Launching things with electromagnetism is pretty fun, with linear induction motors being a popular design that finds use from everywhere in hobby designs like [Tom Stanton]’s to the electromagnetic launchers on new US and Chinese aircraft carriers. Although the exact design details differ, they use magnetic attraction and repulsion to create a linear motion on the propulsive element, like the sled in [Tom]’s design. Much like the electromagnetic catapults on a Gerald R. Ford-class carrier, electrical power is applied to rapidly move the sled through the channel, akin to a steam piston with a steam catapult.

For [Tom]’s design, permanent magnets are used along both sides of the channel in an alternating north/south pole fashion, with the sled using a single wound coil that uses brushes to contact metal rails along both sides of the channel. Alternating current is then applied to this system, causing the coil to become an electromagnet and propel itself along the channel.

An important consideration here is the number of turns of wire on the sled’s coil, as this controls the current being passed, which is around 90 A for 100 turns. Even so, the fastest sled design only reached a speed of 44 mph (~71 km/h), which is 4 mph faster than [Tom]’s previous design that used coils alongside the channels and a sled featuring a permanent magnet.

One way to increase the speed is to use more coils on the sled, with a two-coil model launching a light-weight model airplane to 10.2 m/s, which is not only a pretty cool way to launch an airplane, but also gives you a sense of appreciation for the engineering challenges involved in making an electromagnetic catapult system work for life-sized airplanes as they’re yeeted off an aircraft carrier and preferably not straight into the drink.

Last year Nolen Royalty made a website called One Million Checkboxes, which presented to the user exactly what it claimed on the tin. The gimmick was that the million checkboxes were shared globally. If I toggled checkbox 206,028 in my browser, you’d see checkbox 206,028 flip state in your browser. Totally pointless. Totally fun.

Here, Royalty tells the story of how the site was used by bot-writing teenage hackers:

Lots of people were mad about bots on OMCB. I’m not going to link to anything here — I don’t want to direct negative attention at anyone — but I got hundreds of messages about bots. The most popular tweet about OMCB complained about bots. People … did not like bots.

And I get it! The typical ways that folks — especially folks who don’t program — bump into bots are things like ticket scalping and restaurant reservation bots. Bots that feel selfish and unfair and antisocial.

And there certainly was botting that you could call antisocial. Folks wrote tiny javascript boxes to uncheck every box that they could — I know this because they excitedly told me. [...]

What this discord did was so cool — so surprising — so creative. It reminded me of me — except they were 10 times the developer I was then (and frankly, better developers than I am now). Getting to watch it live — getting to provide some encouragement, to see what they were doing and respond with praise and pride instead of anger — was deeply meaningful to me. I still tear up when I think about it.

Via Jason Kottke, who aptly observes that the way the hackers got in touch with Royalty “reminds me of the palimpsest (layered communication) that the aliens use to communicate with Earth in Carl Sagan’s Contact (and the 1997 movie).”

This Hybrid Dog Harness is by Seoul-based industrial design firm BKID. Designed for situations where your dog can be on- or off-leash, the retractable tether's handle can simply hang from your dog's back, when you don't need to handle him or her. I would've loved to have something like this, back when I used to bring my dogs to a public dog run. It eliminates the hassle of leashing and unleashing.

"TAILHIGH's 2-in-1 harness & leash is lightweight and extremely strong. The 5-foot retractable leash is designed for convenience and safety, providing you just enough length to walk your dog without being tangled in the lead. Our award-winning, patented, two-way lock system provides a safety stop for when you need more control."

Designed during the pandemic, it's in production by pet brand TailHigh. The design has since spawned numerous knock-offs, despite being patented.

These run $60, but at press time their website was encountering difficulties.

There aren’t many mythical animals in operating systems, and the most famous of those is probably Tux the penguin who appeared in Linux around 1996. The Mac’s first mythical animal predates that by more than a decade, and is the distinctive dogcow named Clarus, who appeared in every version of Mac OS until Mac OS X.

When Annette Wagner was designing the Page Setup dialog for Classic Mac OS, she needed a figure to place on the page to show the user its orientation and other options. She was working with an early symbolic font Cairo, created by Susan Kare who was also the designer of Chicago, the first Mac system font, and modified its z character of a dog to make it work better in the dialog. The result was a creature that looked like a hybrid between a dog and a cow.

In 1987, Scott ‘Zz’ Zimmerman coined the term dogcow for this curious beast, which by now was featured in every Page Setup dialog on every Mac, and was becoming quite a celebrity. A little later, Mark ‘The Red’ Harlan gave the dogcow the name of Clarus, a variation on the name of Claris, Apple’s software subsidiary that had been formed in 1987.

As Apple’s campus at 1 Infinite Loop, Cupertino, developed, Clarus was one of several large plastic figures forming the Icon Garden in front of the offices.

The dogcow lived on in Page Setup dialogs until Mac OS X was released, and early in the 2000s she was put out to grass in favour of a stylised icon of a human figure. Those who pined for the reappearance of the dogcow in OS X remained disappointed until macOS Ventura, when she finally returned, although now in full vector graphics glory.

By this time, there was another reference to Clarus tucked away as an Easter Egg in the Emoji & Symbols viewer: type the letters of her name into its search box, and you’ll see the two emoji characters of a dog and a cow, although neither of them resembles Clarus in appearance.

Although not heard in Mac OS, Clarus has been attributed the sound of moof, a portmanteau of moo and woof, of course.

The next time you open the Page Setup dialog, spare a thought for Clarus the dogcow, still doing the same job nearly forty years later.

References

Wikipedia
Macintosh Technical Note 31: The Dogcow, April 1989, written by Mark “The Red” Harlan
History of the Dogcow Part 1, MacTech, by Mark “The Red” Harlan
History of the Dogcow Part 2, MacTech, by Mark “The Red” Harlan

One Houston resident was suspicious of the city's "all plastic accepted" recycling program, and used AirTags to discover where the plastic waste actually ended up.


Brandy Deason, who regularly recycles her packaging and other waste, began to have doubts about the city's plastic recycling program. Houston's program boasted of being able to accept even types of plastic that aren't normally considered recyclable.

Curious as to where the plastic was going, she bought a set of AirTags, and included them in various bags of her plastic recycling. Of the bags she tracked, nearly all of them went to a company called Wright Waste Management, located in nearby Harris County.


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Logical Carry’s pocket driver has two drive modes. In addition to its ratchet mechanism, it has a 1/4″ socket on its tip with a detachable extension rod for extra leverage. Its handle has holders for five bits and a swivel arm that keeps them from falling out. The Ti-Mag V2 also has a pry bar and four slots for glow tubes. Available in titanium or black-finished aluminum.