Day: March 13, 2025

The Mysterious And Important Work Of Prop Design On Severance

March 13, 2025 by 28 Comments

Have you seen Severance? Chances are good that you have; the TV series has become wildly popular in its second season, to the point where the fandom’s dedication is difficult to distinguish from the in-universe cult of [Kier]. Part of the show’s appeal comes from its overall aesthetic, which is captured in this description of the building of one of the show’s props.

A detailed recap of the show is impossible, but for the uninitiated, a mega-corporation called Lumon has developed a chip that certain workers have implanted in their brains to sever their personalities and memories into work and non-work halves. The working “Innies” have no memory of what their “Outies” do when they aren’t at work, which sounds a lot better than it actually ends up being. It’s as weird as it sounds, and then some.

The prop featured here is the “WoeMeter” from episode seven of season two, used to quantify the amount of woe in a severed worker — told you it was weird. The prop was built by design house [make3] on a short timeline and after seeing only some sketches and rough renders from the production designers, and had to echo the not-quite-midcentury modern look of the whole series. The builders took inspiration from, among other things, a classic Nagra tape recorder, going so far as to harvest its knobs and switches to use in the build. The controls are all functional and laid out in a sensible way, allowing the actors to use the device in a convincing way. For visual feedback, the prop has two servo-operated meters and a string of seven-segment LED displays, all controlled by an ESP-32 mounted to a custom PCB. Adding the Lumon logo to the silkscreen was a nice touch.

The prop maker’s art is fascinating, and the ability to let your imagination run wild while making something that looks good and works for the production has got to be a blast. [make3] really nailed it with this one.

Thanks to [Aaron’s Outie] for the tip.

Tracking Deep-Sky Objects

March 13, 2025 by 2 Comments

Astrophotography, and astronomy in general, takes some fairly specialized tools and a high amount of precision. Setting up the equipment can also take a lot of time, especially for amateurs traveling to various locations with their equipment, so anything that can reduce the amount of time spent looking for objects and increasing the amount of time looking at them is a welcome addition, especially since nights where conditions are ideal for these activities can be rare. [Anton] developed this real-time tracking tool for deep sky objects (DSOs) to keep tabs on most of the interesting things out there a telescope can be pointed at.

[Anton] calls his tool the Nova DSO Altitude Tracker and gets its information from SIMBAD, updating every minute for a given location on the planet. With that location data, the program calculates altitude and azimuth for various objects and also helps the user keep track of other important variables like moon illumination and angle above the horizon. It also allows the user to highlight specific objects of interest, making sure they are front and center throughout the session. Each DSO can be selected from a list to display detailed information about it such as its path, time visible in the sky, and other properties.

To get the program running, essentially all that’s required is a computer capable of running Python and a display of some sort. From there it provides a quick view of the best objects to point one’s telescope or camera at without any guesswork. With all of the code available it shouldn’t be too much of a leap to do other things with the underlying software, either, such as tying it into a tracker of some sort like this DIY telescope tracking device we featured a while back.

BritCSS: Write CSS With British English Spellings

March 13, 2025 by 37 Comments

Everyone knows that there is only one proper English, with the rest being mere derivatives that bastardize the spelling and grammar. Despite this, the hoodlums who staged a violent uprising against British rule in the American colonies have somehow made their uncouth dialect dominant in the information technologies that have taken the world by storm these past decades. In this urgent mission to restore the King’s English to its rightful place, we fortunately have patriotic British citizens who have taken it upon themselves to correct this grave injustice. Brave citizens such as [Declan Chidlow], whose BritCSS project is a bright beacon in these harrowing times.

Implemented as a simple, 14 kB JavaScript script to be included in an HTML page, it allows one to write CSS files using proper spelling, such as background-colour and centre. Meanwhile harsh language such as !important is replaced with the more pleasant !if-you-would-be-so-kind. It is expected that although for now this script has to be included on each page to use BritCSS, native support will soon be implemented in every browser, superseding the US dialect version. [Declan] has also been recommended to be awarded the Order of the British Empire for his outstanding services.

Have Li-ion Batteries Gone Too Far?

March 13, 2025 by 84 Comments

The proliferation of affordable lithium batteries has made modern life convenient in a way we could only imagine in the 80s when everything was powered by squadrons of AAs, or has it? [Ian Bogost] ponders whether sticking a lithium in every new device is really the best idea.

There’s no doubt, that for some applications, lithium-based chemistries are a critically-enabling technology. NiMH-based EVs of the 1990s suffered short range and slow recharge times which made them only useful as commuter cars, but is a flashlight really better with lithium than with a replaceable cell? When household electronics are treated as disposable, and Right to Repair is only a glimmer in the eye of some legislators, a worn-out cell in a rarely-used device might destine it to the trash bin, especially for the less technically inclined.

[Bogost] decries “the misconception that rechargeables are always better,” although we wonder why his article completely fails to mention the existence of rechargeable NiMH AAs and AAAs which are loads better than their forebears in the 90s. Perhaps even more relevantly, standardized pouch and cylindrical lithium cells are available like the venerable 18650 which we know many makers prefer due to their easy-to-obtain nature. Regardless, we can certainly agree with the author that easy to source and replace batteries are few and far between in many consumer electronics these days. Perhaps new EU regulations will help?

Once you’ve selected a battery for your project, don’t forget to manage it if it’s a Li-ion cell. With great power density, comes great responsibility.

Got Junk? Then Build This Scrappy TEA Laser

March 13, 2025 by 24 Comments

A piece of glass, some bits of tinfoil, a sheet of plastic, a couple of razor blades, and a few assorted bits and bobs are all it takes to build this TEA nitrogen laser. Oh, and a 5,000-volt flyback supply with enough amperage to stop your heart. You’ll need that too.

Seriously, if you choose to follow [MultiverseCurator] ‘s example and build this laser, you’ll want to take the proper precautions. A transversely excited atmospheric laser is simple in concept, but there are plenty of ways for them to go wrong. Unlike the gas lasers used in laser cutters, there’s no enclosed resonator cavity or mirrors. Rather, the excitation takes place across a narrow gap between two electrodes, using atmospheric nitrogen as the lasing medium. This results in hard UV emissions, which means you can’t see them with the naked eye. Add to that the spark gap creating extremely loud discharges as the laser operates, and hazards abound. Proceed with caution.

Construction starts with a flat glass plate and a pair of large capacitors made from aluminum foil plates separated by a plastic dielectric. The razor blades are connected across the capacitors, separated by a narrow gap, with an inductor made from magnet wire in parallel. A spark gap made from nuts and bolts goes in series, and the whole assembly gets connected to a high-voltage power supply — [Multiverse] used a ZVS driver and a CRT flyback transformer with an eight-megohm resistor in series. The video below has all the build details.

It’ll take a little fiddling to get it lasing, and you’ll need something phosphorescent to see the UV light — a scrap of copy paper should do. But the results are pretty amazing for something made from scrap. If you want to take the design to the next level, you’ll want to check out [Les Wright]’s TEA laser build.

Continue reading “Got Junk? Then Build This Scrappy TEA Laser” →

Linux Fu: Use The Source (Command), Luke

March 13, 2025 by 12 Comments

You can argue if bash is a good programming language or not, but you can’t argue that it is a programming language. However, there are a few oddities about it that make it different from most other languages you probably know. For one thing, variables are dynamically scoped. Second, you can easily change variables in an upper scope. This leads to a problem when you want to do something like reset your path:

#!/bin/bash
#: This does NOT work
PATH=/usr/bin:/bin

Well, actually, it does work; it just doesn’t work the way you imagine it might. The key is to realize that when you execute our script (say, resetpath), a new copy of bash runs. It inherits all the variables from your shell. Now the script sets PATH for the new copy of bash. Anything else you run in that script will see your change. But when the script exits, the new copy of bash is gone and the old copy sees the same old PATH it always did.

Continue reading “Linux Fu: Use The Source (Command), Luke” →

Hacking A Rotary Phone

March 13, 2025 by 15 Comments

[Yaymukund] made an interesting observation. Old-style rotary phones were made to last and made for service. Why? Because you didn’t own them, the phone company did. There was no advantage for them for you to need a service call or a new phone. Of course, many of these old phones are still hanging around like the GPO 746 that appears in the post.

What do you do with an old rotary phone? In this case, you make it play a random tune whenever someone picks up the handset. As you might expect, you don’t need much of the original phone to do this. In particular, you need the handset receiver and the switch hook. We’d have liked to read the dial to select a tune, but perhaps that could be in version two.

All the components wire back to a D92732 circuit board. Finding the right wires was a bit finicky, but eventually, a Teensy, a battery pack, and an audio breakout board were in place. The rest is mostly trivial.

[Yaymukund] spent about £300, but over half of that was on tools most Hackaday readers will already have. The phone itself was £65. You can use these phones as a basis for many projects. Even if you want to go mobile.