Andrew Brady Photo
Spotted this interesting little post on PetaPixel. I really want to know if KP already knew this.
Backpacker Magazine writes:
“If the bubbles amass in the center [of the mug], you’re in a high-pressure system, which is making the coffee’s surface convex (higher in the middle). Since bubbles are mostly air, they migrate to the highest point. It’s going to be a beautiful day. If the bubbles form a ring around the sides of the mug, you’re in a low-pressure system, making the surface concave. Rain is likely. Note: It has to be strong, brewed coffee to have enough oil to work, and the mug must have straight sides.”