Engineering

531 Articles

Mining And Refining: Uranium And Plutonium

April 24, 2024 by 33 Comments

When I was a kid we used to go to a place we just called “The Book Barn.” It was pretty descriptive, as it was just a barn filled with old books. It smelled pretty much like you’d expect a barn filled with old books to smell, and it was a fantastic place to browse — all of the charm of an old library with none of the organization. On one visit I found a stack of old magazines, including a couple of Popular Mechanics from the late 1940s. The cover art always looked like pulp science fiction, with a pipe-smoking father coming home from work to his suburban home in a flying car.

But the issue that caught my eye had a cover showing a couple of rugged men in a Jeep, bouncing around the desert with a Geiger counter. “Build your own uranium detector,” the caption implored, suggesting that the next gold rush was underway and that anyone could get in on the action. The world was a much more optimistic place back then, looking forward as it was to a nuclear-powered future with electricity “too cheap to meter.” The fact that sudden death in an expanding ball of radioactive plasma was potentially the other side of that coin never seemed to matter that much; one tends to abstract away realities that are too big to comprehend.

Things are more complicated now, but uranium remains important. Not only is it needed to build new nuclear weapons and maintain the existing stockpile, it’s also an important part of the mix of non-fossil-fuel electricity options we’re going to need going forward. And getting it out of the ground and turned into useful materials, including its radioactive offspring plutonium, is anything but easy.

Continue reading “Mining And Refining: Uranium And Plutonium” →

How To Properly Patch Your Iowa-Class Battleship

April 6, 2024 by 28 Comments

There’s a saying among recreational mariners that the word “boat” is actually an acronym for “bring out another thousand”, as it seems you can’t operate one for long without committing to expensive maintenance and repairs. But this axiom isn’t limited to just civilian pleasure craft, it also holds true for large and complex vessels — although the bill generally has a few more zeros at the end.

Consider the USS New Jersey (BB-62), an Iowa-class battleship that first served in the Second World War and is now operated as a museum ship. Its recent dry docking for routine repair work has been extensively documented on YouTube by curator [Ryan Szimanski], and in the latest video, he covers one of the most important tasks crews have to attend to while the ship is out of the water: inspecting and repairing the hundreds of patches that line the hull.

These patches aren’t to repair damage, but instead cover up the various water inlets and outlets required by onboard systems. When New Jersey was finally decommissioned in 1991, it was hauled out of the water and plates were welded over all of these access points to prevent any potential leaks. But as the Navy wanted to preserve the ship so it could potentially be reactivated if necessary, care was taken to make the process reversible.

Continue reading “How To Properly Patch Your Iowa-Class Battleship” →

Fictional Computers: The Three Body Problem

April 5, 2024 by 54 Comments

If you intend to see the Netflix series “The Three Body Problem” or you want to read the Hugo-winning story from Chinese author [Cixin Liu], then you should probably bookmark this post and stop reading immediately. There will be some mild spoilers. You have been warned.

While the show does have some moments that will make your science brain cringe, there is one scene that shows a computer that could actually be built. Would it be practical? Probably not in real life, but in the context provided by the show, it was perfectly feasible. It could have, however, been done a little better, but the idea was — like many great ideas — both deceptively simple and amazingly profound. The computer was made of human beings. I’m not talking like Dune’s mentats — humans with super brains augmented by drugs or technology. This is something very different.

Background

This is your last chance. There are spoilers ahead, although I’ll try to leave out as much as I can. In the story, top scientists receive a mysterious headset that allows them to experience totally immersive holodeck-style virtual reality. When they put the headset on, they are in what appears to be a game. The game puts you in a historical location — the court of Henry VIII or Ghengis Kahn. However, this Earth has three suns. The planet is sometimes in a nicely habitable zone and sometimes is not. The periods when the planet is uninhabitable might have everything bursting into flames or freezing, or there might not be sufficient gravity to hold them on the planet’s surface. (Although I’ll admit, I found that one hard to grasp.)

Apparently, the inhabitants of this quasi-Earth can hibernate through the “chaotic eras” and wait for the next “stable era” that lasts a long time. The problem, as you probably know, is that there is no general closed-form solution for the three-body problem. Of course, there are approximations and special cases, but it isn’t easy to make long-term predictions about the state of three bodies, even with modern computers.

Continue reading “Fictional Computers: The Three Body Problem” →

Mining And Refining: Tungsten

April 2, 2024 by 16 Comments

Our metallurgical history is a little bit like a game of Rock, Paper, Scissors, only without the paper; we’re always looking for something hard enough to cut whatever the current hardest metal is. We started with copper, the first metal to be mined and refined. But then we needed something to cut copper, so we ended up with alloys like bronze, which demanded harder metals like iron, and eventually this arms race of cutting led us to steel, the king of metals.

But even a king needs someone to keep him in check, and while steel can be used to make tools hard enough to cut itself, there’s something even better for the job: tungsten, or more specifically tungsten carbide. We produced almost 120,000 tonnes of tungsten in 2022, much of which was directed to the manufacture of tungsten carbide tooling. Tungsten has the highest melting point known, 3,422 °C, and is an extremely dense, hard, and tough metal. Its properties make it an indispensible industrial metal, and it’s next up in our “Mining and Refining” series.

Continue reading “Mining And Refining: Tungsten” →

Big Chemistry: Hydrofluoric Acid

February 27, 2024 by 32 Comments

For all of the semiconductor industry’s legendary reputation for cleanliness, the actual processes that go into making chips use some of the nastiest stuff imaginable. Silicon oxide is comes from nothing but boring old sand, and once it’s turned into ultrapure crystals and sliced into wafers, it still doesn’t do much. Making it into working circuits requires dopants like phosphorous and boron to give the silicon the proper semiconductor properties. But even then, a doped wafer doesn’t do much until an insulating layer of silicon dioxide is added and the unwanted bits are etched away. That’s a tall order, though; silicon dioxide is notoriously tough stuff, largely unreactive and therefore resistant to most chemicals. Only one substance will do the job: hydrofluoric acid, or HFA.

HFA has a bad reputation, and deservedly so, notwithstanding its somewhat overwrought treatment by Hollywood. It’s corrosive to just about everything, it’s extremely toxic, and if enough of it gets on your skin it’ll kill you slowly and leave you in agony the entire time. But it’s also absolutely necessary to make everything from pharmaceuticals to cookware, and it takes some big chemistry to do it safely and cheaply.

Continue reading “Big Chemistry: Hydrofluoric Acid” →

Electrical Steel: The Material At The Heart Of The Grid

February 15, 2024 by 32 Comments

When thoughts turn to the modernization and decarbonization of our transportation infrastructure, one imagines it to be dominated by exotic materials. EV motors and wind turbine generators need magnets made with rare earth metals (which turn out to be not all that rare), batteries for cars and grid storage need lithium and cobalt, and of course an abundance of extremely pure silicon is needed to provide the computational power that makes everything work. Throw in healthy pinches of graphene, carbon fiber composites and ceramics, and minerals like molybdenum, and the recipe starts looking pretty exotic.

As necessary as they are, all these exotic materials are worthless without a foundation of more familiar materials, ones that humans have been extracting and exploiting for eons. Mine all the neodymium you want, but without materials like copper for motor and generator windings, your EV is going nowhere and wind turbines are just big lawn ornaments. But just as important is iron, specifically as the alloy steel, which not only forms the structural elements of nearly everything mechanical but also appears in the stators and rotors of motors and generators, as well as the cores of the giant transformers that the electrical grid is built from.

Not just any steel will do for electrical use, though; special formulations, collectively known as electrical steel, are needed to build these electromagnetic devices. Electrical steel is simple in concept but complex in detail, and has become absolutely vital to the functioning of modern society. So it pays to take a look at what electrical steel is and how it works, and why we’re going nowhere without it.

Continue reading “Electrical Steel: The Material At The Heart Of The Grid” →

Sprint: The Mach 10 Magic Missile That Wasn’t Magic Enough

February 13, 2024 by 74 Comments

Defending an area against incoming missiles is a difficult task. Missiles are incredibly fast and present a small target. Assuming you know they’re coming, you have to be able to track them accurately if you’re to have any hope of stopping them. Then, you need some kind of wonderous missile of your own that’s fast enough and maneuverable enough to take them out.

It’s a task that at times can seem overwhelmingly impossible. And yet, the devastating consequences of a potential nuclear attack are so great that the US military had a red hot go anyway. In the 1970s, America’s best attempt to thwart incoming Soviet ICBMs led to the development of the Sprint ABM—a missile made up entirely of improbable numbers.

Continue reading “Sprint: The Mach 10 Magic Missile That Wasn’t Magic Enough” →