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Hackaday Links: March 17, 2024

A friend of ours once described computers as “high-speed idiots.” It was true in the 80s, and it appears that even with the recent explosion in AI, all computers have managed to do is become faster. Proof of that can be found in a story about using ASCII art to trick a chatbot into giving away the store. As anyone who has played with ChatGPT or its moral equivalent for more than five minutes has learned, there are certain boundary conditions that the LLM’s creators lawyers have put in place to prevent discussion surrounding sensitive topics. Ask a chatbot to deliver specific instructions on building a nuclear bomb, for instance, and you’ll be rebuffed. Same with asking for help counterfeiting currency, and wisely so. But, by minimally obfuscating your question by rendering the word “COUNTERFEIT” in ASCII art and asking the chatbot to first decode the word, you can slip the verboten word into a how-to question and get pretty explicit instructions. Yes, you have to give painfully detailed instructions on parsing the ASCII art characters, but that’s a small price to pay for forbidden knowledge that you could easily find out yourself by other means.

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Absorbing Traffic Noise With Bricks Using Helmholtz Resonators

One inevitable aspect of cities and urban life in general is that it is noisy, with traffic being one of the main sources of noise pollution. Finding a way to attenuate especially the low-frequency noise of road traffic was the subject of [Joe Krcma]’s Masters Thesis, the results of which he gave a talk on at the Portland Maker Meetup Club after graduating from University College London. The chosen solution in his thesis are Helmholtz resonators, which are a kind of acoustic spring. Using a carefully selected opening into the cavity, frequencies can be filtered out, and extinguished inside the cavity.

Basic functionality and formula used to determine the dimensions of a Helmholtz Resonator.
Basic functionality and formula used to determine the dimensions of a Helmholtz Resonator.

As examples of existing uses of Helmholtz resonators in London, he points at the Queen Elizabeth Hall music venue, as well as the newly opened Queen Elizabeth Line and Paddington Station. For indoor applications there are a number of commercial offerings, but could this be applied to outdoor ceramics as well, to render urban environments into something approaching an oasis of peace and quiet?

For the research, [Joe]’s group developed a number of Helmholtz resonator designs and manufacturing methods, with [Joe] focusing on clay fired versions. For manufacturing, 3D printing of the clay was attempted, which didn’t work out too well. This was followed by slip casting, which allowed for the casting of regular rectangular bricks.

But after issues with making casting hollow bricks work, as well as the cracking of the bricks during firing in the kiln, the work of another student in the group inspired [Joe] to try a different approach. The result was a very uniquely shaped ‘brick’ that, when assembled into a wall, forms three Helmholtz resonators: inside it, as well as two within the space with other bricks. During trials, the bricks showed similar sound-deadening performance as  foam and wood. He also made the shape available on Thingiverse, if you want to try printing or casting it yourself.

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Books You Should Read: David Macaulay’s Architecture Series

For a lot of us, there’s a bright line separating the books we enjoyed as children from the “real” books of our more mature years. We all eventually age out of the thin, brightly illustrated picture books we enjoyed in our youth, replacing them with thicker, wordier volumes with fewer and fewer illustrations, until they become so dense with information that footnotes and appendices are needed to convey all the information, and a well-written index is a vital necessity to make use of any of it.

Such books seem like a lot less fun than kids’ books, and they probably are, but most of us adjust to the change and accept the fact that the children’s section of the library doesn’t hold much that’ll interest us anymore. But not all the books that get a “JUV” label on their spines are created equal. Some are far more than picture books, even if the pictures are the main attraction. The books of British-born American author David Macaulay come to mind, particularly the books comprising his Architecture Series.

Macaulay’s books were enormously influential in developing my engineering sensibilities, and are still a pleasure to thumb through these many years later. I still learn something about the history of construction and engineering when I pull one of these books off the shelf, which makes them Books You Should Read.

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Debian Officially Adds RISC-V Support

As time goes on, more and more computer manufacturers are moving towards the ARM architecture and away from the bloated and outdated x86 instruction set. Apple is the most prominent producer to take this step, but plenty others are using ARM for its flexibility and efficiency. The only problem with ARM is that it’s licensed, so if you want to go even further down the open-source path the RISC-V instruction set is the next logical step. Now at least one mainline Linux distribution will officially support this architecture.

While Debian did have some support for RISC-V before this as a Debian port, which was not officially part of Debian. However, the official support will begin with the release of Debian 13, which is currently in the testing phase and hasn’t seen a stable release yet. To that end, the current state of this official version is extremely limited, being described as “almost empty” but with planned support for an initial 90 packages in the coming days. Most users working on a RISC-V platform will most likely to continue to use their Debian ports version.

It might be a little while before the RISC-V version is as full-featured as the ARM or x86 versions of this Linux distribution, but we are happy to see it move in this direction at all. And don’t think that RISC-V is limited to embedded systems or otherwise limited computing platforms, either. We’ve seen full Linux desktops with RISC-V processors since at least 2019.

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Hackaday Links: June 18, 2023

Will it or won’t it? That’s the question much on the minds of astronomers, astrophysicists, and the astro-adjacent this week as Betelgeuse continued its pattern of mysterious behavior that might portend a supernova sometime soon. You’ll recall that the red giant star in the constellation Orion went through a “great dimming” event back in 2019, where its brightness dipped to 60% of its normal intensity. That was taken as a sign that perhaps the star was getting ready to explode — or rather, that the light from whatever happened to the star 548 years ago finally reached us — and was much anticipated by skywatchers, yours truly included. As it turned out, the dimming was likely caused by Betelgeuse belching forth an immense plume of dust, temporarily obscuring our view of its light. Disappointing.

Those who gave up on the hope of seeing a supernova might have done so too fast, though, because now, the star seems to be swinging the other way and brightening. It briefly became the brightest star in Orion, nearly outshining nearby Sirius, the brightest star in the sky. So what does all this on-again, off-again business mean? According to Dr. Becky, a new study — not yet peer-reviewed, so proceed with caution — suggests that the star could go supernova in the next few decades. The evidence for this is completely unrelated to the great dimming event, but by analyzing the star’s long history of variable brightness. The data suggest that Betelgeuse has entered the carbon fusion phase of its life, a period that only lasts on the scale of a hundred years for a star that size. So we could be in for the ultimate fireworks show, which would leave us with a star brighter than the full moon that’s visible even in daylight. And who doesn’t want to see something like that?

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A human hand holds a stack of several plexiglass sheets with needles glued into the ends. Very faint lines can be seen in the transparent stackup.

Biomimetic Building Facades To Reduce HVAC Loads

Buildings currently consume about 50% of the world’s electricity, so finding ways to reduce the loads they place on the grid can save money and reduce carbon emissions. Scientists at the University of Toronto have developed an “optofluidic” system for tuning light coming into a building.

The researchers devised a biomimetic system inspired by the multi-layered skins of squid and chameleons for active camouflage to be able to actively control light intensity, spectrum, and scattering independently. While there are plenty of technologies that can regulate these properties, doing so independently has been too complicated a task for current window shades or electrochromic devices.

To make the prototype devices (15 × 15 × 2 cm), 3 mm PMMA sheets were stacked after millifluidic channels (1.5 mm deep and 6.35 mm wide) were CNC milled into the sheets. Fluids could be injected and removed by needles glued into the ends of the channels. By using different fluids in the channels, researchers were able to tune various aspects of the incoming light. Scaled up, one application of the system could be to keep buildings cooler on hot days without keeping out IR on colder days which is one disadvantage of static window coatings currently in use.

If you want to control some of the light going OUT of your windows, maybe you should try building this smart LED curtain instead?

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An image of a Modulex brick (left) next to a LEGO brick right. Both are 4x2 studs, but the Modulex brick is much smaller at 20x10x5 mm vs the LEGO's 32x16x9.6 mm.

Modulex Is LEGO’s Long Lost Cousin

We love LEGO here at Hackaday, but did you know that LEGO spun off a parallel product line made for architectural models called Modulex?

[Peter Dibble] takes us on a deep dive through the history of Modulex, starting with Godtfred Kirk Christiansen needing a better way to model actual buildings after trying to design a house in LEGO. The LEGO brick’s 5:5:6 ratio proved challenging for modeling full-sized projects, so Modulex was conceived around a 1:1:1 ratio 5 mm cube. This change means Modulex is not compatible with LEGO System bricks.

As architectural styles morphed through the mid-20th Century, designs based around blocky shapes became passe, and Modulex pivoted to targeting factory and city planning customers. Products later branched out to include wall charts and Plancopy photocopy-able planners along with reconfigurable signage. Modulex (now ASI) still goes on as one of the biggest signage companies in the world, but discontinued the bricks in 2004. An attempt was made to revive Modulex bricks in 2015, but LEGO Group bought the company that had the rights to the bricks and has no intention of producing Modulex.

For more LEGO hacks, checkout this machine learning LEGO sorter or these giant LEGO-like pieces.

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