On board the International Space Station, ESA astronaut André Kuipers just put up this ridiculously cool and fun picture of himself playing with water in space:
Wheee! But what are you seeing? SCIENCE! Let me explain. The really short version of this is that the water is acting like a lens, flipping his face over. But there are two images of André's face in there, and one is upside down! What gives? First we need to look a the drop itself. On Earth, sitting on a surface like a tabletop, water drops tend to be flattened. But in space, where gravity's not an issue, water drops form little spheres. That's because of surface tension, an imbalance in the electromagnetic forces between water molecules, and is a whole post all by itself! But for now, what you need to know is that in orbit where there's no net effect from gravity, ...
