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Non-deterministic algorithms explained using Stadia State Share

 One of the big open questions in computer science is known as " P = NP ", meaning the question of whether (the default deterministic) P olynomial algorithms can solve the same problems as N on-deterministic P olynomial algorithms. We computer scientists are lazy fuckers who compress 40 letters into 2. Countless hours has gone into not just the research on this, but also on just wrapping your head around what "non-deterministic algorithms" really means. An algorithm is just an extremely detailed recipe for doing stuff. Non-deterministic? Does that mean you get to throw dice? Or does it depend on there not being a predetermined fate known only to a higher being? Video games to the rescue! Stadia has introduced a feature called " State Share ", in which you can share not just a screenshot or a video clip, but the entire state of the game that you're playing. Other players who own that game can then pick up from there and keep playing. Maybe later they

A pair of pauldrons

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Back in 2019, I decided to finally make some leather pauldrons (technically they're spaulders, not having the extra protection against stabs into the armpit). I succeeded, but they ended up with a fatal design flaw that I have yet to fix - see the end. These are the notes from making them.   The core leather from Leder Hofmann is about 6mm thick, which makes it hard to work with. I don't know where I can get some ~4.5mm leather. I use a Blechschere (tin snips) to cut it. Even dedicated leather scissors are having a hard time with this, but are good for trimming edges. It takes a bit of getting used to how to use it without making a lot of little notches along the edge. One trick is to bend the leather where it hits the scissors so it doesn't press the scissors at an angle. Making many small nibs with the tip seemed to work well. I made holes for rivets with a combination of a regular hand-held rivet punch and a punch tool, both 4mm. The hand riveter, with plenty of f

Sapir-Whorf were full of shit

They didn't seem to consider the human imagination and creativity. Just look at Leonardo da Vinci - he came up with an insane amount of things that there were no words for. And humans have been creating quite elaborate imaginary beings and stories forever. Did S&W not know of science fiction? Just because I wanted to prove a point, one morning while getting up, I came up with three different concepts that are so different from my experience and language that I should not have been able to think of them. On a phase-locked planet, whenever there is a solar eclipse, the constant hurricanes slow down for a while, allowing brave people with heavy heat shields to venture further into the hot side to gather metals. This is extremely dangerous, of course. Especially while the shield is not loaded down with metals, if it tips it can get picked up by the wind and smash into the person. There can also be invisible pools of molten material than can cause this tipping. The best gatherers ar

An ounce of butter

Butter is important in American baking, but not in the way you may think.  I've been doing all these low carb versions of various things, and have hit upon the Butter Brioche Batter Bread from the Fannie Farmer cookbook as a simple, delicious, and more balanced bread. It's essentially one-third flower, one-third butter, one-third eggs. When getting ready to bake another one of this quite delicious recipe, I pondered the weight of these ingredients, and the weight of the butter is 227g, which is rather an odd number.  For those of you who have not been unfortunate enough to have to deal with American measurements, 1 cup is 8 fluid ounces (fl. oz.), one fl. oz. is 2 tablespoons (tbsp), and one tbsp is three teaspoons (tap). Yes, it's that confusing, and that's even leaving out the two other kinds of ounces. With an American wife and the American centric internet, we've had to do conversions so much that we got little fridge magnets with the factors. Only today did I r

Sunflour 1:1 bread

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My recent bread-making has been plagued by a series of disasters, punctuated by not-quite-disasters, but hardly ever anything great like my original 1:1 bread . I read up on various aspects of baking, tried adding less liquid, using warmer water, adding more flour, and various other tweaks, all to no avail. The pattern was that the first rise would be fine, the second rise so-so, but then instead of a great oven spring, the bread would actually deflate in the oven. A very sad experience. Today I looked back at the old recipe, and noticed that it had used flax-seed flour instead of sunflower seed flour ("sunflour"). I changed to the latter because I found the taste of the flax seed flour to be a bit more savory than what I was shooting for. However, looking at my flour tests , I realized the sunflour seed hadn't risen nearly as well as the flax-seed flour. So that could well be my problem! Before going back to the flax-seed flour, I tried one last trick that I had seen i

My Ikea Hack Workbench

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I needed a new workbench. One where my printer could live, where tools and spare parts could be organized, but also where the work surface wouldn't get cluttered or take too much of the space in my room. I started looking around at secretaries and similar, which have the right concept, but never the right size. Eventually I realized I had to do it myself. These are my notes. I used an IKEA Hemnes side table, two Hemnes night stands, and the top part of the two-part Hemnes writing desk. The two night stands on top of the side table, and the writing desk part on top of them, like the cross slab of a megalith, done in wood plank furniture. That part was simple enough, except I didn't want the gaps under the night stands, so I cut a bit of the logs, but cut too much, so now I need to fill some gaps. I'll probably print something eventually. But here's the basic setup: Hemnes, Hemnes everywhere. But they are clearly not designed to go together like these, the sizes don

Some well-explained math

Despite taking a minor in mathematics, I never really grokked matrices. I didn't even realize why it's called linear algebra (or at least I forgot quickly). These blog posts do a good job of making them more intuitive to me: The basics of matrices: https://dhruvp.netlify.com/2018/12/31/matrices / Eigenvectors: https://dhruvp.netlify.com/2018/12/31/matrices /