Smallest ice cube in world constructed

Scientists at the University of North Carolina at Chapel Hill have constructed the smallest ice cube in the world. It wouldn't be much help in chilling a gin and tonic, however, because it contains only six molecules of water. The group was studying water's interacting hydrogen bonds, which control much of biochemistry. It used liquid helium in a process that produced hexagonal rings of ice, mimicking the way ice exists in nature. The tiny cube helps simplify its work because a single drop of water contains about 100,000,000,000,000,000,000 molecules.