Measurement Is Science

June 21, 2025 by Elliot Williams 22 Comments

I was watching Ben Krasnow making iron nitride permanent magnets and was struck by the fact that about half of the video was about making a magnetometer – a device for measuring and characterizing the magnet that he’d just made. This is really the difference between doing science and just messing around: if you want to test or improve on a procedure, you have to be able to measure how well it works.

When he puts his home-made magnet into the device, Ben finds out that he’s made a basically mediocre magnet, compared with samples out of his amply stocked magnet drawer. But that’s a great first data point, and more importantly, the magnetometer build gives him a way of gauging future improvements.

Of course there’s a time and a place for “good enough is good enough”, and you can easily spend more time building the measurement apparatus for a particular project than simply running the experiment, but that’s not science. Have you ever gone down the measurement rabbit hole, spending more time validating or characterizing the effect than you do on producing it in the first place?

Build Your Own Telescope The Modern Way

June 19, 2025 by Al Williams 37 Comments

When we were kids, it was a rite of passage to read the newly arrived Edmund catalog and dream of building our own telescope. One of our friends lived near a University, and they even had a summer program that would help you measure your mirrors and ensure you had a successful build. But most of us never ground mirrors from glass blanks and did all the other arcane steps required to make a working telescope. However, [La3emedimension] wants to tempt us again with a 3D-printable telescope kit.

Before you fire up the 3D printer, be aware that PLA is not recommended, and, of course, you are going to need some extra parts. There is supposed to be a README with a bill of parts, but we didn’t see it. However, there is a support page in French and a Discord server, so we have no doubt it can be found.

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Iron Nitride Permanent Magnets Made With DIY Ball Mill

June 19, 2025 by Maya Posch 10 Comments

Creating strong permanent magnets without using so-called rare earth elements is an ongoing topic of research. An interesting contestant here are iron nitride magnets (α”-Fe₁₆N₂), which have the potential to create permanents magnets on-par with with neodymium (Nd₂Fe₁₄B) magnets. The challenging aspect with Fe-N magnets is their manufacturing, with recently [Ben Krasnow] giving it a shot over at the [Applied Science] YouTube channel following the method in a 2016 scientific paper by [Yanfeng Jiang] et al. in Advanced Engineering Materials.

This approach uses a ball mill (like [Ben]’s planetary version) with ammonium nitrate (NH₄NO₃) as the nitrogen source along with iron. After many hours of milling a significant part of the material is expected to have taken on the α”-Fe₁₆N₂phase, after which shock compaction is applied to create a bulk magnet. After the ball mill grinding, [Ben] used a kiln at 200°C for a day to fix the desired phase. Instead of shock compaction, casting in epoxy was used as alternative.

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Photo of AlphaPhoenix looking at an airplane flying through the air

Weighing An Airplane As It Flies Overhead

June 18, 2025 by John Elliot V 52 Comments

Recently, [AlphaPhoenix] weighed an airplane. Normally, that wouldn’t be much of an accomplishment. Except in this case, the airplane happened to be in flight at the time. In fact we’re not sure what is more remarkable, as he not only weighed real actual airplanes but a paper airplane too!

The sealed box essentially acts as a pressure sensor.

To test the concept, a large scale is made from foamcore and four load cells which feed into an Arduino which in turn is connected to a laptop for a visualization. After a brief test with a toy car, [AlphaPhoenix] goes on to weigh a paper airplane as it flies over the scale. What we learn from the demonstration is that any weight from a flying object is eventually transferred to the ground via the air.

In the second part of the video a new, smaller, type of scale is created and taken to the airport where airplanes flying overhead are weighed over the course of three days. This new apparatus is basically a pressure sensor enclosed in a nominally air-tight box, essentially a fancy type of barometer. Measurements are taken, assumptions are made, and figures are arrived at. Unfortunately the calculated results are off by more than one order of magnitude, but that doesn’t stop this experiment from having been very cool!

If you’re interested in weighing things for fun or profit be sure to check out Hackaday Prize 2022: Arduino-Powered Weighing Scale Has A Real Analog Display or Reverse Engineering A Bathroom Scale For Automated Weight Tracking.

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A DIY Version Of The Franck-Hertz Experiment

June 17, 2025 by John Elliot V 5 Comments

The Franck–Hertz experiment was a pioneering physics observation announced in 1914 which explained that energy came in “packets” which we call “quanta”, marking the beginning of quantum physics. Recently, [Markus Bindhammer] wrote in to let us know he had redone the experiment for himself.

In the original experiment a mercury vacuum tube was used, but in his recreation of the experiment [Markus] uses a cheaper argon tube. He still gets the result he is looking for though, which is quite remarkable. If you watch the video you will see the current readings clump around specific voltage levels. These voltage levels indicate that energy is quantized, which was a revolutionary idea at the time. If you’re interested in how contemporary physics regards, particles, waves, and quanta, check out this excellent presentation: But What Actually Is a Particle? How Quantum Fields Shape Reality.

Before closing we have to say that the quality of [Markus]’s build was exceptional. He made a permanent enclosure for his power supplies, made custom PCBs, used ferrule crimps for all his wire interconnects, included multiple power switches and dials, professionally labeled and insulated everything, and even went to the trouble of painting the box! Truly a first class build. One thing that surprised us though was his use of rivets where we would almost certainly have used bolts or screws… talk about confidence in your workmanship!

If you’re interested in quantum physics it is certainly a topic we have covered here at Hackaday. Check out Quantum Mechanics And Negative Time With Photon-Atom Interactions or Shedding Light On Quantum Measurement With Calcite.

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A circuit board is shown on a white background. It has a USB-A port on the front side, and a coiled wire antenna extending from another circuit board mounted above the first one.

A Remote-Controlled USB Rubber Ducky Clone

June 13, 2025 by Aaron Beckendorf 17 Comments

Despite the repeated warnings of system administrators, IT personnel, and anyone moderately aware of operational security, there are still quite a few people who will gladly plug a mysterious flash drive into their computers to see what’s on it. Devices which take advantage of this well-known behavioral vulnerability have a long history, the most famous of which is Hak5’s USB Rubber Ducky. That emulates a USB input device to rapidly execute attacker-defined commands on the target computer.

The main disadvantage of these keystroke injection attacks, from the attacker’s point of view, is that they’re not particularly subtle. It’s usually fairly obvious when something starts typing thousands of words per minute on your computer, and the victim’s next move is probably a call to IT. This is where [Krzysztof Witek]’s open-source Rubber Ducky clone has an advantage: it uses a signal detected by a SYN480R1 RF receiver to trigger the deployment of its payload. This does require the penetration tester who uses this to be on the site of the attack, but unlike with an always-on or timer-delayed Rubber Ducky, the attacker can trigger the payload when the victim is distracted or away from the computer.

This project is based around the ATmega16U2, and runs a firmware based on microdevt, a C framework for embedded development which [Krzysztof] also wrote. The project includes a custom compiler for a reduced form of Hak5’s payload programming language, so at least some of the available DuckyScript programs should be compatible with this. All of the project’s files are available on GitHub.

Perhaps due to the simplicity of the underlying concept, we’ve seen a few open source implementations of malicious input devices. One was even built into a USB cable.

Simple Open Source Photobioreactor

June 12, 2025 by Al Williams 11 Comments

[Bhuvanmakes] says that he has the simplest open source photobioreactor. Is it? Since it is the only photobioreactor we are aware of, we’ll assume that it is. According to the post, other designs are either difficult to recreate since they require PC boards, sensors, and significant coding.

This project uses no microcontroller, so it has no coding. It also has no sensors. The device is essentially an acrylic tube with an air pump and some LEDs.

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