Bryan Kienlen and his wife, Nicole, have a new routine. When they first wake up, they give bottles to their babies, Cora and Layla. And before taking on their daily tasks, they dedicate quality time ...

Droplets bouncing off surfaces are an everyday phenomenon, like raindrops bouncing off lotus leaves or water drops sizzling in a hot pan, levitating and sliding around—aka the Leidenfrost effect.

For anyone that grew up in the 1960s, the TV show “Sing Along With Mitch” was an absolute must-watch for several years. “Follow the bouncing ball,” the host, Mitch Miller, would say. And I’ll bet ...