A coffee cup — we don’t think about coffee cups, but it’s much more interesting than one might think — a coffee cup is a device, which has a container and a handle. The handle enables you to hold it when the container is filled with hot liquid. Why is that important? Well, it enables you to drink coffee. But also, by the way, the coffee is hot, the liquid is sterile; you’re not likely to get cholera that way. So the coffee cup, or the cup with a handle, is one of the tools used by society to maintain public health.