Here’s a novel gift idea for that nerdy friend: an earring shaped like the inner ear. (It’s an ear-ring! Get it? As in, from ears. Ha!) This paper describes the metal casts of inner ears made by the anatomist M. Wharton Young in the 1930s, using the temporal bone as a mold. It is hard to see the inside of this bone without using X-ray and contrast agents (which Young also did later on), so he used metal to make casts of the bone. (For details of the process, check out the full description below.