Get Compressed Air From Falling Water With The Trompe

If you’re like us, understanding the processes and methods of the early Industrial Revolution involved some hand waving. Take the blast furnace, which relies on a steady supply of compressed air to stoke the fire and supply the oxygen needed to smelt iron from ore. How exactly was air compressed before electricity? We assumed it would have been from a set of bellows powered by a water wheel, and of course that method was used, but it turns out there’s another way to get compressed air from water: the trompe.

As [Grady] from Practical Engineering explains in the short video below, the trompe was a clever device used to create a steady supply of high-pressure compressed air. To demonstrate the process, he breaks out his seemingly inexhaustible supply of clear acrylic piping to build a small trompe. The idea is to use water falling around a series of tubes to create a partial vacuum and entrain air bubbles. The bubbles are pulled down a vertical tube by the turbulence of the water, and then enter a horizontal section where the flow evens out. The bubbles rise to the top of the horizontal tube where they are tapped off by another vertical tube, as the degassed water continues into a second vertical section, the height of which determines the pressure of the stored air. It’s ingenious, requiring no power and no moving parts, and scales up well – [Grady] relates a story about one trompe that provided compressed air commercially for mines in Canada.

Need an electricity-free way to pump water instead of air? Check out this hydraulic ram pump that takes its power from the water it pumps.

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Radio Free Blockchain: Bitcoin From Space

Cryptocurrencies: love them, hate them, or be baffled by them, but don’t think you can escape them. That’s the way it seems these days at least, with news media filled with breathless stories about Bitcoin and the other cryptocurrencies, and everyone from Amazon to content creators on YouTube now accepting the digital currency for payments. And now, almost everyone on the planet is literally bathed in Bitcoin, or at least the distributed ledger that makes it work, thanks to a new network that streams the Bitcoin blockchain over a constellation of geosynchronous satellites.

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Hackaday Visits The Electric City

Much to the chagrin of local historians, the city of Scranton, Pennsylvania is today best known as the setting for the American version of The Office. But while the exploits of Dunder Mifflin’s best and brightest might make for a good Netflix binge, there’s a lot more to the historic city than the fictional paper company. From its beginnings as a major supplier of anthracite coal to the introduction of America’s first electrically operated trolley system on its streets, Scranton earned its nickname “The Electric City” by being a major technological hub from the Industrial Revolution through to the Second World War.

Today, the mines and furnaces of Scranton lie silent but not forgotten. In the 1980’s, the city started turning what remained of their industrial sites into historic landmarks and museums with the help of State and Federal grants. I recently got a chance to tour some of these locations, and came away very impressed. They’re an exceptional look into the early technology and processes which helped turn America into an industrial juggernaut.

While no substitute for visiting these museums and parks for yourself, hopefully the following images and descriptions will give you an idea of what kind of attractions await visitors to the modern day Electric City.

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The Science Of Landing On An Asteroid

Exploiting the resources of the rock-strewn expanse of space between Mars and the outer planets has been the stuff of science fiction for ages. There’s gold in them ‘thar space rocks, or diamonds, or platinum, or something that makes them attractive targets for capitalists and scientists alike. But before actually extracting the riches of the asteroid belt, stuck here as we are at the bottom of a very deep gravity well that’s very expensive to climb out of, we have to answer a few questions. Like, how does one rendezvous with an asteroid? What’s involved with maneuvering near a comparatively tiny celestial body? And most importantly, how exactly does one land on an asteroid and do any useful work?

Back in June, a spacecraft launched by the Japanese Aerospace Exploration Agency (JAXA) finally caught up to an asteroid named Ryugu after having chased it for the better part of four years. The Hayabusa2 was equipped to answer all those questions and more, and as it settled in close to the asteroid with a small fleet of robotic rovers on board, it was about to make history. Here’s how they managed to not only land on an asteroid, but how the rovers move around on the surface, and how they’ll return samples of the asteroid to Earth for study.

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Have Some Candy While I Steal Your Cycles

Distributed computing is an excellent idea. We have a huge network of computers, many of them always on, why not take advantage of that when the user isn’t? The application that probably comes to mind is Folding@home, which lets you donate your unused computer time to help crunch the numbers for disease research. Everyone wins!

But what if your CPU cycles are being used for profit without your knowledge? Over the weekend this turned out to be the case with Showtime on-demand sites which mined Monero coins while the users was pacified by video playback. The video is a sweet treat while the cost of your electric bill is nudged up ever so slightly.

It’s an interesting hack as even if the user notices the CPU maxing out they’ll likely dismiss it as the horsepower necessary to decode the HD video stream. In this case, both Showtime and the web analytics company whose Javascript contained the mining software denied responsibility. But earlier this month Pirate Bay was found to be voluntarily testing out in-browser mining as a way to make up for dwindling ad revenue.

This is a clever tactic, but comes perilously close to being malicious when done without the user’s permission or knowledge. We wonder if those ubiquitous warnings about cookie usage will at times include notifications about currency mining on the side? Have you seen or tried out any of this Javascript mining? Let us know in the comments below.

Cryptocurrency Mining Post-Bitcoin

While the age of using your own computer to mine Bitcoin during spare CPU cycles has long passed, average folks aren’t entirely shut out of the cryptocurrency game yet. Luckily, Bitcoin isn’t the only game in town anymore, and with GPUs coming down in price it’s possible to build a mining rig for other currencies like Etherium.

[Chris]’s build starts with some extruded aluminum and a handful of GPUs. He wanted to build something that didn’t take up too much space in the small apartment. Once the main computer was installed, each GPU was installed upwards in the rack, with each set having its own dedicated fan. After installing a fan controller and some plexiglass the rig was up and running, although [Chris] did have to finagle the software a little bit to get all of the GPUs to work properly.

While this build did use some tools that might only be available at a makerspace, like a mill and a 3D printer, the hardware is still within reason with someone with a little cash burning a hole in their pockets. And, if Etherium keeps going up in value like it has been since the summer, it might pay for itself eventually, providing that your electric utility doesn’t charge too much for power.

And if you missed it, we just ran a feature on Etherium.  Check it out.

World’s Worst Bitcoin Mining Rig

Even if we don’t quite understand what’s happening in a Bitcoin mine, we all pretty much know what’s needed to set one up. Racks of GPUs and specialized software will eventually find a few of these vanishingly rare virtual treasures, but if you have enough time, even a Xerox Alto from 1973 can be turned into a Bitcoin mine. As for how much time it’ll take [Ken Shirriff]’s rig to find a Bitcoin, let’s just say that his Alto would need to survive the heat death of the universe. About 5000 times. And it would take the electricity generated by a small country to do it.

Even though it’s not exactly a profit center, it gives [Ken] a chance to show off his lovingly restored Alto. The Xerox machine is the granddaddy of all modern PCs, having introduced almost every aspect of the GUI world we live in. But with a processor built from discrete TTL chips and an instruction set that doesn’t even have logical OR or XOR functions, the machine isn’t exactly optimized for SHA-256 hashing. The fact that [Ken] was able to implement a mining algorithm at all is impressive, and his explanation of how Bitcoin mining is done is quite clear and a great primer for cryptocurrency newbies.

[Ken] seems to enjoy sending old computer hardware to the Bitcoin mines — he made an old IBM mainframe perform the trick a while back. But if you don’t have a room-size computer around, perhaps reading up on alternate uses for the block chain would be a good idea.

[via Dangerous Prototypes]