A smartphone can tell you where to get a cup of coffee, but it can't go get the coffee for you. Engineers would like to build little machines that can do stuff. They would be useful for a lot more than coffee, if we could figure out how to make them work.
But the rules of mechanics change at small scales. Friction becomes dominant; turbulence can upend a small airplane.
Jordan's fastest-growing city lies in the middle of the desert, where the sand is so white that from a distance it looks like snow. There's little running water and not much electricity.
The name of this place? The Zaatari refugee camp, home to more than 100,000 Syrian refugees.
"This is a city — not one that anybody would want to create if they had a choice," says Caroline Gluck of Oxfam, one of the aid agencies working in the Zaatari camp. "It's certainly not urban planning at its best."
"First they ate their horses, and then fed upon their dogs and cats, as well as rats, mice and snakes."
So says James Horn of the historical group Colonial Williamsburg, paraphrasing an account by colony leader George Percy of what conditions were like for the hundreds of men and women stranded in Jamestown, Va., with little food in the dead of winter in 1609.
They even ate their shoes. And, apparently, at least one person.