I used to wonder how thermos bottles knew how to keep hot things hot and cold things cold. Apparently, its just something that’s built in.
I saw something at the store the other day that seemed like a breakthrough, something that might add to my understanding of the physical properties involved: it’s an insulated bag, advertised to “keep hot things hot and cold things cold”. I really had to have one of these, to put it to the test.
In the morning, I put in a cup of coffee and an ice cream cone, then closed it.
What a disappointment!!!!! When I opened it later that day, the coffee was cold and the ice cream had melted.
I’m going to have to take it back. It doesn’t work as adverticed.