Probably The Simplest Radiation Detector You Already Own

September 26, 2022 by Jenny List 77 Comments

Over the years we’ve featured quite a few radiatioactivity detectors, which usually include a Geiger-Muller tube, or perhaps a large-area photodiode. But in the event of radiation exposure from a nuclear attack, how does the man in the street gauge the exposure without owning a dedicated instrument? This was a question of note at the height of the Cold War, and it’s one that [Dr. Marshall Brucer] answered in a 1962 paper entitled “When Do You Leave A Fallout Shelter“. The full paper is behind a paywall but the part we’re interested in is on the freely available first page.

Dr. Brucer‘s detector is simplicity itself, and it relies on the erosion of a static electric charge by radiation. Should you rub a plastic comb in your hair it will accumulate enough charge to pick up a small piece of paper, and under normal background radiation the charge will ebb away such that it will drop the piece of paper after about 15 seconds. His calculation is that once the field reaches around 10 roentgens per hour it will be enough to erase the charge and drop the paper immediately. There’s a comtemporary newspaper report (Page 7, just to the left of the large advertisment) which tells the reader that since the exposure limit is 100 roentgens (one sievert), this test failing indicates that they have nine hours to create a better shelter. For obvious reasons we can’t test this at the Hackaday bench, but those of us who remember the days when such topics were a real concern will be searching for a handy comb anyway.

Thanks [Victor Matthew] for the tip.

Smart Pills Can Tell Your Doctor That You’ve Taken Them

September 26, 2022 by Lewin Day 50 Comments

We have many kinds of pills available these days to treat all kinds of different disorders. Of course, the problem with pills is that they don’t work if you don’t take them. Even Worse, for some medicines, missing a dose can cause all kinds of undesirable withdrawl effects and set back a patient’s treatment.

Smart pills aim to fix this problem with a simple monitoring solution that can tell when a patient has taken their medication. They’re now publicly available and authorized for use, so let’s look at how they work.

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So How Do You Make A Self-Destructing Flash Drive?

September 26, 2022 by Tom Nardi 57 Comments

A self-destructing storage device that vaporizes its contents at the first sign of trouble would be an invaluable tool for many people, but good luck getting your hands on such a thing if you don’t work for a three-letter agency. Or at least, that’s what we would have said before [Walker] got on the case. He’s working on an open source self-destructing USB flash drive for journalists, security researchers, whistleblowers, or anyone else who really values their privacy.

When we previously covered this project in July, [Walker] had only planned to make the flash drive hide its contents unless you knew to wet your fingers before plugging it in. We admit it sounds a little weird, but as far as clandestine methods of activating something goes, it’s pretty clever. But based on the feedback he received, he decided to go all-in and make the USB drive literally trash itself should it be accessed by somebody who doesn’t know the secret.

An elegant weapon for a more civilized age.

But how exactly do you pull that off? Sure we’d love to see a small thermite charge or vial of acid packed in there, but obviously that’s not very practical. It needs to be safe to carry around, and just as importantly, unlikely to get you into even more trouble with whoever is searching through your belongings. To that end, [Walker] thinks he’s come up with an elegant solution.

The datasheet for his flash memory chip says the maximum voltage it can handle before releasing the Magic Smoke is a meager 4.6 V. So he figures running a voltage doubler on the nominal 5 V coming from a USB port should disable the chip nicely with a minimum of external drama. Will it be enough to prevent the data from being recovered forensically? We don’t know, but we’re eager to find out.

In the write-up, [Walker] takes readers through the circuit designs he’s come up so far, and shows off the source code that will run on the ATtiny25 to determine when it’s time to toast the flash. He says by the next post he should have the entire flash drive built and documented, so stay tuned.

Hackaday Links: September 25, 2022

September 25, 2022 by Dan Maloney 15 Comments

Looks like there’s trouble out at L2, where the James Webb Space Telescope suffered a mechanical anomaly back in August. The issue, which was just announced this week, involves only one of the six imaging instruments at the heart of the space observatory, known as MIRI, the Mid-Infrared Instrument. MIRI is the instrument on Webb that needs the coldest temperatures to work correctly, down to six Kelvins — we’ve talked about the cryocooler needed to do this in some detail. The problem has to do with unexpectedly high friction during the rotation of a wheel holding different diffraction gratings. These gratings are rotated into the optical path for different measurements, but apparently the motor started drawing excessive current during its move, and was shut down. NASA says that this only affects one of the four observation modes of MIRI, and the rest of the instruments are just fine at this time. So they’ve got some troubleshooting to do before Webb returns to a full program of scientific observations.

There’s an old saying that, “To err is human, but to really screw things up takes a computer.” But in Russia, to really screw things up it takes a computer and a human with a really poor grasp on just how delicately balanced most infrastructure systems are. The story comes from Moscow, where someone allegedly spoofed a massive number of fake orders for taxi rides (story in Russian, Google Translate works pretty well) through the aggregator Yandex.Taxi on the morning of September 1. The taxi drivers all dutifully converged on the designated spot, but instead of finding their fares, they just found a bunch of other taxis milling about and mucking up traffic. Yandex reports it has already added protection against such attacks to its algorithm, so there’s that at least. It’s all fun and games until someone causes a traffic jam.

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3D-Printable Sculpture Shows Off Unpredictable Order Of Chains

September 25, 2022 by Donald Papp 7 Comments

[davemoneysign] designed this fascinating roller chain kinetic sculpture, which creates tumbling and unpredictable patterns and shapes as long as the handle is turned; a surprisingly organic behavior considering the simplicity and rigidity of the parts.

3D-printed, with a satisfying assembly process.

The inspiration for this came from [Arthur Ganson]’s Machine With Roller Chain sculpture (video, embeded below). The original uses a metal chain and is motor-driven, but [davemoneysign] was inspired to create a desktop and hand-cranked manual version. This new version is entirely 3D-printed, and each of the pieces prints without supports.

According to [davemoneysign], the model works well with a chain of 36 links, but one could easily experiment with more or fewer and see how that changes the results. Perhaps with the addition of a motor this design could be adapted into something like this chains-and-sprockets clock?

You can see [Arthur Ganson]’s original in action in the video embedded below. It demonstrates very well the piece’s chaotic and unpredictable — yet oddly orderly — movement and shapes. Small wonder [davemoneysign] found inspiration in it.

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Honor Your Hacker Heroes

September 24, 2022 by Elliot Williams 3 Comments

We recently ran an article on a sweet percussion device made by minimal-hardware-synth-madman [Gijs Gieskes]. Basically, it amplifies up an analog meter movement and plays it by slamming it into the end stops. Rhythmically, and in stereo. It’s got that lovely thud, plus the ringing of the springs. It takes what is normally a sign that something’s horribly wrong and makes a soundtrack out of it. I love it.

[Gijs] has been making electro-mechanical musical hacks for about as long as I’ve been reading Hackaday, if not longer. We’ve written up no fewer than 22 of his projects, and the first one on record is from 2005: an LSDJ-based hardware sequencer. All of his projects are simple, but each one has a tremendously clever idea at its core that comes from a deep appreciation of everything going on around us. Have you noticed that VU meters make a particular twang when they hit the walls? Sure you have. Have you built a percussion instrument out of it? [Gijs] has!

Maybe it’s a small realization, and it’s not going to change the world by itself, but I’ve rebuilt more than a couple projects from [Gijs]’ repertoire, and each one has made my life more fun. And if you’re a regular Hackaday reader, you’ve probably seen hundreds or thousands of similar little awesome ideas played out, and maybe even taken some of them on as your own as well. When they accumulate up, I believe they can change the world, at least in the sense of filling up a geek’s life. I hope that feeling comes across when we write up a project. Those of you out there hacking, we salute you!

Chandelier Mimics The Solar Analemma

September 24, 2022 by Lewin Day 14 Comments

The solar analemma is the shape the sun traces out when photographed each day at the same time and same location for a whole year – but you probably knew that already. [makendo] decided to use this skewed figure-eight shape as the inspiration for a chandelier, and the results are stunning.

A laser cutter was used to cut out segments of the analemma shape in plywood, such that they could slot together into the full form. These were then glued together on to a plywood sheet as a template to cut out the full-size form in a single piece. Some laminate edging was then added and the entire thing was given a coat of black gloss paint. String lights were cut up to provide the many globe fittings required, and installed on the back of the chandelier.

[makendo] notes that with a full 51 bulbs in the chandelier, it’s way too bright for most dining room settings. A dimmer is thus used to tone down the output to reduce eyestrain at mealtimes. It’s a fun build, and we’ve always loved light fixtures that are inspired by astronomy. If you like the moon more than the sun, though, there’s a build for you too!