each other tightly. It's called surface tension.

Now consider what happens in space. To help you out, Canadian astronaut Chris Hadfield. He shows what happens when he tried to wring out a soaking wet washcloth. Note: washclothes are packed like hockey pucks for their trip into space!


  1. This was a great video! I didn't know that would happen--excellent explanation of surface tension.

  2. I love this video. Surface Tension continues to amaze!