Engineering

567 Articles

Big Chemistry: Glass

March 5, 2025 by 12 Comments

Humans have been chemically modifying their world for far longer than you might think. Long before they had the slightest idea of what was happening chemically, they were turning clay into bricks, making cement from limestone, and figuring out how to mix metals in just the right proportions to make useful new alloys like bronze. The chemical principles behind all this could wait; there was a world to build, after all.

Among these early feats of chemical happenstance was the discovery that glass could be made from simple sand. The earliest glass, likely accidentally created by a big fire on a sandy surface, probably wasn’t good for much besides decorations. It wouldn’t have taken long to realize that this stuff was fantastically useful, both as a building material and a tool, and that a pinch of this and a little of that could greatly affect its properties. The chemistry of glass has been finely tuned since those early experiments, and the process has been scaled up to incredible proportions, enough to make glass production one of the largest chemical industries in the world today.

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LTA’s Pathfinder 1: The Dawn Of A New Age Of Airships?

March 4, 2025 by 32 Comments

Long before the first airplanes took to the skies, humans had already overcome gravity with the help of airships. Starting with crude hot air balloons, the 18th century saw the development of more practical dirigible airships, including hydrogen gas balloons. On 7 January 1785, French inventor, and pioneer of gas balloon flight Jean-Pierre Blanchard would cross the English Channel in such a hydrogen gas balloon, which took a mere 2.5 hours. Despite the primitive propulsion and steering options available at the time, this provided continued inspiration for new inventors.

With steam engines being too heavy and cumbersome, it wasn’t until the era of internal combustion engines a century later that airships began to develop into practical designs. Until World War 2 it seemed that airships had a bright future ahead of them, but amidst a number of accidents and the rise of practical airplanes, airships found themselves mostly reduced to the not very flashy role of advertising blimps.

Yet despite popular media having declared rigid airships such as the German Zeppelins to be dead and a figment of a historic fevered imagination, new rigid airships are being constructed today, with improvements that would set the hearts of 1930s German and American airship builders aflutter. So what is going on here? Are we about to see these floating giants darken the skies once more?

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Tech In Plain Sight: Magsafe, And How To Roll Your Own

February 25, 2025 by 7 Comments

Apple likes magnets. They started out with magnetic laptop chargers and then graduated to a system that magnetically holds the phone, charges it, and can facilitate communication between the phone and a charger or other device. Even if you are like me and have no Apple devices, you can retrofit other phones to use Magsafe accessories. In fact, with a little work, you can build your own devices. Regardless, the technology is a clever and simple hack, and we are just a little sorry we didn’t think of it.

Terms

Using a magnet to attach a phone isn’t a new idea. But, historically, the phone had either a metal back or an adhesive metal plate attached that would stick to the magnet. This wouldn’t necessarily help with charging, but was perfectly fine for holding the device. The problem is, it is hard to wirelessly charge the phone through the metal.

Magsafe can do several different things. Obviously, it can attach the phone magnetically. However, since it is a ring shape, you can still have a charging coil in the middle of the ring. Better still, the Magsafe system will align the phone and charger with a satisfying click when you put them together.

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The Importance Of Current Balancing With Multi-Wire Power Inputs

February 24, 2025 by 87 Comments

In an ideal world, devoid of pesky details like contact resistance and manufacturing imperfections, you would be able to double the current that can be provided to a device by doubling the number of conductors without altering the device’s circuitry, as each conductor would carry the exact same amount of current as its neighbors. Since we do not actually live inside a simplified physics question’s scenario, multi-wire powering of devices comes with a range of headaches, succinctly summarized in the well-known rule that electricity always seeks the path of least resistance.

As recently shown by NVidia with their newly released RTX 50-series graphics cards, failure to provide current balancing between said different conductors will quickly turn it into a practical physics demonstration of this rule. Initially pinned down as an issue with the new-ish 12VHPWR connector that was supposed to replace the 6-pin and 8-pin PCIe power connectors, it turns out that a lack of current balancing is plaguing NVidia GPUs, with predictably melty results when combined with low safety margins.

So what exactly changed that caused what seems to be a new problem, and why do you want multi-wire, multi-phase current balancing in your life when pumping hundreds of watts through copper wiring inside your PC?

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The “Unbreakable” Beer Glasses Of East Germany

February 17, 2025 by 80 Comments

We like drinking out of glass. In many ways, it’s an ideal material for the job. It’s hard-wearing, and inert in most respects. It doesn’t interact with the beverages you put in it, and it’s easy to clean. The only problem is that it’s rather easy to break. Despite its major weakness, glass still reigns supreme over plastic and metal alternatives.

But what if you could make glassware that didn’t break? Surely, that would be a supreme product that would quickly take over the entire market. As it turns out, an East German glassworks developed just that. Only, the product didn’t survive, and we lumber on with easily-shattered glasses to this day. This is the story of Superfest.

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Understanding The Miller Effect

February 13, 2025 by 13 Comments

As electronics rely more and more on ICs, subtle details about discrete components get lost because we spend less time designing with them. For example, a relay seems like a simple component, but selecting the contact material optimally has a lot of nuance that people often forget. Another case of this is the Miller effect, explained in a recent video by the aptly named [Old Hack EE].

Put simply, the Miller effect — found in 1919 by [John Milton Miller] — is the change in input impedance of an inverting amplifier due to the gain’s effect on the parasitic capacitance between the amplifier’s input and output terminals. The parasitic capacitance acts like there is an additional capacitor in parallel with the parasitic capacitance that is equivalent to the parasitic capacitance multiplied by the gain. Since capacitors in parallel add, the equation for the Miller capacitance is C-AC where C is the parasitic capacitance, and A is the voltage gain which is always negative, so you might prefer to think of this as C+|A|C.

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The Science Behind Making Buildings Comfortably Non-Combustible

February 11, 2025 by 33 Comments

Although the most fire-resistant building is likely a windowless, concrete bunker, this tends to be not the vibe that most home owners go for. This is why over the years construction of buildings in areas prone to bush- and wildfires – i.e. an uncontrolled fire in an area with combustible vegetation – has adapted to find a happy medium between a building that you’d enjoy living in and a building that will not instantly combust the moment an ember from a nearby wildfire gently touches down upon any part of it.

To achieve this feat, the primary means include keeping said combustible vegetation and similar away from the building, and to make the house as resistant to ember attacks as possible. That this approach is effective has been demonstrated over the course of multiple wildfires in California during the past years, whereby houses constructed more recently with these features had a much higher chance of making it through the event unscathed.

Naturally, the devil is in the details, which is why for example the Australian standard for construction in bushfire-prone areas (AS 3959, last updated in 2018, 2009 version PDF) is rather extensive and heavy on details, including multiple Bushfire Attack Level (BAL) ratings that define risk areas and legally required mitigation measures. So what does it take exactly to survive a firestorm bearing down on your abode?

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