explain xkcd - User contributions [en]

Talk:2956: Number Line Branch

2024-07-08T23:30:43Z

141.101.105.47:

Is it significant that the branch point is close to the value of π? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:28, 8 July 2024 (UTC)
:I was thinking the same thing, but decided it was probably nothing worth mentioning - probably just an arbitrary starting point. *Possibly* referencing the strange appearance of π but I doubt it. Anything can be significant if you believe hard enough, anyway.--[[Special:Contributions/162.158.158.60|162.158.158.60]] 20:30, 8 July 2024 (UTC)
How does adding a new branch to a railway line reduce congestion? Isn't this more like a highway? [[Special:Contributions/141.101.105.47|141.101.105.47]] 23:30, 8 July 2024 (UTC)

1897: Self Driving

2022-01-06T15:09:55Z

141.101.105.47:

{{comic
| number = 1897
| date = October 2, 2017
| title = Self Driving
| image = self_driving.png
| titletext = "Crowdsourced steering" doesn't sound quite as appealing as "self driving."
}}

==Explanation==
This comic references the approach of using {{w|CAPTCHA}} inputs to solve problems, particularly those involving image classification, which are not solvable by computers, specifically {{w|reCAPTCHA}} v2's fallback puzzle, and hCaptcha's puzzle, both of which are based on identifying road features and vehicles. A reCAPTCHA version of this puzzle would ask "check all squares containing a STOP SIGN" using one or more images derived from {{w|Google Street View}}.

Such an approach can serve to create the learning set as the basis for training an {{w|artificial intelligence}} (AI) to better recognize or respond to similar stimuli. This approach was used by Google, the owners of reCAPTCHA, to identify house numbers in Street View to improve their mapping, and nowadays Google also uses CAPTCHAs to identify vehicles, street signs and other objects in Street View pictures. This might be a reasonable way to help improve the performance of the AI in a self-driving car that responds to video input, by reviewing images it might encounter and flagging road signs, etc. that it should respond to. Later a similar approach to learning important things, for the robots, was used in [[2228: Machine Learning Captcha]].

However, the temptation might be to simply sidestep the hard problem of AI by having all instances 'solved' by "offloading [the] work onto random strangers" through CAPTCHAs. For example, this has been used to defeat CAPTCHAs themselves; people were asked to solve CAPTCHAs to unlock pornographic images in a computer game, while the solution for the CAPTCHA was relayed to a server belonging to cybercriminals. (See [http://news.bbc.co.uk/2/hi/technology/7067962.stm PC stripper helps spam to spread] and [https://doi.org/10.1016/S1353-4858(08)70036-9 Humans + porn = solved CAPTCHA]).

Alarmingly, the developers of this '{{w|Self-driving car|self driving}}' car seem to have gone for the lazy approach. Instead of teaching an AI, the CAPTCHA answer is used in real time to check whether the "self-driving" car is about to arrive at an intersection with a stop sign. This information is pretty critical, as failing to mark the stop could cause an accident. The user is unlikely to respond to the CAPTCHA in time to avert disaster, not to mention that any interruption to the car's internet connection could prove fatal. [[:Category:Self-driving cars|Self driving cars]] have become a recurrent theme on xkcd.

The system depicted is a {{w|Wizard of Oz experiment}} (as is the "Mechanical Turk" which a popular crowdworking system is named after) whereas actual self-driving cars, to the extent that they can use reCAPTCHA-style human detection systems, would involve an asynchronous decision system. Other synchronous decision systems which actually exist are political voting and money as a token of the exchange value of trade.

The title text explains that this method could be called "crowdsourced steering", {{w|crowdsourcing}} meaning sending the data on the internet to let several users provide their ideas and input on a problem. People would naturally suspect that this is considerably less safe than a car which is actually capable of self-driving; if the internet can barely [[1333: First Date|collectively steer a videogame character]], what chance do they have steering an actual, physical vehicle?

This also suggests that [[Randall]] is a bit skeptical of the current stage of AI, as this doubts whether the AI technology really is working in the way that we expect. It also comments on how what we call 'progress' actually is putting our work onto other people.

==Transcript==
:[Inside a frame there is the following text above an image:]
:To complete your registration, please tell us whether or not this image contains a stop sign:

:[The square image is a drawing of a road leading up to a sign post with a hard to read word at the top part of the eight-sided sign. The sign also has two smaller signs left and right with unreadable text. The image is of poor quality, but trees and other obstacles next to the road can be seen. Darkness around the edges of the image could indicate that it is night and the landscape is only lit up by a cars head lights.]
:Sign: Stop

:[Beneath the image there are two large gray buttons with a word in each:]
:No Yes

:[Beneath the buttons are the following text:]
:Answer quickly – our self-driving car is almost at the intersection.

:[Caption beneath the frame:]
:So much of "AI" is just figuring out way to offload work onto random strangers.

{{comic discussion}}

[[Category:Self-driving cars]]
[[Category:Artificial Intelligence]]
[[Category:CAPTCHA]]

2529: Unsolved Math Problems

2021-10-22T20:25:20Z

141.101.105.47:

{{comic
| number = 2529
| date = October 15, 2021
| title = Unsolved Math Problems
| image = unsolved_math_problems.png
| titletext = After decades of studying the curve and the procedure that generates it, the consensus explanation is "it's just like that."
}}

==Explanation==
{{incomplete|Created by a EULER FIELD GÖDEL-ESCHER-KURT-HALSEY STRANGE "CURVE" WALKING RANDOMLY ON A HYPERDIMENSIONAL FOUR-SIDED QUANTUM KLEIN MANIFOLD. Do NOT delete this tag too soon.}}

Math has many problems that remain "unsolved." This is not simply a matter of finding the correct numbers on both sides of an equal sign, but usually require proving or finding a counterexample to some conjecture, or explaining some property of some mathematical object. Sometimes this might involve extending an existing proof to a wider range of numbers like reals, complex numbers, or matrices.

A concrete problem is one that is very obviously connected to a real world process, while an abstract problem is one which seems unconnected to actual problems. In modern math, many problems tend to be very abstract, requiring complicated notation to adequately state the problem in the first place, like many of the {{w|millennium problems}}. On the other hand, many unsolved problems are very concrete; for example, there are very many problems related to packing objects into spaces that are very difficult to solve although quite easy to state, such as the {{w|Collatz conjecture}}. Finally, Randall describes a third category of "cursed problems," that have strange, seemingly random behavior, such as the behavior of turbulence or the distribution of prime numbers.

In the first panel, Ponytail describes a weird abstract problem. Her description seems to be a meaningless jumble of terms that are either mathematical or just ''sound'' mathematical. And the mathematical terms are from disparate branches of mathematics: group theory, topology, and calculus.

*'''Euler field:'''
*'''{{w|Manifold}}:'''
*'''{{w|Hypergroup}}:'''
*'''Isomorphic:''' {{w|Isomorphism}} describes whether all the attributes of one structure can be mapped to properties of another structure. The structures usually have to be of the same type; it is unclear how a hypergroup would map to a "conjection".
*'''Gödel-Klein:''' {{w|Kurt Gödel}} was a 20th-century mathematician who studied logic and philosophy (he's most well known for {{w|Gödel's incompleteness theorems}}) and {{w|Felix Klein}} was a 19th century mathematician who studied group theory and geometry; the two probably never collaborated.
*'''Meta-algebra:'''
*'''ϵ<0:''' a joke about how in analysis, {{w|ϵ}} is usually defined to be an arbitrarily small ''positive'' number.
*'''quasimonoid:''' A [[Malamanteau|malamanteau]], combining the prefix "quasi" (meaning "partially" or "seemingly") and "monoid" (an object from group theory) and is probably meant to evoke the character {{w|Quasimodo}} from ''The Hunchback of Notre-Dame'' (although quasimonoids are a type of algebraic object, namely a non-associative {{w|monoid}})
*'''Sondheim Calculus:''' This refers to {{w|Stephen Sondheim}}, one of the most successful composers and lyricists of American musical theatre -- the producer of his musical "Into the Woods" once [https://www.indiewire.com/2015/01/watch-singing-sondheim-is-like-calculus-in-into-the-woods-behind-the-scenes-video-exclusive-189507/ remarked] that "Singing Stephen Sondheim is like calculus for singers and actors."
*'''conjection:''' This may combine conjecture and conjunction, or be a joke on pros and cons plus projection.

Finally she asks whether the problem statement is ill-formed; considering that it's mostly gibberish, this may be true.

Many real unsolved math problems appear similarly abstract. One example is the {{w|Hodge conjecture}}, a {{w|Millennium Prize Problems|Millennium Prize}} problem. It states "Let X be a non-singular complex projective manifold. Then every Hodge class on X is a linear combination with rational coefficients of the cohomology classes of complex subvarieties of X." These words may appear nonsensical to a layperson. And even to an expert, the question is `abstract'. (Given a specific manifold, even an abelian fourfold, how on earth do you determine if a given 2,2 class is a cycle?)

In the second panel, Cueball describes a concrete {{w|random walk}} problem, and then mentions that this somehow has applications in three unrelated fields. This is actually not uncommon. The Wikipedia article says that "random walks have applications to engineering and many scientific fields including ecology, psychology, computer science, physics, chemistry, biology, economics, and sociology. Walking randomly on a grid never visiting any square twice is known as a {{w|self-avoiding walk}}." This panel may have been inspired by some of the tricky unsolved problems about self-avoiding walks. Many of these problems have to do with rigorously proving properties of random walks that have been guessed by physics intuition, so these problems are connected to physics. The part about the maximum number of points in a line is reminiscent of problems in combinatorial geometry, which often involve counting points lying on different lines. Python code simulating this situation can be found here: [https://colab.research.google.com/drive/1nWrByCGBckwVdbAwow7tCYTOvqObYXyR?usp=sharing].

In the final panel, Megan is looking at a strange curve that seems to have no consistent pattern. At the bottom it's mostly straight, with a few little wobbles. In the middle it looks like a wild, high-frequency wave that suddenly bursts and then dies down. And the top is a spiral that looks like a question mark or a Western-style {{w|Crosier}}. She wonders if this could even be mathematical.
On one hand, considering the weird shapes that come from plotting some mathematical processes (e.g. the {{w|Mandelbrot set}}), it could well be. For example the unsolved {{w|Riemann hypothesis}}, another Millennium Prize problem, concerns the properties of {{w|File:RiemannCriticalLine.svg|a weird and at-first-glance random curve}}. In number theory, the term "cursed curve" [https://www.quantamagazine.org/mathematicians-crack-the-cursed-curve-20171207/ has been used] to describe the [https://annals.math.princeton.edu/wp-content/uploads/annals-v173-n1-p13-s.pdf "split Cartan" modular curve] of level 13, which resisted attempts for many years to compute its [https://www.jstor.org/stable/10.4007/annals.2019.189.3.6 set of rational points].
On the other hand, the question if could even be mathematical suggests that this may indeed not be a mathematical symbol. The curve looks like the unalome symbol, which is a Buddhist symbol which represents the path taken in life, or the journey to enlightenment. It could be argued that thi indeed represents an unsolved problem, although not a mathematical one - which might then be part of the humoristic meaning.

In the title text, the curve in the final panel is further explained based on the consensus of supposedly a group who has studied it and the procedure that generates it, commenting that "it's just like that" as their conclusion, which is really not an explanation at all.

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

The Three Types Of Unsolved Math Problem

:First: Weirdly Abstract
:[Ponytail stands in front of an equation]
:Is the Euler Field Manifold Hypergroup Isomorphic to a Gödel-Klein Meta-Algebreic ε<0 Quasimonoid Conjection under Sondheim Calculus?
:Or is the question ill-formed?
:⬙ℝंℤ/Eℵ₅ The Z is raised and underneath it is a double-ended arrow bent at a right angle. One points toward the R the other toward the Z. The ₅ is double-struck (𝟝) like the ℝ and ℤ

:Second: Weirdly Concrete
:[Cueball stands in front of a grid with 6 columns and 7 rows]
:If I walk randomly on a grid, never visiting any square twice, placing a marble every ''N'' steps, on average how many marbles will be in the longest line after N*K steps?
:Somehow the answer is important in like three unrelated fields.
:[The path starts in the 3rd row and 3rd column, a small circle indicates the start. It takes the path: North, East, North, East (a black dot representing the 1st marble is placed here, so N=4), South, East, South, South (2nd marble), West, South, West, North (3rd marble), West, South, South, South (4th Marble), West, North, West, West (this goes offgrid to the West. There is no visible line or marble outside the grid). The 1st, 3rd, and 4th marbles are colinear and there is a dotted line connecting them. The line's slope is 3.]

:Third: Cursed
:[A Megan with unkempt hair stands next to a curve]
:What in God's name is going on with this curve?
:Is it even math?
:[The curve starts at the bottom of the screen, rises straight upward, begins to wobble left and right a little. It lists to the left and the left-right motion increases, then decreases. It begins a large counter-clockwise arc, spiraling inwards twice, then ends]

{{comic discussion}}
[[Category: Comics featuring Cueball]]
[[Category: Comics featuring Megan]]
[[Category: Comics featuring Ponytail]]
[[Category: Math]]

Talk:2531: Dark Arts

2021-10-22T17:34:00Z

141.101.105.47: Added a comment

Whoo, my first "first explanation". It's not a particularly thorny comic but my explanation could still use some judicious editing I'm sure. [[User:Esogalt|Esogalt]] ([[User talk:Esogalt|talk]]) 06:51, 21 October 2021 (UTC)

I added a "citation needed" to the claim that letting arbitrary websites modify your filesystem is a Bad Idea, because I couldn't resist >.<
[[Special:Contributions/172.68.132.74|172.68.132.74]] 08:40, 21 October 2021 (UTC)
:{{citation needed}} [[Special:Contributions/162.158.88.113|162.158.88.113]] 10:45, 21 October 2021 (UTC)

The previous comment is almost worth an XKCD comic of its own. --[[Special:Contributions/162.158.203.24|162.158.203.24]] 10:10, 21 October 2021 (UTC)

WTH did Randal do that lead him to put ext4 and javascript in the same search, and why does he think hardlinks are the problem with such a cursed search? [[Special:Contributions/172.69.69.182|172.69.69.182]] 10:17, 21 October 2021 (UTC)

Which specific IT professional is the explanation referring to? [[Special:Contributions/141.101.105.35|141.101.105.35]] 12:40, 21 October 2021 (UTC)

: None in particular, just in general. [[Special:Contributions/172.69.90.11|172.69.90.11]] 14:01, 21 October 2021 (UTC)

: It's an expression. It's essentially the same as saying "An'''y''' experienced IT professional", but a little more stylistic. That whole sentence seems slightly gatekeeper-ish to me anyway. [[User:Esogalt|Esogalt]] ([[User talk:Esogalt|talk]]) 13:51, 21 October 2021 (UTC)

As an added wrinkle, the alt text's search is cursed because there is [https://en.wikipedia.org/wiki/Ext_JS a javascript framework] completely unrelated to the ext filesystem that is ''also'' called ext, which had a version 4 and would thus muddy the waters of the search.
-- [[Special:Contributions/172.70.178.51|172.70.178.51]] 13:15, 21 October 2021 (UTC)

: Explanation should include why the alt text's search is "cursed." Seems like this comment hints at it, but I don't know enough about the topic to know if that is the full curse. [[Special:Contributions/162.158.107.234|162.158.107.234]] 17:22, 21 October 2021 (UTC)

:: It's mentioned in the paragraph about Javascript, because I saw the cursedness coming mainly from the combination of JS (high level) with ext4 (low level). It could probably be explained more directly and in more depth though. [[User:Esogalt|Esogalt]] ([[User talk:Esogalt|talk]]) 17:41, 21 October 2021 (UTC)

XKCD and its weirdly fitting timing in relation to my life again… Just 4 hours earlier, I had dealt with hardlinks in a Bash script and produced things like <code>cd "$(readlink -f "$(pwd)")"</code>. [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 13:53, 21 October 2021 (UTC)

I believe that Microsoft's implementation of '''OneDrive is cursed''' by evil intention. The intention (and default behavior) is to keep the actual file contents in the cloud with nothing but a reference on the machine in my control. The presumed benefit is that it is easy to have the files available on any machine the user logs into ... because they aren't really on the machine at all. Other perceived benefit is it saves space on the local machine. The evil consequence is that files are unavailable when the machine is offline. My opinion is that most users almost never need their OneDrive files on anything but their primary machine, and would be pretty sore if the files in the cloud got wiped out with no backup on their primary machine. I presume that most people view the files on their machine as primary and view the cloud copies as their backup. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 22:23, 21 October 2021 (UTC)
: And don't forget that Microsoft will definitely search through the stuff you stored on OneDrive. You may find out that something you stored was declared dangerous by them and deleted ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 02:36, 22 October 2021 (UTC)

I don't think there is anything dark or problematic on most stuff mentioned in the article. And they generally work without problems on Linux. On the other hand, in most of movies where hero says something like this I think he's chicken-hearted coward and the mentioned dark arts is cool think I would like to know. So, maybe I'm just already on dark side. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 02:36, 22 October 2021 (UTC)

File Systems! GRRRR!! File Systems Management was the class that kept me from getting a 4.0 GPA while getting my degree in Computer Science. Oh well, I was probably doing only C work, so I was happy to get the B. That was a long time ago, and I wound up not doing anything at all involved with programming or anything else related to Computer Science.... [[Special:Contributions/172.70.130.87|172.70.130.87]] 11:09, 22 October 2021 (UTC)

I use game mod managers that use hard links frequently. Never had a problem with those, but as that is below-the-hood, it might not count. My problems with partition tables as a dual booter, including cloning, boot records etc, have been far worse.
[[Special:Contributions/141.101.105.47|141.101.105.47]] 17:34, 22 October 2021 (UTC)
== Cursed ==

I've thought this before (not sure if I ever wrote it anywhere, perhaps I did in the now long-deceased fora), but given the reappearance of 'cursed'ness in fairly recent comics, there maybe should be a Cursed category (of which [[:Category:Cursed Connectors]], recently created for a close run of four items, would obviously be a subset, if not members in their own right). Cursedicity seems to be a recurring Munroe meme (I counted more than a dozen distinct examples from a quick search), so consider this a suggestion. For all things mentioned/depicted/contemplated as cursed. [[Special:Contributions/141.101.98.199|141.101.98.199]] 19:16, 21 October 2021 (UTC)

== Examples ==

Are there some examples to give of characters with great powers that they don't use because reasons? Perhaps a TV Tropes page or three in this area? I actually wondered if the dialogue in this xkcd was mostly a direct quote from something.
Start with these maybe. But I'm hoping that someone recognises a scene.
https://tvtropes.org/pmwiki/pmwiki.php/Main/RetiredBadass
https://tvtropes.org/pmwiki/pmwiki.php/Main/DangerousForbiddenTechnique

The first found from "Obi-Wan Kenobi", who appears to be a crazy hermit although later it's established that he lives on Tatooine specifically to protect Luke Skywalker, secretly. The second, found from the first. But halfway down "Dangerous techniques", I haven't found an example that precisely fits this comic. I did skip the "anime and manga" entries, which are said to be many. Oh, wait: under Literature, "Babylon 5" (spin off books evidently) mentions a telepath interrogating someone by mind reading when they are dying or brain dead. That is unhealthy, and actually does correspond to some scenarios of struggling with data filesystems: rescuing data from a dead disk. [[Special:Contributions/141.101.107.43|141.101.107.43]] 11:29, 22 October 2021 (UTC) Robert Carnegie rja.carnegie@gmail.com
:Non-mystical examples I thought of were CPO Ryback (Under Siege, though not so much regretting past expertise as intending to settle back into 'normal' trivial service until forced) or John Rambo (First Blood, pushed too far by an unlucky sadist ignorant of the nature of the dragon he was poking at). For "You're messing with forces you do jot understand" I was thinking more Indianna Jones (having witnessed, and expected shortly in advance, the Nazis' and collaborator's demise, he would have been concerned about the safety of Top Men if he believed there were any).
:I haven't yet gone to the TVTs site links, as that way lies similar dangers</inMyPortentousVoice!> that I'm reluctant to reawaken, but arcane and ancient knowledge is always ripe for meddling with by an upstart, with elderly mentors who are the (surviving) past-meddlers generally being the voice of caution (rightly or wrongly, according to how the plot should twist - depends if the Upstart is the One Who Was Prophecised But Nobody Knows It, or not) and perhaps even the (ultimately ineffective?) Guardian Of The Thing whether that's a ring or tome or a mystical stone. [[Special:Contributions/141.101.107.29|141.101.107.29]] 15:02, 22 October 2021 (UTC)

== Relatable comic ==
This is actually how I feel whenever someone asks for help dealing with proprietary software or hardware. Remote functionality that could be local, service which supplants intrinsic functionality, wireless for devices that don't wander (looking at you, bike shifters), trust in place of secure practice, gimmicks used to distract from downgraded end-user agency, downgrades pushed as security\simplification, these are things that drove me away from modern computing, 'smart'phones, automobiles, & other mass-market junk of today. The whole market of consumer goods & services is full of bad practices, & bad practices are contagious. Now when someone asks me "do you work with computers" I shake my head & toss up my hands & say "I try not to." <nowiki>
</nowiki>[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 14:26, 22 October 2021 (UTC)

347: Brick Archway

2021-10-21T12:47:40Z

141.101.105.47: /* Explanation */ added {{citation needed}}

{{comic
| number = 347
| date = November 21, 2007
| title = Brick Archway
| image = brick_archway.png
| titletext = The TI-86 was bad enough. I don't know how I'd have gotten through high school if I'd had a laptop+wifi.
}}

==Explanation==
''{{w|Breakout (video game)|Breakout}}'' is a video game first created in 1976, and since then it has gained much popularity and has been recreated in many different versions. In the game, the player controls a horizontal 'bat' at the bottom of the screen to make it move left or right. Above it are several layers of bricks that are destroyed when hit by the ball. The ball is not affected by gravity and will float around, bouncing off the walls, bricks, and the bat. The aim of the game is to keep the ball from touching the bottom of the screen (by deflecting it with the bat) long enough for the ball to hit and destroy all of the bricks.

[[Cueball]]'s approach to the game is to actually stand underneath a brick archway and throw a tennis ball at the structure above him in an attempt to destroy the bricks. Naturally, the physics in the game don't work in real life,{{citation needed}} and the aftermath of Cueball's actions is that one of the bricks in the archway comes loose and falls onto Cueball's head, causing possibly fatal damage.

The sentence at the bottom of the comic points out the illogical nature of the game when compared to real life.

The title text relates to a {{w|TI-86|programmable calculator}} from the late 1990s that could have a ''Breakout''-like game easily programmed into. This calculator, and others like it, were a requirement in many high school advanced math classes in the United States after the early 1990s, despite costing over $100. [[Randall]] speculates that, given the amount of distraction this simple game provided him back then, he would not be able to focus on study at all with modern technical instruments like {{w|Laptop|laptops}} using {{w|Wi-Fi|wireless LANs}}.

==Transcript==
:[An inset panel to the left shows Cueball getting ready to throw a tennis ball upward.]
:[Cueball lies on the ground, underneath the titular brick archway, next to two halves of a brick. A pool of blood is coming from his head. Dust falls from the place in the archway where the he knocked the brick from with the tennis ball. The ball, meanwhile, has rolled about a meter away.]
:"Breakout" is a stupid game.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Video games]]
[[Category:Comics with color]]
[[Category:Comics with blood]]