The Stern-Gerlach Experiment Misunderstood

December 13, 2024 by 15 Comments

Two guys — Stern and Gerlach — did an experiment in 1922. They wanted to measure magnetism caused by electron orbits. At the time, they didn’t know about particles having angular momentum due to spin. So — as explained by [The Science Asylum] in the video below — they clearly showed quantum spin, they just didn’t know it and Physics didn’t catch on for many years.

The experiment was fairly simple. They heated a piece of silver foil to cause atoms to stream out through a tiny pinhole. The choice of silver was because it was a simple material that had a single electron in its outer shell. An external magnet then pulls silver atoms into a different position before it hits some film and that position depends on its magnetic field.

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Hack On Self: How’d My Day Go?

December 13, 2024 by 4 Comments

Humans are well overdue for a technological revolution – not a profit-driven one like we’re having now, a human-centric one. Sci-fi is wonderful for having your brain run wild. Over the last century, we’ve had writers try and imagine what world would’ve had looked like if a new technology were to address different aspects of human condition, or, work to undercut us all in yet unseen ways, for a change.

Quite a few leading HaD projects have clear sci-fi inspiration, too, and same goes for a large number of Hackaday Prize entries. Over here, we live for fantasy made reality through skill, wit, and insights.

Ever got a sci-fi-esque dream that you’ve tried to implement with modern-day tech, only to fail because something fundamental was missing about how your phone/laptop/smartwatch functions? You’re not alone here, for sure – this describes a large chunk of my tech journey. In real life, you work with audience-tailored devices, the few fun usecases pre-cooked into the hardware-firmware blob.

Still, how much can you build on top of a consumer device? Alternative OSes that liberate you from the trend of enshittification, for instance, that one’s brilliant and a lifeline for preserving one’s sanity. Alternative platforms that bring a reprieve from a modern combative and ad-filled social media environment, sure. Still, feels limited

How about diary keeping? Personal diaries are really rad, aren’t they? Surely, that one’s a low-hanging fruit? Continue reading “Hack On Self: How’d My Day Go?” →

Hackaday Podcast Episode 300: The Dwingeloo 25 M Dish, A Dead-Tech Twofer, And Deconstructing PCBs

December 13, 2024 by 6 Comments

This week on the big 300th episode, Hackaday’s Elliot Williams and Kristina Panos teamed up to bring you the latest news, mystery sound, and of course, a big bunch of hacks from the previous week. So basically, business as usual.

First up in the news: it’s time for the Hackaday Europe 2025 call for proposals! Do you have a tale of hardware, firmware, or software that must be shared with the Hackaday crowd? Then this is your chance to regale us with a 20- or 40-minute talk. You know we love to hear new voices, so be sure to consider proposing a talk.

On What’s That Sound, it’s a results show week. Congratulations to [Kelvin] who was one of many that correctly identified it as the Wii startup sound. Kristina will just be over here with her Pikachu64 with the light-up cheeks.

Then it’s on to the hacks and such beginning with a rather nice reverse-engineering of the PS1, which surprisingly did it with a two-sided board. Then it’s on to a smartphone home server, magic eye images in a spreadsheet, and the math behind the music of 80s. Finally, we talk about disc cameras, the hovercraft revolution, and a whole mess of keyboards.

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 and savor at your leisure.

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Saving An Electron Microscope From The Trash

December 13, 2024 by 16 Comments

Who wouldn’t want to have a scanning electron microscope (SEM)? If you’re the person behind the ProjectsInFlight channel on YouTube, you certainly do. In a recent video it’s explained how he got his mittens on a late 1980s, early 1990s era JEOL JSM-5200 SEM that was going to be scrapped. This absolute unit of a system comes with everything that’s needed to do the imaging, processing and displaying on the small CRT. The only problem with it was that it was defective, deemed irreparable and hence the reason why it was headed to the scrap. Could it still be revived against all odds?

The JEOL JSM-5200 SEM after being revived and happily scanning away. (Credit: ProjectsInFlight, YouTube)

The good news was that the unit came with the manual and schematics, and it turns out there’s an online SEM community of enthusiasts who are more than happy to help each other out. One of these even had his own JSM-5200 which helped with comparing the two units when something wasn’t working. Being an SEM, the sample has to be placed in a high vacuum, which takes a diffusion vacuum pump, which itself requires a second vacuum pump, all of which requires voltages and electronics before even getting to the amplification circuitry.

Since the first problem was that this salvaged unit wasn’t turning on, it started with the power supply and a blown fuse. This led to a shorted transformer, bad DC-DC converters, a broken vacuum pump, expired rubber hoses and seals, and so on, much of which can be attributed simply to the age of the machine. Finding direct replacements was often simply impossible to very expensive, necessitating creative solutions along with significant TLC.

Although there are still some small issues with for example the CRT due to possibly bad capacitors, overall the SEM seems to be in working condition now, which is amazing for a unit that was going to be trashed.

Thanks to [Hans] for the tip.

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This Week In Security: Recall, BadRAM, And OpenWRT

December 13, 2024 by 6 Comments

Microsoft’s Recall feature is back. You may remember our coverage of the new AI feature back in June, but for the uninitiated, it was a creepy security trainwreck. The idea is that Windows will take screenshots of whatever is on the screen every few seconds, and use AI to index the screenshots for easier searching. The only real security win at the time was that Microsoft managed to do all the processing on the local machine, instead of uploading them to the cloud. All the images and index data was available unencrypted on the hard drive, and there weren’t any protections for sensitive data.

Things are admittedly better now, but not perfect. The recall screenshots and database is no longer trivially opened by any user on the machine, and Windows prompts the user to set up and authenticate with Windows Hello before using Recall. [Avram] from Tom’s Hardware did some interesting testing on the sensitive information filter, and found that it worked… sometimes.

So, with the public preview of Recall, is it still creepy? Yes. Is it still a security trainwreck? It appears that the security issues are much improved. Time will tell if a researcher discovers a way to decrypt the Recall data outside of the Recall app.

Patch Tuesday

Since we’re talking about Microsoft, this week was Patch Tuesday, and we had seventy-one separate vulnerabilities fixed, with one of those being a zero-day that was used in real-world attacks. CVE-2024-49138 doesn’t seem to have a lot of information published yet. We know it’s a Heap-based Buffer Overflow in the Common Log File driver, and allows an escalation of privilege to SYSTEM on Windows machines. Continue reading “This Week In Security: Recall, BadRAM, And OpenWRT” →

Chirality Could Kill Us All, If We Let It

December 13, 2024 by 81 Comments

In our high school chemistry classes we all learn about chirality, the property of organic molecules in which two chemically identical molecules can have different structures that are mirror images of each other. This can lead to their exhibiting different properties, and one aspect of chirality is causing significant concerns in the field of synthetic biology. The prospect of so-called mirror organisms is leading to calls from a group of prominent scientists for research in the field to be curtailed due to the risks they would present.

Chirality is baked into all life; our DNA is formed of right-handed molecules while our proteins are left handed. The “mirror” organisms would reverse either or both of these, and could in theory be used to improve biochemical production processes. The concern is that these organisms would evade both the immune systems of all natural life forms, and any human defences such as antibiotics, thus posing an existential risk to life. It’s estimated that the capacity to produce such a life form lies more than a decade away, and the scientists wish to forestall that by starting the conversation early. They are calling for a halt to research likely to result in these organisms, and a commitment from funding bodies not to support such research.

Warnings of the dangers from scientific advances are as old as science itself, and it’s safe to say that many such prophecies have come from dubious sources and proved not to have a basis in fact. But this one, given the body of opinion behind it, is perhaps one that should be heeded.

Header: Original: Unknown Vector: — πϵρήλιο, Public domain.

Use Your RTL, In The Browser

December 13, 2024 by 14 Comments

The web browser started life as a relatively simple hypertext reading application, but over the 30+ years since the first one displayed a simple CERN web page it has been extended to become the universal platform. It’s now powerful enough to run demanding applications, for example a full software-defined radio. [Jtarrio] proves this, with an application to use an RTL-SDR, in HTML5.

It’s a fork of a previous Google-Chrome-only FM receiver, using the HTML5 WebUSB API, and converted to TypeScript. You can try it out for yourself if you have a handy RTL dongle lying around, it provides an interface similar to the RTL apps you may be used to.

The Realtek digital TV chipset has been used as an SDR for well over a decade now, so we’re guessing most of you with an interest in radio will have one somewhere. The cheap ones are noisy and full of spurious peaks, but even so, they’re a bucket of fun. Now all that’s needed is the transmit equivalent using a cheap VGA adapter, and the whole radio equation could move into the browser.