Can You Identify This Mystery Unicode Glyph?

April 24, 2022 by Jenny List 58 Comments

For anyone old enough to have worked with the hell of multiple incompatible character sets, Unicode has been a liberation; a true One Character Set To Contain Them All. We have so many Unicode characters to play with that there’s a fascinating pursuit in itself in probing at the obscure corners of what can be rendered on screen as a Unicode glyph. With so many disparate character sets having been brought together to make the Unicode standard there are plenty of unusual characters to choose from, and it’s one of them that [Jonathan Chan] has examined in detail.

U+237C ⍼, or the right angle with downwards zigzag arrow, is a mysterious Unicode symbol with no known use and from an unknown origin. XKCD featured it as a spoof “Larry Potter”, but as [Jonathan]’s analysis shows it’s proving impossible to narrow down where it came from. Mystical cult symbol? Or perhaps fiscal growth in an economy in which time runs downwards? Either way, when its lineage has been traced into the early 1990s with no answer to the question it appears that there may be a story behind it.

Hackaday readers never cease to amaze us with the breadth of their knowledge, ingenuity, and experience, so we think it’s not impossible that among you there may be people who will turn and pull a dusty computer manual from the shelf to give us the story behind this elusive glyph. We’d love to hear in the comments below.

Meanwhile if Unicode sparks your interest, we’ve given it a close look in the past.

Thanks [Jonty] for the tip.

High Temp Heat Engine Achieves 40% Efficiency

April 23, 2022 by Al Williams 17 Comments

People generate lots of waste heat. It makes sense that there is a desire to convert that heat into usable energy. The problem is one of efficiency. Researchers from MIT and the National Renewable Energy Lab have announced a new heat converter that they claim has 40% efficiency. Of course, there’s a catch. The temperature range for the devices starts at 1,900 °C .

The thermophotovoltaic cells are tandem devices with two cells mated on one substrate. Each cell is multiple layers of very thin and somewhat exotic materials. So this probably isn’t something you will cobble up in your basement anytime soon unless you’re already manufacturing ICs down there. It appears that the secret is in the multiple layers including a reflective one that sends any missed photons back through the stack.

The paper is pretty dense, but there’s a Sunday-supplement summary over on the MIT site. Using heat storage leads to the ability to make heat batteries, more or less, and harness what would otherwise be waste energy.

We’ve noticed a lot of interest in drawing power from hot pipes lately. All of them techniques we’ve seen rely on some kind of exotic materials.

Add Conductive Traces On Vacuum Formed Plastic With 3D Printing

April 22, 2022 by Anne Ogborn 3 Comments

Surface conductors on vacuum formed parts appear in many hacks, from cosplay armor to 3D touch pads and smart objects. But making them has always been painful. Either they had to be hand painted after forming, which looked sloppy and was labor intensive, or they had to be printed with some difficult to use stretchable ink tech. [Freddie Hong] and his group have another solution, using tech most hackers already have – a 3D printer and a vacuum former.

plastic tray with electrodes to sense foil wrapped chocolates — Smart tray created by this method.

They 3D print the traces with conductive PLA filament directly onto a base plastic sheet, and then vacuum form the whole thing. The filament is happy to deform when heated – it’s printer filament.

We like this process. We’ve found conductive filament isn’t reliably resistive across vertical layers, but is reliable in the XY plane. Their method only requires one layer. Also, they suggest 3D printing a layer of non conductive PLA atop most of the conductor, like a PCB solder mask.

Conductive filament has a fair bulk resistance. They suggest electroplating it before applying the top mask layer. They also are exploring 3D printing logos, stripes, and such with colored filament, or even making surface detail like rivets on model parts or adding thickness where the plastic thins during vacuum forming.

Designing the 3D print requires guessing what bit of plastic sheet ends up where in the vacuum formed final part. His group used a commercial program, t-sim, to do the prediction and Grasshopper to import the result into Rhino3D. This seems a lot for a home hacker. Drawing lines on a test sheet and vacuum forming seems simpler.

We’ve looked at vacuum forming before. We did a piece on 3D printing bucks , and covered [Ted Brull]’s Kevo vacuum former back in 2015.

Thanks to [howielowe] for the tip.

This Week In Security: Java’s Psychic Signatures, AWS Escape, And A Nasty Windows Bug

April 22, 2022 by Jonathan Bennett 2 Comments

Java versions 15, 16, 17, and 18 (and maybe some older versions) have a big problem, ECDSA signature verification is totally broken. The story is a prime example of the dangers of unintended consequences, the pitfall of rolling your own crypto, and why to build a test suite for important code. In Java 15, the ECDSA verification code was re-written, moving the code from C++ to a Java-native implementation. The new code misses an important check, that the initialization and proof values are both non-zero.

Continue reading “This Week In Security: Java’s Psychic Signatures, AWS Escape, And A Nasty Windows Bug” →

Electric Chopsticks Bring The Salt, Not The Pain

April 21, 2022 by Kristina Panos 12 Comments

The Japanese people love their salt, perhaps as much as Americans love their ~~sugar~~ high fructose corn syrup and caffeine. But none of these are particularly good for you. Although humans do need some salt in their diets to continue existing, the average Japanese person may be eating too much of it on a regular basis — twice the amount recommended by the World Health Organization, according to Reuters. Cue the invention of electric chopsticks, which provide salty flavor without the actual sodium.

No, you won’t get shocked — not even a fresh 9 V to the tongue’s worth. The tips of the chopsticks are made of something food-safe and conductive, and one is wired to a bracelet that contains a small computer. Using a weak current, the chopsticks transmit sodium ions from the food to the tongue, which increases the perceived saltiness by 1.5x. The device was co-created by a Meiji University professor and a Japanese beverage maker, who hope to commercialize it sometime next year.

This isn’t the first time humans have used trickery when it comes to diets. The older among you may remember the miracle berry weight loss craze of the 1970s. When ingested first, miracle berries make sour things taste sweet, so chowing down on grapefruits and lemons suddenly sounds like a good idea. What people failed to realize was that the acidity would still wreak havoc on their teeth and tongues, leaving them regretful the next day.

Images via Reuters

Honey, Did You Feed The Lamp? Company Wants To Create Living Light Bulbs

April 18, 2022 by Al Williams 30 Comments

The BBC’s [Peter Yeung] had an interesting post about a small French town experimenting with using bioluminescent organisms to provide lighting. A firm called Glowee is spearheading the effort in Rambouillet and other towns throughout France, using a variety of biological techniques to harness nature’s light sources.

Glowing animals are reasonably common ranging from fireflies to railroad worms. In the case of the French street lighting, Glowee is using a marine bacterium known as aliivibrio fischeri. A salt-water tube contains nutrients and when air is flowing through the tube, the bacteria glow with a cool turquoise light. The bacteria enter an anaerobic state and stop glowing if you shut off the air.

Continue reading “Honey, Did You Feed The Lamp? Company Wants To Create Living Light Bulbs” →

Vintage Computer Festival East Is This Weekend

April 18, 2022 by Tom Nardi 1 Comment

This weekend the InfoAge Science and History Museum in Wall, New Jersey will once again play host to the Vintage Computer Festival East — the annual can’t-miss event for anyone who has even a passing interest in the weird and wonderful machines that paved the way for the supercomputers we now all carry around in our pockets. Ticket holders will have access to a program absolutely jam packed with workshops, talks, and exhibits that center around the dual themes of “Women in Computing” and “Computers for the Masses”, plus a consignment and vendor area that almost guarantees you’ll be going home a little poorer than when you got there. But hey, at least you’ll have some new toys to play with.

For those that can’t make the pilgrimage to the tropical wonderland that is the Jersey Shore in April, all three days of the Festival will be live-streamed to the VCF YouTube page. There’s even an official Discord server where you can chat with other remote attendees. We’re glad to see more events adopting a hybrid approach after two years of COVID-19 lockdown, as it gives the far-flung a chance to participate in something they would otherwise miss completely. That said, there’s no virtual replacement for the experience of browsing the exhibits and consignment areas, so if it’s at all possible we recommend you get yourself to InfoAge for at least one of the days.

Incidentally, don’t worry if you’ve got the sneaking feeling that it hasn’t been anywhere near a year since the last time the VCF descended on Wall Township. The 2021 Festival got pushed to October because of the lingering plague, but rather than permanently change the date going forward, the 2022 Festival has returned to its traditional season. Of course that means the wait until VCF 2023 will seem unusually long after this double-shot, so here’s hoping we see another swap meet at the InfoAge campus before the end of the year.