explain xkcd - User contributions [en]

2841: Sign Combo

2023-10-14T10:09:27Z

Gpvos: you might stop just before the sign

{{comic
| number = 2841
| date = October 13, 2023
| title = Sign Combo
| image = sign_combo_2x.png
| imagesize = 322x334px
| noexpand = true
| titletext = Speed Limit: 45 MPH / Minimum: 65 MPH
}}

==Explanation==
{{incomplete|Created by a trapped driver - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic depicts a trio of road signs that provide legal instructions that are, in combination, impossible to follow: "Do not enter" precludes passing the point of the sign, the No-U-Turn sign precludes turning around, and the "No Stopping Any time" sign precludes halting before the sign. A driver approaching this sign combo would seemingly be forced to violate at least one of the three.
In addition, the lane divisions are plain until the signs, forbidding any preliminary measures.
However, the driver could technically put the car in reverse or slow down exponentially to comply with all three signs. They could also veer off the highway and drive perpendicular to it.

Depending on the jurisdiction, signs may only apply to the road ''after'' them, so you could validly stop just before it.

The title text mentions something similar: you cannot be slower than 45 MPH while being faster than 65 MPH, which is obviously also impossible.{{citation needed}}

For another of Randall's adventures in road signage (he does live in the Greater Boston area, after all), see [[1116: Traffic Lights]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A two-lane highway stretching out to the horizon, with the lanes separated by a double solid white line in the foreground which becomes a partially solid, partially dotted double white line as it approaches the horizon. To the right of the highway is a pole with three traffic signs.]
:[Top sign, featuring a white rectangle on a red circle on a white background:]
:DO NOT
:ENTER
:[Middle sign is the No U-Turn symbol, a U-turning arrow with the red prohibition circle symbol.]
:[Bottom sign with red text:]
:NO
:STOPPING
:ANY
:TIME

:[Caption below the panel:]
:Oh no.

{{comic discussion}}

[[Category:Comics with color]]

Talk:2841: Sign Combo

2023-10-14T10:02:03Z

Gpvos: reasons why stopping might be illegal

Theoretically you can get around this limitation by turning off the road before the sign and doing whatever maneuvers you need to out in the wide open area to the right or left of the road. It's not a U-turn if you're not on the road, and you didn't enter a restricted part of a road either, and didn't stop on the road. After which you calmly make a turn onto the road when traffic is clear. [[Special:Contributions/108.162.245.207|108.162.245.207]] 02:34, 14 October 2023 (UTC)
:I'm pretty sure swerving off of a road is also illegal. [[User:SteveTheNoob|SteveTheNoob]] ([[User talk:SteveTheNoob|talk]]) 04:41, 14 October 2023 (UTC)
:: You can always just pull over - if a cop asks, just tell him you were lost or tired or had to take a phone call. And then take the opportunity to ask about the bloody sign! Anonymous 07:30, 14 October 2023 (UTC)
So does making a three point turn count as a u-turn? [[Special:Contributions/172.69.58.66|172.69.58.66]] 02:40, 14 October 2023 (UTC)
Wouldn't putting it in reverse stop you briefly as you switched from forward acceleration to reverse?
:Yes, this is also an example of Rolle's theorem as seen in [[2042]]. [[User:SteveTheNoob|SteveTheNoob]] ([[User talk:SteveTheNoob|talk]]) 04:56, 14 October 2023 (UTC)

[https://en.wikipedia.org/wiki/Immelmann_turn Immelmann!] [https://en.wikipedia.org/wiki/Stall_turn Hammerhead!] [https://en.wikipedia.org/wiki/Cuban_eight Half Cuban Eight!] [[User:Jordan Brown|Jordan Brown]] ([[User talk:Jordan Brown|talk]]) 03:21, 14 October 2023 (UTC)

You could obey the title text if it was 45 miles per hour and 65 meters per hour, respectively. [[Special:Contributions/162.158.90.96|162.158.90.96]] 04:04, 14 October 2023 (UTC)

Take notice of the road markings too. At least here in Europe double white lines are not to be crossed. And they go past the point of the sign.--[[User:Henke37|Henke37]] ([[User talk:Henke37|talk]]) 07:06, 14 October 2023 (UTC)

:Double lines are also "do not cross" in America. And I think in this case it's supposed to be yellow, the dashed-and-solid combo indicates a one-sided passing zone into a lane with on-coming traffic, and double lines in general are only use to separate anti-parallel lanes of traffic, both of which use yellow. "Solid double white lines" do exist, but are only used in very specific cases. Near me, there's a very congested exit, and the solid double whites are used to indicate "no really, you should have switched lanes ages ago, it's too late now!", but since it isn't a Jersey barrier or a line of rods or even a full on median, nobody actually follows the rule. Anonymous 07:30, 14 October 2023 (UTC)

:: BTW in Europe, yellow lines are reserved for temporary use, and then take precedence over any existing white lines. Makes lots of sense, because there are so many construction sites here. (And the yellow lines are actually just adhesive tape.) --[[Special:Contributions/162.158.87.102|162.158.87.102]] 08:28, 14 October 2023 (UTC)

And I completely forgot why I was posting in the first place: I think there's good reason to create a full "traffic signs" or "road signs" tag, not just "traffic lights". I know there's a page with a very complicated "this is what the road ahead looks like" sign that just says "good luck", and of course there's "Next Five Miles" and "Ahead Stop". Thoughts? Anonymous 07:58, 14 October 2023 (UTC)

More thoughts: if you must not make a U-turn to the left, you should do it to the right.
And then return on the same lane, because of the double line.
And finally, the sign itself may be valid and not contradicting itself; it is your fault if you got on this road. ;) --[[Special:Contributions/162.158.87.102|162.158.87.102]] 08:28, 14 October 2023 (UTC)

In the Netherlands, the message on signs are only valid behind the sign (with the exception of the "precedence way" (voorrangsweg), where outside of built-up areas, the signs are after a junction (though technically... way before the ''next'' junction) , so a driver stopping /u-turning here wouldn't be violating anything except the double white lines.
Also, stopping out of necessity (e.g. the car in front is also stopped) is ''never'' illegal. [[User:IIVQ|IIVQ]] ([[User talk:IIVQ|talk]]) 09:06, 14 October 2023 (UTC)

:Stopping on a road with double white lines to your left may count as obstructing the road, which I can imagine to be illegal in many places? [[User:Gpvos|Gpvos]] ([[User talk:Gpvos|talk]]) 10:02, 14 October 2023 (UTC)

2254: JPEG2000

2020-01-14T11:23:06Z

Gpvos: also in pdf

{{comic
| number = 2254
| date = January 13, 2020
| title = JPEG2000
| image = jpeg2000.png
| titletext = I was actually a little relieved when I learned that JPEG2000 was used in the DCI digital cinema standard. I was feeling so bad for it!
}}

==Explanation==
{{incomplete|Created by a BADLY COMPRESSED IMAGE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
[[wikipedia:JPEG 2000|JPEG2000]] is a standard for digital image storage created by the Joint Photographic Experts Group from 1997 to 2000 to improve on the original JPEG standard, published in 1992. As of 2020, it is supported by Photoshop and the Safari browser, but it remains unsupported or poorly supported by other popular software, including Google Chrome and Mozilla Firefox browsers, as well as the GIMP (a free and open source image editor).
The conventional file name extensions for files using the JPEG2000 standard, .jp2 and .jpx, remain unfamiliar to many users for whom the .jpg extension, denoting the original standard, is well known.
The JPEG2000 standard was seen an improvement by its creators, supporting many features not included in the original standard, such as multiple resolutions, progressive transmission, a lossless compression option, and alpha channel transparency. The complexity of fully implementing the standard, as well as patent concerns, may have slowed adoption.

The people in the comic seem to have some desire for JPEG2000 adoption, and may have been involved in its creation, and seem to care more about its eventual use than rapid adoption.

The core concept of this comic is that engineers often expect that a superior technology or standard will catch on, though often other factors keep an "inferior" standard dominant. (See various comics referencing [[:Category:Dvorak|Dvorak]] keyboards, as well as the term "[https://whatis.techtarget.com/definition/betamaxed betamaxed].")
The "we are in this for the long haul" statement might refer to the engineers believing that superior technology will eventually win despite the evidence to the contrary. Its humor comes from the fact that as of the comic publication in 2020, JPEG2000 shows no sign of becoming a widely-used standard.

The title text suggests that Randall feels bad that the standard hasn't been adopted, perhaps because he empathizes with the engineers who worked hard to develop it or anthropomorphizes the standard itself, which has been ignored by most of the computer-using world. DCI, short for {{w|Digital Cinema Initiatives}}, is a collaboration of several major film studios to establish standards for the security and proper display of digital films.

==Transcript==
:[Cueball and Hairbun are both at a table, facing each other, both working on their own respective computers.]

:[Cueball leans back and stops typing. Hairbun continues to type.]

:[Cueball looks over at Hairbun.]
:Cueball: I'm starting to worry that JPEG 2000 isn't catching on as fast as we expected.
:Hairbun: Don't worry! We're in this for the long haul.

==Trivia==
* Cueball's keyboard seems to have inexplicably disappeared in the last panel.
* A JPEG2000 version of the image file is available here: https://imgs.xkcd.com/comics/jpeg2000.jp2 . It is only 20% smaller than the PNG version, and has visible compression artifacts.
* JPEG2000 is also supported as an image compression method in PDF.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Hairbun]]
[[Category:Computers]]

1470: Kix

2019-07-21T10:28:56Z

Gpvos: well known in US (not necessarily elsewhere)

{{comic
| number = 1470
| date = January 7, 2015
| title = Kix
| image = kix.png
| titletext = My parents sent me to several years of intensive Kix test prep.
}}

==Explanation==
This comic may be a commentary about the uselessness of brainstorming sessions or the bad ideas that come out of them, as they are often started with the phrase “there are no bad ideas”. As the brainstorming session continues the original meaning of the slogan is lost, much like a game of telephone, and the session becomes less productive.

{{w|Kix (cereal)|Kix}} is an American brand of cold breakfast cereal made of extruded and expanded cornmeal. Its slogan, "Kid tested, Mother approved," is well known in the United States, and is meant to suggest that children generally enjoy the cereal and their mothers, who are naturally concerned about the health of their children, approve of its ingredients. However, in this brainstorming session, the word "Approved" has apparently not yet been considered. A number of possible words and phrases for the ending have been presented and {{w|Strikethrough|stricken out}}, indicating that they were rejected; each one causes the slogan to be subject to increasingly absurd and comedic interpretations:

#'''Selected''': This word may have been chosen as a {{w|slant rhyme}} of "Tested". This word shares a definition with "Approved", and states that mothers specifically choose this cereal over others. This phrase could also suggest that one mother ''herself'' had been chosen for some unstated purpose.
#'''Perfected''': It's likely that the previous word inspired someone in the brainstorming session to find a similarly positive word that rhymes with "Selected". It states that one or more mothers were directly involved in developing and refining the cereal's composition to a high degree. Much like with "Selected", this could also suggest that the mother was somehow improved to perfection during the test.
#'''Not Notified''': Relates to the world of experimental research and clinical trials. This phrase suggests that the children who tested the cereal did not obtain the required consent, which would generally involve notifying and getting permission from both parents.
#'''Watching Helplessly''': Again we can see that in a brainstorming session such the previous option may trigger this one as it is related to the dangers of testing. This phrase suggests that mothers were forced to watch their children test the cereal, and that the cereal or the test is unhealthy or dangerous.
#'''Infected''': This may be intended to show the group dynamic of the brainstorming session as it is inspired by option one and two, as infected rhymes with both selected and perfected, and by the third option as both relate to dangerous testing. This slogan states that an infectious agent was passed to the mother as a result of the test. This could also be interpreted as the mother having introduced the infectious agent into the cereal or testing environment.
# '''Consumed''': Continuing the trend of dark slogans this slogan says that the mothers were ''themselves'' consumed, perhaps by their children (by virtue of the mother being an ingredient in the cereal), the cereal itself, or something otherwise related to the test. Another possible interpretation is that the mother ate the cereal after the kid tested it, possibly because the kid did not enjoy the taste.
#'''Fucker''': This expletive is often paired with "Mother" to form the compound word "Motherfucker". In this case, the slogan changes to {{w|vocative case}}: "[This cereal has been] Kid Tested, Motherfucker!". This appears to be an "elephant" - a ponderous ending of a joke that contrasts sharply with the refined and mild humor of the previous options. The phrase itself basically only states that a child tested the cereal and implies that nothing else matters.

The title text conflates the phrase "Kid tested" with college entrance exams such as the {{w|Standardized Aptitude Test}} (SAT) or the {{w|ACT (test)|ACT}}. Instead of stating that a child tasted the cereal and gave his or her opinion on its quality, the cereal itself is an academic subject on which the child was tested. Randall, referring to how some parents enroll their children in special {{w|test prep|classes or schools}} to prepare them to score well in this type of test, states that his parents extensively prepared him for a college entrance exam about Kix cereal.

Cereal advertising has previously been referenced in [[38: Apple Jacks ]].

==Transcript==
:[Ponytail, Megan, and Cueball are standing around a whiteboard, holding markers. The whiteboard on easel reads:]
:[in Large] '''Kix'''
:[Underlined] Slogan ideas
:Kid Tested, Mother...

[following lines all in red and each crossed out]
:Selected
:Perfected
:Not notified
:Watching helplessly
:Infected
:Consumed
:Fucker

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Food]]

1470: Kix

2019-07-21T10:21:48Z

Gpvos: /* Explanation */ just explain what Kix is up front

{{comic
| number = 1470
| date = January 7, 2015
| title = Kix
| image = kix.png
| titletext = My parents sent me to several years of intensive Kix test prep.
}}

==Explanation==
This comic may be a commentary about the uselessness of brainstorming sessions or the bad ideas that come out of them, as they are often started with the phrase “there are no bad ideas”. As the brainstorming session continues the original meaning of the slogan is lost, much like a game of telephone, and the session becomes less productive.

{{w|Kix (cereal)|Kix}} is an American brand of cold breakfast cereal made of extruded and expanded cornmeal. Its slogan, "Kid tested, Mother approved," is meant to suggest that children generally enjoy the cereal and their mothers, who are naturally concerned about the health of their children, approve of its ingredients. However, in this brainstorming session, the word "Approved" has apparently not yet been considered. A number of possible words and phrases for the ending have been presented and {{w|Strikethrough|stricken out}}, indicating that they were rejected; each one causes the slogan to be subject to increasingly absurd and comedic interpretations:

#'''Selected''': This word may have been chosen as a {{w|slant rhyme}} of "Tested". This word shares a definition with "Approved", and states that mothers specifically choose this cereal over others. This phrase could also suggest that one mother ''herself'' had been chosen for some unstated purpose.
#'''Perfected''': It's likely that the previous word inspired someone in the brainstorming session to find a similarly positive word that rhymes with "Selected". It states that one or more mothers were directly involved in developing and refining the cereal's composition to a high degree. Much like with "Selected", this could also suggest that the mother was somehow improved to perfection during the test.
#'''Not Notified''': Relates to the world of experimental research and clinical trials. This phrase suggests that the children who tested the cereal did not obtain the required consent, which would generally involve notifying and getting permission from both parents.
#'''Watching Helplessly''': Again we can see that in a brainstorming session such the previous option may trigger this one as it is related to the dangers of testing. This phrase suggests that mothers were forced to watch their children test the cereal, and that the cereal or the test is unhealthy or dangerous.
#'''Infected''': This may be intended to show the group dynamic of the brainstorming session as it is inspired by option one and two, as infected rhymes with both selected and perfected, and by the third option as both relate to dangerous testing. This slogan states that an infectious agent was passed to the mother as a result of the test. This could also be interpreted as the mother having introduced the infectious agent into the cereal or testing environment.
# '''Consumed''': Continuing the trend of dark slogans this slogan says that the mothers were ''themselves'' consumed, perhaps by their children (by virtue of the mother being an ingredient in the cereal), the cereal itself, or something otherwise related to the test. Another possible interpretation is that the mother ate the cereal after the kid tested it, possibly because the kid did not enjoy the taste.
#'''Fucker''': This expletive is often paired with "Mother" to form the compound word "Motherfucker". In this case, the slogan changes to {{w|vocative case}}: "[This cereal has been] Kid Tested, Motherfucker!". This appears to be an "elephant" - a ponderous ending of a joke that contrasts sharply with the refined and mild humor of the previous options. The phrase itself basically only states that a child tested the cereal and implies that nothing else matters.

The title text conflates the phrase "Kid tested" with college entrance exams such as the {{w|Standardized Aptitude Test}} (SAT) or the {{w|ACT (test)|ACT}}. Instead of stating that a child tasted the cereal and gave his or her opinion on its quality, the cereal itself is an academic subject on which the child was tested. Randall, referring to how some parents enroll their children in special {{w|test prep|classes or schools}} to prepare them to score well in this type of test, states that his parents extensively prepared him for a college entrance exam about Kix cereal.

Cereal advertising has previously been referenced in [[38: Apple Jacks ]].

==Transcript==
:[Ponytail, Megan, and Cueball are standing around a whiteboard, holding markers. The whiteboard on easel reads:]
:[in Large] '''Kix'''
:[Underlined] Slogan ideas
:Kid Tested, Mother...

[following lines all in red and each crossed out]
:Selected
:Perfected
:Not notified
:Watching helplessly
:Infected
:Consumed
:Fucker

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Food]]