An evaporating colloidal particle–laden droplet leaves behind a ring-like residue after drying. We routinely observe this ubiquitous phenomenon for dried coffee drops; thus, it is known as the "coffee ...

WASHINGTON, Aug. 22, 2017 -- "What's in your water?" has become an increasingly fraught question for many people in the U.S. and around the world. Getting the answer isn't always easy or cheap. Today, ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. The physics of the so-called "coffee-ring effect" — how particles in liquid cause darkened areas ...

Spilled coffee forms a ring as the liquid evaporates, depositing solids along the edge of the puddle. This 'coffee ring effect' has fascinated scientists for decades, but now a team says they have ...