How-To: Tell Mammoth Ivory from Elephant Ivory

Cross sections of elephant (left) and mammoth tusks (right) with outer Schreger lines marked, showing characteristic angle difference.

Whatever the larger implications of the mammoth ivory trade may be, it has created a practical forensic problem for law enforcement. Buying mammoth ivory is, generally, legal, while buying elephant ivory, generally, is not. But when you're a customs official staring at a crate full of tusks, how do you... Read more »

“Electric Lungs”

Anatomical neon

Welsh sculptor Jessica Lloyd-Jones created a series of four gas discharge tubes in the shape of human organs. Besides Electric Lungs, shown above, it includes Optic Nerve, Brain Wave, and Heart. Read more »

How Wood Hardness is Measured

Images from USDA Forest Products Laboratory Research Note FPL-RN-0303, "Janka Hardness Using Nonstandard Specimens."

In fact, there are a now a couple of different tests, but the traditional method is known as the Janka hardness test, named for Austrian wood researcher Gabriel Janka, who invented it in 1906. The test measures the force required to embed a standard-sized steel ball (of 0.444in/11.28mm diameter) exactly... Read more »

Nanometer Scale 3D Printer


Researchers Jan Torgersen and Peter Gruber at Vienna University of Technology (TU Vienna) have successfully printed intricately detailed models of various objects at the nanometer scale using a process called “two-photon lithography”. In the process, they also managed to speed things up a bit and have gone from printing in... Read more »

How-To: Extract Your DNA


It's news to me that it's possible to extract the DNA from your own cells with just a few household products such as bottled water, dish soap, food coloring, table salt, and isopropyl alcohol. You can learn how to see your own DNA in this fun video from PBS's NOVA. Read more »

Build the Eyeboard Open Source Eye-Tracking Project

Eyeboard Eye Tracking from MAKE Volume 29

When 18-year-old Honduran maker Luis Cruz met a quadriplegic high school classmate and learned about the challenges he and other folks with disabilities face in the light of expensive assistive communication technologies, he was inspired to devise a solution. What Luis came up with is the Eyeboard: an inexpensive yet... Read more »