explain xkcd - User contributions [en]

Talk:2431: Leap Year 2021

2021-03-05T11:43:38Z

162.158.155.72:

It's amazing how quickly some of us got to edit this. I hope I didn't cause too much edit-conflict confusion just by my changing the date value. Honestly just checked, before turning in, to find two (so far) other edits follow so quickly after... [[Special:Contributions/141.101.98.152|141.101.98.152]] 02:03, 2 March 2021 (UTC)

Sorry,I did not see anything when I started
:I wouldn't expect you to (the first Categories adder, yes?), until you perhaps tried to save. But that's what being shown edit-conflicts is important for. [[Special:Contributions/141.101.98.244|141.101.98.244]] 03:02, 2 March 2021 (UTC)

If someone actually did this, how many years would it take for the calendar to line back up again where it started? 365? [[User:Captain Video|Captain Video]] ([[User talk:Captain Video|talk]]) 02:20, 2 March 2021 (UTC)
: 365 years plus (around) 33% more because every fourth year (except every hundredth, except except every 400th) is already ''expected'' to have a 29th, so you'd not be able to shift the year that year and have to do those days after the first 365 mostly-shifted consecutive years - with the necessary overflow days ''still'' being only to be done for 3/4(ish) of the next 91ish years, leaving maybe 23 more years to be shifted. But 24 years would only allow 18 shifts, so 6 more years than that ''probably'' would use 5 years. And one year may be absorbed already, or left over. So 365+91+23+6. Ish. Because it'd depend exactly which year you start as to which non-expandable years occur within the strict (0.75)+(0.25*0.75)+(0.25*0.25*0.75)+... series. But that's the likely area of the answer, off the top of my head. Around 485 years, give or take. Unless I've made a big error! [[Special:Contributions/141.101.98.244|141.101.98.244]] 03:02, 2 March 2021 (UTC)
::A quick evaluation of the geometric progression (a/1-r = 365/(1-1/4)) gives an answer of 486.666... This means it would take at least 487 years to come past full circle (488 on a leap year) if not for the pesky 400-year rule. Given where the date lies, there can be either one or two per cycle; thus, we find a minimum of 488 years and a maximum of 490. If we started this current year, on a non-leap year with no round 400 in the next 87 years, it would take the minimum amount, 488 years, to cycle through 489 revolutions of the Earth around the Sun. Happy Leap Year, my friends! [[User:BlackHat|BlackHat]] ([[User talk:BlackHat|talk]]) 03:52, 2 March 2021 (UTC)
::It's a bit messier, but the rough calculation was indeed close. I did a quick Excel calculation (well, OpenOffice Calc, but essentially the same - easiest thing at hand without Perl-diving). Actual 'next synchronised' period is 482-484 (solar) years, in an intruiging but not surprising pattern. Prior to 2000's unusual leap-day (but not too early to miss encompassing the one in 2400) it is 484 actual years (483 uniformly 'enhanced' ones) - but if you start in the period of any year leading up to a LD (I was running of 28th of February baselines, but any time from March 1st the prior year would count) you get the 485th year meshed too. (These periods contain two quatrocentenial LDs. And obviously ''starting'' with a 'normal' leap-year means the very next year is just as accurate, before it gets shifted the year after.)
::2001 until the late 2010s it's one set of 483 years to three of 484 (one of each has two synchronised years, 484th and 485th, because of adjacent starts landing on the same end), having just one century LD within. As you get close to 2020 you get a further non-LD century in (2020+480_and_change is 2500+) and 482 and/or 483 actual-years. "And/or" because only every second 482 ends on run-up to a LD so that the 483rd meshes as well, the 483s are not meshed correctly to do the same.
::The cycle ''beyond'' that is individually roaming through the same 482 to 484 range (and a number of end-point adjacents) but as it plays hopscotch through and around the centennial patterns it adopts an off-rhythm variation that doesn't even really make simple sense at the millenial level, as you might imagine. It might make an interesting artistic 'regularly purturbed noise' at even longer sample-sizes, though. Hack it into a graphical format, maybe, various possible options according to taste. [[Special:Contributions/141.101.99.193|141.101.99.193]] 08:22, 2 March 2021 (UTC)

Can someone make a [[:Category:Calendar]] that is a subcategory of [[:Category:Time]]? I feel like there are several comics that could fit, e.g. [[994: Advent Calendar]], [[1140: Calendar of Meaningful Dates]], [[1930: Calendar Facts]], [[1073: Weekend]], [[1061: EST]], etc. [[Special:Contributions/162.158.255.210|162.158.255.210]] 02:39, 2 March 2021 (UTC)

Sweden tried something like this in the early 18th century. When switching from Julian to Gregorian calendar, some bright spark decided to do it gradually, by removing all leap days between 1700 and 1740. The leap day of 1700 was skipped (It was a leap day in the Julian calendar, but not the Gregorian), but due to war and other things they 'forgot' to annul the leap days of 1704 and 1708. In 1712 it was decided to revert to Gregorian calendar, by adding a double leap day, resulting in the only known occurrence of [https://en.wikipedia.org/wiki/List_of_non-standard_dates#February_30 February 30]. From 1700 to 1712 Sweden was out of sync with both the Gregorian and Julian calendars, resulting in quite a lot of confusion. For example, Carl Linnaeus birthday can be given as May 12, 13 or 23, depending on what calendar is used. [[User:Popup|Popup]] ([[User talk:Popup|talk]]) 07:22, 2 March 2021 (UTC)

I disagree with the explanation of the title text. I understood it to be spoken by Black Hat to reinforce his disregard of people who might suffer in the future since he lives firmly in the present, one day at a time, as it were. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 12:54, 2 March 2021 (UTC)

My take on the title text was just a reference to the common statement (esp. as people get older), "I've lived in <city/state/etc.> for my whole life and I'm not about to move now." [[Special:Contributions/172.68.65.222|172.68.65.222]] 15:39, 2 March 2021 (UTC)Pat

I don't see why the explanation is incomplete. Can someone please tell me why so I can fix it? [[User:Quillathe Siannodel|Quillathe Siannodel]] ([[User talk:Quillathe Siannodel|talk]]) 17:17, 2 March 2021 (UTC)

I think the title text is black hat using "living in the present" as a justification for causing unnecessary problems in the future. [[Special:Contributions/172.69.34.148|172.69.34.148]] 19:51, 2 March 2021 (UTC)

There needs to be some reference to how "living in the present" has a different meaning than "living at some time which is neither the past nor the future." It can also mean that they "live for today" or that "they are aware of that happens around them" or other, similar platitude. [[User:Cwallenpoole|Cwallenpoole]] ([[User talk:Cwallenpoole|talk]]) 20:27, 2 March 2021 (UTC)

Another interpretation of the title text is that the calendar only affects people who (live in/plan for) the future, as in those concerned about events other than those in the present. As a calandar is arguably useless to those who don't plan for future events, such a change would not really affect them.

For me, the comic itself was not available until the day after it was expected (March 2, 2021). I wonder if this was deliberate, and refers to how we readers often use the regularity of the xkcd comics as a calendar. Anyway to check the actual (Gregorian) date it was posted? Will future comics now be released on Tuesdays Thursdays Saturdays, until leap year 2022?
[[Special:Contributions/172.69.55.164|172.69.55.164]] 06:21, 4 March 2021 (UTC)
: 2022? Don't you mean 2024? [[Special:Contributions/162.158.63.60|162.158.63.60]] 07:56, 4 March 2021 (UTC)
:: Every year deserves to leap. [[User:BlackHat|BlackHat]] ([[User talk:BlackHat|talk]]) 04:17, 5 March 2021 (UTC)
:https://www.explainxkcd.com/wiki/index.php?title=2431:_Leap_Year_2021&oldid=206922. ;) [[Special:Contributions/162.158.155.72|162.158.155.72]] 11:43, 5 March 2021 (UTC)

2405: Flash Gatsby

2020-12-31T22:22:17Z

162.158.155.72: Reinstating what appears to be a mistaken deletion of a whole paragraph ( https://www.explainxkcd.com/wiki/index.php?title=2405:_Flash_Gatsby&oldid=203888 ). No reason given, happened within 5 minutes, thus presumed accidental via Edit Conflict

{{comic
| number = 2405
| date = December 31, 2020
| title = Flash Gatsby
| image = flash_gatsby.png
| titletext = Protip: At midnight your excuse for not having read The Great Gatsby can switch from "I'm worried about violating copyright" to "I think my copy requires Flash."
}}

==Explanation==
{{incomplete|Created by a green light. Please mention here why this explanation isn't complete. It's hard to enumerate why the moments that the copyright expires and flash is no longer officially supported, are not exactly the same, but randall seems to expect us to do this. Do NOT delete this tag too soon.}}

This comic unfolds over the last few seconds of 2020 and the first few seconds of 2021. [[Cueball]] is attempting to do something requiring the overlap of two eras that only abut: creating an "unauthorized" adaptation of The Great Gatsby, using the Adobe Flash plugin platform.

''{{w|The Great Gatsby}}'' is a classic novel written by {{w|F. Scott Fitzgerald}} in 1925. Copyright law in the United States of America, where ''The Great Gatsby'' was first published, was retroactively extended several times in the 1990s and early 2000s, causing the copyright on ''The Great Gatsby'' to extend [https://www.mentalfloss.com/article/595567/why-the-great-gatsby-isnt-public-domain until the end of 2020]. In 2021, it will finally enter the public domain so that it will become legal to make a copy without violating copyright law.

{{w|Adobe Flash}}, formerly known as Shockwave Flash, is a web plugin that was commonly used by many websites in the late 1990s and 2000s. It allowed website creators to add animations, sound and complex logic, to build games, videos and other interactive experiences. Presumably, the Flash version of the novel is some kind of animated cartoon, or perhaps even a game.

Over the years, Adobe Flash was repeatedly exploited by hackers, incurring heavy costs on {{w|Adobe Inc.|Adobe}} as they tried to update Flash against these attacks after rushing features out before stabilising them. Newer technologies are now able to provide comparable features with more compatibility, more community involvement, and less risk, so support for Flash is being phased out by most web browsers. Adobe is officially [https://www.adobe.com/ca/products/flashplayer/end-of-life.html ending support for Flash] after December 31, 2020.

In line with Adobe's decision, [https://www.chromium.org/flash-roadmap#TOC-Upcoming-Changes Chrome is blocking Flash in January]. This will make [https://www.newgrounds.com/games entire internet culture histories spanning many years of making and engaging Flash experiences] unusable for most people. Therefore, Cueball's Flash version of ''The Great Gatsby'' will become legal at the very moment that everyone should stop using it.

In this comic, [[Cueball]] suggests that the withdrawal of Flash support occurs after the copyright expiration rather than simultaneously with it. This is most likely because the applicable copyright law in the United States states that the creative work becomes public domain at the end of the year 2020 and Flash gets disabled at the beginning of the year 2021. So it is conceivable (but not practical) that there is one second when when the novel is public domain and Flash is still enabled.

By late 2020, Flash Player was already blocked by most browsers, but could still be whitelisted on individual sites. Using old versions of browsers, or workarounds to run blocked extensions, Cueball's Great Gatsby may still be readable after the official Flash End of Life date of January 1, 2021. Even with these workarounds, Flash Player itself will block Flash content from playing on January 12, 2021, making that the final death date for official modern versions of Flash.

After January 12, Flash content may still be accessible through older builds of Flash Player, and through various [https://archive.org/details/softwarelibrary_flash_showcase archival] and [https://ruffle.rs/ emulation] projects.

The title wording does multiple work with a number of possible meanings to it. It's the 'Gatsby' book via the medium of the electronic Flash format. Because of the briefest of availability (at best, a single moment), it appears and disappears again 'in a flash'. Being 'flash' is a very apt description of the millionaire Gatsby character himself (just as 'flash the cash' is being ostentatious). And, if the endeavour is not actually as legitimate as hoped, the word has also refered to felonious behaviours and forged copies.

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

:[Cueball is sitting and using his laptop.]
:Off panel voice: 3... 2... 1... ''Happy New Year!''
:Cueball: Ok, It’s up!
:Cueball: Annnnnd... support was pulled, it’s down again.

:[Caption below the panel:]
:There's only a very short window of time in which I can post my unauthorized Flash® adaptation of ''The Great Gatsby''.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Fiction]]
[[Category:Internet]]
[[Category:New Year]]
[[Category:Protip]] <!-- title text ->

2400: Statistics

2020-12-25T19:28:59Z

162.158.155.72: /* Explanation */ explain title test and remove the notice

{{comic
| number = 2400
| date = December 18, 2020
| title = Statistics
| image = statistics.png
| titletext = We reject the null hypothesis based on the 'hot damn, check out this chart' test.
}}

==Explanation==

This comic is another comic in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.

===Graph===

The main focus of the comic is a graph showing cases of COVID-19 versus time for two groups: one group was vaccinated and the other group was not. Graphs are ways to visualize data, and for real data indicate specific values. Fictitious or purely illustrative graphs often omit any numerical values and simply draw a shape, like this one. The higher line ("placebo group") rises in a steep curve. The lower line ("vaccine group") follows the first for a bit but then levels out to a much slower rate of climb. The caption eschews statistical analysis in favor of a holistic assessment: the vaccine is clearly working; just look how much those lines diverge.

This comic was released one day after the [https://www.fda.gov/media/144434/download FDA's Dec 17th briefing document] for the {{w|mRNA-1273|Moderna COVID-19 vaccine}} was released. The document includes the following [https://www.zq1.de/~bernhard/images/share/mRNA-1273-trial.png chart]. The charts draw the integral of the incidence data rather than the data itself ("cumulative" rather than "rate"): this results in changes in disease rate towards the left side of the chart, being added into the data on the right side, amplifying their difference. This technique for emphasizing the data is valid: the spread between the lines only continues to increase if the effect continues happening, such that the total spread at the right is proportional to the total effect the vaccine had. The charts do not show any information on other possible variables. Randall has described previously in his webcomics how very clear charts can be made to hide misleading data. The linked graph does not leave the numbers out, and the numbers indicate the vaccine is 91% effective at preventing the disease (and a 95% chance of being between 85 and 95% efficient).

The advice here could be seen as the inverse of the "science tip" in [[2311: Confidence Interval]], in which the data was so ''bad'' that its error bars fell outside of the graph and were not shown. Also there's some association with [[1725: Linear Regression]] where the data is not so good that you don't need to perform linear analysis.

===Null hypothesis===

The null hypothesis, mentioned in the title text, is the hypothesis in a statistical analysis that indicates that the effect investigated by the analysis does not occur, i.e. 'null' as in zero effect. For example, the null hypothesis for this study might be "The vaccine has no effect on whether subjects catch COVID." The null hypothesis was previously the subject of [[892: Null Hypothesis]]. The null hypothesis is rejected when the probability of something like the observed data would be very low were the null hypothesis true.

For a simplified example, imagine there are 10 000 people in the vaccinated group, and each has a 5% chance of catching COVID under the null hypothesis; we expect 500 people to catch COVID. If only 490 catch COVID, the null hypothesis remains plausible, but if just 10 do, the odds are (in Python; see {{w|binomial distribution}}) <code>sum([math.comb(10000, i) * 0.05**i * 0.95**(10000-i) for i in range(0,10)])</code> = 1.5 × 10<sup>-204</sup>. In other words, it is wildly improbably that an ineffective vaccine would have produced such excellent results. We therefore conclude that the vaccine is not ineffective, and have rejected the null hypothesis.

Most people however, on seeing the raw results, would have concluded that the vaccine worked and statistics were just a formality. As the title test says, they would have "reject[ed] the null hypothesis based on the 'hot damn, check out this chart' test."

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Shown is a graph with the x-axis labeled "time" and the y-axis labeled "COVID cases." There is a black line on the graph labeled "placebo group", which has a roughly linear slope moving toward the top right corner. There is a red line labeled "vaccine group", which follows the black line for about an eighth of the width of the graph before leveling off.]
:[Caption beneath the graph]:
:Statistics tip: Always try to get data that's good enough that you don't need to do statistics on it

{{comic discussion}}

[[Category:COVID-19]]
[[Category:Comics with color]]
[[Category:Statistics]]
[[Category:Tips]]

Talk:2372: Dialect Quiz

2020-10-16T02:43:58Z

162.158.155.72:

Fun fact: shallots, scallops, and scallions ran against each other in [[1529: Bracket]]. (This will probably end up in the Trivia tab when one is created.) [[Special:Contributions/172.69.10.135|172.69.10.135]] 20:50, 14 October 2020 (UTC)

Cosmetology both sounds like "Cosmology" but it's also the fancy word for people who study cosmetics. --[[Special:Contributions/172.68.174.92|172.68.174.92]] 21:22, 14 October 2020 (UTC)
: Aren't stars the people we took cosmetics advice from before there were influencers? Or are they the same thing? Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/162.158.155.102|162.158.155.102]] 00:55, 15 October 2020 (UTC)

I mean the water fountains might as well be gutter pipes
21:49, 14 October 2020 (UTC)

@kswoll: Pretty sure this is a direct parody of the NYTimes quiz here: https://www.nytimes.com/interactive/2014/upshot/dialect-quiz-map.html

* I agree, this was also tweeted about 3 days earlier by Nate Silver [https://twitter.com/NateSilver538/status/1315348221565206530] - based on [[2371: Election Screen Time]], it's likely that Randall saw that tweet [[Special:Contributions/162.158.62.27|162.158.62.27]] 03:29, 15 October 2020 (UTC)

The Google pronunciation question might be a reference to a reference to [https://youtu.be/epj8OzP6z-M?t=177 a scene] from the second-to-last episode of Halt and Catch Fire. [[Special:Contributions/162.158.79.165|162.158.79.165]] 23:35, 14 October 2020 (UTC)

My guess is it is a reference to Yahoo another search engine that had commercials with high pitched yelp and some might put emphasis on either the "Ya" or the "hoo"

While I agree that most people know what a hammer is, this is not hammer - or rather, may not be considered "standard" hammer. Personally I would call it "Hammer with that thing for pulling nails out", but I could be easily convinced that it has some other name which doesn't include the word "hammer", instead of (presumably correct) {{w|claw hammer}}. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:55, 14 October 2020 (UTC)
:My feeling is that claw hammers are the type of hammer that most people are familiar with, and would consider the archetype of hammer. If you go to {{w|hammer}} the first picture is a claw hammer. [[User:Barmar|Barmar]]
:: Objection, your honor! In German, this would be called a "Zimmermannshammer" (carpenter's hammer, which IS a claw hammer). But the Plato hammer has a simple wedge on the other side. Maybe a German almost never has the need to pull out nails again, /schweinhund/! :-) [[Special:Contributions/162.158.158.103|162.158.158.103]] 08:08, 15 October 2020 (UTC)
([[User talk:Barmar|talk]]) 06:02, 15 October 2020 (UTC)
::: Well, this quiz is about English dialects, so German words aren't very relevant, and that term includes "hammer" as part of it anyway, as with most terms an English speaker would call this type of hammer, as people would indeed recognize it as a type of hammer and understand anyone referring to it as just "hammer" even if they might have a more specific name for the variety of hammer it is. People would not normally use the terms listed here for it.--[[Special:Contributions/162.158.74.109|162.158.74.109]] 08:49, 15 October 2020 (UTC)
* Yeah, I was thinking it was a claw hammer, also. I do have a friend that pronounces the word jen-er-uh, even though I have specifically said the word correctly around him after he has used it. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 00:40, 15 October 2020 (UTC)
:: "genera" is a word. I typed it into Google, marvelled at the incomprehensible phonetic version, and tapped a speaker button. My computer said "Genera" and a box popped up that reads "Learn to pronounce", which I consider to be rude. But after all, I pressed the button. Robert Carnegie rja.carnegie@excite.com [[Special:Contributions/162.158.158.225|162.158.158.225]] 00:51, 15 October 2020 (UTC)
::Russian probe sent to Venus? And I'm so confident about that, that I shall not even check before posting. (No idea how it's said in Russian, but the Anglophone versios doesn't differ between anglophonic countries as much as "Moscow" does.) [[Special:Contributions/162.158.155.72|162.158.155.72]] 01:34, 15 October 2020 (UTC)
::Yeah, yeah, so I now know I merged two different Russian space-thingies. [[Special:Contributions/162.158.159.140|162.158.159.140]] 01:40, 15 October 2020 (UTC)

Ok, who’s the joker that put “Citation needed” at the end of “ "Google" is not generally pronounced with a high-pitched yelp on either syllable.[citation needed]”

"Many-legged scaly creature" makes me think of silverfish, centipedes or millipedes, though they have exoskeletons rather than scales, and ''certainly'' don't eat light bulbs. It seems to me that a segmented exoskeleton is reminiscent of scales, though. [[Special:Contributions/162.158.154.167|162.158.154.167]] 07:37, 15 October 2020 (UTC)
:Question 8 sounds like a hybrid, to me, with another part coming from a glow worm / firefly question. [[Special:Contributions/141.101.68.12|141.101.68.12]] 10:19, 15 October 2020 (UTC)

13 seems to be referring to [https://en.wikipedia.org/wiki/Pholcidae these] to me. [[Special:Contributions/173.245.52.169|173.245.52.169]] 12:30, 15 October 2020 (UTC)

Please feel free to edit/condense my rambly explanation of shallots/scallions. Debating removing the second and third detailed paragraphs entirely. I'm from NSW and have seen confusion on recipes posted online so not exactly impartial. [[Special:Contributions/103.22.201.134|103.22.201.134]] 16:40, 15 October 2020 (UTC)

I'm half remembering in the original Thunderbirds series, an old NASA colleague of Geoff Tracey who 'poses' as an generic ¿Deep South? country-bumpkin/local-yokel (grown up in the area, though obviously smart enough to get into NASA and then later 'retire' to become a trusted International Rescue local agent... or so I may extrapolate) calling Lady Penelope Creighton-Ward, with whom he was clearly familiar, "Penn elope" (to "rhyme with antelope"). I shall have to dig up my complete VHS tapes to confirm... and probably spend a couple of days just watching them all, for old times' sake ...but clearly the script called for an uneducated (mis)pronunciation of her name - maybe feigned as part of his act/through habit. So if it aint an actual misconception/affectation by ''someone'', that the scriptwriters (or voice-actor) used, then it needs far more explanation. [[Special:Contributions/162.158.155.72|162.158.155.72]] 02:43, 16 October 2020 (UTC)

Talk:2372: Dialect Quiz

2020-10-15T01:34:53Z

162.158.155.72: