Have you ever taken a walk through the rain on a warm spring day and seen that perfect puddle? You know, the one where the raindrops seem to touch down at just the right pace, causing a dance of ...

Sloppy, muddy puddles created by summer rainstorms owe their boundaries to the dips in pavement or ground. But if a glass of wine spills on a (hypothetically) perfectly flat countertop, what keeps the ...