Mining And Refining: Lead, Silver, And Zinc

If you are in need of a lesson on just how much things have changed in the last 60 years, an anecdote from my childhood might suffice. My grandfather was a junk man, augmenting the income from his regular job by collecting scrap metal and selling it to metal recyclers. He knew the current scrap value of every common metal, and his garage and yard were stuffed with barrels of steel shavings, old brake drums and rotors, and miles of copper wire.

But his most valuable scrap was lead, specifically the weights used to balance car wheels, which he’d buy as waste from tire shops. The weights had spring steel clips that had to be removed before the scrap dealers would take them, which my grandfather did by melting them in a big cauldron over a propane burner in the garage. I clearly remember hanging out with him during his “melts,” fascinated by the flames and simmering pools of molten lead, completely unconcerned by the potential danger of the situation.

Fast forward a few too many decades and in an ironic twist I find myself living very close to the place where all that lead probably came from, a place that was also blissfully unconcerned by the toxic consequences of pulling this valuable industrial metal from tunnels burrowed deep into the Bitterroot Mountains. It didn’t help that the lead-bearing ores also happened to be especially rich in other metals including zinc and copper. But the real prize was silver, present in such abundance that the most productive silver mine in the world was once located in a place that is known as “Silver Valley” to this day. Together, these three metals made fortunes for North Idaho, with unfortunate side effects from the mining and refining processes used to win them from the mountains.

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Java Ring: One Wearable To Rule All Authentications

Today, you likely often authenticate or pay for things with a tap, either using a chip in your card, or with your phone, or maybe even with your watch or a Yubikey. Now, imagine doing all these things way back in 1998 with a single wearable device that you could shower or swim with. Sound crazy?

These types of transactions and authentications were more than possible then. In fact, the Java ring and its iButton brethren were poised to take over all kinds of informational handshakes, from unlocking doors and computers to paying for things, sharing medical records, making coffee according to preference, and much more. So, what happened?

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Static Electricity And The Machines That Make It

Static electricity often just seems like an everyday annoyance when a wool sweater crackles as you pull it off, or when a doorknob delivers an unexpected zap. Regardless, the phenomenon is much more fascinating and complex than these simple examples suggest. In fact, static electricity is direct observable evidence of the actions of subatomic particles and the charges they carry.

While zaps from a fuzzy carpet or playground slide are funny, humanity has learned how to harness this naturally occurring force in far more deliberate and intriguing ways. In this article, we’ll dive into some of the most iconic machines that generate static electricity and explore how they work.

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Retro Gadgets: Things Your TV No Longer Needs

It is hard to imagine that a handful of decades ago, TV wasn’t a thing. We’ve talked a few times about the birth of television. After an admittedly slow slow start, it took over like wildfire. Of course, anything that sells millions will spawn accessories. Some may be great. Then there are others.

We wanted to take a nostalgic look back at some of the strange add-ons people used to put on or in their TVs. Sure, VCRs, DVD players, and video game consoles were popular. But we were thinking a little more obscure than that.

Rabbit Ears

A state-of-the-art set of rabbit ears from the 1970s

Every once in a while, we see an ad or a box in a store touting the ability to get great TV programming for free. Invariably, it is a USB device that lets you watch free streaming channels or it is an antenna. There was a time when nearly all TVs had “rabbit ears” — so called because they made an inverted V on the top of your set.

These dipoles were telescoping and you were supposed to adjust them to fit the TV station you were watching but everyone “knew” that you wanted them as long as possible at all times. Holding one end of them gave it a ground and would give you a major improvement in picture. People also liked to wrap tin foil around the tips. Was it like a capacitive hat? We aren’t sure.

The better rabbit ears had knobs and switches along with multiple elements. If you lived close to a TV station, you probably didn’t need much. If you didn’t, no number of fancy add-ons would likely help you. Continue reading “Retro Gadgets: Things Your TV No Longer Needs”

An excerpt from Lord Rayleigh’s published manuscript.

Estimating The Size Of A Single Molecule Of Oil Using Water

What is the size of a single molecule of oil? What may initially seem like a trick question – answerable only through the use of complicated, high-tech scientific equipment – is actually as easy to calculate as the circumference of planet Earth. Much like how [Eratosthenes] used a couple of sticks to achieve the latter feat back in about 240 BCE, the size of a molecule of olive oil was calculated in 1890 by [Lord Rayleigh], which is the formal title of [John William Strutt]. Using nothing but water and said olive oil, he managed to calculate the size of a single olive oil molecule as being 1.63 nanometers in length.

To achieve this feat, he took 0.81 mg of olive oil and put it on a known area of water. Following the assumption that the distributed oil across the water surface would form a monolayer, i.e. a layer of oil one molecule thick, he divided the volume of the oil by the covered area, which gave him the thickness of the oil layer. Consequently, this result would also be the dimension (diameter) of a single olive oil molecule.

Many years later we know now that olive oil is composed of triacylglycerols, with a diameter of 1.67 nm, or only about 2% off from the 1890 estimate. All of which reinforces once more just how much science one can do with only the most basic of tools, simply through logical deduction.

An Ode To The SAO

There are a lot of fantastic things about Hackaday Supercon, but for me personally, the highlight is always seeing the dizzying array of electronic bits and bobs that folks bring with them. If you’ve never had the chance to join us in Pasadena, it’s a bit like a hardware show-and-tell, where half the people you meet are eager to pull some homemade gadget out of their bag for an impromptu demonstration. But what’s really cool is that they’ve often made enough of said device that they can hand them out to anyone who’s interested. Put simply, it’s very easy to leave Supercon with a whole lot more stuff than when you came in with.

Most people would look at this as a benefit of attending, which of course it is. But in a way, the experience bummed me out for the first couple of years. Sure, I got to take home a literal sack of incredible hardware created by members of our community, and I’ve cherished each piece. But I never had anything to give them in return, and that didn’t quite sit right with me.

So last year I decided to be a bit more proactive and make my own Simple Add-On (SAO) in time for Supercon 2023. With a stack of these in my bag, I’d have a personalized piece of hardware to hand out that attendees could plug right into their badge and enjoy. From previous years I also knew there was something of an underground SAO market at Supercon, and that I’d find plenty of people who would be happy to swap one for their own add-ons for mine.

To say that designing, building, and distributing my first SAO was a rewarding experience would be something of an understatement. It made such an impression on me that it ended up helping to guide our brainstorming sessions for what would become the 2024 Supercon badge and the ongoing SAO Contest. Put simply, making an SAO and swapping it with other attendees adds an exciting new element to a hacker con, and you should absolutely do it.

So while you’ve still got time to get PCBs ordered, let’s take a look at some of the unique aspects of creating your own Simple Add-On.

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Remembering CompuServe: The Online Experience Before The World Wide Web

July 1981 cover of CompuServe's magazine.
July 1981 cover of CompuServe’s magazine.

Long before the advent of the Internet and the World Wide Web, there were other ways to go online, with Ohio-based CompuServe being the first to offer a consumer-oriented service on September 24, 1979. In an article by [Michael De Bonis] a listener-submitted question to WOSU’s Curious Cbus is answered, interspersed with recollections of former users of the service. So what was CompuServe’s contribution to society that was so important that the state of Ohio gave historical status to the building that once housed this company?

The history of CompuServe and the consumer-facing services which it would develop started in 1969, when it was a timesharing and remote access service for businesses who wanted to buy some time on the PDP-10s that Golden United Life Insurance as the company’s subsidiary used. CompuServe divested in 1975 to become its own, NASDAQ-listed company. As noted in the article, while selling timeshares to businesses went well, after business hours they would have these big computer systems sitting mostly idly. This was developed by 1979 into a plan to give consumers with their newfangled microcomputers like the TRS-80 access.

Originally called MicroNet and marketed by Radio Shack, the service offered the CompuServe menu to users when they logged in, giving access to features like email, weather, stock quotes, online shipping and booking of airline tickets, as well as online forums and interactive text games.

Later renamed to CompuServe Information Service (CIS), it remained competitive with competitors like AOL and Prodigy until the mid-90s, even buying one competitor called The Source. Ultimately it was the rise of Internet and the WWW that would close the door on this chapter of computing history, even as for CompuServe users this new Internet age would have felt very familiar, indeed.