Depleted uranium would be my first choice for this; we had big bars of the stuff laying around the lab that we used for door stops. (The lab was a place that designed nuclear weapons.)
DU is harmless unless you eat or breathe it but alas it's now illegal to possess more than a minute quantity of it.
Tungsten is actually slightly denser and it has the advantage of being obtainable.
Midwest Tungsten sells a 1.5" cube (1 kg) for $200. I have one, as well as a magnesium cube of the same size. They look identical but the Mg cube weighs 1/10 as much. It's fun to let someone hold the W cube to feel the weight and then toss them the Mg cube with "Here, catch!"
I used to put suet cages out. Then I'd walk outside on summer mornings to find my porch and gutters utterly destroyed. Finally figured out it was black bears that came in the night trying to get at the bird food.
Protecting Earth from asteroids is part of the job we hired the Moon to do. I mean, have you seen the back side of that thing?
Kidding aside, an argument can be made that life on Earth would never have had time to evolve if not for the Moon's protective effect against cataclysmic impacts.
"Lisp is so powerful that problems which are technical issues in other programming languages are social issues in Lisp."
So true. Lisp was designed to give individual programmers tremendous power. That means Lisp programmers sometimes prefer to reinvent solutions to problems rather than learn to use some existing solution. This tendency can be an absolute nightmare on a software engineering team.
Not that using Lisp on a software engineering team cannot be done, but it requires very strong discipline and leadership. The absence of strong discipline and leadership on a Lisp SWE team can lead to enormous amounts of wheel reinvention and technical debt.
Obviously discipline and leadership are necessary for any SWE team but languages like C don't encourage reinvention nearly as much as Lisp does, and Lisp programmers in general tend to be very resistant to the imposed discipline that SWE requires. (I say this as a diehard Lisp programmer, so I'm talking about myself.)
> So true. Lisp was designed to give individual programmers tremendous power. That means Lisp programmers sometimes prefer to reinvent solutions to problems rather than learn to use some existing solution. This tendency can be an absolute nightmare on a software engineering team.
I've found that there's a world of difference between my tendency to wheel-reinvent when I'm messing around on my own vs. my tendency in an industrial setting. When I'm messing around on my own, Lisp gives me so much more reach it's incredible, and yeah, I kinda do want to reinvent the application server, or the TCP/IP stack, or something sometimes.
But when I'm getting paid and there are milestones and deadlines? Fuck it, I'll just use what's available to build what's needed. The difference is that in a Lisp codebase, some really smart people have come before and built some really cool abstractions. Like a test framework that makes automated testing so much simpler it's ridiculous. Like, two lines of code and you have a test for a new feature. You get access to tools and techniques that let you close the gap between "ticket lands in your lap" and "done" much faster than you would in Java.
Completely agree. If everybody on the team has your attitude it's not a problem. But often, a few people don't. It's so damned tempting to reinvent a testing framework in Lisp, because we have lambdas and code is data right? Lisp is tailor-made for testing frameworks!
Until you're two weeks in to what you expected to be a 2-hour project and you realize you can't meta-dot your tests and you made too many assumptions about which equality functions to support, so you let the user just specify a lambda for the relation function and Poof! Now you can't reason about your tests nearly as well.
And oh yeah I used a macro-centric approach when I should have used CLOS so again, I can't easily grovel my tests. Damn.
Designing a test framework in Lisp looks easy but doing it well is surprisingly hard. So using one of the better ones in Quicklisp is almost always a win.
Related question: Why is welding pretty mainstream while blacksmithing is a much more niche craft? Blacksmithing is a more overarching skill: After all every blacksmith knows how to weld but relatively few welders can forge effectively.
Possible answers:
1. Blacksmiths enjoy making custom tools for each domain while welders just want to get on with solving their domain problem.
2. Blacksmithing is harder to learn. Welding using modern techniques is easy to learn. (Caveat: Welding well is quite difficult. But learning to weld good enough to repair a broken hitch on your tractor is easy.)
3. Welding can solve a very large chunk of metalwork problems. Not all of them--and not always with elegance--but it gets the job done quickly. Blacksmithing can solve a larger set of metalwork problems with more elegance but it also takes more time and skill.
you can very reasonably do welding in your garage. aside from a welder (as little as $150 for a barely-usable mig), all you need is an angle grinder to cut and finish the welds. commercially you can get a mid-range mig and a couple more smallish tools and you can start selling custom fencework and mounting brackets and such.
blacksmithing you need a forge, which immediately takes up more space and is somewhat more likely to start a fire. an anvil, and tongs, and hammers. its also a lot more physically demanding, even if you use a power hammer.
your #2 and #3 are pretty key. most importantly most fabrication jobs are much happier to get quick work with reasonable precision using stock shapes. once you start talking about real free-form hot shaping you're immediately going up at least 10x in price/time. welded table base - $500. handcrafted wrought table base - $10,000.
really its that metalwork is mostly functional (fences, stairs, railings, walkways, enclosures, stainless for commercial kitchens, pipefitting, etc). its very difficult to stay in business as a actual craftsman making well-designed objects. architectural metal is probably the easiest in (wall coverings, nice looking railing and stairs, lamps, and other decorative elements). and there its still dominated by fabrication processes (machining and welding of stock shapes), although nicer materials like bronze start to have their place.
edit: you know I left this thinking I was missing something and I realized what it is. welding you make shapes out of like-shapes. like making drawings in figma. I don't think a lot of people have what it takes to learn to be a really good freehand artist. and even if you have the skill, being able to design those kind of organic arbitrary shapes so that they are emotive and attractive is another step up. do you want a piece of art which is a direct expression of the concept held by the artist? or do you want a 3x5' 32" inch high workbench for 1/20 the cost?
Also, if you live in the city (including suburbs), your neighbors are likely to get pretty annoyed by the sound of hammering metal. Welding makes noise too, but a lot less of it. That's the main reason why I haven't gotten into blacksmithing even though I think I would really enjoy it. I just don't think it'd go over well with the neighbors.
You need a forge too. If you're a traditionalist that means coal, which produces black smoke, which your neighbors also won't like.
Or you use a gas-powered forge which is smaller and produces no smoke. But gas-powered forges don't get as hot so you can't forge-weld with them. No big deal IMHO. That's what TIG is for.
> you can very reasonably do welding in your garage
Let me just clarify one thing: you can reasonably do _arc_ welding in your garage, not torch welding. Source: my house burned down once due to the guy next door torch welding in his garage.
Blindsight is remarkable for its exploration of what intelligent life without consciousness might be like.
For me personally I was amazed that one of the lead characters is a vampire. I'm completely burned out on vampire stories yet Watts made one I very much enjoyed. Even if you're also bored with vampires, I recommend you try this book.
They're a hominid and belong to our species but are completely alien and terrify humans at a deep, genetic, evolutionary level. I love the way Watts describes Siri's involuntary reaction to the vampire, as though his fear and awareness of being viewed as little more than a potential meal are baked into his biology.
Similar to a newborn duckling that instinctively hides from shadows of a certain shape even though it has no concept of birds of prey, Siri experiences, when he interacts with the vampire, some similarly ancient, autonomic memory from the time when our ancestors were prey animals. We become little more than flighty, paranoid herd animals, jumping at the merest snap of a twig, like deer, when we find ourselves in the presence of an animal that flips the appropriate switch in our biology.
It's a wild, compelling subversion of so many sci-fi tropes and so much self-congratulatory tree-of-life bullshit and so much of our instinctual belief system regarding the way we fit into the world. It's also a completely novel (as far as I know) approach to undermining the notion of humanity's specialness, highlighting the fact that we're just animals -- and that our betters are, too, just as the invading aliens are, in a very different way.
I once had a jumping spider on top of my computer monitor and it would chase the cursor around as I moved the mouse. I have a video that I should post online somewhere
Microcode updates were first implemented in the Pentium Pro. When the original Pentium had the infamous FDIV bug, the only fix was for Intel to replace the processors at a cost of $475 million.
DU is harmless unless you eat or breathe it but alas it's now illegal to possess more than a minute quantity of it.
Tungsten is actually slightly denser and it has the advantage of being obtainable.
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