explain xkcd - User contributions [en]

Talk:2788: Musical Scales

2023-06-17T05:28:20Z

172.69.33.162:

The page says it was last edited about four hours from now. I'm wondering wether the lineage of in the hall... is worth mentioning. ie Grieg composed it for an Ibsen play. [[Special:Contributions/172.70.175.178|172.70.175.178]] 23:06, 12 June 2023 (UTC)
:(It's server time. Which is set as UTC. Currently matches central European summer time, I guess, but is one hour behind me (using BST in ordinary life), but matches me nicely when I'm back on GMT. If I read you right, I'm guessing you're on the US east-coast TZ (or equivalent, elsewhere in the Americas), and if you're on DST right now you'll find you have to mentally adjust by ''five'' whenever you're not. I imagine that logged-in people can configure dynamic time displays to local time (for themselves), but 'hard written records like on these signatures probably aren't converted 'live' (no good way to not mess up with false-changes/false-nonchanges) so there's probably no point doing that anyway. Just realise that you need to remember that it's an offset of four/five/whatever-it-might-be for your current time and place and rejoice that (with a spherical Earth, not somehow unified under one global political system that can tell all people to work with ever stranger hours of daylight, therefore with necessarily disjointed timezones) at least there's no possibility of falling off the 'edge' and perhaps into the jaws of the world-serpent. There are plenty of other problems, but not that! ...and no doubt there was discussion as to whether to align with Randall's habitual locale, instead, but more people know how to convert between their local UTC±whatever and straight UTC (or don't have to) than might be expected to reliably cross convert between two different ± values, correctly and accounting for whether either or both are DST at the moment. So I don't just say I'm happy with the situation because (for half a year) it matches my own TZ, I think it's just best all round. And doubtless various Europeans think so too (especially the other half of the year!). With apologies to Kiwis, Hawaiians and everyone else for the minor (but predictable) time-shifts they pretty kuch always have to consider, but still would even if you were happily aligned by circumstance... ;) ) [[Special:Contributions/141.101.98.220|141.101.98.220]] 09:42, 13 June 2023 (UTC)

::No, central European summer time is TWO hours away from UTC. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:06, 13 June 2023 (UTC)
::The UTC times are usually 4 hours ahead of me, and I'm Eastern, the first North American time zone, same as New York City and Miami (i.e. now it's just past midnight, on the West coast of North America it's just past 9pm). Usually I find my friends in U.K. are 5 hours away from me (and my time zone is always listed as -5), my family in Europe tend to be 6, but I think that changes with Daylight Savings (we ALMOST got rid of the stupid useless Daylight Savings last year, I'm hoping for this year). UTC always seems to resolve to the middle of the ocean, I always wonder why UTC exists at all, why not go with Greenwich Mean Time in such cases??? So, yeah, the "last edit" was probably just before your comment, and you're in the same time zone as me. [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:22, 17 June 2023 (UTC)
:::UTC==GMT (for all practical purposes), i.e. Greenwich-zeroed, straight down the Prime Meridian (solar time) and UK-wide time when not we're not on BST==UTC+1. East Coast US is 5 hours from us, ''except'' for the week or three when either the entry or the exit from DST (I forget which one, but it ''is'' just the one or other) is not the same weekend for both UK and US, so we're disjointed by an hour (I think it reduces to 4 hours, but it's been a while since I needed to know that to avoid disturbing anyone's sleep/lunch). However, UTC definitely isn't in the ocean (well, not the main bits) like you seem to say. [[Special:Contributions/172.70.85.169|172.70.85.169]] 05:25, 17 June 2023 (UTC)

Now I have to re-listen to In the Hall…; I think there are some errors here.[[Special:Contributions/172.71.146.212|172.71.146.212]] 01:23, 13 June 2023 (UTC)

Can someone make a midi of Hall of the Mountain King but with an exponential time scale to "compensate" for the log transform? I want to hear a version that both starts and ends at 200 bpm. Is there any music that actually uses mathematically varying tempos? [[User:Quantum7|Quantum7]] ([[User talk:Quantum7|talk]]) 06:35, 13 June 2023 (UTC)
: I can't make a midi but I can make an mp3: https://voca.ro/17QJDbYxNnlh [[User:Viliml|Viliml]] ([[User talk:Viliml|talk]]) 20:25, 13 June 2023 (UTC)

Ein belegtes Brot mit Schinken, ein belegtes Brot mit Ei...(Germans will understand.) [[Special:Contributions/198.41.242.94|198.41.242.94]] 06:50, 13 June 2023 (UTC)
: das sind zwei belegte Brote, eins mit Schinken und eins mit Ei. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 07:28, 13 June 2023 (UTC)
:: und dazu eisgekühlter Bommerlunder, Bommerlunder eisgekühlt.
:: But what does that have to do with dead pants?? [[Special:Contributions/172.71.26.254|172.71.26.254]] 13:36, 13 June 2023 (UTC)
:: I don't really understand much German, and my Dutch is too weak to compensate, so I used my translator... :) (NOW I recognize some words, LOL!) I suspect that's the German equivalent to the English saying "Six of one, half a dozen of the other", :) Basically "Eh, either way works". [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 04:30, 17 June 2023 (UTC)

Why "mistakenly"? Sure there are some-half notes in there, but it's generally linear in the sense that every 7 steps correspond to a doubling of the frequency no matter where you start from {{unsigned ip|172.68.51.197|07:30, 13 June 2023}}
::For the line spacing it doesn't matter much. A true linear-scale staff which takes half-steps into account would have spacings of 0.9, 1.8, 4 and 8. The one glaring discrepancy is that on a true linear scale, the note E5 (659 Hz) would be closer to F5 (698 Hz) than to D5 (587 Hz). [[User:Rick4|Rick4]] ([[User talk:Rick4|talk]]) 14:29, 13 June 2023 (UTC)

Most sheet music is not truly linear in time to begin with. It's pseudo-logarithmic but in the sense that the shorter notes (8ths and 16ths and heaven forbid 32nds for us da**ed drummers) are given MORE space relative to the (fixed) size of the note heads compared to quarter, half, and full notes. This then affects the on-page length of measures: measures with faster notes are longer (as measurable with a small ruler) than those with longer/slower notes, even though -- assuming a fixed tempo -- their play speed (time duration) stays the same. And then you get modifiers like "rit(ardando)", "rall(entando)", "accel(erando)", "piu mosso", "meno mosso", and the like which modify tempo and throw the whole page-space-to-time relation out the window as if the page of sheet music itself (or the audience) sped to near-light speeds. Randall's going off the deep end trying to make this insane notation fit into fixed science rules; best to leave it to us crazy musicians and just enjoy the music. [[Special:Contributions/172.69.65.46|172.69.65.46]] 10:44, 13 June 2023 (UTC)

"Randall seems to have mistakenly assumed" what? no, the entire point of the comic is that Randall knows standard staves do *not* represent a linear increase in frequency. A treble clef is centered on G4, which has a frequency of 392 Hz, F4 has a frequency of 349, and E4 has a frequency of 330. The drawn stave has one line between E4 and F4, corresponding to a jump of about 19 Hz. Two lines between F4 and G4, and we're assuming a linear scale, so that's about right to get to 392. The size of the games grows geometrically, as you expect. Again, this is the entire point of the comic.

:That's not what it says, though. It says he may have assumed it's a linear increase in *pitch*, and therefore a *exponential* increase in frequency.[[Special:Contributions/172.70.86.2|172.70.86.2]] 08:40, 14 June 2023 (UTC)

::is that not correct? Doesn't an equal temperament scale exactly mean that it is a linear increase in pitch? [[Special:Contributions/172.70.114.240|172.70.114.240]] 16:11, 14 June 2023 (UTC)

:::An equal temperament scale means there's a linear increase in pitch by half-step/semitone, correct. However, any Western scale or mode regardless of quality will only include 7 notes, while there are 13 when including accidentals; the quality is determined by which notes are adjacent or separated by an accidental, or in other words if they are separated by one half-step or two. *However*, since standard notation uses other symbols to indicate deviation from the expected frequency and not separate lines, I'd argue that such would be the approach taken in a world where this sheet music was used. Therefore, I'd say this whole paragraph is unnecessary and misguided. Randall is taking a standard piece of sheet music and warping the scales of the axes, nothing more. He's not trying to make a valid, coherent new system of notation, he's making a graph joke. [[Special:Contributions/162.158.159.125|162.158.159.125]] 17:27, 14 June 2023 (UTC)

::::But the point is that not only is his 'mistake' version 'wrong' (non-standard), but his remedy would result in notation that was 'wrong' as well, on both 'axes'.[[Special:Contributions/172.70.85.49|172.70.85.49]] 08:37, 15 June 2023 (UTC)

::::I'm not following. Don't the lines in a staff indicate equal spaced whole steps (between consecutive lines) or half-steps (between lines and spaces)? What is the "mistake" that randall is alleged to have made, and have we agreed that it is infact a mistake or not? [[Special:Contributions/162.158.158.58|162.158.158.58]] 04:01, 17 June 2023 (UTC)

2777: Noise Filter

2023-05-18T04:43:13Z

172.69.33.162:

{{comic
| number = 2777
| date = May 17, 2023
| title = Noise Filter
| image = noise_filter_2x.png
| imagesize = 298x345px
| noexpand = true
| titletext = Party Mode also enables the feature, but reverses the slider.
}}

==Explanation==
{{incomplete|Created by a 30-YEAR-OLD BOT WITH A NOISE LEVEL SEARCH - elaborate on search engines of the type demonstrated in the comic and offer examples of the noise levels shown; also why such a filter may be desirable for 30+. Do NOT delete this tag too soon.}}
This comic portrays a generalized, minimalist version of a search engine's front end. The engine helps the user find things (in this case, restaurants) that conform to user preferences. Preferences shown are hours of opening, mean of review scores, price range, and current noise level. All but "current noise level" are grayed out. The user, setting the parameters for deir search, adjusts the slider to select the maximum tolerable noise level. Interestingly, the slider indicates increasing noise tolerance until it reaches "Any", thus shifting abruptly from maximum to zero tolerance.
The caption's statement that the noise slider should automatically appear when the user reaches the age of 30 (ignoring the privacy concerns implicit in such a function) plays on the common perception that a person's ability to tolerate background noise while dining (or anywhere else) deteriorates with age. Such declines have been documented, linked to changes in the inner ear and associated nerves with aging, and can occur in the absence of other hearing-loss symptoms. The term "SPiN (Speech Perception in Noise) threshold" has been conceived to measure this loss. Other studies suggest that personality traits and gender, as well as age, contribute to declines in the ability to perceive speech in noise, so the trope is less precise than is indicated here, and in advertisements by health providers for hearing loss treatments.

The title text shows that Randall imagines a "Party Mode" which also includes this filter, but reversed, presumably so that a loud party won't disrupt a quiet restaurant.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

There is a search bar with the word “restaurants” typed into it.

Below there are filters:

Open hours: Any Open now (selected) Open at…
{{comic discussion}}

Talk:2694: Königsberg

2022-11-05T20:37:27Z

172.69.33.162: reply

; 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? [[Special:Contributions/172.71.146.65|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. [[Special:Contributions/172.70.206.205|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. [[Special:Contributions/172.68.146.80|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. [[Special:Contributions/172.71.142.88|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. [[Special:Contributions/162.158.166.173|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…
::::::: Before they put them in the fridge? ;o)
:::::::: Perhaps BBQing vegitables? [[Special:Contributions/172.69.33.162|172.69.33.162]] 20:37, 5 November 2022 (UTC)
::::: 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! [[Special:Contributions/172.70.86.12|172.70.86.12]] 05:38, 5 November 2022 (UTC)
::::::"Aim for brevity while avoiding jargon." —Edsger Dijkstra [[Special:Contributions/172.69.33.210|172.69.33.210]] 06:33, 5 November 2022 (UTC)
::::: Re: wealth signaling via aluminum - When aluminum was first extracted, one of its main early uses was in jewelry. Victorian examples are still around and are not terribly rare. [[User:Miamiclay|Miamiclay]] ([[User talk:Miamiclay|talk]]) 20:33, 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. [[Special:Contributions/172.71.178.187|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. [[Special:Contributions/172.70.211.126|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. [[Special:Contributions/172.71.178.207|172.71.178.207]] 16:53, 5 November 2022 (UTC)
::...ok, so looking at it myself, maybe [https://www.explainxkcd.com/wiki/index.php?title=2694:_K%C3%B6nigsberg&diff=298234&oldid=298231 this change] removes both parties' objections. (Probably not, but perhaps a way ''towards'' a final rapprochement.) [[Special:Contributions/172.70.85.24|172.70.85.24]] 17:02, 5 November 2022 (UTC)

I read somewhere (maybe some Martin Gardner book?) that nowadays in Koenigsberg (or Kaliningrad as it is called today) there IS an eight bridge. But I couldn't confirm it.--[[Special:Contributions/162.158.129.49|162.158.129.49]] 17:26, 5 November 2022 (UTC)
: There's a link to the Google Maps aerial view in the map caption. [[Special:Contributions/172.70.210.242|172.70.210.242]] 20:31, 5 November 2022 (UTC)