We always like to call out a commercial success stemming from projects that got their start on Hackaday.io, and so we’re proud to announce the release of MAKE: Calculus by Joan Horvath and Rich Cameron, a book that takes a decidedly different approach to teaching calculus than traditional courses. Geared to makers and hackers, who generally tend to have a visual style of learning, the book makes heavy use of 3D-printed models to illustrate the relationships between functions. The project started five years ago as a 2017 Hackaday Prize entry, and resulted in a talk at the 2019 Supercon. Their book is now available for preorder, and might be a great way to reacquaint themselves with calc, or perhaps even to learn it for the first time.

So what were you doing at 11:15 UTC on Friday, July 8? Whatever it was, chances are excellent that you were doing it under at least partial sunlight. That’s because at that moment, an estimated 99% of the world’s 8 billion or so people are somewhere between dawn and dusk. A glimpse at the day-night map for that moment shows what happened — with the Sun directly above northern Niger, the only populous continent (sorry, Antarctica) in the dark is Australia. The curve of the terminator almost exactly matches the outline of the other continents, from Japan where the Sun was just setting to the west coasts of the Americas, where it was just coming up. This bit of trivia is almost certainly of zero practical use to anyone, but that doesn’t make it any less cool or worth thinking about.

It seems like we might need to talk about RadioShack. Depending on how old you are, you’ll either recall a Radio Shack (notice the space) which was a one-stop shop for everything from rebadged stereo gear to individual resistors, or later as the camel-cased place where your parents bought their cell phones. We’ve been tracking the storied retailer’s downward spiral since at least 2011, including a few head-fakes that seemed to promise its return to brick-and-mortar or at least as an online entity. But now were hear that RadioShack has transmogrified itself yet again, this time into a mean-tweeting crypto exchange. Somewhere along the way, Retail Ecommerce Ventures, the private equity firm that bought RadioShack in 2020 along with such dying retailers as Pier 1 Imports and Modell’s Sports, launched crypto exchange RadioShack Swap, and started blasting out some pretty raunchy tweets for some reason. It’s… really weird.

If you’re looking for a palate cleanser after that, you could do worse than listening to the dulcet tones of WWV, the Colorado-based “all time, all the time” radio station. WWV has been on the air pretty much since there’s been air to be on, transmitting time signals from their atomic clocks. Trouble is, their signals are on the shortwave and HF bands, so unless you’ve got a radio to receive them, you’re out of luck. Or are you? Turns out that if all you’re interested in is the sounds of WWV, there’s an app for that. The WWV Simulator plays the unique combinations of tones, clicks, and voice announcements that WWV listeners have come to love. It’s not clear whether the simulation includes WWV’s digital time codes; we’d guess no, but it should be easy enough to figure out.

And finally, if you’ve never seen the work of a beaver up close, consider yourself somewhat deficient in your engineering education. What these fur-bearing critters can accomplish in a single night or work is beyond belief, if sometimes beyond the pale, as their infrastructure projects have the capacity to flood out human structures. And so some clever social engineering by their human neighbors has been required to relocate them, as this gem with footage from 1948 shows. A passel of pesky beavers caught by the Idaho Fish and Game Department was relocated by dropping them from airplanes. Unlike fish-bombing, beavers require a gentler landing, so the Fish and Game people came up with a clever box that keeps each animal contained during its ride to the ground on surplus WWII parachutes. The box opens on touchdown and out pops the critter, no doubt confused by his new surroundings and the wicked strange thing that just happened to him.