By Daniel Allen for Spring 2013 Get Wet.
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When a water balloon is popped by a pellet gun, the contracting rubber skin and pressure drop disturbs the surface. The water seems to float momentarily before falling. Filmed at up to 1000 fps by a Casio EX-ZR100. When Guinness Draught Stout is poured into a glass with sloping sides, the bubbles formed by nitrogen and CO2 coming out of solution rush upward in the middle of the glass, and the liquid recircualtes downward near the walls, carrying small bubbles along.