Talk:2694: Königsberg

Aluminum foil

Why would aluminum foil be valuable? I can see how it would be hard to produce at the time. But how would it be used and why would people of the time see a lot of value in it? 172.71.146.65 03:42, 5 November 2022 (UTC)

Good question, but I'm persuaded the novelty and scarcity of metallic aluminium would have made it plenty valuable among those already wealthy enough to recognize what it was. Prussia was wealthy and Königsberg was its largest port city back then, so probably the mayor would have been able. 172.70.206.205 03:49, 5 November 2022 (UTC)

Aluminium was very valuable - methods for its extraction from ore didn't exist in any useful form until much later. 172.68.146.80 03:55, 5 November 2022 (UTC)

Would scarcity be enough to make it valuable? Since nobody had this material back then, there wouldn't be any known applications for it. Compared to bringing e.g. a simple pocket calculator, a flashlight, a solar-powered e-book reader, etc. If an alien landed in my house and brought me some weird, shiny material that would be unable to build on earth, I wouldn't be too interested. But if they had some cool gadget or books full of alien information, I would immediately see its value. 172.71.142.88 04:05, 5 November 2022 (UTC)

At the time, there were few chemists who could have recognized what it was, but the Mayor of Königsberg would plausibly have been able to commission one. It likely would have taken months if not years, though. I guess if you have a time machine such details don't matter. 162.158.166.173 04:11, 5 November 2022 (UTC)

Bear in mind that platinum was once 'an inferior substance that got in the way of accumulating silver', and cobalt was the stuff that the underground spirits mischievously put in the way of those seeking copper. To different degrees, their attractiveness has increased since those times they were considered less than desirable.

But, for aluminium foil, I suspect it would have been like pineapples in English(/European?) stately circles... Not to be used for anything practical, but shown off (as long as it did not deteriote beyond a certain point), possibly there'd be money to be made in 'hiring it out' to decorate tables at fancy dinners (in carefully handled fragments, after the first few tearing incidents). L

“Not to be used for anything practical”: Well they could wrap their leftovers in it…

No doubt a natural philosopher or somesuch would give his eyeteeth to analyse the substance, but being so far beyond the ability to recreate (assuming they discovered what they might even need to do) it would take the bankrolling of an extremely rich patron to obtain permanent posession of some without obligation to return it to the social circuit situations. So easily destructed (I wonder if they'd discover thermite a hundred and more years early, before they ran out of potentially finely shredded aluminium?) or at least aesthetically denatured.

I suppose a screwed up ball of foil (carefully glued together internally, of all fragments still reobtainable) could be the end-game for the original roll, and a wonder it could still be (again, taking the "pineapple place" on the tables of the high and mighty, relatively untarnishing as it would be and gingerly some lucky few would be allowed to hold it and marvel at its sharp fragility and metallic lightness.

...or, in another destiny, perhaps it would be given to a master tailor, in order to (try to?) create some sartorial masterpiece for one or other monarch of the age. Not that I'm sure they'd be able to accomplish that properly (limited pre-offcut trials on how to attach it to underfelts/whatever and to somehow exploit its flexibility without exceeding its very low tolerance for shear-force damage). It'd be a story and a half, whatever happened to it! 172.70.86.12 05:38, 5 November 2022 (UTC)

"Aim for brevity while avoiding jargon." —Edsger Dijkstra 172.69.33.210 06:33, 5 November 2022 (UTC)

Noting that "the citizens' old coffeehouse problem" (c.f. linked reference), originally of how to cross the bridges was never solved but instead proven by Euler to be insoluble. He did give a proof to satisfy those who had henceforth decided there perhaps could be no solution, but that necessarily postdates the initial issue that could not originally be solved, and which Euler (in turn) also did not solve. But how to rewrite this to everyone's satisfaction? I see a bit of a tussle of interpretation in the edit history over this. 172.71.178.187 13:50, 5 November 2022 (UTC)

Proving that a problem has no solution is still called solving it in math and logic. 172.70.211.126 15:34, 5 November 2022 (UTC)

That's solving the issue of the solution (if you've proved there is none), at the meta- level. It is described as a "negative resolution" in the primary wikilink, which adds another semantic complexity but at least points to what was proven. Right in its first paragraph. For the everyday reader that hasn't yet burrowed into the wikilink, and without in-depth knowledge of terminological scope, they shouldn't be given the wrong idea about what question was actually answered. And "We've solved it: there's no solution!" is not a particularly helpful reduction of this kind of outcome. 172.71.178.207 16:53, 5 November 2022 (UTC)