When you spill a bit of water onto a tabletop, the puddle spreads — and then stops, leaving a well-defined area of water with a sharp boundary.
There’s just one problem: The formulas scientists use to describe such a fluid flow say that the water should just keep spreading endlessly. Everyone knows that’s not the case — but why?
This mystery has now been solved by researchers at MIT — and while this phenomenon might seem trivial, the finding’s ramifications could be significant: Understanding such flowing fluids is essential for processes from the lubrication of gears and machinery to the potential sequestration of carbon dioxide emissions in porous underground formations.
