In the Star Wars movies, the droid R2-D2 carries messages, puts out fires, and while trapped on Jabba the Hutt’s sail barge, even carries a tray of drinks. R2-D2 also saves the heroes’ lives on several occasions . C-3PO and R2-D2 are both servants and friends. The idea that people might create machines to do tasks for them has been around for centuries— but only in myths and science fictions. Golems, animated clay statues, march through Jewish folklore. And Greek myths describe living metal statues called Automata.

In fairy tales, a wizard waves a magic wand and poof! There’s a carriage or a cake or a pair of shoes. We don’t have magic wands, and probably never will. But we do have 3D printers. A 3D printer can’t make something out of nothing. But it can create just about anything you can imagine. Feed one a design for an object, and it will print that object. You just have to give it a raw material to print with. Many 3D printers are small machines—around the size of a microwave oven—so they can be carried anywhere.