Surface tension

The photo shows a huge spherical water drop acting like a convex lens, imaging the face of the astronaut.

Raindrops are round, water is a trampoline for a bug, and water climbs to the top of tall trees. Molecular attraction (cohesion) forms a skin on water, mercury etc. The resulting surface tension drives capillary waves (l< 1 cm) faster at shorter wavelengths.

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