I've never been that interested in gemstones of any sort, but my understanding (from geology classes decades ago) is that natural diamonds on the surface of the earth result from some rather exotic processes.
First, they form deep down in the mantle around 100 miles down. The only way they get up here is through rare and violent high velocity eruption events that bring mantle material up to the surface. Most are very old, too; greater than a billion years old.
I don't recall the source of the carbon they're made from, but it's certainly not any sort of organic material like coal or dinosaurs. ;)
Or I could be totally wrong. I really have no interest in these things beyond the geology behind them and it's possible the science has uncovered new stuff since I last studied them.
Likewise, I have no idea how these synthetic diamonds are being made nowadays, but I bet that's pretty cool, too.
Funny you should mention this. Just yesterday my wife and I went to the local Ikea to pick up some bookcases. I was originally just going to buy a bunch of the Billy bookcases; we have a few and know their limitations.
But then I noticed they had a much better series called the Hemnes made with actual solid wood shelves and legs so you can route power cords and clean under them. Nice.
So instead of a bunch of Billy's for $70 each I ended up with a bunch of Hemnes' for $350 each. We'll see if it's worth it when they get delivered tomorrow.
I converted my cheap Billy shelves into what look like fitted shelves. They're all bolted together, screwed to the wall, filled in around the edges with wooden panels, and finished off with 2.5m decorative strips of pine at all the edges and joins. Then I painted the whole lot the same colour and filled them with books. Looks amazing, cheap as hell. Nobody guesses they're Billy shelves.
Bought four Hemnes last year for my sitting room library and various pieces of molded hardwood for a kick board and fascia. Finished up as a single fairly solid built-in bookcase the full length of one wall. The legs allowed for passing wires under (accessible via the removable bottom shelf) and up behind so it can have lighting.
Ward Cunningham and I did something similar back in 2008.
We were both at a startup in Portland and our office was along the railroad tracks east of the Willamette. We were up on the 4th or 5th floor right above a lot of train traffic including Amtrak.
I brought in some extra Mac gear I had including one of the early iSight cameras which back then was an external device you stuck on the top of your display and connected to the Mac via FireWire. We set it up and rolled the desk over to the window in the office and turned the camera around pointing down at the tracks and Ward got to work hacking something up to do a slit scan.
It was a fun little project; the speed of the trains affected the horizontal compression of the images. We could tweak the software to expand or contract the size of the image by adjusting the number of slit scans per unit of time. Of course, that affected the exposure but I recall the camera having some automatic adjustments that gave us trouble.
That's about all we did with it. Just a quick afternoon hacking project. Neither of us thought much about it at the time so we didn't save anything.
> It was a fun little project; the speed of the trains affected the horizontal compression of the images.
A few years ago I took a photo out the window of a Shinkansen going 150 mph and was amused that everything in the foreground tilted significantly to the left because of this effect. This is about as close as I'll get to seeing what it's like to get sucked into a black hole.
The ship can operate for a bit on decay heat. And they have battery banks to run major systems until conditions allow running at snorkel depth on the diesel engine.
And rumor has it some of the nuclear subs may work with a Stirling engine which can operate systems on heat alone.
out of curiosity, where's the heat for a Stirling engine coming from, or what would be the thermodynamic advantage if you were already collecting decay heat from the reactor? People breathing hotly in a tube?
AIP range is still limited though, especially at fast speeds. Thats why even the newest 212CDs still have have snorkels for their diesel and diesels are loud. SSNs are much better for global power projection.
Fine for running electric power for a time though. Which is probably what you'd use it for on a nuclear sub. Assuming you can spare the space/weight in your design.
Whenever I see these sorts of stories I think about the civic life we're missing out on by not socially gathering with our neighbors to hunt down woolly mammoths with sharp sticks so we don't all collectively starve to death.
The way things are going maybe we'll get back to those wonderful days. ;)
A bunch of families in the town I grew up in bought a fairly large cabin together in northern Ontario they just called "the hunting camp". My family wasn't involved but I got to go up there quite a few times as a guest of my friends.
In theory, the adults were hunting or fishing (although not with pointy sticks). In reality they were smoking, drinking, playing cards, screwing around on the little boat and atvs that were there (three wheelers!), and telling lies around a campfire. Us kids were pretty much on our own the entire time. We too were smoking, drinking, and screwing around on the boat and atvs.
So I agree with you- pointy stick hunting is a great weekend activity.
(I'm not aware of longer dashes native to LaTeX, though I believe doubled en or em dashes are occasionally used.)
Many Markdown flavours incorporate this, such that en / em dash usage in Markdown-authored docs should not be entirely unexpected. I believe many LLMs output Markdown which is subsequently rendered, based on watching intermediate outputs and saved sessions. I tend to adopt LaTeX / Markdown semantics elsewhere.
I grew up behind the bowling machines. My dad was a bowling machine mechanic and worked on machines all around the midwest. He often moon-lite as the on-duty mechanic during league nights and I'd go with him.
Mostly he worked at the local 16-lane alley with ancient AMF machines. The logic was all relays in a "chassis" on each machine. Relays would fail, pins and balls would end up where they're not supposed to be, folks would roll the ball into the sweep. All kinds of stuff. As a kid was was fantastic to see. A pinsetter machine is a real Rube Goldberg type contraption. Probably lead me to being an engineer.
We had the several opportunities to buy a small-town bowling center, but looking at the economics -- even back in the 1980's -- wasn't good. Most of the operating profit back then came from alcohol sales and that's a totally different business.
Good luck! Recently Facebook has been showing me a lot of bowling content. Be cool if it's making a comeback.
> Most of the operating profit back then came from alcohol sales and that's a totally different business.
I think this is typical of a lot of similar-ish businesses. Restaurants, bowling alleys, movie theaters, all run on high margin alcohol (or concessions) and make very little profit on the primary business.
yeah, even gas stations mostly make their money off of other stuff. if anything it's a little weird for a business to make their money off their primary business model.
Bowling by itself isn't coming back, but bowling with other entertainment activities has been trending for a few years now. These lanes are usually low(er)-maintenance string lanes.
Same here; grew up in Joplin before escaping to move to California in 1988.
It was wild growing up in that area with the chat piles hundreds of feet tall towering over these little towns.
When I was in high school the drinking age across the state border in Kansas was 18 so every weekend we'd all go over to the night clubs in Galena.
For folks interested in such things, Joplin has a Mineral Museum in Schifferdecker Park that has tons of info and exhibits on the mining that went on in this area. Has some pretty impressive (and massive) mineral samples, too. It's worth checking out if you're ever in the area.
> It was wild growing up in that area with the chat piles hundreds of feet tall towering over these little towns.
Especially when the area is extremely flat. Town I lived in (near, but not, Galena), the only places it was possible to snow-sled were man-made, with the only publicly-accessible one being the banks of the sole road overpass for miles around (I wanna say it went over railroad tracks? But it might have been another highway, regardless it had a remarkably long ramp-up to the actual part where it crossed over the other thing, and that left plenty of space for sledding) or if you happened to own land with coal mining strip-pits that still had the huge tailings/overburden pile, like you mention, and had the brush cleared from part of it.
Those kinds of things are practically the only hills of any kind in some counties in the region. Just outside any of those towns you can look down grid-straight rural roads that disappear into the horizon, and it's not hard to find them. It is flat. (Joplin area, slightly less so) Like, it's flat for Kansas. Many other parts of the state are, relatively speaking, blessed with great altitudinal diversity. Not that part.
It's a bit more south-of-Springfield than SE Kansas (or even Joplin) but the film Winter's Bone kinda felt like visiting home. All those familiar, scraggly trees. They really nail the feel of (a particular, more rural-leaning experience of) the area (I think it was actually filmed in Southern Missouri, so that makes sense, but the cinematographic "eye" of the movie really conveys it, too)
(Incidentally, if there's one thing to do in the very-flat part of Kansas that anyone who finds themselves remotely nearby should detour for, it's the Kansas Cosmosphere, somewhat West of the part otherwise under discussion but still the ultra-flat zone. It might be my favorite space exploration museum, and yes, I've been to most of the big ones in the US. It's shockingly good for being so far from basically anything else worth traveling for. If you have kids, hit the nearby Sedgwick County zoo, too, it's nothing special but it's alright and as long as you're there, why not. Area also has a state park built around some sand dunes left by retreating glaciers, which is kinda neat, though the park's a bit weak mostly due to just about everything outdoors being a really ugly in the region and the key feature of the park covering only a small area, and I make that judgement as someone who still feels weirdly at-peace and like things are correct when I visit, but like objectively it's really goddamn ugly, you gotta search to find anything natural that's as pleasant to look at as just your average view out a window many places, and if you turn around to look the other way you're probably back to ugly)
There used to be a big chat pile called Snowball on the north side of Joplin near the old Eagle-Picher smelter. I once saw someone fly off the top of that in a hang glider.
My grandfather on my mom's side was a miner in the lead mines. Or so I've been told; I don't remember him as he died when I was a baby. My grandmother lived near Snowball in what is best called a shack. No indoor plumbing; had to use a outhouse. She did have a telephone, although it was a party-line; you had to check the line was clear before using it.
So, yeah, that move Winter's Bone captured the feel of the area and the effects of systemic poverty really well.
I really appreciate you highlighting exactly how exceptionally flat Kansas is. I've never thought of a place as flat for Kansas, now I'll pay more attention when driving through it. I was already startled by how far horizons seem in Kansas.
Lots of the central-eastern portion of the state is the beautiful Flint Hills area, which is obviously… hilly. Much of I-70 (the main route across the state east-west) features long horizons but lots of low hills in the distance. The West, central, and southwestern parts have the slowly but consistently rolling, low hills of something like the film The Wind or the famous painting Christina’s World (the one with the girl on late summer or early fall green-and-tan grass, looking away from the viewer toward a white farmhouse up a low hill). They’re all much flatter than much of the country, but they’re not flat flat. They’re not Central Nevada flat.
South-central and southeastern Kansas are about that flat. Though with somewhat more trees.
[edit] I mean the remake of The Wind from a few years ago. I’ve never seen the original Lillian Gish film.
[edit edit] Further, those kinds of super-long views like you mentioned are actually kind of hard to come by on the really flat parts of Kansas. You need a little elevation (for the spot you're at) to get over obstructions like bushes, trees, barns, corn, et c, and that's what delivers those impressively-long views that vanish at the horizon in other parts of the state. That's why you need to find one of the (many) very-straight rural roads in the really flat parts of KS to see the "flat all the way to the horizon" effect. Or stand on the roof of a barn or something like that.
There are lots of things to test besides basic aerodynamics. And even for that sometimes you want real data to validate models before building the full size thing.
Things that are tested/validated in wind tunnels nowadays: effect of different paint and coatings, engine inlet flow, noise, tunned mass dampers, effect of placement of sensors, control surface flutter.
First, they form deep down in the mantle around 100 miles down. The only way they get up here is through rare and violent high velocity eruption events that bring mantle material up to the surface. Most are very old, too; greater than a billion years old.
I don't recall the source of the carbon they're made from, but it's certainly not any sort of organic material like coal or dinosaurs. ;)
Or I could be totally wrong. I really have no interest in these things beyond the geology behind them and it's possible the science has uncovered new stuff since I last studied them.
Likewise, I have no idea how these synthetic diamonds are being made nowadays, but I bet that's pretty cool, too.
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