It’s Friday, do you really want me to make you think? Instead, I bring you a “90 degree index ratchet,” realized in LEGO in what I gather was a single evening by Dan Zimmerman. Dan is a physicist at the University of Maryland whose day job is building a 30-ton sphere filled with liquid sodium that may or may not spontaneously generate a magnetic field like Earth’s.

Dan got the design for this ratchet from a book first published in 1930, Ingenious Mechanisms for Designer and Inventors.

There was a time before computers and the Internet that budding geeks who wanted to “program” in any sense of the word were limited to physical computers. Mechanisms like this one have the added benefit of affecting the material world rather than just someone’s eyeballs, so we called it mechanical engineering, revolutionized industrial production and only later started taking it for granted enough to ship it overseas.

Dan has also built an upright bass out of LEGOs. It even has a nice sound.