時(shí)差N小時(shí):咖啡漬的奧秘(下)

　　Why is that? It’s because the edges of the spill arewhere the fluid is at its thinnest. A spill sitting on aflat surface is something like a pancake. Big in themiddle and thin on the rim. As the thin edgesevaporate, they are replenished by liquid andparticles of coffee from the denser interior. Thatstarts an outward push going in the puddle. Themore it dries, the more particles get drawn out tothe edges. When all of the liquid has evaporatedwe’re left with a ring of coffee particles making astain.

　　這是為什么?這是因?yàn)樾孤┑倪吘壛黧w在其最薄。泄漏坐在平坦的表面上是像煎餅的東西。在中，大輪輞上薄。由于薄邊蒸發(fā)，它們是補(bǔ)充液體和顆粒密集的室內(nèi)咖啡。這開(kāi)始向外推，在水坑。它干得更會(huì)抽出更多的粒子邊緣。所有的液體蒸發(fā)時(shí)，我們剩下的咖啡污漬顆粒環(huán)。