Mechanical Timekeeping Hack Chat With Clickspring

Join us on Wednesday, February 3 at noon Pacific for the Mechanical Timekeeping Hack Chat with Clickspring!

The reckoning of the passage of time has been of vital importance to humans pretty much for all our history, but for most of that time we were stuck looking at the movements of heavenly bodies or noting the changing of the seasons to answer questions of time. The search for mechanical aids to mark the passage of time began surprisingly early, though, pretty much from the time our ancestors first learned to work with metals.

Timekeeping devices were often created to please a potentate or to satisfy a religious imperative, but whatever the reason for their invention, these early clocks and calendars were key to a ton of discoveries. Timekeeping devices were among the first precision mechanisms, and as such formed the basis of much of our mechanical world. A mechanical representation of the passage of time also gave us some of the first precise observations of the physical world, which led to an enormous number of discoveries about the nature of the universe, not to mention practical skills such as navigation, which allowed us to explore the world with greater confidence.

In our era, precision timekeeping has moved beyond the mechanical realm into the subatomic world, and mechanisms built to please a prince are relegated to museums and collectors. That’s not to say there isn’t plenty to learn from the building of mechanical timepieces, as anyone who has watched any of the videos on Clickspring’s YouTube channel can attest. Clickspring not only makes some magnificent modern timepieces, like his famous open-frame clock, but recently he’s also branched out into the timekeeping mechanisms of the ancients. He built a reproduction Byzantine sundial-calendar, and tackled a reproduction of the famous Antikythera mechanism. The latter was undertaken using only the tools and materials that would have been available to the original maker. That led to an unexpected discovery and a detour into the world of scholarly publishing.

Clickspring has been busy lately, but he made some time to stop by the Hack Chat and talk about mechanical timepieces. We’ll talk about his modern builds, his forays into the mechanisms of antiquity, and his serendipitous discovery. On the way we’re likely to talk about what it takes to build precision mechanisms in a small shop, and whatever else that crops up.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, February 3 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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Hackaday Links: January 31, 2021

There are an awful lot of machines on the market these days that fall under the broad category of “cheap Chinese laser cutters”. You know the type — the K40s, the no-name benchtop CO2 cutters, the bigger floor-mount units. If you’ve recently purchased one of these machines from one of the usual vendors, or even if you’re just thinking about doing so, you’ll likely have some questions. In which case, this “Chinese Laser Cutters 101” online class might be right up your alley. We got wind of this though its organizer, Jonathan Schwartz of American Laser Cutter in Los Angeles, who says he’s been installing, repairing, and using laser cutters for a decade now. The free class will be on February 8 at 5:00 PM PST, and while it’s open to all, it does require registration.

We got an interesting tip the other day that had to do with Benford’s Law. We’d never heard of this one, so we assumed was a “joke law” like Murphy’s Law or Betteridge’s Rule of Headlines. But it turns out that Benford’s Law describes the distribution of leading digits in large sets of numbers. Specifically, it says that the leading digit in any given number is more likely to be one of the smaller numbers. Measurements show that rather than each of the nine base 10 digits showing up about 11% of the time, a 1 will appear in the leading digit 30% of the time, while a 9 will appear about 5% of the time. It’s an interesting phenomenon, and the tip we got pointed to an article that attempted to apply Benford’s Law to image files. This technique was used in a TV show to prove an image had been tampered with, but as it turns out, Hollywood doesn’t always get technical material right. Shocking, we know, but the technique was still interesting and the code developed to Benford-ize image files might be useful in other ways.

Everyone knew it was coming, and for a long time in advance, but it still seems that the once-and-for-all, we’re not kidding this time, it’s for realsies shutdown of Adobe Flash has had some real world consequences. To wit, a railroad system in the northern Chinese city of Dalian ground to a halt earlier this month thanks to Flash going away. No, they weren’t using Flash to control the railroad, but rather it was buried deep inside software used to schedule and route trains. It threw the system into chaos for a while, but never fear — they got back up and running by installing a pirated version of Flash. Here’s hoping that they’re working on a more permanent solution to the problem.

First it was toilet paper and hand sanitizer, now it’s…STM32 chips? Maybe, if the chatter on Twitter and other channels is to be believed. Seems like people are having a hard time sourcing the microcontroller lately. It’s all anecdotal so far, of course, but the prevailing theory is that COVID-19 and worker strikes have lead to a pinch in production. Plus, you know, the whole 2020 thing. We’re wondering if our readers have noticed anything on this — if so, let us know in the comments below.

And finally, just because it’s cool, here’s a video of what rockets would look like if they were transparent. Well, obviously, they’d look like twisted heaps of burning wreckage on the ground is they were really made with clear plastic panels and fuel tanks, but you get the idea. The video launches a virtual fleet — a Saturn V, a Space Shuttle, a Falcon Heavy, and the hypothetical SLS rocket — and flies them in tight formation while we get to watch their consumables be consumed. If the burn rates are accurate, it’s surprising how little fuel and oxidizer the Shuttle used compared to the Saturn. We were also surprised how long the SLS holds onto its escape tower, and were pleased by the Falcon Heavy payload reveal.

Run The Math, Or Try It Out?

I was reading Sonya Vasquez’s marvelous piece on the capstan equation this week. It’s a short, practical introduction to a single equation that, unless you’re doing something very strange, covers everything you need to know about friction when designing something with a rope or a cable that has to turn a corner or navigate a wiggle. Think of a bike cable or, in Sonya’s case, a moveable dragon-head Chomper. Turns out, there’s math for that! Continue reading “Run The Math, Or Try It Out?”

Hackaday Podcast 103: Antennas For Everyone, A Clock Made Of Chains, Magic Eye Tubes, And A Little Google Bashing

Hackaday editors Mike Szczys and  Elliot Williams discuss the greatest hacks of the week that was. Antennas aren’t rocket science, so this week we really enjoyed a video that demystifies antenna designs and a project that tunes up the antennas on cheap wireless modules in the simplest of ways. Google’s in the news this week with the end to project Loon, and a dust-up with the volunteer package maintainers who have spent years making sure Chromium browser is in the Linux repos. Elliot is gaga for magic eye tubes and crazy musical instruments, while Mike is over the moon for a chain-based clock display. We close up the episode talking about the Concorde, and the math behind cable mechanisms.

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 (~65 MB)

Places to follow Hackaday podcasts:

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This Week In Security: Sudo, Database Breaches, And Ransomware

We couldn't resist, OK?
Obligatory XKCD

Sudo is super important Linux utility, as well as the source of endless jokes. What’s not a joke is CVE-2021-3156, a serious vulnerability around incorrect handling of escape characters. This bug was discovered by researchers at Qualys, and has been in the sudo codebase since 2011. If you haven’t updated your Linux machine in a couple days, you may very well be running the vulnerable sudo binary still. There’s a simple one-liner to test for the vulnerability:

sudoedit -s '\' `perl -e 'print "A" x 65536'`

In response to this command, my machine throws this error, meaning it’s vulnerable:

malloc(): corrupted top size
Aborted (core dumped)

To understand the problem with sudo, we have to understand escape characters. It really boils down to spaces in file and folder names, and how to deal with them. You want to name your folder “My Stuff”? That’s fine, but how do you interact with that directory name on the command line, when spaces are the default delimiter between arguments? One option is to wrap it in quotation marks, but that gets old in a hurry. The Unix solution is to use the backslash character as an escape character. Hence you can refer to your fancy folder as My\ Stuff. The shell sees the escape character, and knows to interpret the space as part of the folder name, rather than an argument separator. Escape characters are a common vulnerability location, as there are plenty of edge cases. Continue reading “This Week In Security: Sudo, Database Breaches, And Ransomware”

Swine Of The Times: Pig-to-Human Organ Transplants On Track For 2021

Every day in the US, seventeen people die because they couldn’t get a organ transplant in time. An American biotech company called United Therapeutics is looking to pick up the lifesaving slack by producing a line of genetically-modified pigs for the purpose of harvesting their organs, among other therapeutic uses. United Therapeutics’ pig-farming subsidiary Revivicor is a spin-off of PPL Therapeutics, the company that gave us Dolly the cloned sheep back in 1996. They intend to start transplanting pig organs into humans as early as this year.

Baby Fae after transplant surgery. Image by Duane Miller-AP via Time Magazine

Although it sounds like science fiction, the idea of transplanting animal cells, organs, and tissue into humans has been around for over a hundred years. The main problem with xenotransplantation is that it usually triggers severe immune system reactions in the recipient’s body. In one of the more noteworthy cases, a baby girl received a baboon heart in 1984, but died a few weeks later because her body rejected the organ.

The leading cause of xenotransplant rejection is a sugar called alpha-gal. This sugar appears on the cell surfaces of all non-primate mammals. Alpha-gal is problematic for other reasons, too: a condition called alpha-gal syndrome usually begins when a Lone Star tick bites a person and transmits alpha-gal cells from the blood of animals they have bitten. From that point on, the person will experience an allergic reaction when eating red meat such as beef, pork, and lamb.

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Before Google, There Was The Reference Librarian

I know it is a common stereotype for an old guy to complain about how good the kids have it today. I, however, will take a little different approach: We have it so much better today when it comes to access to information than we did even a few decades ago. Imagine if I asked you the following questions:

  • Where can you have a custom Peltier device built?
  • What is the safest chemical to use when etching glass?
  • What does an LM1812 IC do?
  • Who sells AWG 12 wire with Teflon insulation?

You could probably answer all of these trivially with a quick query on your favorite search engine. But it hasn’t always been that way. In the old days, we had to make friends with three key people: the reference librarian, the vendor representative, and the old guy who seemed to know everything. In roughly that order. Continue reading “Before Google, There Was The Reference Librarian”