Author: Al Williams

4312 Articles

The Sanskrit Square Root Algorithm

November 10, 2025 by 13 Comments

Years ago, no math education was complete without understanding how to compute a square root. Today, you are probably just reaching for a calculator, or if you are writing a program, you’ll probably just guess and iterate. [MindYourDecisions] was curious how people did square roots before they had such aids. Don’t remember? Never learned? Watch the video below and learn a new skill.

The process is straightforward, but if you are a product of a traditional math education, you might find his terminology a bit confusing. He will refer to something like 18b meaning “a three-digit number where the last digit is b,” not “18 times b,” as you might expect.

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An Unnecessary (But Cool) Processor

November 10, 2025 by 18 Comments

[Bob] calls his custom 16-bit computer “Bob’s Unnecessary Retro Processor” or BURP for short. While we suppose it is technically unnecessary, we love the look of it, and we hope he just used it to get the quirky acronym.

When we build custom CPUs they look suspiciously like FPGA development boards, but not BURP. We immediately thought of the IMSAI and the H8 when we saw it, but [Bob] points out it also borrows from the PDP-11.

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Concrete Lathe Turns Metal

November 9, 2025 by 43 Comments

Full disclosure. If you want a lathe capable of turning metal stock, you probably should just buy one. But what fun is that? You can do like [kachurovskiy] and build one with your 3D printer. If you are chuckling, thinking you can’t make 3D printed parts sturdy enough, you aren’t exactly wrong. [Kachurovskiy’s] trick is to 3D print forms and then cast the solid parts in concrete. The result looks great, and we don’t doubt his claim that it “can surpass many comparable lathes in rigidity and features.”

Even he admits that this is a “… hard, long, and expensive project…” But all good projects are. There’s a GitHub page with more details and informative videos below. The action shots are in the last video just before the six-minute mark. Around the seven-minute mark, you can see the machine cut a conical thread. Color us impressed!

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What Has 5,000 Batteries And Floats?

November 8, 2025 by 72 Comments

While it sounds like the start of a joke, Australian shipmaker Incat Tasmania isn’t kidding around about electric ships. Hull 096 has started charging, although it has only 85% of the over 5,000 lithium-ion batteries it will have when complete. The ship has a 40 megawatt-hour storage system with 12 banks of batteries, each consisting of 418 modules for a total of 5,016 cells. [Vannessa Bates Ramierz] breaks it down in a recent post over on IEEE Spectrum. You can get an eyeful of the beast in the official launch video, below. The Incat Tasmania channel also has other videos about the ship.

The batteries use no racks to save weight. Good thing since they already weigh in at 250 tonnes. Of course, cooling is a problem, too. Each module has a fan, and special techniques prevent one hot cell from spreading. Charging in Australia comes from a grid running 100% renewable energy. When the ship enters service as a ferry between Argentina and Uruguay, a 40-minute charge will be different. Currently, Uruguay has about 92% of its power from renewable sources. Argentina still uses mostly natural gas, but 42% of its electricity is sourced from renewable generation.

The ship is 130 meters (426 feet) long, mostly aluminum, and has a reported capacity of 2,100 people and 225 vehicles per trip. Ferry service is perfect for electric ships — the distance is short, and it’s easy to schedule time to charge. Like all electric vehicles, though, the batteries won’t stay at full capacity for long. Typical ship design calls for a 20-year service life, and it’s not uncommon for a vessel to remain in service for 30 or even 40 years. But experts expect the batteries on the ferry will need to be replaced every 5 to 10 years.

While electric ferries may become common, we don’t expect to see electric cargo ships plying the ocean soon. Diesel is hard to beat for compact storage and high energy density. There are a few examples of cargo ships using electric, though. Of course, that doesn’t mean you can’t build your own electric watercraft.

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Hackaday Podcast Episode 344: Board With Lasers, Op-Amp Torture, And Farewell Supercon 9

November 7, 2025 by No comments

Hackaday Editors Tom Nardi and Al Williams spent the weekend at Supercon and had to catch up on all the great hacks. Listen in as they talk about their favorites. Plus, stick around to the end to hear about some of the highlights from their time in Pasadena.

If you’re still thinking about entering the Component Abuse Contest, you’re just about out of time. Need some inspiration? Tom and Al talk about a few choice entries, and discuss how pushing parts out of their comfort zone can come in handy. Do you make your own PCBs? With vias? If you have a good enough laser, you could. Or maybe you’d rather have a $10 Linux server? Just manage your expectations. The guys both admit they aren’t mechanical geniuses and, unlike [4St4r], aren’t very good at guessing sounds either. They round up with some 3D printing projects and a collection of quick hacks.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 no PDP-1, 3D Printer, or lasers needed to listen.

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The Deadliest US Nuclear Accident Is Not What You Think

November 5, 2025 by 47 Comments

When you think of a US Nuclear accident, you probably think of Three Mile Island. However, there have been over 50 accidents of varying severity in the US, with few direct casualties. (No one died directly from the Three Mile Island incident, although there are some studies that show increased cancer rates in the area.)

Indeed, where there are fatalities, it hasn’t been really related to the reactor. Take the four people who died at the Surry Nuclear Power Plant accident: they were killed when a steam pipe burst and fatally scalded them. At Arkansas Nuclear One, a 525-ton generator was being moved, the crane failed to hold it, and one person died. That sort of thing could happen in any kind of industrial setting.

But one incident that you have probably never heard of took three lives as a direct result of the reactor. True, it was a misuse of the reactor, and it led to design changes to ensure it can’t happen again. And while the incident was nuclear-related, the radiation didn’t kill them, although it probably would have if they had survived their injuries. Continue reading “The Deadliest US Nuclear Accident Is Not What You Think” →

This Reactor Is On Fire! Literally…

October 29, 2025 by 51 Comments

If I mention nuclear reactor accidents, you’d probably think of Three Mile Island, Fukushima, or maybe Chernobyl (or, now, Chornobyl). But there have been others that, for whatever reason, aren’t as well publicized. Did you know there is an International Nuclear Event Scale? Like the Richter scale, but for nuclear events. A zero on the scale is a little oopsie. A seven is like Chernobyl or Fukushima, the only two such events at that scale so far. Three Mile Island and the event you’ll read about in this post were both level five events. That other level five event? The Windscale fire incident in October of 1957.

If you imagine this might have something to do with the Cold War, you are correct. It all started back in the 1940s. The British decided they needed a nuclear bomb project and started their version of the Manhattan Project called “Tube Alloys.” But in 1943, they decided to merge the project with the American program.

The British, rightfully so, saw themselves as co-creators of the first two atomic bombs. However, in post-World War paranoia, the United States shut down all cooperation on atomic secrets with the 1946 McMahon Act.

We Are Not Amused

The British were not amused and knew that to secure a future seat at the world table, it would need to develop its own nuclear capability, so it resurrected Tube Alloys. If you want a detour about the history of Britan’s bomb program, the BBC has a video for you that you can see below.

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