Mining And Refining: Graphite

In my teenage years I worked for a couple of summers at a small amusement park as a ride operator. Looking back on it, the whole experience was a lot of fun, although with the minimum wage at $3.37 an hour and being subjected to the fickle New England weather that ranged from freezing rains to heat stroke-inducing tropical swelter, it didn’t seem like it at the time.

One of my assignments, and the one I remember most fondly, was running the bumper cars. Like everything else in the park, the ride was old and worn out, and maintenance was a daily chore. To keep the sheet steel floor of the track from rusting, every morning we had to brush on a coat of graphite “paint”. It was an impossibly messy job — get the least bit of the greasy silver-black goop on your hands, and it was there for the day. And for the first few runs of the day, before the stuff worked into the floor, the excited guests were as likely as not to get their shoes loaded up with the stuff, and since everyone invariably stepped on the seat of the car before sitting on it… well, let’s just say it was easy to spot who just rode the bumper cars from behind, especially with white shorts on.

The properties that made graphite great for bumper cars — slippery, electrically conductive, tenacious, and cheap — are properties that make it a fit with innumerable industrial processes. The stuff turns up everywhere, and it’s becoming increasingly important as the decarbonization of transportation picks up pace. Graphite is amazingly useful stuff and fairly common, but not all that easy to extract and purify. So let’s take a look at what it takes to mine and refine graphite.

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All About Cats, And What Ethernet Classifications Mean Beyond ‘Bigger Number Better’

Although it probably feels like forever to many of us since Category 5 Ethernet cabling became prevalent, now that 2.5 and even 5 Gbit Ethernet has trickled into the mainstream, a pertinent question that many probably end up asking, is when you should replace Cat-5e wiring with Cat-6, or even Cat-7. Since most of us are likely to use copper network wiring for the foreseeable future in our domiciles and offices, it is a good question that deserves a good answer. Although swapping a Cat-5e patch cable with a Cat-7 one between a network port and computer is easy enough, replacing all the network cable already pulled through the conduits of a ‘future-proofed’ home is not.

The good news is probably that Category 8 Class II (Cat-8.2) is all you need to run your 40 Gbit Ethernet network with standard twisted pair wiring. The bad news is that you’re limited to runs of only thirty meters before signal degradation begins to kick in. If you take things down a notch to Cat-6A or Cat-7 (ISO/IEC 11801 Class EA and F, respectively), you can do 100 meter runs at 10 Gbit/s just like 100 meters runs at 1 Gbit/s were possible with Cat-5e before. Yet what differentiates these categories exactly?

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Looking At How Pyramids Were Built Using Their Casing Stones

As one of the most famous Ancient Egyptian pyramids, the Pyramid of Khafre on the plateau of Giza has been a true wonder of the Ancient World ever since its construction around 2570 BCE. Today, well over 4,500 years later, we are still as puzzled as our ancestors over the past hundreds of years how exactly this and other pyramids were constructed. Although many theories exist, including ramps that envelop the entire pyramid, to intricate construction methods from the inside out, the only evidence we have left are these pyramids themselves.

This is where the jokingly called [History for Granite] channel on YouTube has now pitched some new ideas, involving the casing stones that used to fully cover the Pyramid of Khafre, prior to widespread theft and vandalism.

Bonding stones within the casing stones on the Pyramid of Khafre. (Credit: History for Granite, YouTube)
Bonding stones within the casing stones on the Pyramid of Khafre. (Credit: History for Granite, YouTube)

Despite the pyramids of Giza in particular being a veritable tourist trap, said tourists are heavily discouraged from climbing onto the pyramids, or even set up high-powered camera gear on tripods near them. Even with drone footage available, it was necessary to get a zoomed-in look on the casing stones that remain on the pyramid of Khafre near its top at well over 100 meters. Working within these limitations, it was possible to take detailed photos of three sides of the pyramid, which revealed interesting details.

In the top screenshot from the video the top of the pyramid is visible, which gives some indication of just how much the pyramid may have shifted out of alignment due to earthquakes over the millennia. This turned out to be not significant enough to account for some purported ‘gaps’ between the casing stones, with supposed ‘filler material’ from scaffolding holes explainable as just broken off sections of these casing stones. What was more interesting was that a pattern could be found in so-called bonding stones.

Pattern of bonding stones on the north face of the pyramid of Khafre. (Credit: History for Granite, YouTube)
Pattern of bonding stones on the north face of the pyramid of Khafre. (Credit: History for Granite, YouTube)

These bonding stones have a slanted end, so that they can be lifted slightly above a matching slanted stone, before being lowered to complete a row of bricks or stonework. After analyzing the three faces of the still mostly intact casing stones, a clear pattern emerged, such as that on the north face, pictured here.

What this suggests is that each row of casing stones were laid down by multiple groups of workers, each starting at a specific point before coming together where those sections would be joined with a bonding stone. This lends credence to the theory that the pyramid was constructed layer by layer, including the outer covering. To further examine these clues, the even older Bent Pyramid at the royal necropolis of Dahshur with mostly intact casing stones will be examined in more detail next.

If anything this series shows just how much there still is that we don’t know about these massive construction projects that are really only preceded by the works of the Sumerian and Akkadian people.

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Saving Apollo By Decoding Core Rope

One of our favorite retro hardware enthusiasts, [CuriousMarc], is back with the outstanding tale of preserving Apollo Program software, and building a core rope reader from scratch to do it. We’ve talked about [Marc]’s previous efforts to get real Apollo hardware working again, and one of the by-products of this effort was recovering the contents of the read-only core rope memory modules that were part of that hardware.

The time finally came to hand the now-working Apollo guidance computer back to its owner, which left the team without any hardware to read core rope modules. But the archive of software from the program was still incomplete, and there were more modules to try to recover. So, the wizardly [Mike Stewart] just decided to roll up his sleeves and build his own reader. Which didn’t actually work as expected the first time.

And this leads us into one of [Marc]’s elevator music explainers, where he gives a beautiful rundown on how core rope works. And if you are thinking of core memory based on ferrite cores, get ready for a brain stretch, as core rope is quite a bit different, and is even more complicated to read. Which brings us to the bug in [Mike]’s reader, which is actually a bug in the block II design of the core rope modules.

Reading a byte off the module requires setting multiple inhibit wires to select an individual core. An innovation in block II allowed those inhibit wires to run at half current, but it turns out that didn’t actually work as intended, and partially selected multiple cores on the other half of the module. And [Mike] forget to re-implement that bug — the reader needs to literally be bug-for-bug compatible. A quick recompile of the FPGA code makes everything work again. And the conservation effort can continue. Stay tuned for more in the Apollo story!

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Black 4.0 Is The New Ultrablack

Vantablack is a special coating material, moreso than a paint. It’s well-known as one of the blackest possible coatings around, capable of absorbing almost all visible light in its nanotube complex structure. However, it’s complicated to apply, delicate, and not readily available, especially to those in the art world.

It was these drawbacks that led Stuart Semple to create his own incredibly black paint. Over the years, he’s refined the formula and improved its performance, steadily building a greater product available to all. His latest effort is Black 4.0, and it’s promising to be the black paint to dominate all others.

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How Framework Laptop Broke The Hacker Ceiling

We’ve been keeping an eye on the Framework laptop over the past two years – back in 2021, they announced a vision for a repairable and hacker-friendly laptop based on the x86 architecture. They’re not claiming to be either open-source or libre hardware, but despite that, they have very much delivered on repairability and fostered a hacker community around the laptop, while sticking to pretty ambitious standards for building upgradable hardware that lasts.

I’ve long had a passion for laptop hardware, and when Hackaday covered Framework announcing the motherboards-for-makers program, I submitted my application, then dove into the ecosystem and started poking at the hardware internals every now and then. A year has passed since then, and I’ve been using a Framework as a daily driver, reading the forums on the regular, hanging out in the Discord server, and even developed a few Framework accessories along the way. I’d like to talk about what I’ve seen unfold in this ecosystem, both from Framework and the hackers that joined their effort, because I feel like we have something to learn from it.

If you have a hacker mindset, you might be wondering – just how much is there to hack on? And, if you have a business mindset, you might be wondering – how much can a consumer-oriented tech company achieve by creating a hacker-friendly environment? Today, I’d like to give you some insights and show cool things I’ve seen happen as an involved observer, as well as highlight the path that Framework is embarking upon with its new Framework 16.

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The UK Online Safety Bill Becomes Law, What Does It Mean?

We’ve previously reported from the UK about the Online Safety Bill, a piece of internet safety legislation that contains several concerning provisions relating to online privacy and encryption. UK laws enter the statutes by royal assent after being approved by Parliament, so with the signature of the King, it has now become the law of the land as the Online Safety Act 2023. Now that it’s beyond amendment, it’s time to take stock for a minute: what does it mean for internet users, both in the UK and beyond its shores? Continue reading “The UK Online Safety Bill Becomes Law, What Does It Mean?”