How to Build a Tiny Sand Castle

A scientist named Lord Kelvin wrote an equation to describe capillary forces. This force works because water bends, but when things get so small that you only have like one molecule of water, it can't bend. And the equation that Kelvin wrote doesn't necessarily allow for that. Jen and her team were sort of thinking like, we actually don't know what's happened at this scale. So they decided to figure out how to build not a sand castle, but a very, very, very narrow tube.