Wait, why would a really skinny mug keep coffee hot longer than usual? Wouldn't that mean more surface area to cool a given volume. Ideally, you want a spherica

Wait, why would a really skinny mug keep coffee hot longer than usual? Wouldn't that mean more surface area to cool a given volume. Ideally, you want a spherical coffee cup (impracticalities of that aside) Edit: Nevermind, its the cooling surface of the top of the coffee directly exposed to air. I'm just over here thinking about spherical chickens in a vacuum...