explain xkcd - User contributions [en]

2768: Definition of e

2024-08-26T06:04:37Z

172.70.42.129: /* Explanation */

{{comic
| number = 2768
| date = April 26, 2023
| title = Definition of e
| image = definition_of_e_2x.png
| imagesize = 571x186px
| noexpand = true
| titletext = Yeah, my math teacher back in high school set up the system to try to teach us something or other, but the 100% rate was unbelievably good, so I engineered a hostile takeover of his bank and now use it to make extra cash on the side.
}}

==Explanation==
In this comic the teacher [[Miss Lenhart]] is asked by the student [[Hairy]] to explain what the constant ''e'' actually means.

The mathematical constant ''{{w|e (mathematical constant)|e}}'' is known as Euler's number. It is typically demonstrated in terms of compound interest. Here, Miss Lenhart seems to be setting up such an example, but in a typical Lenhart style she is actually asking her student to give her money.

The constant ''e'' can be described {{w|E (mathematical constant)#Compound interest|in the context of compound interest}}. For a bank account that pays interest at a rate of 100% per year, and that interest is paid ''n'' times a year and compounded, then a $1 deposit will grow to $1 * (1 + 100%''/n'')^''n'' after a year. As ''n'' approaches infinity (continuous compounding), the amount approaches ''e'' dollars. In the comic, minutely compounding is used as an approximation of continuous compounding; here ''n'' = 365 * 24 * 60 = 525,600 (527,040 for leap years with 366 days), and the resulting amount would be $2.7182792…, less than one part per million different from that of a straight multiplication by ''e'' (which is 2.7182818…).

As such, one would expect Miss Lenhart to say in the last panel something like "you'll have ''e'' dollars in a year". It is not clear if Miss Lenhart sees the growth of the deposited amount as answer enough to explain ''e'' or if she's just charging $1 for answering the question of what ''e'' is. The supposed interest rate the teacher can earn off this deposit, alone, is so high that the $1 principal will grow to over $22,000 in ten years, $485 million in twenty years, or $10.68 trillion in thirty years.

In the title text, Randall remembers that his high school teacher, like Miss Lenhart in the comic, had a bank account that paid 100% annual interest. This is an extremely high rate, and a bank that is able to offer it must have a very lucrative source of revenue. Therefore, he bought the bank, via a {{w|Takeover#Hostile|hostile takeover}}, in order to gain direct access to that source, and now uses it as a source of supplementary income. It is unlikely that this story is true.

It is also plausible that the title text is Miss Lenhart explaining how she acquired the bank to set up her account there, and that she regularly charges people $1 for trivial services, such as explaining concepts to her students.

==Transcript==
:[Hairy is seated behind a classroom desk with his hand raised asking the teacher Miss Lenhart a question. She is standing in front of him with a board behind her. Beneath the board there are ledge with writing tools on it (markers or chalk).]
:Hairy: Can you explain what the constant ''e'' actually ''means?''
:Miss Lenhart: Sure.

:[Zoom in on Miss Lenhart's upper half, as she raises one hand palm up.]
:Miss Lenhart: I have a bank account that pays 100% annual interest, compounded every minute.

:[In a frame-less, and very slim panel, Miss Lenhart is shown holding a hand up with one finger raised.]
:Miss Lenhart: If you deposit $1 now,

:[Miss Lenhart now has both arms down as she continues to address the off-panel Hairy.]
:Miss Lenhart: I will answer your question.

{{comic discussion}}

[[Category:Comics with lowercase text]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Miss Lenhart]]
[[Category:Math]]

Talk:2924: Pendulum Types

2024-04-26T13:40:22Z

172.70.42.129:

Example of the creepy fingers: https://youtu.be/3zoTKXXNQIU?si=MgZgSRFFyxrNGhw3 [[Special:Contributions/172.70.175.25|172.70.175.25]] 12:58, 24 April 2024 (UTC)
:If that's as creepy as Maxwell's Demon gets, you have to wonder if he's related to Gachnar: https://www.facebook.com/watch/?v=3090746901188850 [[Special:Contributions/172.70.91.12|172.70.91.12]] 14:47, 24 April 2024 (UTC)

Fortunately, Maxwell's Demon can be banished with a silver hammer. [[Special:Contributions/172.69.246.151|172.69.246.151]] 15:08, 24 April 2024 (UTC)
:Is this a Dungeons and Discourse reference? [[User:Psychoticpotato|Psychoticpotato]] ([[User talk:Psychoticpotato|talk]]) 18:23, 24 April 2024 (UTC)
::Ultimately that'd be from {{w|Maxwell's Silver Hammer|The Beatles}}... (Don't know that particular D'n'D thing, if that's a thing. Bet that's also a reference of its own.) [[Special:Contributions/172.71.242.70|172.71.242.70]] 18:46, 24 April 2024 (UTC)

Thank you, whoever completed the transcript. I didn't know the bullet tag and the comics are starting to get more complicated to explain and transcribe. So again, my thanks. <3 [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 16:12, 24 April 2024 (UTC)

David Acheson showed that any finite number of inverted pendulum segments can be made stable through vibration. related video here: https://www.youtube.com/watch?v=BJ7_fFABc9s&t=0s [[Special:Contributions/108.162.238.131|108.162.238.131]] 17:23, 24 April 2024 (UTC)

Considering that Maxwell's demon can reverse entropy, I welcome our new demon overlord. We must all put more starch onto speakers! [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 18:10, 24 April 2024 (UTC)
:Summon Ba'al the Soul-Eater to rule beside Maxwell's Demon!!!!!!!!!!!!!!!! [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 19:22, 24 April 2024 (UTC)

Should we use "pendula" as the plural to "pendulum"? {{unsigned ip|172.70.110.47|21:38, 24 April 2024}}

:The plural of pendulum would be penduli, as it is Latin second declension.[[Special:Contributions/172.70.42.128|172.70.42.128]] 13:31, 26 April 2024 (UTC)

Should we mention that Netflix's airing of 3-body problem means people are probably more interested in chaotic systems right now?--[[Special:Contributions/172.70.39.36|172.70.39.36]] 03:01, 25 April 2024 (UTC)
:Plus there's the US elections coming up...[[Special:Contributions/162.158.95.97|162.158.95.97]] 09:09, 25 April 2024 (UTC)

A double pendulum requires 2 weights, and additional one at the center joint. Surprisingly Randal has that wrong.
[[Special:Contributions/172.69.60.177|172.69.60.177]] 00:25, 26 April 2024 (UTC)
:Traditionally, I've seen that fudged by a massive 'link'. In fact, the two pendulum lengths can be dense bars, without even a terminating weight.
:This obviously changes the dynamics, as the idealised pendulum has all its mass in the swinging weight at its end (the CoG in its centre), a swinging bar is 'twice as long as its swing-factor' (CoG is half way along). So a two-bar double-pendulum (assuming negligable weight bonus/deficit in the mid-joint mechanism) is a half-length-effect secondary pendulum sat at the end of an extended primary.
:As if •-O-•-O-, •=joint (zero mass, zero size), -=extension (zero mass, zero flexibility), O=mass (zero size, zero flexibility)...). This is obviously differently 'tuned' to •—©—O (©=weight+joint, at a point).
:...or else the inter-length joint, though not obviously so, is suitably overwhelmingly massive to do weight+jointing. [[Special:Contributions/172.69.43.185|172.69.43.185]] 02:25, 26 April 2024 (UTC)

I wonder if Randall was playing Don’t Starve whose main antagonist is Maxwell, described as demonic, whose world is filled with nightmare themed contraptions, and which feature an entity called night hands that are creepy long fingers that come out at night to snatch your light. {{unsigned ip|162.158.158.234|01:55, 26 April 2024}}

:{{w|Maxwell's_Demon|Maxwell's Demon}} ultimately refers to a though experiment about entropy, and may very well be the inspiration for the Don't Starve character. However, here, it is most likely that he is referring to the thought experiment.[[Special:Contributions/172.70.42.129|172.70.42.129]] 13:40, 26 April 2024 (UTC)

Talk:2924: Pendulum Types

2024-04-26T13:30:50Z

172.70.42.129:

Example of the creepy fingers: https://youtu.be/3zoTKXXNQIU?si=MgZgSRFFyxrNGhw3 [[Special:Contributions/172.70.175.25|172.70.175.25]] 12:58, 24 April 2024 (UTC)
:If that's as creepy as Maxwell's Demon gets, you have to wonder if he's related to Gachnar: https://www.facebook.com/watch/?v=3090746901188850 [[Special:Contributions/172.70.91.12|172.70.91.12]] 14:47, 24 April 2024 (UTC)

Fortunately, Maxwell's Demon can be banished with a silver hammer. [[Special:Contributions/172.69.246.151|172.69.246.151]] 15:08, 24 April 2024 (UTC)
:Is this a Dungeons and Discourse reference? [[User:Psychoticpotato|Psychoticpotato]] ([[User talk:Psychoticpotato|talk]]) 18:23, 24 April 2024 (UTC)
::Ultimately that'd be from {{w|Maxwell's Silver Hammer|The Beatles}}... (Don't know that particular D'n'D thing, if that's a thing. Bet that's also a reference of its own.) [[Special:Contributions/172.71.242.70|172.71.242.70]] 18:46, 24 April 2024 (UTC)

Thank you, whoever completed the transcript. I didn't know the bullet tag and the comics are starting to get more complicated to explain and transcribe. So again, my thanks. <3 [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 16:12, 24 April 2024 (UTC)

David Acheson showed that any finite number of inverted pendulum segments can be made stable through vibration. related video here: https://www.youtube.com/watch?v=BJ7_fFABc9s&t=0s [[Special:Contributions/108.162.238.131|108.162.238.131]] 17:23, 24 April 2024 (UTC)

Considering that Maxwell's demon can reverse entropy, I welcome our new demon overlord. We must all put more starch onto speakers! [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 18:10, 24 April 2024 (UTC)
:Summon Ba'al the Soul-Eater to rule beside Maxwell's Demon!!!!!!!!!!!!!!!! [[User:Z1mp0st0rz|Z1mp0st0rz]] ([[User talk:Z1mp0st0rz|talk]]) 19:22, 24 April 2024 (UTC)

Should we use "pendula" as the plural to "pendulum"? {{unsigned ip|172.70.110.47|21:38, 24 April 2024}}
The plural of pendulum would be penduli, as it is Latin second declension.
Should we mention that Netflix's airing of 3-body problem means people are probably more interested in chaotic systems right now?--[[Special:Contributions/172.70.39.36|172.70.39.36]] 03:01, 25 April 2024 (UTC)
:Plus there's the US elections coming up...[[Special:Contributions/162.158.95.97|162.158.95.97]] 09:09, 25 April 2024 (UTC)

A double pendulum requires 2 weights, and additional one at the center joint. Surprisingly Randal has that wrong.
[[Special:Contributions/172.69.60.177|172.69.60.177]] 00:25, 26 April 2024 (UTC)
:Traditionally, I've seen that fudged by a massive 'link'. In fact, the two pendulum lengths can be dense bars, without even a terminating weight.
:This obviously changes the dynamics, as the idealised pendulum has all its mass in the swinging weight at its end (the CoG in its centre), a swinging bar is 'twice as long as its swing-factor' (CoG is half way along). So a two-bar double-pendulum (assuming negligable weight bonus/deficit in the mid-joint mechanism) is a half-length-effect secondary pendulum sat at the end of an extended primary.
:As if •-O-•-O-, •=joint (zero mass, zero size), -=extension (zero mass, zero flexibility), O=mass (zero size, zero flexibility)...). This is obviously differently 'tuned' to •—©—O (©=weight+joint, at a point).
:...or else the inter-length joint, though not obviously so, is suitably overwhelmingly massive to do weight+jointing. [[Special:Contributions/172.69.43.185|172.69.43.185]] 02:25, 26 April 2024 (UTC)

I wonder if Randall was playing Don’t Starve whose main antagonist is Maxwell, described as demonic, whose world is filled with nightmare themed contraptions, and which feature an entity called night hands that are creepy long fingers that come out at night to snatch your light. {{unsigned ip|162.158.158.234|01:55, 26 April 2024}}

Talk:2912: Cursive Letters

2024-03-28T03:30:24Z

172.70.42.129: Updated my username (I made a username lol)

That Q is pretty easy to read, but a lot of people write it in a way that looks more like 2. That Q always throws me off. The 2 goes close to the bottom left, neither cool nor legible. [[User:EebstertheGreat|EebstertheGreat]] ([[User talk:EebstertheGreat|talk]]) 21:28, 27 March 2024 (UTC)

Cursive has been in the news lately, almost half the US states have recently passed laws requiring that cursive writing be taught in elementary schools. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 21:30, 27 March 2024 (UTC)
:Recently? I think only California did it recently, most of those laws are older. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:14, 27 March 2024 (UTC)

Is this the default cursive taught in US American schools? I’ve often seen this capital I, G and Q on (older) Hollywood films, but the (standard) cursive writing in Germany or France looks completely different. --[[Special:Contributions/162.158.154.99|162.158.154.99]] 21:49, 27 March 2024 (UTC)

Labelled: https://i.imgur.com/dTdLgO6.png [[User:Bewa|Bewa]] ([[User talk:Bewa|talk]]) 22:09, 27 March 2024 (UTC)

Meanwhile if this was Russian/Cyrillic cursive, almost every letter would be at y=0! [[Special:Contributions/172.69.7.49|172.69.7.49]] 00:10, 28 March 2024 (UTC)

Is that a "u" in the lower left? [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 03:11, 28 March 2024 (UTC)
:Hi, so this is my first ever comment; feel free to yell at me if I’m doing it wrong. But to answer your question, nope, that’s a lowercase v. That said, the two can be frustratingly similar in some handwritings. Also, while this isn’t the point of the comic (and I assume it uses Munroe’s own handwriting) some of those letters can be made more legible and/or much cooler looking if you just write them with an alternate style. — [[Special:Contributions/172.70.42.129|172.70.42.129]] 03:30, 28 March 2024 (UTC)

Talk:2638: Extended NFPA Hazard Diamond

2022-06-28T04:18:33Z

172.70.42.129:

Are we going to try identifying what material this is? [[Special:Contributions/172.70.82.179|172.70.82.179]] 01:50, 28 June 2022 (UTC)
:first one off the top of my head, aqua regia? [[Special:Contributions/172.70.38.69|172.70.38.69]] 02:46, 28 June 2022 (UTC)Bumpf
::Doesn't aqua regia score a 0 in reactivity? [[User:N-eh|N-eh]] ([[User talk:N-eh|talk]]) 03:23, 28 June 2022 (UTC)
:My guess would be something radioactive, like uranium or plutonium. [[User:Clam|Clam]] ([[User talk:Clam|talk]]) 03:29, 28 June 2022 (UTC)
The center square is a free space, but if you win without it you get a special bonus prize. [[Special:Contributions/172.70.42.129|172.70.42.129]] 04:18, 28 June 2022 (UTC)

1636: XKCD Stack

2022-01-20T21:20:42Z

172.70.42.129: clarification

{{comic
| number = 1636
| date = January 29, 2016
| title = XKCD Stack
| image = xkcd_stack.png
| titletext = This site requires Sun Java 6.0.0.1 (32-bit) or higher. You have Macromedia Java 7.3.8.1¾ (48-bit). Click here [link to java.com main page] to download an installer which will run fine but not really change anything.
}}

==Explanation==
In software engineering, a {{w|Solution stack|tech stack}} is the set of technology platforms and tools that a company or app uses. A common tech stack is {{w|LAMP (software bundle)|LAMP}}, composed of a {{w|Linux}} {{w|Operating system|operating system}}, an {{w|Apache HTTP Server|Apache}} {{w|Web server}}, a {{w|MySQL}} {{w|Database}}, and the {{w|PHP}} programming language. In this comic, the XKCD stack is introduced. The technologies it comprises are either non-existent, unreliable, outdated, or entirely irrelevant.

Another example of a tech stack is featured in [[2166: Stack]].

===Explanation of Layers===
;EBNF/CSS
:BNF or {{w|Backus–Naur Form}} is a syntax used for describing {{w|context-free grammars}}. {{w|Extended Backus–Naur Form|EBNF}} is "Extended BNF", it is the same thing as BNF with a few more syntactic constructs intended to ease its use in the most common cases. [[1343: Manuals]] mentioned EBNF.
:CSS or {{w|Cascading Style Sheets}} is a language used to describe what a web page should look like. Web pages are usually written in {{w|HTML}}, which describes the ''structure'' of the page (i.e. divides the document into paragraphs, lists, etc.) complemented with CSS which describes the ''look and feel'' of the page (colors, fonts, margins, etc.). EBNF/CSS would suggest CSS with strange syntax.
;Broken Java Applet
:In recent years it has become more difficult to run {{w|Java (programming language)|Java}} {{w|Applet|applets}} in several browsers. {{w|Google Chrome|Chrome}} 45 stopped supporting {{w|NPAPI}}, {{w|Mozilla Firefox|Firefox}} dropped support in version 52, and {{w|Microsoft Edge|Edge}} does not support NPAPI plugins at all. Furthermore, two days before this comic was published {{w|Oracle Corporation|Oracle}} (the developer of Java) [https://blogs.oracle.com/java-platform-group/entry/moving_to_a_plugin_free announced] plans to officially end support of Java applets in an upcoming version.
;Archive.org Mirror
:{{w|Internet Archive|Archive.org}} is a website which archives websites, and created the {{w|Wayback Machine}}. It's ambiguous whether the "Archive.org mirror" would be a copy of the xkcd server or of Archive.org itself.
;Hypercard.js
:{{w|HyperCard}} can be considered as a kind of predecessor for powerpoint developed at {{w|Apple Inc.|Apple}}. The file extension .js indicates that is was rewritten in {{w|JavaScript}}. A similar reference to JavaScript is found in [[1508: Operating Systems]].
;QBasic on Rails
:A mix between {{w|QBasic}} and {{w|Ruby on Rails}}. {{w|BASIC}} is a programming language that was very widespread during the 80s. QBasic is an implementation of BASIC created by Microsoft in early 90s, that, among other things, added support for {{w|structured programming}}. QBasic, lacking several of the features present on modern computer languages, is known for its spaghetti code. {{w|Ruby (programming language)|Ruby}} is a rather modern language, often used with Ruby on Rails web application {{w|Software framework |framework}}. QBasic on Rails would likely mean a port of Ruby on Rails, replacing Ruby with QBasic. QBasic no longer runs on modern computers, but there are a couple of free {{w|open source}} implementation of QBasic, one being [http://www.qb64.net/ QB64] and the other [http://www.freebasic.net/ FreeBASIC], which are available for Windows, Linux, Mac, and Android. There also exists a webserver on BASIC called [http://www.runbasic.com/ RunBasic].
;[Blocked by AdBlocker]
:{{w|Ad blocking}} software are extensions to browsers that try to remove ads from web pages, so the user is not distracted by them. [[624: Branding]] shows what "browsing without adblock" looks like. The joke is that AdBlocker is preventing us from seeing what makes up this portion of the stack. This could be because:
:*Someone inserted an ad in the stack description. Some sites do insert ads in the middle of tables and lists, a typical case being between posts in forums.
:*An ad is actually an integral part of the stack. Some sites make ads an integral part of the site content, so that users with ad blocking software will be forced to disable ad blocking to be able to properly interact with the site. Usually, in real life, this is not really a case of ads being part of the site, only that the site artificially refuses to work until it has some confirmation that ads have been properly loaded in the client side (by means of some script within the ads which sends the confirmation to the server).
:*Ad blocking software has misidentified that portion of the stack as an ad, when in fact it is not (i.e. a false positive). This happens in real life, and it is a common source of great pains for the owner of the site which is being misidentified as an ad.
;MongoDB/Excel
:{{w|MongoDB}} is a modern {{w|NoSQL}} {{w|Database|database}} system, {{w|Microsoft Excel}} is a {{w|Spreadsheet|spreadsheet}} program from Microsoft, which is sometimes used as a database system (rarely a good choice).
;Some piece that works so nobody asks any questions
:Writing any non-trivial piece of software always require a phase of {{w|debugging}}, which consists in finding and fixing {{w|Software bug|bugs}}. With complex software, this is a long and tiring process, so when the product is finally finished no one dares to modify it any further for fear that it will fail in unexpected ways. After some time passes, it is even worse because nobody really remembers how the software was ''supposed'' to work, so the product becomes some kind of godlike treasure which must be treated with the utmost respect and reverence because, you know, if it stops working we're all doomed ([[1421: Future Self]]). After completion, {{w|Refactoring}} is the process of rewriting code for greater efficiency or reliability. However, if the performance is not 'too bad' (i.e. not unusably terrible in normal use) there is a great temptation to avoid this, in favour of the 'if it ain't broke, don't fix it' methodology. This could lead, for example, to a trained monkey and an abacus being used to crunch numbers. It works, but could be done far better. However, nobody wishes to change it, for fear of breaking a presently functional, if inefficient, system.
;Triply-Nested Docker
:{{w|Docker (software)|Docker}} is a {{w|Operating-system-level virtualization|software container}}, which is a way that allows a complete operating system to run under different operating system (OS) (as long they share the same kernel, among other things). Triply-nested docker would mean OS A running under OS B running under OS C running under OS D (running under OS E?). That would likely be a performance and management nightmare
;Paravirtual Boy®
:This is a reference to the {{w|Virtual Boy}}, a failed portable console created by {{w|Nintendo}}. It was [https://www.youtube.com/watch?v=MKKK6FH1vGw promoted as being a highly immersive, incredible experience], but the poor technology that it used caused it to be [https://youtu.be/OyVAp0tOk5A?t=56s very criticized] for not meeting the high expectations. {{w|Paravirtualization}} is a way of virtualization, that requires cooperation of the guest operating system, contrary to {{w|full virtualization}}, on which the guest operating system is not required to do anything special and the host handles everything.
;A dev typing real fast
:A dev is a {{w|Software developer|software developer}}. This is possibly a reference to [[341: 1337: Part 1]], where [[Mrs. Roberts]] edits the {{w|Transmission Control Protocol|TCP}} stream live while wearing oven mitts and baking cookies. It looks like the xkcd Webserver is not a computer after all -- we have a person manually replying to HTTP protocol queries. Such a feat would indeed require real fast typing. If this is the case, then its possible that almost none of the other layers of the stack actually do anything.
;Older version of our software
:People are often reluctant to switch to newer versions of software because, even though newer versions are supposed to have more features and fewer bugs, they end up confusing users. Users of older versions are used to doing everything with less features and circumventing old bugs. They don't know how to use the new features, which of course come with new bugs they haven't learned how to circumvent yet. It is also often the case that newer versions remove weird unused old features, breaking the workflow of users who actually did use such features and are left without a suitable replacement ([[1172: Workflow]]). Alternately, since higher parts of a stack are dependent on lower parts, this could also be a reference to how the consumer versions of Microsoft Windows (3.x, 95, 98, and ME) ran on the "older version" software Microsoft DOS until Windows NT. Paired with the previous layer, it could instead mean that the human is merely retyping the output of the older version.
;Mystery Networking Horror
:Randall suggests here that the whole networking stuff behind the XKCD service is both mysterious (no one actually knows the details) and horrific (technically questionable architecture and implementation, or somehow tentacled and eldritch in nature).
;Microsoft Bob Server®
:{{w|Microsoft Bob}} was a short-lived, failed attempt by Microsoft, around 1995, to provide a user-friendly interface for the {{w|Microsoft Windows|Windows}} 3.1x, Windows 95 and Windows NT operating systems. It consisted of a virtual "house" and "rooms", and clicking on objects in the room would open applications, for instance clicking on a pen would open the word processor. It was heavily criticized and was soon discontinued. Randall seems to be making the suggestion that Bob has continued to be developed and now there's a Bob Server, similarly to Windows server.
;A giant {{w|Central processing unit|CPU}} someone built in Minecraft
:{{w|Minecraft}} is a popular sandbox game where you place blocks to build things. Since the introduction of Redstone objects (materials used to create basic electric circuits within the game) people have made many machines within Minecraft, including calculators and clocks. The most complex of these machines simulate simple computers, capable of storing several lines of code and performing basic mathematical operations such as division, which requires thousands of blocks and extremely complex designs. A Minecraft CPU capable of hosting a website would be ridiculously huge.

=== Title text ===

The title text contains several jokes about the Java programming language:

*First, it refers to Java both as {{w|Sun Microsystems|Sun}} Java and {{w|Macromedia}} Java. This is a pun on the fact that older documents refer to "Sun Java" where newer documents refer to "{{w|Oracle Corporation|Oracle}} Java", as if there were two different languages. The fact is that Java was designed originally by Sun and then bought by Oracle, so it "changed name" even though the language is the same. Macromedia was the company that developed Flash before it was bought by Adobe. Both Flash and Java were popular in the early WWW to have interactive web pages, but both are being deprecated in favor of JavaScript.

*Second, the version numbers: older software products used to have two version numbers: major and minor (e.g. in {{w|MS-DOS}} 6.22 the major number is 6 and the minor is 22). Newer products tend to have hundreds of minor revisions, all of them numbered, so a typical user may well find themselves updating version 6.0.0.1 to 7.3.8.1 without knowing at all the differences between both versions or which other versions are in between. The ¾ in the Macromedia Java version is a joke on complex version numbers, which (so far) have never included fractions.

*Third, the 32-bit or 48-bit version: The {{w|Intel 80386}} processor used an architecture known as {{w|IA-32}}, which implies the {{w|Address bus|address bus}} is 32-bit wide and thus able to handle up to 4{{w|Gibibyte|GiB}} of {{w|Random-access memory|RAM}} memory. This was plenty for the early 1990s, when a typical home PC would have about 8MiB (this is 512 times less than 4GiB). However, about 10 years after that, a typical home PC could well use more than 4GiB of RAM, so several {{w|64-bit computing|64-bit architectures}} were created. These architectures are not compatible(32b SW runs on 64b HW but 64b SW doesn't work on 32b HW), so programs (including the Java Runtime Environment, or JRE) often have 32-bit and 64-bit versions. Furthermore, the JRE is heavily used by many web browsers, and for this to work the JRE and browser need to be the same "number of bits". This means that most people have installed both versions of the JRE to be able to use it with both 32-bit and 64-bit browsers. There's no 48-bit architecture (though some 64-bit processors including the {{w|x86-64|most common ones}} don't actually <b>use</b> all 64 bits everywhere, ignoring some bits so actual virtual or physical memory is smaller (in the case of the most common ones, 48bits virtual and 40bits physical), they simulate a full 64-bit environment to allow adding more bits later, so there are no specific 48-bit applications).

*Fourth, an application trying to let the user install a new version of the JRE should direct the user to the download page in the [http://java.com/ java.com site], not to the main page which deals with lots of issues with java and is not particularly helpful when trying to update the JRE.

*Fifth, and continuing with the joke of users updating from 7.3.8.1¾ to 6.0.0.1 and not knowing why they should, the new version is said to "run fine but not really change anything". This is the usual behavior for Java updates: they run fine (possibly in opposition to [[1197: All Adobe Updates]], where updating must be done several times and the user is never sure they have installed all the newest updates), but after finished updating the user can't see any difference with the previous behavior, and/or may still be told that an update is required. Considering that 7.3.8.1¾ is bigger number than 6.0.0.1, it can also refer to the fact that the test for upgrading is incorrect and 7.3.8.1¾ is actually newer version or that a downgrade is required for the applet to work properly, because no one fixed it to work with the newer version.

==Transcript==
:[A simple table with only one column and fifteen rows is shown. Text above:]
:Introducing
:'''The XKCD Stack'''

:[The list of cells:]
:EBNF/CSS
:Broken Java Applet
:Archive.org Mirror
:Hypercard.js
:QBasic on Rails
:[Blocked by AdBlocker]
:MongoDB/Excel
:Some piece that works so nobody asks any questions
:Triply-Nested Docker
:Paravirtual Boy®
:A dev typing real fast
:Older version of our software
:Mystery Networking Horror
:Microsoft Bob Server®
:A giant CPU someone built in Minecraft

{{comic discussion}}
[[Category:Computers]]
[[Category:Programming]]
[[Category:Video games]]
[[Category:Minecraft]]

Talk:2555: Notifications

2021-12-19T05:37:27Z

172.70.42.129:

I wrote that the time in the title text does not seem to have any special meaning, the only thing a quick google search gave me was the bible verse "Think not that I am come to send peace on earth: I came not to send peace, but a sword." which is irrelevant to the comic as far as I can tell. Is there something I missed? -- [[User:256.256.256.256|256.256.256.256]] ([[User talk:256.256.256.256|talk]]) 08:52, 16 December 2021 (UTC)
:I assume it has something to do with time zones, but not sure.[[Special:Contributions/162.158.222.123|162.158.222.123]] 09:40, 16 December 2021 (UTC)
::Yes for sure, it is late in the recipients time zone. And thus the program asks if the notification is so important at this later hour. On the internet you are often in communication with someone in another time zone. Has updated explaination.--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:17, 16 December 2021 (UTC)
:::But it doesn't have a special meaning. 10:32 or 10:41 would have done the same job. --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 07:15, 17 December 2021 (UTC)

Is it just a weird coincidence that today’s smbc is also about how to stop a tedious conversation? {{unsigned ip|198.41.238.107}}
:It sure is funny. The [https://www.smbc-comics.com/index.php SMBC] comic from 2021-12-15, [https://www.smbc-comics.com/comic/econs Econs], was about paying someone to stop with a boring discussion. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:21, 16 December 2021 (UTC)

I got to thinking about the difference from saying "I perceive that you have mistaken me for someone who cares", or very often "someone who gives a (vulgar word)". I suppose the difference is that talking about Notifications means "Not just now" or "That's enough for now", but you could just say that. It doesn't forbid continuing the subject later. Robert Carnegie rja.carnegie@gmail.com [[Special:Contributions/162.158.159.105|162.158.159.105]] 11:15, 16 December 2021 (UTC)

Are you sure Cueball is sending notification to White Hat? When I saw this comic I thought that White Hat wants to say it annoys him when someone ignores others notifications settings and, voilà, Cueball just does it the same moment. [[User:Tkopec|Tkopec]] ([[User talk:Tkopec|talk]]) 12:58, 16 December 2021 (UTC)
:Well, if White Hat is complaining about anything like that (we never even get a hint what) it should be more about those who sets to ignore notifications (what Cueball does) or else it is about those who set about to ignore others' "ignore-notifications" settings but then he turns out not to be that kind of annoying person, as he actually respects that situation.
:Whether Cueball knows what is about to be (re)complained about, from hearing this tiraid multiple times, I don't know. Or maybe it was mentioned as the pre-"...another thing" spouting of opinion, and thus quickly inspired him to act upon the suggestion.
:It doesn't really matter. Whatever Randall might have conceived as being said before/after the short slice of Whitehat's rant, he gives no direct clue so it's likely to just be a generic stream of opinionated verbosity, making Cueball even more clever and inspired to have discovered this 'life hack' to cut it short. A bit like telling Sheldon that something is a "non-optional social convention".
:...incidentally, one of John Finnemore's radio sketches in his 'Souvenir Programme' series (if you can, look it up (the whole series!) to listen to - I'm sure xkcders would be prime candidates to enjoy, or at least be able to appreciate, the (over?)intelligent humour) was basically if the Russian Revolution were being organised via email, with one character's involvement being (mostly!) a bog-standard Out Of Office reply. Best listened to, although if you can't you can definitely find a script-transcript site or two with the right Google-Fu. [[Special:Contributions/172.70.86.22|172.70.86.22]] 13:46, 16 December 2021 (UTC)

I don't think it's necessarily "past their bedtime"; that's an oversimplification. I think it's implying "they need to go home, prepare for bed, and hopefully get a full night's sleep by the time they have to get up in the morning." It might easily be that they're fifteen minutes from home and want to go to sleep by 11:00 PM. It also might not be their "normal" bedtime; they specifically have "a thing" early tomorrow, an important event which presumably isn't a normal occurrence.[[Special:Contributions/172.70.35.70|172.70.35.70]] 20:01, 16 December 2021 (UTC)
:10:34 is time which can easily be past "normal" - meaning, week day - bedtime and at the same time not that late on party or other social activity. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 00:30, 17 December 2021 (UTC)
::Sure, it ''could'' be past their bedtime, but you're making an assumption. People prefer different amounts of sleep, have different regular schedules, consider different times "early", etc. It's not necessarily true that it's past their normal bedtime, so the explanation shouldn't make that unfounded assumption.[[Special:Contributions/172.70.42.129|172.70.42.129]] 05:37, 19 December 2021 (UTC)

Joke's on White Hat, I put my phone in airplane mode at night. Ain't no notifications waking me up except my alarm. [[Special:Contributions/162.158.106.53|162.158.106.53]] 05:38, 17 December 2021 (UTC)
:...but it's also likely to have flown away, surely? ;) [[Special:Contributions/172.70.86.22|172.70.86.22]] 11:56, 17 December 2021 (UTC)

I don't have the time nor care to fix it myself, but this explanation acts as if Cueball and White Hat are in the same timezone, but "10:34 PM" could mean the same thing "Good Morning" means in XKCD 448. [[User:Tsumikiminiwa|Tsumikiminiwa]] ([[User talk:Tsumikiminiwa|talk]]) 20:39, 17 December 2021 (UTC)

Does anyone know what time #2555 was posted to xkcd.com? It would be entertaining if it was near 10:34pm in Randall's time zone.

I thought the comic was about how the "notify anyway" option sort of leaves you paralyzed with indecision. Because whenever it happens, you have to decide whether your text is important enough to notify them about, and how rude it would be to bypass the turned off notifications, is it worth it to keep notifying them, etc. Because White Hat is just standing there, not moving or doing anything after cueball blocks notifications, could this be an alternate explanation? (for instance, if it had just been that notifications were turned off with no bypass option, White Hat would simply be annoyed and probably keep talking anyway. But because he's given the option to bypass the filter, now he has to make a rather complicated choice and is paralyzed with indecision.)

Talk:2519: Sloped Border

2021-09-25T13:15:29Z

172.70.42.129:

I might be old-fashioned, but I've always wanted to live in Mandelbrotistan 3D. [[Special:Contributions/162.158.89.156|162.158.89.156]] 15:49, 23 September 2021 (UTC)

I would make the country's border an Alexander horned sphere. [[Special:Contributions/108.162.221.245|108.162.221.245]] 03:21, 23 September 2021 (UTC)

:Waaait ... how can we define the border to maximize area of both countries? I'm talking non-measurable sets invoking something like {{w|Banach–Tarski paradox}} here ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 00:01, 24 September 2021 (UTC)

At least this border doesn't have [https://youtu.be/Mw44wHG4KOc thickness]. --[[User:Angel|Angel]] ([[User talk:Angel|talk]]) 04:48, 23 September 2021 (UTC)
-yet [[Special:Contributions/172.69.55.107|172.69.55.107]] 05:46, 23 September 2021 (UTC)

GIS: Geographic Information System, that are the systems where maps (and the borders) are defined. They won't care much though, because for them the ground information is the relevant one.
Once you get into air, you'll get a problem, because if the border is very sloped, and not in average straight, then an airplane might still be in the airzone of a different country than where it's flying over. Which will cause all kinds of problems, security wise.
Liechtenstein might loose all control over its airspace, yet their inhabitants want safety even from aircraft flying above them.
Can't imagine that going well, but bureaucrazy is that: it creates paperwork when it is not busy enough with the procedures it already created. [[Special:Contributions/172.69.55.107|172.69.55.107]] 05:46, 23 September 2021 (UTC)

Liechtenstein and air control is a bad example for the problems with sloped borders because it's quite often the case that the air space of one country is done by air space controllers of another country. In the case of Liechtenstein this is done by SKYGUIDE in Switzerland that is also doing it for southern parts of Germany (being responsible for the collision of two planes near Überlingen: https://en.wikipedia.org/wiki/2002_%C3%9Cberlingen_mid-air_collision) [[Special:Contributions/162.158.89.156|162.158.89.156]] 06:34, 23 September 2021 (UTC)

Wouldn't sloped borders also have interesting consequences underground when mining, building tunnels etc. ? [[Special:Contributions/162.158.88.239|162.158.88.239]] 08:39, 23 September 2021 (UTC)

:That was my immediate concern as well: Residents of a single building could be divided between two jurisdictions, by residing one above the other. Mining & water rights & airspace might be similarly complicated. If airspace ended earlier than international waters, & undersea oil fields extended even beyond that... Oh, wait. 👀
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 05:27, 25 September 2021 (UTC)

I introduced into the explanation a hint of the more precise problem with airborne geometry upon spherical (or, possibly, geodesic) coordinates. The shallower the angle, the more possible that the 'curves with the ground' altitude calculation is to actually wrap itself all the way round the Earth before (presumably), whatever altitude limit there is to make space the same upper edge as International Waters are to horizontal edges. Taking the Liechtenstein case, as above, you could easily enclose them in a 'pyramidal' (or wedged, if not applied from all around them) air-claim by angling over them - ''or'' greatly increase their air-claim over neighbours if the angle is away. With inverse issues for the Mineral Rights issue. You need to agree in advance what happens when angled boundaries hit perpendicular ones, ''and'' whether the 'rhumbs' projected from the border mash together when equidistant points on a crinkly border project their own air-distance line. ''And'' if it is from an agreed surface level datum or local ground level, with the complications that arise from both cases. (Yeah, I originally thought there were about four different bones of contention that need to be ironed out in the codicil on curvature, but I now think there's about six of them needing strict definition, not counting the compound cases which further may need specifying in advance or forever requirev adhoc arbitration.) And none of this even takes account of Relativity and curved ''space'' frame of reference that might very subtly shift whatever reference you just agreed upon, if you let it go high enough. [[Special:Contributions/172.70.34.165|172.70.34.165]] 12:05, 23 September 2021 (UTC)

Should there be a part of the explanation talking about how GIS is already a nightmare? Because the hobby is "_new_ ways to make life a nightmare" [[Special:Contributions/162.158.75.159|162.158.75.159]] 13:35, 23 September 2021 (UTC)
:There should ; I expect it's because the borders are often defined by natural features, which may be very detailed AND changing in time. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 00:06, 24 September 2021 (UTC)

It's not worth wondering: is the boarder sloped across cardinal directions, like East to West, or is it sloped inward or outwards from the country in question? If the latter, outwards will make it like a funnel, meaning country A has greater airspace than its surface area at "ground" level. (Which is another consideration: where does the initial angle begin?) If sloped inwards, well then that country loses a lot of advantage. If it's based on cardinal directions... I do not want to consider how many complications that would create along various sections of the border. [[Special:Contributions/108.162.219.51|108.162.219.51]] 16:55, 23 September 2021 (UTC)

:Also, NERD SNIPE! [[Special:Contributions/108.162.219.51|108.162.219.51]] 16:56, 23 September 2021 (UTC)
:My presumption would be that the line-on-the-ground, however it winds around (e.g. following the centre of a river, the apex of a ridge or the point-to-point (with or without Great Circle adjustment) between two defining nodes) is a sequence of presumed horizontal line segments of arbitrary length, normalised to be parallel to the horizontal at the whatever ground elevation they cross. That line and the perpendicular through that line from the centre of the Earth (the vertical, by all accounts) thus define the third mutually perpendicular line that is the 'slopeward'(/antislopward) baseline. The defined angle indicates the inclination from the vertical on the vertical/slopeward plane.
:Where landforms complicate matters the border rises or falls across contours, or twists and turns with a convex and/or concave groundtrack, the dominant inclined border is that originating from the closest source-point wherever there is potentially conflict.
:If Cueball's border was around an enclave otherwise within his area of control, this would result in a tent-like (but strangely irregular) territorial enclosure (assuming not truncated by the Karman Line 'air limit', or similar). But I think he's content to make this just ''any'' shared border (e.g. the mostly 'straight' US-Canada fifty-whatever-parallel one) which means probably all other territorial limits (in that case, maritime) remain vertical (certainly not similarly leaning, in non-right-prismatic form) and except in a ''very few'' edge cases would end up dominating the slope-vs-vertical intersections.
:As to 'advantage' (except for the territory sloped away from), I don't think there really is one. At best, it makes true geofencing of drones a bit more complicated than saying "don't cross this line; don't go above/below these altitudes" for some doubtless functional reason. For the people in the RHS 'illustrative' sub-image, it seems to have no practical effect other than to identify limbs/other extremities as cross-border in rather more unusual slices of the body than a normal border-straddler would expect. [[Special:Contributions/162.158.159.11|162.158.159.11]] 22:33, 23 September 2021 (UTC)
Hmm, defining the calculation of the slope is tricky indeed. The commenter above suggests that the slope is relative to "vertical". However, the interpretation of "ground level" could deal with "level" meaning the ground slope, not the ground height. In other words, consider the slope on the side of a mountain. Let's suppose that in a local area, with a section of border running north/south, the ground is sloped 30 degrees to the east. Does that mean the 74 degree border is 104 degrees to the east at that point? The ground changing shape (whether due to natural erosion or bulldozers) could change the borders significantly.[[Special:Contributions/108.162.246.220|108.162.246.220]] 00:01, 24 September 2021 (UTC)

Sloped borders wouldn't be so weird, if the 3D component of the borders would follow the same rules as most 2D sea borders would do, which is that the border lies at a line of points equidistant from the coastlines.
If country A is flat and B has a mountain range and the border is at the foot of this mountain range which has a 30° slope, the border would be at a 15° slope inward from being perpendicular (to sea level) leaning in on A. [[Special:Contributions/141.101.77.144|141.101.77.144]] 04:51, 24 September 2021 (UTC)

Borders are usually vertical; what definition of "vertical", though? Some geodetic system? (Which one?) Local plumb line? Something else? [[User:Sabik|Sabik]] ([[User talk:Sabik|talk]]) 06:48, 24 September 2021 (UTC)

Just had the additional thought that this is probably creating additional borders, which will need more treaties. If the sloping border is quite shallow, there's a chance that the country on the left (with more airspace than ground) will now have an airborne border with whatever country is on the far side of the country on the right. And conversely for the mineral rights issue, the country on the right may now have an underground border with whatever country is on the far side of the one on the left. How does international law deal with a border treaty between two countries causing a non-signatory to have an extra border with one of them? Would those countries need to be consulted? --[[User:Angel|Angel]] ([[User talk:Angel|talk]]) 09:21, 24 September 2021 (UTC)

This kind of thing can happen with tunnels and bridges. For example, the border between the City of London (north of the river) and the Borough of Southwark (south of the river) runs right down the middle of the Thames as you might expect. But the whole of London Bridge belongs to the City. So if you happen to be on a boat underneath the bridge and on the southern half of the river, you're in Southwark; while a passenger on a bus crossing the bridge directly above you is in the City. So the border really must be sloped - and curved - and, as you trace the arches of the bridge, in some places horizontal. [[Special:Contributions/162.158.159.95|162.158.159.95]] 14:21, 24 September 2021 (UTC)

Note that the only data point we have is at ground level, and the knowledge that the border is at least somewhat vertically curved. For all we know, there may be specific plausible landmarks defining the border at different altitudes, and a from a long distance away, the border might appear to be essentially vertical.

If, say, planes define the border by the top of the mountain range, underground defines the border by the longest mines built by either country, and ground level is halfway up the mountain side, but angled to allow structural supports to be at a right angle to the slope.... And then you start defining curves to merge the various points into a uniform line plot..... This might almost make sense. And it probably returns to vertical once you get below the mines, or above the aircraft. [[Special:Contributions/172.69.90.15|172.69.90.15]] 15:35, 24 September 2021 (UTC)

The Earth is not a sphere. In general the local vertical does not go through the center of the Earth. I would expect international law to be based on the local vertical (easily measured since antiquity by plumb bob or similar) rather than the line though the Earth's center (requiring surveying precision not widely available till the late 20th century). Or perhaps international law just defines the Earth as flat.[[Special:Contributions/172.68.65.107|172.68.65.107]] 20:17, 24 September 2021 (UTC)
...it probably does, alongside Pi being 4. ;) [[Special:Contributions/172.70.42.129|172.70.42.129]] 13:15, 25 September 2021 (UTC)

2518: Lumpers and Splitters

2021-09-21T00:04:09Z

172.70.42.129: Added Anna Karenina basic explanation

{{comic
| number = 2518
| date = September 20, 2021
| title = Lumpers and Splitters
| image = lumpers_and_splitters.png
| titletext = Anna Karenina is a happy family lumper and unhappy family splitter.
}}

==Explanation==
{{incomplete|Created by a CATEGORIZATION META-PEDANT CHUNGUS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
It is common to categorize groups of people into certain categories. "Lumpers" lump what might at first seem to be distinct categories of people into the same categories, while "Splitters" do the opposite: split what seems to be a cohesive group of people into smaller categories. The comic itself categorizes [[Megan]] and [[Cueball]] into those two types of categorizers. [[Megan]] describes herself and [[Cueball]] as as both being categorization pedants, lumping the two distinct categories of people into one, while [[Cueball]] subcategorizes [[Megan]] into a specific type of lumper: a meta-lumper, since the people Megan was categorizing were themselves lumpers.

The opening line of the novel Anna Karenina by Leo Tolstoy reads, “ Happy families are all alike; every unhappy family is unhappy in its own way.” In the title text, Randall is drawing a parallel between this line and the lumper/splitter distinction because the line talks about a group of things being similar (happy families) and another group being different (unhappy families).

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Megan and Cueball are shown with labels below them saying "Lumper" and "Splitter", respectively]
:[Megan]: Really, we're both just categorization pedants.
:[Cueball]: Ahh, so you're a ''meta''-lumper.

:[Caption below frame:]
:Anna Karenina is a happy family lumper and unhappy family splitter.

{{comic discussion}}