Because not only did he lock and encrypt his entire hard drive, but once you'd unlock that, there was another layer of security inside.

NPR: The Math Behind Pellicano's Code

The meringue that I'd spread on top of the thin layer of batter had insulated the batter so completely that it did not bake at all.

WSJ: The Cake That Steals the Party

C. and A.D. 500 by brushing away the dark top layer of barren desert to reveal the light, sandy soil underneath, wrote Clive Ruggles, an archaeologist from the University of Leicester in the United Kingdom, in an email.

MSN: Peru's mysterious Nazca Lines form a labyrinth, says study

Existing 3-D printers, also called rapid prototyping machines, build structures layer by layer.

FORBES: MIT Architect Plans to Print Her Own Buildings

Information about each layer is transmitted from the computer to a laser beam, which melts the PCL into a 3-D structure.

CNN: 3-D printer helps save dying baby