TV Repair By Mail

November 17, 2022 by Al Williams 49 Comments

I don’t think there was ever a correspondence school called the “Close Cover Before Striking School” but since book matches — which used to be a thing when most people smoked — always had that text on them anyway perhaps there should have been. There was a time when electronic magazines, billboards, and even book matches were constantly bombarding us with ads to have a career in electronics. Or computers. Or TV repair. So while we think of distance learning as a new idea, really it is just the evolution of these old correspondence schools which date back quite some time.

How far exactly? Hard to say. There’s evidence of some distance learning going back as far as 1728. In 1837, there was a correspondence course to learn shorthand. By 1858, the University of London started its external program for correspondence work and the University of Chicago had a home study division in 1892. Radio was an early choice of topic, too. In the United States, the United Wireless Telegraph company started a training school — later the Marconi Institute — in 1909. However, it is doubtful that there was any correspondence training going on there until much later.

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The Importance Of Physical Models: How Not To Shoot Yourself In The Foot Or Anywhere Else

November 10, 2022 by Al Williams 73 Comments

We take shortcuts all the time with our physical models. We rarely consider that wire has any resistance, for example, or that batteries have a source impedance. That’s fine up until the point that it isn’t. Take the case of the Navy’s Grumman F11F Tiger aircraft. The supersonic aircraft was impressive, although it suffered from some fatal flaws. But it also has the distinction of being the first plane ever to shoot itself down.

So here’s the simple math. A plane traveling Mach 1 is moving about 1,200 km/h — the exact number depends on a few things like your altitude and the humidity. Let’s say about 333 m/s. Bullets from a 20 mm gun, on the other hand, move at more than 1000 m/second. So when the bullet leaves the plane it would take the plane over three seconds to catch up with it, by which time it has moved ever further away, right?

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Nazi Weapons Of The Future

September 23, 2022 by Al Williams 137 Comments

We know. The title sounds like a bad newsreel from 1942. Turns out, though, that the Nazis were really good at pouring money into military research and developing — or trying to develop — what they called “wunderwaffe” — wonder weapons. While we think of rockets and jets today as reasonably commonplace, they were state-of-the-art when Germany deployed them during WWII. While the rockets were reasonably successful, the jets were too few and too late to matter. However, those were just the tip of the iceberg. The German war industry had plenty of plans ranging from giant construction to secret weapons that seem to be out of the pages of a pulp science fiction magazine.

Size Matters

Part of the plans included huge ships including one aircraft carrier displacing 56,500 tons. Many of these were never completed and, in some cases, were never actually started. In contrast, the Essex-class USS Hornet displaces 31,300 tons and the Lexington was 37,000 tons. The H-class battleships would have had as much as 140,000 tons of displacement dwarfing the Yamato class (73,000 tons) and the Iowa class (53,000 tons).

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IGY: The Year We All Got Along

September 20, 2022 by Al Williams 24 Comments

If you are a Steely Dan fan, you might know the Donald Fagen song, “IGY.” In it, Fagen sings about a rosy future with high-speed undersea rail, solar power, giant computers making life better, and spandex jackets. Since that song was on the 1982 album Nightfly, it is already too old for some people to remember, but the title goes back even further: the International Geophysical Year which was actually a little longer than a year in 1957 and 1958. The year was a concerted effort by 67 countries to further mankind’s knowledge of the Earth. It was successful, and was big news in its day, although not much remembered now.

The real origin dates back to even earlier. In 1882 and 1932 there were International Polar Years dedicated to researching the polar regions of the Earth. In a way, it makes sense to do this. Why should 60 or more countries each mount difficult, dangerous, and expensive expeditions to such a hostile environment? However, instead of a third polar year, James Van Allen (who has a famous belt) and some other scientists felt that advances in many fields made it the right time to study geophysics. From the scientific point of view, the IGY coincided with the solar activity cycle maximum. But there were other forces at play, too.

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Building A Glowing Demon Core Lamp

August 31, 2022 by Lewin Day 15 Comments

The so-called Demon Core was a cursed object, a 6.2 kilogram mass of plutonium intended to be installed in a nuclear weapon. Instead, slapdash experimental techniques saw it feature in several tragic nuclear accidents and cause multiple fatalities. Now, you can build yourself a lamp themed after this evil dense sphere.

A later recreation of the infamous “Slotin Accident” that occurred with the Demon Core. Credit: Public Domain, Los Alamos National Laboratory

Creator [skelly] has designed the lamp to replicate the Slotin incident, where the spherical Demon Core was placed inside two half-spheres of beryllium which acted as neutron reflectors to allow it to approach criticality. Thus, the core is printed as a small sphere which is thin enough to let light escape, mimicking the release of radiation that doomed Louis Slotin. The outer spheres are then printed in silvery PLA to replicate the beryllium half-spheres. It’s all assembled atop a stand mimicking those used in the Los Alamos National Laboratory in the 1940s.

To mimic the Core’s deadly blue glow, the build uses cheap LED modules sourced from Dollar Tree lights. With the addition of a current limiting resistor, they can easily be run off USB power in a safe manner.

The Demon Core has become a meme in recent times, perhaps as a new generation believes themselves smart enough not to tinker with 6.2 kilograms of plutonium and a screwdriver. That’s not to say there aren’t still dangerous nuclear experiments going on, even the DIY kind. Be careful out there!

Buy The Right To Build A Nakagin Tower Anywhere

August 25, 2022 by Jenny List 41 Comments

We’re guessing that among Hackaday’s readership are plenty of futurists, and while the past might be the wrong direction in which to look when considering futurism, we wouldn’t blame any of them for hankering for the days when futurism was mainstream.

Perhaps one of the most globally iconic buildings of that era could have been found in Tokyo, in the form of the Nakagin Capsule Tower, Kisho Kurokawa’s 1972 Metabolist apartment block. This pioneering structure, in which individual apartments were conceived as plug-in units that could be moved or changed at will, never achieved its potential and was dismantled, looking more post-apocalyptic than futuristic in early 2022, but it could live on in both digital form and reconstructed elsewhere as the rights to its design are being auctioned.

Unfortunately there appears to be some NFT mumbo-jumbo associated with the sale, but what’s up for auction is a complete CAD model along with the rights to build either real or virtual copies of the building. It’s unlikely that any Hackaday readers will pony up for their own Metabolist skyscraper, but the interest lies not only in the love of a future that never quite happened, but in the engineering behind the structure. Where this is being written as in many other places there is simultaneously a chronic housing shortage and a housing system wedded to the outdated building techniques of a previous century, so the thought of updated equivalents of the Nakagin Tower offering the chance of modular interchangeable housing in an era perhaps more suited to it than the 1970s is an intriguing one. Now that we’re living in the future, perhaps it’s time to give futurism another chance.

Regular readers will have spotted this isn’t the first time we’ve brought you a taste of futuristic living.

Header: Svetlov Artem, CC0.

Integrated Circuit Manufacturing At Bell Labs In 1983

August 23, 2022 by Dave Rowntree 13 Comments

With the never ending march of technological progress, arguably the most complex technologies become so close to magic as to be impenetrable to those outside the industry in which they operate. We’ve seen walkthrough video snapshots of just a small part of the operation of modern semiconductor fabs, but let’s face it, everything you see is pretty guarded, hidden away inside large sealed boxes for environmental control reasons, among others, and it’s hard to really see what’s going on inside.

Let’s step back in time a few decades to 1983, with an interesting tour of the IC manufacturing facility at Bell Labs at Murray Hill (video, embedded below) and you can get a bit more of an idea of how the process works, albeit at a time when chips hosted mere tens of thousands of active devices, compared with the countless billions of today. This fab operates on three inch wafers, producing about 100 die each, with every one handled and processed by hand whereas modern wafers are much bigger, die often much smaller with the total die per wafer in the thousands and are never handled by a filthy human.

Particle counts of 100 per cubic foot might seem laughable by modern standards, but device geometries back then were comparatively large and the defect rate due to it was not so serious. We did chuckle somewhat seeing the operator staff all climb into their protective over suits, but open-faced with beards-a-plenty poking out into the breeze. Quite simply, full-on bunny suits were simply not necessary. Anyway, whilst the over suits were mostly for the environment, we did spot the occasional shot of an operator wearing some proper protective face shielding when performing some of the higher risk tasks, such as wafer cleaning, after all as the narrator says “these acids are strong enough to eat through the skin” and that would certainly ruin your afternoon.

No story about integrated circuit processing would be complete without mentioning the progress of [Sam Zeloof] and his DIY approach to making chips, and whilst he’s only managing device counts in the hundreds, this can only improve given time.

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