explain xkcd - User contributions [en]

2885: Spelling

2024-01-24T15:04:04Z

172.70.162.223: /* Explanation */

{{comic
| number = 2885
| date = January 24, 2024
| title = Spelling
| image = spelling_2x.png
| imagesize = 281x333px
| noexpand = true
| titletext = Any time I misspell a word it's just because I have too much integrity to copy answers from the dictionary.
}}

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

Some words are difficult to remember how to spel, but Google and other search engines have autocorrect for misspelled words in search terms, which will return results with the correct spelling, so some people enter their best guess of the spelling on Google, then copy the corrected version and paste it into their document.

Cueball is having a moral dilemma about whether it is okay to do that for the word 'plagiarism' (taking other's work without permission or credits) because he thinks that doing so would be plagiarism, and perhaps undermine the point he might be intending to make (e.g. "I don't support plagiarism", "I have never committed plagiarism in my life" or even "To steal ideas from one person is plagiarism; to steal from many is research."). This doesn't really make sense as a specific dilemna. If it's wrong to do this for this word, it would be equally wrong to do it for any other word - the meaning of the word in question has no particular relevance to the ethics of the case.

The title text is referring to a similar moral dilemma, in which Cueball says he tends to misspell words because he would rather not "copy from the dictionary," considering that plagiarism. This is against the point of the dictionary, however, which is to serve as a reference precisely for people to look up what words are in the language, how they are spelled, defined, derived, and so on. The individual words being defined in the dictionary, by definition, cannot actually be the copyrighted intellectual property of a specific person, since they represent words already in use, rather than original work. Thus it wouldn't actually be plagiarism to copy the correct spelling from there. Only if you were to copy the accompanying entry without attribution would there be ethical and legal issues. But if one was really paranoid about avoiding plagiarism, one could always quote the source of each word they copied out of the dictionary, listing which dictionary they copied the word or words out of.

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

[Cueball and Megan are looking at a laptop being operated by Cueball]

Megan: When I can't spell a word I usually just google and copy and paste it from the results.

Cueball: Yeah, but I can't do that '''HERE!!'''

[Caption below the panel:]
Why spelling "plagiarism" is especially hard
{{comic discussion}}

2813: What To Do

2023-09-01T10:29:09Z

172.70.162.223: /* Explanation */ Bad style, and unnecessary, to abbreviate 'and' to '&' in formal writing.

{{comic
| number = 2813
| date = August 9, 2023
| title = What To Do
| image = what_to_do_2x.png
| imagesize = 740x723px
| noexpand = true
| titletext = FYI: The 'drop, cover, and hold on' advice only applies to earthquakes. If you encounter a mountain lion, you should absolutely not drop to the ground, crawl under it, and hold on to one of its legs.
}}

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

Similar to [[1890: What to Bring]], this comic takes four unrelated dangerous situations (mountain lion sighting, nearby lightning, fire alarm, and bleeding), and tries to mix-and-match the solutions. Predictably, mixing up good advice leads to fairly nonsensical behavior, so only the original four matches are marked green as acceptable.

The title-text introduces another disaster, an earthquake, into the mix-and-match. A common safety precaution during an earthquake is to [https://www.shakeout.org/dropcoverholdon/ drop, cover, and hold on], which helps prevent you from being thrown about and/or hit by debris. However, attempting to "drop, cover, and hold on" in response to a mountain lion sighting is more likely to get you into danger than out of it.

;Advice

{| class="wikitable" | style="background:#E6C3C3;"
! (problem) vs (solution)
! scope="col"| Stand Up Straight, Speak Firmly, and Slowly Back Away
! scope="col"| Run Toward a Building or Hard-Topped Vehicle
! scope="col"| Calmly Exit the Building
! scope="col"| Apply Firm Pressure
|-
! scope="row"| {{w|mountain lion}}
| style="background:#C5E6C3;"| This is a common recommendation when encountering a mountain lion (puma, cougar, etc) out in nature.
| Running away may cause the animal to chase you, and it may consider you as prey. If you safely make it into a building or vehicle, you may be able to hide or drive away from the animal and may be safer than being outdoors with it; however, it is safer to approach said building or vehicle ''slowly'', so as to not provoke the animal.
| Exiting a building and approaching the animal is not a good idea. If the animal is inside the building, however, it is recommended to combine this advice with (1).
| Applying "firm pressure" to the (wild) animal is a terrible idea and may result in injury or death. Applying light pressure to a domesticated cat may make it less likely to attack, but wild cats do not respond positively to it.
|-
! scope="row"| {{w|lightning}}
| Yelling at lightning is ineffective. {{citation needed}} Also, making yourself stand more erect to maximize your apparent height and backing away slowly from a lightning strike will make you more of a target as you will then become more prominent above the surrounding terrain.
| style="background:#C5E6C3;"| This is the recommended solution when encountering lightning - to go indoors or inside of a hard-topped vehicle to avoid being struck, or to be ''inside'' some form of Faraday cage if lightning does strike your location. Staying inside of a metal vehicle may cause other problems, but it's generally better than being directly struck.
| Exiting a building is a poor idea, as the risk of getting struck by lightning is increased, as are the chances of being caught in any associated rainstorm or fulminogenic fire.
| There is no safe way to "apply firm pressure" to lightning. In the diagram, Cueball applies pressure to the tree, which is just about the worst possible thing to do in a storm, as when lightning strikes the tree the electric charge will pass through Cueball, not to mention the associated risk of the tree exploding or a limb detaching and falling on him.
|-
! scope="row"| {{w|fire alarm}}
| Yelling at a fire alarm is ineffective. {{citation needed}}
| When a fire alarm is sounding, it is terrible advice to run ''towards'' the sound of the alarm, unless you are a trained fire fighter with suitable tools. If, however, you happen to be the cause of the fire, running towards a vehicle is completely understandable.
| style="background:#C5E6C3;"| This is the recommended advice when hearing a fire alarm - to calmly exit the building, and move to a safe location.
| Applying firm pressure to a fire alarm will not result in stopping the alarm, unless you are able to damage the device, suppress the sound (either by covering the noisemaker or by pressing the alarm's button to temporarily silence it), or block the fire alarm sensors. Regardless, this will not stop the actual fire. Also, there is no safe way to "apply firm pressure" to fire, unless applying firm pressure is interpreted as using a fire blanket.
|-
! scope="row"| {{w|bleeding}}
| Yelling at a bleeding wound is ineffective. Yelling at a bleeding person may make them feel worse.
| Running toward a building or vehicle is not a typical solution if someone is bleeding. However, there could be medical supplies and/or medically trained people (nurses, doctors, paramedics, etc.) inside the building or vehicle, so this idea is not completely incorrect.
| Exiting a building is not helpful if someone is bleeding, if either the exiting one is the injured one, or the non-injured one. Although, if someone/something in the building (such as a mountain lion) is the cause of the bleeding, this could be a good idea so that the bleeding or injury does not get worse.
| style="background:#C5E6C3;"| This is the recommended solution to stop bleeding - apply firm pressure to staunch the bleeding, using some kind of absorbent material (cloth bandages are the gold standard, but any clean fabric (such as clothing, towels, sheets etc. will suffice), or, '''if you are trained in first-aid''' and the bleeding is particularly heavy, applying a tourniquet around the limb above the wound.
|}

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

:[The comic is laid out like a grid, with situations down the left-hand side (mountain lion / lightning / fire alarm / bleeding) and the solutions across the top (stand up straight, speak firmly, and slowly back away / run toward a building or hard-topped vehicle / calmly exit the building / apply firm pressure ). The grid illustrates the "match-ups", with a green square denoting a "correct" match-up and a red square denoting a bad idea.]

:[From the top left corner, going from left to right, top to bottom, with each first item being on its own line in the grid, the squares are as follows:]

:[Green square, a mountain lion (drawn as a large cat) sits on the left, on a perch. Cueball and Megan have their arms raised and are speaking to it. Lines in front of them indicate they are backing up.]
:Cueball: ''HEY. STOP.''
:Megan: ''SHOO.''
:*'''stand up straight, speak firmly, and slowly back away''' -> '''mountain lion'''

:[Red square, Cueball and Megan are being chased by a mountain lion, and are running towards a building to their right.]
:*'''run toward a building or hard-topped vehicle''' -> '''mountain lion'''

:[Red square, Cueball and Megan exit a building and approach a mountain lion.]
:Megan: ''Hello.''
:*'''calmly exit the building''' -> '''mountain lion'''

:[Red square, Cueball is putting his hands firmly on a mountain lion.]
:*'''apply firm pressure''' -> '''mountain lion'''

:[Red square, lightning strikes a tree. Cueball is standing outside, with his arms raised, yelling at the lightning. Lines in front of him indicate he is backing up.]
:''BOOM''
:Cueball: ''NO!''
:*'''stand up straight, speak firmly, and slowly back away''' -> '''lightning'''

:[Green square, lightning strikes a tree. Cueball and Megan run toward a building to their right.]
:''BOOM''
:*'''run toward a building or hard-topped vehicle''' -> '''lightning'''

:[Red square, lightning strikes a tree. Cueball and Megan exit a building and approach the lightning-struck tree.]
:''BOOM''
:*''' calmly exit the building''' -> '''lightning'''

:[Red square, lightning strikes a tree. Cueball pushes on the lightning-struck tree.]
:''BOOM''
:*'''apply firm pressure''' -> '''lightning'''

:[Red square, a fire alarm is beeping. Cueball yells at the alarm, with his arms raised. Lines in front of him indicates he is backing up.]
:''BEEP BEEP BEEP''
:Cueball: ''HEY.''
:*'''stand up straight, speak firmly, and slowly back away ''' -> '''fire alarm'''

:[Red square, a fire alarm is beeping next to a building with flames on its roof. Cueball and Megan run toward the burning building.]
:''BEEP BEEP BEEP''
:*'''run toward a building or hard-topped vehicle''' -> '''fire alarm'''

:[Green square, a fire alarm is beeping next to a house with flames on its roof. Cueball and Megan are exiting the burning building.]
:''BEEP BEEP BEEP''
:*'''calmly exit the building''' -> '''fire alarm'''

:[Red square, a fire alarm is beeping, and Cueball is trying to "suppress" the beeping sound. Behind him are flames.]
:''BEEP BEEP BE-eep eep eep eep eep''
:*'''apply firm pressure''' -> '''fire alarm'''

:[Red square, Cueball is bleeding from his right arm, and holds it. Megan to his right yells at him with her arms raised. Lines in front of her indicates she is backing up.]
:Megan: ''HEY!''
:Megan: ''STOP IT!''
:*'''stand up straight, speak firmly, and slowly back away''' -> '''bleeding'''

:[Red square, Megan, holding a first aid kit in one hand and a bandage in the other, runs with a bleeding Cueball towards a building to their right.]
:*'''run toward a building or hard-topped vehicle''' -> '''bleeding'''

:[Red square, Megan holds a bandage, and to the ground in front of her is a first aid kit. Cueball is walking to the right of the panel, with an injured and bloody left arm raised.]
:Cueball: Bye!
:*'''calmly exit the building''' -> '''bleeding'''

:[Green square, Cueball sits in a chair and Megan is treating him by putting her hands on his injured limb. Behind her on the ground is a first aid kit.]
:*'''apply firm pressure''' -> '''bleeding'''

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Charts]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Animals]]
[[Category:Weather]]

2750: Flatten the Planets

2023-03-16T02:26:36Z

172.70.162.223: /* Explanation */

{{comic
| number = 2750
| date = March 15, 2023
| title = Flatten the Planets
| image = flatten_the_planets_2x.png
| imagesize = 740x647px
| noexpand = true
| titletext = We'll turn the asteroid belt into ball bearings to go between different rings orbiting at different speeds.
}}

==Explanation==
{{incomplete|Created by an OFF BY THREE ORDERS OF MAGNITUDE ERROR. Do NOT delete this tag too soon.}}
This comic depicts a situation where the solar system is flattened to create a ring system around the Sun. This may be inspired by the {{w|Alderson disk}}, a hypothetical megastructure intended to gain truly massive amounts of living space by constructing a literal disk of matter around a star. This would require several solar systems' worth of matter to do, and materials with a tensile strength beyond what is likely physically possible for any known form of matter. The planets of our solar system would not be suitable for this endeavor.{{Citation needed}}

{| class="wikitable"
! rowspan="2" | Planet
! colspan="2" | Thickness
|-
!Inches
!Millimeters
|-
| Mercury || 1/8" || 3.2 mm
|-
| Venus || 1" || 25 mm
|-
| Earth || 3/4" || 19 mm
|-
| Mars || 0.01" || 0.25 mm
|-
| Jupiter || 18" || 460 mm
|-
| Saturn || 3" || 76 mm
|-
| Uranus || 1/8" || 3.2 mm
|-
| Neptune || 1/16" || 1.6 mm
|}

The title text explains what would happen to the asteroid belt if this was done. He is proposing that the asteroids should be turned into ball bearings to go in between the planetary discs. There is not enough matter in the asteroid belt to do this,{{Actual citation needed|Surely depends upon the size and radial density of the inserted race of bearings}} and furthermore it implies that the discs would actually have small gaps between them. Unless the discs were made of material with impossibly high tensile strength, the whole structure would soon be torn apart by the relative forces between the inner and outer fringes of each disc trying to both 'orbit' at the rate more suited to a radial distance somewhere between the two, and crushing the bearings placed between adjacent ones. Although less so than with a single structural disc rotating at any single given compromise rotation (or not at all).

==Transcript==
:[This comic depicts a situation where the planets of the Solar System are flattened using a roller pin to create a contiguous ring system around the Sun, with each planet taking up the part within their orbit to the next planet (or the Sun).]

:[The top part shows a normal image of the Solar System with the eight planets orbiting the Sun, and their orbits shown as circles. The Sun is yellow and the planets have approximately the color they typically are shown in. Earth has more features than the other three rocky planets. Jupiter has clear features including the red spot, while Saturn has its rings. Beneath this is a broad arrow pointing down.]
:↓
:[The arrow points to a roller pin. A similar arrow points down to the next image.]
:↓
:[The second large image shows the Solar System with the planets flattened to fill out the gap between the Sun and each of the planets, so they each cover the area of the circle within their orbits, into the next planet (or the Sun). Each segment has kept a similar color as used for the planets in the first image. The Sun is not flattened and is now the center of a huge ring with eight different colors, some with patterns, mainly Earth, but also Jupiter and Saturn's discs show features.]

:[Beneath this to the right is a side view of the flattened Earth, with its thickness indicated with two arrows pointing in at the top and up at the bottom of two dotted lines continuing where the "Earth" stops. A label has been written between these two lines, and the thickness is compared to US quarter and penny coins.]
:Earth
:3/4"

:[Below this and going all the way across the panel is a side view with a segment of the Sun to the left followed by all the flattened planets, labeled with their name and their thicknesses. Arrows point to the relevant segment from the three rocky planets other than Earth. Above Jupiter and Saturn is a label between two arrows. Text alternates between being above and below the planets. Their thicknesses differ quite a lot, with Mars being the thinnest and Jupiter by far the thickest. Cueball stands on the flattened Earth.]
:← Not to scale →
:Mercury 1/8"
:Venus: 1"
:Earth 3/4"
:Mars 250 microns
:Jupiter 18"
:Saturn 3"
:Uranus 1/8"
:Neptune 1/16"

:[Caption below the panel:]
:I don't know why NASA keeps rejecting my proposals to improve the Solar System

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Astronomy]]
[[Category:Space]]

2172: Lunar Cycles

2023-03-15T23:46:52Z

172.70.162.223: /* Explanation */ Rationalising wikilinks, while things are edited.

{{comic
| number = 2172
| date = July 5, 2019
| title = Lunar Cycles
| image = lunar_cycles.png
| titletext = The Antikythera mechanism had a whole set of gears specifically to track the cyclic popularity of skinny jeans and low-rise waists.
}}

==Explanation==

This comic shows a mixture of real, scientific lunar cycles and cycles that are comedic or fictional in nature. The first four cycles are factual, while the ones following them are not.

*'''Nodal precession:''' The Moon's orbital plane is tilted slightly compared to the Earth's orbital plane around the sun (the {{w|ecliptic}}). This tilt is why we don't constantly see eclipses; most of the time, the Moon's orbital plane is tilted higher or lower than the Sun, so they generally don't cross each other. The two points at which these planes ''do'' cross are called {{w|lunar nodes}}. {{w|Nodal precession}} is the gradual rotation of these nodes over time, a gyroscopic consequence of Earth's equatorial bulge. For the Moon this follows an 18.6 year cycle.

*'''Apsidal precession:''' All orbits have two points where the orbiting body is either closest to, or furthest away from, the thing they are orbiting. These points are called {{w|apsides}}, and the imaginary line between them is called the ''line of apsides''. {{w|Apsidal precession}} is the gradual rotation of this line over time, which occurs in cycles of around 8.9 years for the Moon.

*'''Phase:''' {{w|Lunar phase}} describes the change in shape of the sunlit side of the Moon as viewed from the Earth's surface, which is caused by the changing angle between Moon and Sun as the Moon revolves around the Earth. The cycle of lunar phases takes 29.5 days, a figure referred to as the ''synodic month''.

*'''Distance:''' Because the Moon's orbit around the Earth is elliptical, its distance from the Earth varies slightly over the course of an orbit. This means that the moon's distance also follows a cycle which is the same as the length of one lunar orbit: approximately 27.5 days. This figure is referred to as the ''anomalistic month''. Note that the synodic month is (perhaps counterintuitively) two days ''longer'' than the sidereal month — or to put it another way, it takes 2 more days for the Moon's phases to cycle than it does for the Moon to go around the Earth. This is due to the fact that the Earth is also moving ''around'' the Sun while the phases are going on, which means that the Moon has to spend 2 extra days "catching up" to the point at which the lunar phase cycle can restart.

*'''Earth-Moon relative size''': This is a joke cycle; the Earth and Moon do not physically change size, nor does the Moon ever become larger than the Earth. This may be playing on the idea that the Moon often ''appears'' to change size to viewers on Earth, due to various factors; most commonly, this is due to the {{w|Moon illusion}}, which tricks the brain into perceiving the Moon as much larger than it really is. There are also so-called {{w|supermoon}}s, which occur when the full moon coincides with the Moon's closest approach to Earth; these actually do increase the Moon's apparent size, although by a relatively insignificant amount.

*'''Lunar shape:''' Again, this is a joke cycle; the Moon does not actually change shape. A shape intermediate between circle and square is known as a {{w|squircle}}, a subclass of the {{w|superellipse}}.

*'''Lunar mood:''' The moon does not have a mood, although humans can have moods that fluctuate over time, sometimes with a regularity akin to a cycle. Ironically, the section of the graph that shows a good (i.e. happy) mood has the graph line curving up then down like the mouth of a frown, and for the bad (unhappy) mood it curves down and then up, as in the mouth of a smile.

* The final diagram shows many different cycles superimposed on each other, highlighting areas where several cycles are coinciding. This is likely satirizing the media trend of overhyping astronomical coincidences and giving them grand-sounding names:
:*The light gray "phase × distance" plot does not correspond to the product of periods given for phase and distance, which [https://i.imgur.com/0i0mcPn.png look like this] instead.
:*A {{w|harvest moon}} is the traditional name for the full moon closest to the autumnal equinox, but there is nothing astronomically significant about it.
:*A {{w|supermoon}} is a full or new moon when the Moon is closest to the Earth, resulting in a slightly larger-than-usual apparent size. A full supermoon is roughly 14% larger in diameter than when the Moon is furthest away. See also [[1394: Superm*n]].
:*A {{w|blue moon}} was originally a description of the very rare occurrence of atmospheric conditions that gave the Moon a bluish tinge, hence the expression "once in a blue moon" for something that happens only rarely. However, the actual blue-hued appearance of the moon is so rare that it the phrase "blue moon" has been reinterpreted as referring to a merely uncommon event: the occurrence of two full moons in a single calendar month. That kind of "blue moon" naturally does not look any different from a regular full moon.
:*A {{w|Blood Moon (eclipse)|blood moon}} refers to the moon during a lunar eclipse.
:*While the popularity of '''skinny jeans''' ({{w|slim-fit pants}}) does change over time, the idea that this is connected to a lunar cycle is also a joke.
:*The {{w|Golden Age of Television}} is said to have occurred in the 1940s and 50s, and the 2000s.
:*'''Pork''' {{w|Mooncake|'''moon'''cakes}} have been prepared in the rural areas west of Shanghai since more than a thousand years ago, for the Chinese {{w|Mid-Autumn Festival}}.
:*[https://scryfall.com/card/m20/120/vampire-of-the-dire-moon "The Vampire of the '''Dire Moon'''"] is a recently introduced, uncommon card from the {{w|Magic: The Gathering}} card game.
:*{{w|Astrology}} is a pseudoscience which claims that the positions of the celestial bodies can be used to predict human affairs. The chart jokingly suggests that astrology actually ''does'' work, but only within a very specific two-week timeframe.
:*Finally, while the idea of a '''total eclipse of the sea''' seems absurd, [https://www.deepseanews.com/2017/08/what-happens-in-the-sea-during-a-solar-eclipse/ an eclipse was famously used to explain the migration of maritime animals]:
:::''biologists were beginning to unravel the mystery of this ‘false bottom’–a layer in the ocean that looks the the sea floor on the sounder but isn’t–which covered much of the ocean. This false bottom rises in up at night and sinks down during the day. This rising and falling is in fact caused by the largest migration of animal on Earth–everything from fish, shrimp and jellyfish, moving hundreds of meters in unison up and down each day.... the moon moved into its place in front of the sun, daylight rapidly faded, and the scientists solved the migration mystery: the deep layer of animals began to rise. Bioluminescent creatures started to shine, and nocturnal creatures started a frantic upward thrust. As the world grew darker, they swam upward nearly 80 meters. But this frantic migration didn’t last long. As the moon receded and the sun revealed itself, the massive animal layer did an about-face, scrambling back into the safety of the darkness.''
:: (Backus, Clark, and Wing (1965) [https://sci-hub.tw/10.1038/205989a0 "Behaviour of certain marine organisms during the solar eclipse of July 20, 1963"] ''Nature'' '''4975:'''989-91.)
The '''{{w|Antikythera_mechanism|Antikythera mechanism}}''' mentioned in the title text is an ancient Greek machine, rediscovered in 1901, designed to calculate astronomical positions. The title text jokes that there is a set of gears on said mechanism that is used to predict the popularity of "skinny jeans" and "low-rise waists." Since it was likely created in the 1st or 2nd century B.C., it is impossible for the creators to have had any knowledge of skinny jeans or low-rise waists - both are modern-day clothing fashions{{citation needed}}.

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

:Understanding lunar cycles

:Nodal precession
:[A diagram showing a broad cosine-like wave with wavelength labelled as 18.6 years. To the right are two diagrams showing an orbital cycle moving in and out of plane.]

:Apsidal precession
:[A diagram similar to the one above but with a slightly shorter wavelength, labelled as 8.9 years. To the right are two diagrams showing an elliptical orbit around a planet and the same orbit rotated.]

:Phase
:[A diagram similar to those above with a shorter wavelength, labelled as 29.5 days. To the right is a diagram showing four phases of the moon: New, Waxing crescent, Waxinf gibbos, Full.]

:Distance
:[A diagram similar to those above with a shorter wavelength, labelled as 27.5 days. To the right is a diagram showing the distance of the moon from the Earth over time, with distances marked by arrows.]

:Earth-Moon relative size
:[A wave with long wavelength with an arrow pointing to the minimum labelled 'Earth bigger' and an arrow pointing to the maximum labelled 'Moon bigger'. To the right are two diagrams of the moon and Earth, one showing the Earth bigger than the Moon and the other showing the Moon bigger than the Earth.]

:Lunar shape
:[A wave with long wavelength with an arrow pointing to the minimum labelled 'Circle' and an arrow pointing to the maximum labelled 'Square'. To the right is a diagram showing a circle, a circle transforming into a square with outward arrows at each corner and a square transforming into a circle with inward arrows.]

:Lunar mood
:[A wave with long wavelength with an arrow pointing to the minimum labelled 'Bad' and an arrow pointing to the maximum labelled 'Good'. To the right are four emojis: :), :|, :(, :|]

:[A superimposed graph of all the above waves. Different points on the graph are labelled: Harvest moon, Supermoon, Blue moon, Skinny Jeans popular, Super blood moon, Golden age of TV, Dire moon, Pork moon, Two week window in which astrology works, Total eclipse of the sea.]

[[Category:Astronomy]]

{{comic discussion}}

2739: Data Quality

2023-02-24T19:00:44Z

172.70.162.223: /* Details */ Various improvements. Probably.

{{comic
| number = 2739
| date = February 17, 2023
| title = Data Quality
| image = data_quality_2x.png
| imagesize = 671x211px
| noexpand = true
| titletext = [exclamation about how cute your cat is] -> [last 4 digits of your cat's chip ID] -> [your cat's full chip ID] -> [a drawing of your cat] -> [photo of your cat] -> [clone of your cat] -> [your actual cat] -> [my better cat]
}}

==Explanation==
{{incomplete|Created by a SUPERIOR FELINE. needs review by software engineer to correct mistakes. should link to the comic on taking the fourier transform of a cat. Do NOT delete this tag too soon.}}


Digital data can be compressed to make transmission and/or storage more efficient; some {{w|compression algorithms}} discard some information to improve the compression, which is known as lossy compression, since some of the information is lost (this can be acceptable in audio or visual data, since the difference may be hard for humans to perceive).

This comic shows a chart in the form of a line, increasing quality from very lossy to most lossless. This means that it goes, at the extremes, from having so little information as to make it effectively meaningless, to having significant extra information included (eventually making the original actually an unnecessary distraction). Some of this extra information mitigates the risk of another sense of 'loss' in data - digital data are transferred in bits, and {{w|data loss}} is the process by which some of these bits are lost or altered during data transport. However the highest quality, "better data", is using a different sense of the term "quality", referring more to the general excellence of the data than how accurately it represents the original.

The title text uses your cat as an example of this range of losses (or, in the case of the latter reaches of the graph, gains) in the information. This is possibly a reference to [https://www.goodreads.com/quotes/8157292-the-best-material-model-of-a-cat-is-another-or Norbert Wiener]'s quote, "The best material model of a cat is another, or preferably the same, cat." The most lossy is an exclamation about how cute your cat is, which is ephemeral and obviously carries very little significance in terms of actually providing specific, transferable information about your cat. The example then progresses into your cat's chip ID; presumably your cat has been microchipped, and between the last four digits (commonly used in sensitive information as an identifier without revealing the full number) or the entire chip ID, provides a still-uninformative yet slightly improved way of identifying your cat. A drawing of your cat and a photo of your cat would portray the cat reasonably well, while a clone of your cat and (of course) your actual cat would be the best way of gaining information about your cat. However, as in the actual comic, the final, most lossless (in this case, with the most gain) form of data transfer has nothing to do with your cat, but is simply Randall's better cat. This is apparently made out by Randall to be the pinnacle of cat data.

=== Details ===
{| class="wikitable"
|-
! Item
! Explanation
|-
| {{w|Bloom filter}}
| A Bloom filter is a probabilistic data structure that can efficiently say whether an element is ''probably'' part of the dataset, while it can say "element is not in set" with 100% accuracy. If a Bloom filter is used to represent the contents of a book, reference to the Bloom filter could perhaps reconstruct everything, just by guessing, but in a highly inefficient and potentially inaccurate way.
|-
| {{w|Hash table}}
| A hash table allows you to find data very fast. Randall probably means hashing the contents of entire books. Calculating a hash value for an entire book means that there is (most probably) a unique relationship between the book and a hash value - e.g. "58b8893b172d00e9". This means this exact version of the book will yield this exact hash value, though it's practically impossible to reconstruct the book's potential content from a hash value. It is a method of checking that a copy is the same as the original, but is meaningless on its own and has the possibility of being wrong. An average book contains several millions of bits, yet the SHA-2 hash has only 256 bits, so there are theoretically many (mostly nonsensical, but not necessarily) 'wrong' versions that might look correct.
|-
| {{w|JPEG|JPG}}, {{w|GIF}}, {{w|MPEG-1|MPEG}}
| Image and video formats that are considered 'lossy'. JPG (or "JPEG") format and the MPEG {{w|MPEG-2|group}} {{w|Advanced Video Coding|of}} formats typically use a range of data-compression methods that save space by selectively fudging (thus losing) what details it can of the image (and audio, where appropriate), to make disproportionate gains in compression; best used for real world images (and films) where real-world 'noise' can afford to be replaced by a more compressible version, without too much obvious change.
GIF compression is not 'lossy' in the same way, i.e. whatever it is asked to encode can be faithfully decoded, but Randall may consider its limitations (it can only write images of 256 unique hues, albeit that these can come from anywhere across the whole 65,536 "True color" range, plus transparency) to be a form of loss, as conversion from a more sophisticated format (e.g. PNG, below) could lose many of the subtle shades of the original and produce an inferior image. For this reason, GIF format becomes one best left to render diagrams and other computer-generated imagery with swathes of identical pixels and mostly sharp edges (and to utilize the optional transparent mask), for which JPEG compression will create prominant image artefacts. Alternatively, he may just have included it as a joke/nerd-snipe.
|-
| {{w|PNG}}, {{w|ZIP (file format)|ZIP}}, {{w|TIFF}}, {{w|WAV}}
| A series of formats using lossless compression. PNG and TIFF are image formats that are suitable for photos, but without (necessarily) resorting to reduced accuracy in order to assist compression. WAV is an audio format that also does not arbitrarily sacrifice 'unnecessary' details, unlike the more recently developed {{w|MP3|MPEG Audio Layer III}} which has become the de-facto consumer audio format for many.
ZIP is a generic compression algorithm (and the name of the format it creates) that can be used to store any other digital files. Anything put within a ZIP file can be exactly decompressed into the original state later on, although any such file already compressed in some way (such as any of the image formats mentioned in this comic, or other ZIPs) are unlikely to recompress significantly more.
|-
| Parity bits for error detection
| In the number 135, the sum of its digits is 9. So the number 135 could be written as "1359", for example, slightly increasing the amount of data that needs to be sent. But with the slight advantage that, if the number was tampered with, the parity bits may be able tell you that an error has occured. (Possibly that the parity itself was the digit that was miswritten.) But a change from "135" to "153" could not be detected, in this method.
There are more reliable means to detect errors, such as CRC-32 (now considered obsolete), MD5 and the much more modern {{w|Secure Hash Algorithm|SHA}}. Such values were alluded to in the Hash Table section. But here they are sent ''alongside'' the data, slightly increasing the amount of data transmitted/stored (in order to confirm its accuracy), rather than instead of it and vastly decreasing the amount of data (but leaving the virtually impossible task of correct reconstruction).

However it is done, if the check indicates a problem then you can only seek a new copy (of the data, and/or the parity or hash) until the problems seem to be resolved.
|-
| Parity bits for error correction
| With extra error-checking, there are ways to immediately restore the original data with the given additional data. One method is to 'overlap' multiple error-detection parities such that any small enough corruption of data (including of parity bits themselves) can be reconstructed to the correct original value by cross-comparison between all parity bits and the supposed data. One of the first modern methods developed was {{w|Hamming(7,4)}}, invented around 1950, which was a balanced approach designed to handle the typical error conditions typically encountered at the time and has inspired even contemporary electronic methods of maintaining data integrity. Another practical application of error correction bits would be that present in {{w|QR_code#Error_correction|QR Codes}}, using {{w|Reed–Solomon error correction|Reed–Solomon error correction}}.
|}

==Transcript==
:[A line chart is shown with eight unevenly-spaced ticks each one with a label beneath the line. Above the middle of the line there is a dotted vertical line with a word on either side of this divider. Above the chart there is a big caption with an arrow pointing right beneath it.]
:<big>Data Quality</big>
:Lossy ┊ Lossless

:[Labels to the left of the dotted line from left to right:]
:Someone who once saw the data describing it at a party
:Bloom filter
:Hash table
:JPEG, GIF MPEG

:[Labels to the right of the dotted line from left to right:]
:PNG, ZIP, TIFF, WAV, Raw data
:Raw data + parity bits for error detection
:Raw data + parity bits for error ''correction''
:Better data

{{comic discussion}}

[[Category:Charts]]
[[Category:Cats]]

2740: Square Packing

2023-02-21T08:56:03Z

172.70.162.223: /* Explanation */ Nicifying the reference placement, to (at least partially) site standards. Though refs aren't used that much *at all*, surprisingly, and (if it weren''t for the detail attached) I'd have converted to a plain link...

{{comic
| number = 2740
| date = February 20, 2023
| title = Square Packing
| image = square_packing_2x.png
| imagesize = 326x295px
| noexpand = true
| titletext = I also managed to improve the solution for n=1 to s<0.97, and with some upgrades I think I can hit 0.96.
}}

==Explanation==
{{incomplete|Created by a HYDRAULIC PRESSED SQUARE - This appears to be referring to a specific puzzle that merits explanation before going into description of the comic. Do NOT delete this tag too soon.}}
The {{w|Square packing in a square|square packing problem}} is a type of geometry problem. The goal is to find the smallest possible "outer square" that will fit N "inner squares" that are each 1 unit wide and 1 unit tall. In the comic N=11, leading to its name of "The N=11 Square Packing Problem," and s is the length of the outer square's sides.

A few days before this comic's post, a web page [https://erich-friedman.github.io/packing/squinsqu/ ''Squares in squares''] gained interest on social media platforms such as [https://twitter.com/KangarooPhysics/status/1625436240412540928 Twitter] and [https://news.ycombinator.com/item?id=34809023 Hacker News]. For many values of N, that page depicts the best known solutions, some of them known to be optimum. The one for N=11 (best known but not proven to be optimum) is shown on the left here; its general arrangement was found by Walter Trump in 1979 and slightly improved by Thierry Gensane et al. in 2004.<ref>Gensane, T., Ryckelynck, P. – ''Improved dense packings of congruent squares in a square''. Discrete Comput Geom 34, pages 97–109 (2005). https://doi.org/10.1007/s00454-004-1129-z</ref>

Randall claims to have found a more efficient solution for this N=11 case, by physically deforming the squares involved in the best-known solution with a hydraulic press. The size of the resulting bounding square is indeed smaller, but the "solution" isn't actually one because the inner shapes have countless wrinkles and are no longer squares. Geometrical shapes in packing problems are not conventionally assumed to be deformable in this manner.{{citation needed}}

The title text mentions the same approach "improved" the solution for 1 unit square, whose optimum solution is obviously that unit square itself with s=1. Randall remarks that if he had "some upgrades", presumably a more powerful hydraulic press, he could get the resulting square to be even smaller.

‎<references />

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[11 squares optimally packed inside a square arrangement]
:Previous best
:s<3.877084
:(Gensane, 2004)

:[11 deformed squares crushed together to pack them into a smaller square arrangement]
:New record
:s<3.40

:[Caption below the panel:]
:I've significantly improved on the solution to the n=11 square packing problem by using a hydraulic press.

{{comic discussion}}
[[Category:Math]]
[[Category:Geometry]]

Talk:2736: Only Serifs

2023-02-13T01:14:09Z

172.70.162.223:

first two letters are "A" and "R" I think [[Special:Contributions/172.71.167.10|172.71.167.10]] 04:35, 11 February 2023 (UTC)Bumpf

It's AaBbCcDd. Most likely in Caslon, based on the uppercase A. [[Special:Contributions/172.68.174.149|172.68.174.149]] 04:54, 11 February 2023 (UTC)

So much for a hidden message. [[Special:Contributions/172.68.238.22|172.68.238.22]] 05:05, 11 February 2023 (UTC)

If we've come to this page for an explanation, we probably don't know what a "solum-serif font" is. update the transcript with something more widely known? [[Special:Contributions/172.69.65.224|172.69.65.224]] 05:42, 11 February 2023 (UTC)
:Agreed, enthusiastically! Someone trying to show off, Google doesn't even know what it means, it found ONE result, which is a font of curved corners someone made (when I put "solum-serif" in quotes, to not allow Google to just search one or the other). But while I was Googling someone fixed it before I could, LOL! Which is weird as it's past midnight here in the Eastern time zone. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:56, 11 February 2023 (UTC)
:: Perhaps you haven't realised that nighttime for Americans is daytime for, um, somewhere around 80-90% of the world's population? [[User:Paddles|Paddles]] ([[User talk:Paddles|talk]]) 14:54, 11 February 2023 (UTC)
::: Of course I realize this. :) Seems like YOU don't realize that this site is one of many where it seems like most activity centers around the EST time zone... Perhaps related to Randall being in this time zone, perhaps not, but I'm usually alone at this time of night (for example, I almost NEVER get Edit Conflicts because seemingly everyone is asleep). For years I'm almost always the only person making contributions at this hour. Maybe think of that before making a misguided condescending reply. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 06:19, 12 February 2023 (UTC)

::I think that's probably because it was a joke. In fact the ridiculous of the notion of a "solum-serif" font is more or less the entirety of the joke of this comic. You're right, in the future we should make sure that these descriptions are devoid of humor.[[Special:Contributions/172.70.211.92|172.70.211.92]] 18:17, 11 February 2023 (UTC)
:::But that's in the transcript particularly, the transcript should make sense as to what the image shows without prior knowledge [[Special:Contributions/108.162.216.10|108.162.216.10]] 02:45, 12 February 2023 (UTC)
:::Yes, as Mr./Ms. 216.10 pointed out, this was the transcript. PLENTY of room for jokes in the Explanation, but the Transcript should be as concise and straightforward as possible, in an effort to be clear. NOT the place for what seemed to be a self-coined term and trying to be clever. :) I've heard some blind and sight-impaired people follow the comic by having a reading program read these Transcripts, last thing they need is a non-word the program might trip over and can't define for them. [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 06:19, 12 February 2023 (UTC)
::For anyone who is confused, 'solum' (solus) is Latin for 'only', as opposed to 'sans' (from the Latin 'sine'), without. I suppose the joke is rather hard to get, though, since the top Google search results for 'solum' refer to soil. (Not my joke, by the way. Also, first ever comment - hope I've done this right.) [[User:CryptekCathekh|CryptekCathekh]] ([[User talk:CryptekCathekh|talk]]) 21:21, 11 February 2023 (UTC)
:::Thanks for the clarification, yes that makes sense. And yes, finely commented there. :) Yes, I got loads of industrial results for "Solum", which is why I had to force the search to include the "serif". [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 06:19, 12 February 2023 (UTC)

There was a whole thing on Wikipedia about formatting the f symbol for an arbitrary function. One camp held that f is just f, it always is and always was and if you italicize f in a san-serif font, you get an oblique ''f'' but if you italicize f in a serif font, you get a proper italic version, which I'm not sure how to display here. The italic f resembles ƒ, a character called the "hooked f," which is technically an oblique f with a descender ("hook"). That symbol has been used for florins, but sometimes it is also used to imitate the italic f to represent functions, because it has the descender in all environments. But Wikipedia uses a san-serif script, while most mathematical literature uses a serif script. However, it renders expressions in LaTeX with serif fonts and therefore these equations get an f with a descender. So some people were arguing that given this environment, the ƒ character was practically superior, even if it was conceptually wrong, because it most closely resembled the formatted LaTeX expressions. And on and on with the back and forth. I'm glad they eventually settled on just using f for f, like they use g for g and h for h, but still, it was amusingly nitpicky. [[Special:Contributions/172.70.100.50|172.70.100.50]] 07:58, 11 February 2023 (UTC)
:What you listed as resembling italic f looks on my system like ⨍. There are lots of fun variations (some unrelated, just similar looking): ∫⨎ʄ∮∬∰⨏ƒʆᶘᔑ [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 08:48, 11 February 2023 (UTC)
:That entire argument seems silly. Obviously the correct answer to "how do you write the function $f$ outside of math mode" is "don't". Just use math mode and let KaTeX handle the formatting. --[[Special:Contributions/162.158.63.61|162.158.63.61]] 16:48, 12 February 2023 (UTC)

The title text teases the idea of a font made by adding the Times New Roman serifs to Comic Sans, and now I actually want to see such a cursed font. [[Special:Contributions/108.162.241.237|108.162.241.237]] 11:03, 11 February 2023 (UTC)

I think Caslon is correct:
[https://ibb.co/J2WhP1g Caslon] [https://ibb.co/MG77JMX Overlay] [https://ibb.co/3yQtqbN Low Opacity Overlay]
via [http://www.identifont.com/identify?58+.+5J+1JU+3YB+3RZ+35YX+94+JIA+58C+97+22X+8R8+1JY+2Z3A+6ZR+3Q+5BU+9J+1L0+76P+8Z+1QN+7UF+DG+5QE+J+JPK+8C+99+PAE+2AA6+2ZI+8X+8W+8J+1KS+JI6+2Z36+79+8E+53K+2E+1KI+8N+7VS+7S+2C6+1U6+8A+8R0+8F+3WO+2ZGL+1LA+7G+1QY+8B+A0 questions] in Identifont. If someone can add these to the wiki, please do. [[User:DragonDave|DragonDave]] ([[User talk:DragonDave|talk]]) 12:55 11 February 2023 (UTC)

I wonder if this is related to the US State Department dropping Times Roman in favor of Calibri, under the argument that the latter is easier to read. --[[Special:Contributions/172.70.114.198|172.70.114.198]] 13:47, 11 February 2023 (UTC)

I call these fonts seul serif, keeping with the theme of using French terminology. [[Special:Contributions/172.71.147.59|172.71.147.59]] 16:30, 11 February 2023 (UTC)

A free, existing example of [http://www.fontgrill.com/fonts/free/comic-serif/comic-serif.php Comic Serif].
[[Special:Contributions/172.70.214.242|172.70.214.242]] 16:43, 11 February 2023 (UTC)

:^ TBH Comic Serif doesn't look half bad, if only it had a consistent baseline [[Special:Contributions/198.41.231.179|198.41.231.179]] 17:01, 11 February 2023 (UTC)
:Of course, since Comic is supposed to mimic casual handwriting, and people don't hand write serifs {{Citation needed}}, this messes up the concept, LOL! [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 07:02, 12 February 2023 (UTC)
::Does not, if you go back far enough. Remember that a lot of old handwriting had serif-like parts due to the use of quills.

This comic reminds me of something I once actually did as a child: I once wrote a notepad full of game ideas and story concepts but wanted to keep them a secret; so I created my own "cipher" font where any straight lines in letters were removed, leaving only the curved lines. However, because some letters such as c and d would look similar without the straight lines, I gave some letters curved "serifs", which would be retained in my "font". --Jinji@donphan.social 20:32, 11 February 2023 (UTC)

I'm most instances where the word "font" is used, the correct word is "typeface". "Times Roman" is a typeface whereas "Times Roman bold" is a font. -Jez [[Special:Contributions/172.70.93.42|172.70.93.42]] 20:56, 11 February 2023 (UTC)
:I'd be inclined to suggest that "font", in common parlance, means what everyone here means it to mean, and that means that it is "correct". Nobody - OK, fine, potentially a negligible number of people - might wonder what's going on when "font" is used where you would prefer "typeface". It's not a matter of being "correct" though, unless we are (and we aren't) a community of people using typesetting language in a formal, technical sense. You know what ''is'' incorrect though? Writing "I'm" when you mean "In". Would I have said any of that had you not been so pedantic? You bet your sweet ass I wouldn't.[[User:Yorkshire Pudding|Yorkshire Pudding]] ([[User talk:Yorkshire Pudding|talk]]) 22:08, 12 February 2023 (UTC)

That can't POSSIBLY be the right link under the word "events". We have an entire category of "my hobby"/"Cueball getting kicked out of events" comics and that isn't any of them. [[Special:Contributions/172.71.158.90|172.71.158.90]] 22:29, 11 February 2023 (UTC)
:I concur. It links directly to comic 514, which has nothing to do with events or getting kicked out (I can't even think what comic they meant). I took a peek at 1514 and 2514, but those don't fit, either. ??? [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 07:07, 12 February 2023 (UTC)
::Maybe [[541]] was meant? But I guess just linking to Category:Banned_from_conferences or even adding this to Category:Compromise would be better. --[[Special:Contributions/198.41.242.166|198.41.242.166]] 14:58, 12 February 2023 (UTC)

It looks very similar to [http://tom7.org/lowercase/ Comic Sands] by tom7! [[Special:Contributions/172.71.30.106|172.71.30.106]] 16:49, 12 February 2023 (UTC)Bumpf

;A note for No Idea If There's A Character Limit LMAO
:''(...because you don't have a Talk page I can write to...)''
In response to recent edits from you with, for example, "(am i doing something wrong? THERE ARE TWO MANY JOKE TAGS!)" as the comment... The tag is the Incomplete (i.e. {{template|incomplete}}, and it is indeed arguable if all those marked as such are truly so (though you can bet your bottom dollar that plenty of times where the tag is removed, someone will then quite soon find something worth editing into an Explanation). But the "joke tag" is the community replacing the 'Bot-created reference to being created by A BOT with something an editor decides is funny. (They aren't always right, but someone else may impose their own humour - right or wrong - in place of the first comedian's attempt... And possibly the process repeats a few more times.)
 So, anyway, that's what the joke ''part'' of the tag is about, though the presence of the tag itself is a bit more serious. Maybe you could say that an explanation a couple of weeks old (from time of creation, at comic-publication) is only going to be 'normally and irregularly tweaked, from now on', and so would lose the Incompleteness happily enough, but some might say sooner ''or'' later than that, perhaps depending upon the comic concerned. Mega-comics in particular (e.g. interactive April Fool ones, or Time-like in scope, or those needing a "larger" version to be linked to to red properly) where genuinely there are potentially still more discoveries to be made for quite some time.
 Far more certain are the Incomplete Transcript statuses, because as soon as everything in the comic image is properly described (give or take subjective opinions), and it's in the de facto meta-notation, then removal of that status can be swift and painless (and still open to edits). Though do note that Transcripts do ''not'' currently need to contain the Title Text (it's already transcribed into the comic template header area, if done correctly), and in fact this is discouraged by the consensus view. The transcript just puts in text what is not aready in machine-readable text (for various purposes). So it's not Incomplete if every bit of Randall-drawn text is in there, every bit of drawn imagery is (sufficiently) described and - if necessary - the layout and relationships of things are also described (e.g, "There is a table which has...", rather than trying to render the table only in wikitable markup). It may not be ''correct'', but it should at least be considered complete, give or take a detail or so. ;)
 You might understand the community process best by actually going through page history for a comic's page, from the very first creation by theusafBOT (or whoever) and looking at successive diff-pages. Depends on how much time you have, though :-p [[Special:Contributions/172.70.162.223|172.70.162.223]] 01:14, 13 February 2023 (UTC)

Talk:2736: Only Serifs

2023-02-11T12:55:14Z

172.70.162.223: Added low opacity overlay

221: Random Number

2023-01-29T11:32:50Z

172.70.162.223: /* Trivia */ remove Hibernate reference (referenced method returns the version of the UUID standard, not a random number).

{{comic
| number = 221
| date = February 9, 2007
| title = Random Number
| image = random_number.png
| titletext = <nowiki>RFC 1149.5</nowiki> specifies 4 as the standard IEEE-vetted random number.
}}
==Explanation==
The comic specifies a function (in a {{w|C (programming language)|C}} similar syntax), which judging by its name should be designed to return a random number. Most functions of this form are random number ''generators'', meaning that on subsequent calls they return ''different'' random numbers. But the programmer has instead implemented a function that just returns the ''same'' random number each time, which, while it could indeed have been truly randomly chosen by rolling a die as the [[156: Commented|comment]] documented, is essentially worthless were it ever to be called more than once (with the expectation of different, i.e., random, results). In other words, the results over time would not be random at all, but completely predictable and deterministic.

The {{w|IEEE}} is the organization responsible for maintaining a number of computer standards. An RFC, or {{w|Request for Comments}}, is a formal document put out to computing experts by {{w|IETF}} in the hopes of becoming a future standard. However, RFC 1149 was an {{w|April Fools' Day Request for Comments|April Fools' joke}}, defining how carrier pigeons can be used to transmit Internet packets. "<nowiki>RFC 1149.5</nowiki>," meanwhile, simply does not exist.

==Trivia==

* The well-known "helper website" ([http://gChq.github.io/CyberChef/#recipe=XKCD_Random_Number() CyberChef]) has a function that simulates XKCD's program.
* Esolangs.org features a [http://esolangs.org/wiki/user:XKCD_Random_Number challenge] that requires you to rewrite the program in XKCD's comic in another programming language, as either a function or a full program that prints the "4".

==Transcript==
[A computer program.]
int getRandomNumber()
{
return 4; // chosen by fair dice roll.
// guaranteed to be random.
}

{{comic discussion}}
[[Category:Programming]]
[[Category:Computers]]
[[Category:Comics with lowercase text]]

Talk:2726: Methodology Trial

2023-01-19T17:56:28Z

172.70.162.223: /* But what if researchers did actually go through this? */

Woah! This is the first time I've seen a new comic without an explanation. It's pretty weird. [[User:SilverTheTerribleMathematician|SilverTheTerribleMathematician]] ([[User talk:SilverTheTerribleMathematician|talk]]) 02:36, 19 January 2023 (UTC)
:You just need to have checked at the right (or wrong?) time, which is different every publication day so you can't generally predict it. But at least three readers find empty explanations every week, and now it's your turn!. ''OR'', maybe this is just the first time you've unknowingly checked the placebo wiki... ;) [[Special:Contributions/172.70.91.75|172.70.91.75]] 02:54, 19 January 2023 (UTC)
04:10, 19 January 2023 (UTC)~ Comment on the title text. IRB is an Institutional Review Board, which I guess is a committee that decides if research is ethical and ok to do. The title text refers g to a placebo IRB, which I suppose is a fake IRB that can approve research as part of an experiment to determine the real effects of IRBs. Or something.

Why would this experiment be more unethical than any regular placebo trial? In either case you're telling patients they're getting actual medication when in reality they're getting sugar pills (or whatever you use as placebo). [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 08:22, 19 January 2023 (UTC)
:In a normal trial, the patients are told the researcher is giving out some candidate medicine and some placebo - typically they'd have a 50% chance of receiving a medicine that may help them. In this case, none of the treatments given will actually contain the active ingredient. I suppose it depends what you consider the "trial" (whether it includes all the test sites or just the one Cueball is running).[[Special:Contributions/172.70.85.46|172.70.85.46]] 10:40, 19 January 2023 (UTC)
::Placebo-based trials may have a threshold at which particularly significant results (as detected upon the half-unblinded results by the number crunchers that monitor progress) bring the primary study to a quick close and perhaps prepare to roll out the more than sufficiently proven treatment to all participants, for equal benefit from this point on. And now monitor for Adverse Events on both "early" and "late" treatment groups. (It might not benefit those who are "late", compared to the initial enrollment criteria, it might actually show greater improvement to them or it could even exibit a surge of unexpected AEs from those who have been on longer-term dosage regimes; that all still needs teasing out from the stats.)
::Probably, in such a case, the patients (and blinded doctors) are only told that the study phase is over, not whether they are now necessarily being switched treatments, for continued double-blindedness. Once the study is truly finished, it would depend upon what the participant actually signed up for as to whether they (or their next of kin) ever learn the historic details of their participation.
::Conversely, significant AEs (by frequency or severity) that are identified as cropping up worse in the test treatment (vs placebo ''or'' in studies vs whatever prior treatment they are comparing against) should result in early ending and all those being changed to already accepted treatments.
::(But, for the latter, it could also just initially be a pause. To review the circumstances and determine relevent details behind the bare data. Such as the unexpectedly recorded death in a small nasal-spray trial being 'just' from being a passenger in a car accident, unlikely to have any connection with which cohort the participant was in – absent of a reported spate of other unusual AEs that indicated hightened tendencies to dangerous physical impulses, anyway.)
::The study design should have levels of significance that the core stats team (unblinded as far as "Patients X, Y, Z took the active treatment") will raise escalating concerns about continuing in the face of the more convincing or ''un''convincing results, even if the AE discrepancy is not as clear (or, in some cases, expected) as actual death. Like raised/lowered levels of reported bedsores, etc. With viagra being the obvious "secondary side-effect" examplar, detected as useful beyond the intended scope of the initial studies. [[Special:Contributions/172.71.242.139|172.71.242.139]] 12:07, 19 January 2023 (UTC)

I'd sort of assume a placebo IRB would approve or deny projects randomly, where as a real one would "work" and actually analyse the projects being proposed. You could use this to see if the IRB is more ethical than a placebo, which you'd seriously hope. There'd obviously be a whole conversation on what constitutes more ethical, but you could prove that experimentally with a trial involving real and placebo philosophy and ethics departments [[Special:Contributions/172.70.250.245|172.70.250.245]] 09:29, 19 January 2023 (UTC)

Should we be so quick to dismiss their results as poor study design, or a statistical blip? Isn't it possible that they have detected a real world phenomenon - that the particular sub-group in question is more susceptible to the placebo effect - and that this therefore needs controlling for in the real treatment trial? [[Special:Contributions/172.70.162.56|172.70.162.56]] 15:10, 19 January 2023 (UTC)

== Fun with ChatGPT ==
=== Prompt 1 ===
Read the following XKCD comic strip transcript. Classify the roles of the characters (occupation). Explain the punchline. Explain the concepts of double-blind studies, the placebo effect, appropriate statistical significance, p-hacking and ethical considerations in medical research, and how they are portrayed in the comic strip.

[Cueball stands in front of a poster holding a pointer. The poster shows a scatter plot with four points and error bars, with one data point labeled "Subgroup" is marked with an asterisk and is placed somewhat higher up than the other three points.]
Cueball: However, we see clear evidence that the treatment is more effective than the placebo for some subgroups.
Off-panel voice: Thank you.
Off-panel voice: However, we can now reveal that the London team was studying the real treatment. Both groups in your study got a placebo.
Cueball: Aw, maaan...
[Caption below panel]
Researchers hate it when you do placebo controlled trials of their methodology.

=== Response 1 ===
The characters in this comic strip are researchers.

The punchline of the comic strip is that the researcher (Cueball) was presenting data that seemed to show that a treatment was effective, but it was revealed that both groups in the study actually received a placebo, and the researcher did not realize it.

Double-blind studies are a type of research design where neither the participants nor the researchers know which participants are receiving the treatment or the placebo. This is done to prevent bias in the results.

The placebo effect is a phenomenon where a person's condition improves after receiving a placebo, which is a treatment that has no active ingredient. This effect can occur because the person believes they are receiving a real treatment.

Appropriate statistical significance is a measure of how likely it is that a result is due to chance. A commonly used threshold for statistical significance is a p-value of less than 0.05, which means that there is less than a 5% chance that the results are due to chance.

P-hacking refers to the practice of manipulating data or analysis in order to achieve a desired level of statistical significance.

Ethical considerations in medical research include ensuring that the rights and well-being of participants are protected and that the research is conducted in an honest and transparent manner.

The comic strip portrays the researcher's frustration when their methodology is tested by other researcher using a placebo controlled trial, and their results are not significant. It also highlights the importance of double-blind studies and appropriate statistical significance in research, as well as the dangers of p-hacking and the importance of ethical considerations in medical research.

=== Prompt 2 ===
Take on the role of the researcher from the comic strip. Make a follow-up comic strip abut another research project this researcher undertakes. Come up with a funny and surprising, moderately nerdy punchline in XKCD style.

=== Response 2 ===
[Cueball is standing in front of a poster holding a pointer. The poster shows a bar graph with two bars, one labeled "Treatment" and one labeled "Placebo". Both bars are the same height.]
Cueball: Our latest study on the effectiveness of a new drug shows no significant difference between the treatment and the placebo.
Off-panel voice: But wait, there's more!
Off-panel voice: We have just discovered that both groups were accidentally given the same dosage of the drug.
Cueball: (groans) I guess we'll have to redo the study with the correct dosages.
[Caption below panel]
Researchers hate it when you do a dosage controlled trials of their methodology.

In this follow-up comic strip, the researcher (Cueball) is presenting the results of a study on a new drug, and it is revealed that the study was flawed because both the treatment group and the placebo group received the same dosage of the drug, thus not allowing the researcher to determine the effectiveness of the drug. The punchline is that researchers hate it when you do a dosage controlled trial of their methodology, highlighting the importance of proper research design and execution.

== The Simpsons did it before ==

Nope, for once NOT The Simpsons. A German SF TV classic:

https://de.wikipedia.org/wiki/Das_Blaue_Palais#Die_einzelnen_Folgen
(Nr. 4, "Unsterblichkeit" - "Immortality")

Spoiler (as if anyone cares): Some mad scientist invented immortality
(but only in the sense of "not aging", which is relevant, see below).
The treatment is now tested in a placebo/true stuff split experiment,
with the foreseeable effect that the "immortal" ones now are afraid
of literally everything. (If you die anyway, you might as well smoke,
drive a car, start a war, etc. pp.)
Until it is revealed that another group interfered and, fearing the
ethical consequences (the mad scientist didn't care about),
substituted everything for placebo.

== But what if researchers did actually go through this? ==

I can't help but wonder what if researchers did have to go through this. [[User:Fephisto|Fephisto]] ([[User talk:Fephisto|talk]]) 16:46, 19 January 2023 (UTC)
:I've heard of newly employed team of 'fresh' statiticians being 'broken in' on a fully placebo study (no actual patients, but looks like a regular one and may have some deliberate features added to it to make it interesting but not actually worrying) to see what they'd be actually like in the deep end (without them drowning themselves or anybody else, if they panic). But it's not as usual as each just individually serving in an assistive role/'apprenticeship'.
:I think it might have been a make-work thing, too, as they were hired for a project that was delayed, and it seemed easier to concoct a 'training scenario' than distribute them around the other groups (or let them go, again, for the duration) until they needed to be hauled back together to work with the main lead (who had plenty of other things too keep themselves busy, even after generating the simulated data-run they'd be trickle-fed).
:Not sure what ''they'' thought about the ethics of it, but as it affected nobody except themselves (and they were still earning the promised wages)... [[Special:Contributions/172.70.85.46|172.70.85.46]] 17:51, 19 January 2023 (UTC)

859: (

2023-01-19T11:09:50Z

172.70.162.223: /* Explanation */ The unterminated paren example-joke was done in the para above, so restoring (if that was the intent, and not mistaking a code-tagged close paren for 'real'). And the "in" and "they" just caused awkward phrasing, whatever the ()ing.

{{comic
| number = 859
| date = February 11, 2011
| title = (
| image = (.png
| titletext = Brains aside, I wonder how many poorly-written xkcd.com-parsing scripts will break on this title (or ;;"'<nowiki/>'{<<[' this mouseover text."
}}

== Explanation ==

In programming, punctuation is often used to mark sections of code. Paired punctuation marks must always be matched up with a corresponding closing mark, otherwise a so-called {{w|syntax error}} occurs. The programming language {{w|Lisp_(programming_language)|Lisp}} (also featured in [[224: Lisp]] is known for large numbers of nested/paired parentheses. Even in literary works intended only for human consumption, the absence of a matching closing parenthesis as appears in this sentence or other "balanced" punctuation sets creates a mental expectation of eventual closure and completion that remains unfulfilled even long after the unmatched mark is encountered.

There is also reference to [[312: With Apologies to Robert Frost]] which could contain the missing parentheses.

It can also be interpreted as a {{w|metaphor}}, which compares the reader with a Lisp {{w|Interpreter (Computing)|interpreter}}. The interpreter looks for the parenthesis until the end of the file, where it eventually halts, and prints out the error. The comic claims that if you read an unmatched parenthesis, you will look for it for the rest of the day too.

It also refers to an awkward feeling when you see something out of place in a piece of literary text (like unmatched parentheses, spellying error or a randomly-plac,ed comma..

Finally, some countries (Russia in particular) use just parentheses instead of text smileys so that <code>:)</code> turns into <code>)</code> and <code>:(</code> becomes <code>(</code>. Hence those readers can magically resist the unresolved tension of the comic but may feel a bit sad instead as a side effect.

The title text refers to the same issue as already highlighted in [[327: Exploits of a Mom]]: if your scripts trust external input, you sometimes will be surprised. At the time of this comic, there were quite a few websites that would grab the xkcd comic three times a week and publish them on their own site. This comic likely broke at least some of the websites because of either the unmatched paren or the extra unmatched markup that is in the title text.

==Transcript==
:[Caption inside an oblong panel:]
:(An unmatched left parenthesis creates an unresolved tension that will stay with you all day.

==Trivia==

* The well-known "helper website" ([http://gChq.github.io/CyberChef/# CyberChef] has a text on its loading page that is a reference to this comic, probably as a joke.

{{comic discussion}}
[[Category:Programming]]

Talk:2722: Etymonline

2023-01-10T10:25:06Z

172.70.162.223: Comment reply

Random fact: I recently finished reading etymonline.com from beginning to end. It taught me things about the English language that I didn't know that I didn't know. [[User:Darthpoppins|Darthpoppins]] ([[User talk:Darthpoppins|talk]]) 00:46, 10 January 2023 (UTC)
:Nice. [[Special:Contributions/172.71.167.235|172.71.167.235]] 04:16, 10 January 2023 (UTC)

Dear whomever wrote the current explanation, please take an English composition course. It's clear you mean well, but it's really hard to read your work. [[Special:Contributions/172.71.158.216|172.71.158.216]] 04:44, 10 January 2023 (UTC)

In the comic, french word "étymologie" is incorrectly spelled "ethimologie" which is referred to as "Old French". I wonder whether that mistake was done on purpose ?
[[Special:Contributions/141.101.68.222|141.101.68.222]] 08:12, 10 January 2023 (UTC)
: "Old French etimologie, ethimologie (14c., Modern French étymologie), from Latin etymologia, from Greek etymologia" from the Etymonline entry for "etymology"[[Special:Contributions/172.70.162.223|172.70.162.223]] 10:25, 10 January 2023 (UTC)

: Given that it's over 350 years from now, it really ought to say 'from Old English etymology', with what we currently call Old English now being known as Really Old English.[[Special:Contributions/172.71.178.65|172.71.178.65]] 09:09, 10 January 2023 (UTC)

2715: Pando

2022-12-23T14:13:20Z

172.70.162.223: /* Explanation */ Wikilink the Populus Tremuloides, and reverse the "tree/stalk" to "stalk/tree" to reflect functional and/or temporal primacy rather than assumed/actuality situation.

{{comic
| number = 2715
| date = December 23, 2022
| title = Pando
| image = pando_2x.png
| imagesize = 422x372px
| noexpand = true
| titletext = The presents under the tree are actually a single gift connected by an underground ribbon system.
}}

==Explanation==
{{incomplete|Created by a CHRISTMAS PANDA — Please change this comment when editing this page. Do NOT delete this tag too soon.}}

{{w|Pando_(tree)|Pando}} is a {{w|Populus tremuloides|quaking aspen}} tree colony in {{w|Fishlake National Forest}}, Utah. Depending on how you measure[https://www.youtube.com/watch?v=vWAA-SrrFUQ], Pando is the largest living organism on earth, and is thereby also the largest tree on earth. By dry mass (weight not including water), Pando is the largest living thing humans have found. There is [https://www.forbes.com/sites/linhanhcat/2019/02/22/largest-organism-in-the-world/?sh=43fdf2a444ac one fungus in Oregon] which may weigh more including water, but that fungus is not a tree.

Pando is a Tree colony, a type of {{w|Clonal colony}} made of trees. Clonal colonies all form from the same seed or other origin, and are all genetically identical. Tree colonies spread using their extensive root system. Under all trees there are {{w|Root|roots}}, which gather nutrients and water from soil. On clonal trees (such as the {{w|Populus tremuloides|Quaking Aspen}}, Pando's species), when roots from one tree surface they can form another stalk/tree. This additional stalk is a genetic clone of the original. This clone then grows its own root network, and where they surface they too form more clones. However, crucially, the roots between the clones do not naturally separate, so all clones naturally stay attached. Each clone has a limited lifespan, only a few decades/centuries, but the colony can live for millennia. For example, the only known wild example of {{w|Lomatia tasmanica|''Lomatia tasmanica'', aka King's lomatia}}, is a clonal shrub thought to be at least 43,600 years old, and Pando itself is thought to be around 14,000 years old.

{{w|Christmas}} is a celebration on the 25th of December, traditionally celebrating the birth of {{w|Jesus}}, but that festival being built heavily upon pagan traditions[https://chefin.com.au/blog/these-6-christmas-traditions-are-actually-pagan-customs/] and annual social customs, then arguably converted into a far more secular event (with or without rampant consumerism). This comic was published on the 23rd of December, 2 days until Christmas, or [[Christmas Eve Eve]]

The concept of a {{w|Christmas tree}}, itself, is rooted in various pre-Christian folkloric traditions and, in the modern era, may be adapted or adopted as required by local and personal circumstances, and need not be an {{w|Evergreen}} fir tree with an angel (or star) atop, but merely any handy plant (or artificial substitute) strewn with such decorations and/or {{w|Christmas lights|lights}} as the owner wishes. Because humans are, well, humans, people and places often compete to hold the record for the largest Christmas tree. At time of publishing (and writing), the tallest Christmas tree is officially a 64.36m (221ft) tall {{w|Douglas fir}} that was displayed in {{w|Northgate Station (shopping mall)|Northgate Shopping Center}}{{Actual citation needed}}, Seattle, WA in 1950[https://www.guinnessworldrecords.com/world-records/77271-tallest-christmas-tree][https://www.historylink.org/File/21359]. The most widely spread, however, is likely the [https://www.italybyevents.com/en/events/umbria/world-largest-christmas-tree-gubbio/ Christmas tree display] in {{w|Gubbio}}, a town in Umbria, Italy, where hundreds of trees on a mountain face are lit up with light to form a Christmas tree shape.

Sidenote: A lot of articles say that the Gubbio tree has a Guinness world record. However, I can't find a citation for that. If anyone can, please add it. That would be appreciated.

In this comic, [[Randall]] proposes putting Christmas lights all the way around Pando to turn into (technically) a Christmas tree. As Pando is the worlds largest tree then, if this plan were to be carried out, it would safely take the record and hold it for quite some time.

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

:[The main comic frame is a profile view of a number of separated trees, of varying heights and maturity, across each of which (of those with sufficient height) has apparently been draped a single chain of decorative lights that goes from off-image at one side to off-image at the other.]

:[Inset in the bottom right is a mini-map implicating that these light-linked 'trees' are actually all risers from a single large superorganism (as a shaded complex but contiguous shape labelled "Pando"), the map has a "N"orth pointer, a scale bar indicating the length of "1,000 ft" (approximately a third of the shaded mass's full width) and a convex hull perimeter line tightly fitting the shaded area that has an indicative arrow from a label informing us that its length would be "9,300 ft".]

:[Caption below:] Christmas Science Fact: Pando is approximately 9,300 feet away from being the world's largest Christmas Tree.

{{comic discussion}}

[[Category:Comics with lowercase text]]

2707: Astronomy Numbers

2022-12-07T15:56:29Z

172.70.162.223: /* Explanation */ Better way of explaining why 12 potentially equals 13-and-a-bit...

{{comic
| number = 2707
| date = December 5, 2022
| title = Astronomy Numbers
| image = astronomy_numbers_2x.png
| imagesize = 593x315px
| noexpand = true
| titletext = I adopted a cat that weighs 12 solar masses. Laser pointers love chasing it.
}}

==Explanation==
{{incomplete|Created by A WARPED SPACE-TIME CONTINUUM - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
Space is big[https://www.youtube.com/watch?v=Hv1spjsvu-A] and the things that are in space can also end up being very big themselves. As a result of this, most quantities in astronomy can vary by huge scales. For example, Earth has a mass 10^23 times more than the average human, and the Sun is 10^5 times more than that, which itself is 10^12 times less massive than the Milky Way. The same applies to speeds, distances, and time, which can often be measured in terms of light speed, light-years, and millions (or even billions) of years. Because of this, it's a truly unusual occurrence for anything in space to end up in the fairly narrow range of scales of mass, size, speed, or time that humans can easily grasp.

Ponytail, a scientist apparently researching something related to Earth's orbit, finds that on the next January 1, Earth will be approaching the sun at a velocity of 65 miles per hour—an extremely common and normal-sounding velocity to American ears, often used as a speed limit on highways in the US. Ponytail is clearly a little thrown-off by this, and remarks that she finds it "suspicious" when reasonably human-scaled numbers come up.

She then extends this paranoia to things that should be measured in regular numbers, such as the weight of cats. The vet (Megan) is seemingly used to this problem (perhaps she gets a lot of physicists), so she restates the 12-lb weight of Ponytail's cat in solar masses. Since using this unit yields an ''incredibly'' small number, 3*10^-30 (a three preceded by a decimal point and 29 zeroes), it evidently sounds more plausible to the astronomer. This exact weight is in fact somewhere about 13lb 2oz, slightly heavier than the initial figure given for the cat, but where the precision was kept [[2585: Rounding|or lost]], during conversion, is debatable.

==Details on the numbers==
Although the Earth's orbital velocity around the Sun is far above any "normal" scales (around 30 kilometers per second or 108,000 kilometers per hour), Earth has a pretty circular orbit around the Sun so most of this speed ends up being tangential (sideways) rather than radial (towards or away from) the Sun, which is the value relevant for Ponytail's calculations. On January 1, Earth's radial velocity is close to its smallest value because we reach our closest point to the Sun in the first few days of January each year (in 2023, {{w|Perihelion|perihelion}} happens on January 4) so by January 1, it's nearly come to a standstill before it starts traveling away from the Sun again. On the other hand, by April 3, 2023, Earth will be receding from the Sun by almost 500 meters per second or 1800 kilometers per hour, a slightly less normal speed for the average person to encounter in everyday life.{{citation needed}}

65 miles per hour is approximately equal to 105 kilometers per hour, although the even more typical scientific value (in {{w|International System of Units|SI}} derived units) would be 29 meters per second. 3 × 10^−30 solar masses is approximately equal to 6 kilograms or 13 pounds (consistent with the 12 pounds, or slightly under 5.5 kilograms, of the original figure) and is normal, if perhaps slightly overweight, for a cat.

==Title text==
The title text suggests that laser pointers "love chasing" a new cat with a weight of 12 solar masses (an inversion of the typical cat behavior of [[729: Laser Pointer|chasing laser pointer dots]]). A 12 solar mass cat would have the dominant gravitation well in our solar system which would let fall everything towards the cat – including laser pointers. Furthermore, all gravitational fields bend light towards their center; a 12 solar mass object would bend quite a lot. A Laser pointer pointed at such a cat would bend towards it or "chase" it. In fact, 12 solar masses, would have a Schwarzschild radius of around 36 kilometers, so a cat with that mass would very definitely be a black hole, drawing all light within 72 kilometers around it into its singularity.

Another interpretation of the title text is that Randall has (presumably) accidentally adopted a distant star instead, which astronomers usually take a liking to pointing laser pointers at during both star parties & normal parties they were unwisely invited to. Assuming Randall's 12-solar-mass cat goes through similar life cycles to a 12-solar-mass star, his cat will probably end up living a violent, short life of just a few million years before expanding into a red supercat and exploding as a feline supernova, which might explain why astronomers are so interested in pointing it out. Or maybe a {{w|Laser guide star}} for a telescope with adaptive optics is being referred to.

==Transcript==
:[Ponytail is standing in front of a whiteboard writing on it with a pen, while Cueball looks over her shoulder from behind her. On the board is an almost circular ellipse with a cross that centers on a dot towards the left side of it. On the right side there is a small circle on the ellipse's line. There are several lines of wiggles representing unreadable text. To the left of the ellipse there are two lines near the top of and four near at the bottom of the ellipse. Ponytail is writing a fifth line below these almost under the ellipse. At the bottom to the left there is a rectangular frame with a line of text beneath it and at the bottom left corner there is a line forming a half closes rectangle around two dots.]
:Ponytail: …And we need to correct for our elliptical orbit. On January 1st, Earth will be approaching the sun at a rate of ...let's see...
:Ponytail: 65 miles per hour.
:Ponytail: Weird. Okay.
:Cueball: Weird?

:[Ponytail has turned towards Cueball, the pen is no longer in her hand and the white board is no longer shown.]
:Ponytail: I get suspicious whenever I see a normal number in astronomy. We're not supposed to have those. Feels wrong.
:Ponytail: Scales should all be incomprehensible.

:[Megan in a lab-coat raised her hand palm up towards an animal carrier cage standing on her desk. The cage has a handle and five air holes are at the top. Behind two of them something black inside the cage can be seen. Ponytail is standing on the other side of the desk looking at Megan. Above the top of the panels frame there is a panel with a label:]
:Earlier, at the vet:
:Megan: Your cat weighs 12 lbs.
:Ponytail: Ridiculous, nothing weighs "12". You must mean 10-20? Or 1040?
:Megan: Fine. Your cat weighs 3x10-30 solar masses.
:Ponytail: Okay. Better.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Megan]]
[[Category:Astronomy]]
[[Category:Cats]]

2705: Spacetime Soccer

2022-12-01T12:46:27Z

172.70.162.223: /* Transcript */

{{comic
| number = 2705
| date = November 30, 2022
| title = Spacetime Soccer
| image = spacetime_soccer_2x.png
| imagesize = 740x280px
| noexpand = true
| titletext = Spacetime Soccer, known outside the United States as '4D Football' is a now-defunct sport. Infamous for referee decisions hinging on inconsistent definitions of simultaneity, it is also known for the disappearance of many top players during... [more]
}}

==Explanation==
{{incomplete|Created by a FOUR-DIMENSIONAL GOALIE - I still don't know what the offside rule actually is. I think it might... [more]. Do NOT delete this tag too soon.}}
This comic proposes Spacetime Soccer, an impossible{{Citation needed}} sport consisting of a "regular" football field with a gravitational well in the center of it (although given the size of the indent presented, it would likely be spanning the size of planetary orbits). Not only would it be impossible for human players to travel through more than three spatial dimensions, it would also be very difficult to keep track of score and rules such as offsides. This comic was likely published in relation to the 2022 World Cup.

{{w|Offside (association football)|Offside}} is a description in soccer that applies to players who are in certain positions relative to the boundaries of the pitch, the ball, and the second-last opponent on the opposing team. Players in such positions are eligible for being judged guilty of an offside offence if they become involved in the ongoing play before rectifying their status. It is of special importance to know the different players' positions at the exact moment the ball gets passed, rather than when the passed ball may be received or the offside player is otherwise considered active. But in relativistic spacetime there is no universal definition of an exact moment, beyond a single point, as time may run at different speeds for multiple observers in varying situations (where they are moving relative to each other, are influenced by differing local gravity or – as seems very likely in this example – both).

The title text is written in the style of the beginning to a Wikipedia article on the topic. It mocks the fact that most countries in the world refer to the sport with that particular obscure offside rule as football (or some translation thereof, like fútbol or Fußball) while the USA call it soccer, which comes from the British shortening of "association football", because they already used the name "football" for gridiron football.

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

Some of the lines of a standard Association Football pitch are drawn on a "rubber sheet" visualisation of a gravity well in four dimensional spacetime. Visible features of the standard pitch are the outside borders, the goals and the small and large boxes around each. Absent are the corner quarter circles, the penalty spots and associated D, and the centre line. The central circle seems absent, but could be concealed by the curvature of the sheet. There are a number of other lines encircling and radial to the gravity well, they are visually identical to the familiar pitch markings so it is unclear whether these are intended to be drawn on the pitch or merely indications of the shape of the surface. A total of twenty figures can be seen on the pitch. Two are standing near the goal mouths, the rest are distributed around, and (as stick figures) it is impossible to say which are on each team or if one is the referee. A ball with motion lines is landing by the feet of one player who is running up one wing. There are six figures plus the goalkeeper closer to the goal in the direction the player and ball are travelling, so (if the image shows "simultaneous" positions) the player is unlikely to be offside.

:Spacetime soccer got a lot of criticism for how many players fell into the gravity well, but what ultimately doomed it was the advanced mathematics required to figure out the offsides rule.

{{comic discussion}}

Talk:2699: Feature Comparison

2022-11-17T09:52:23Z

172.70.162.223:

The image has changed. Now Mastodon includes USER-RUN INSTANCES (though I believe it should also have a check next to DOESN'T REQUIRE CENTRAL SERVER).

I tried googling "wikipedia feature comparison chart". Instead of finding a page explaining how these charts work, I got a chart comparing different wiki softwares. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 23:22, 16 November 2022 (UTC)

Of course, it wouldn't be hard to make apps on smartphones support mesh networks ... however, the manufacturers and app developers prefer to work hard to make sure they don't work without being connected to internet and serving advertisement. [https://en.wikipedia.org/wiki/Wi-Fi_Direct Although ...] -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 00:25, 17 November 2022 (UTC)

There seems to be a lot of wrongness about this matrix. Besides that mastodon instances can be run by user (which is fixed):
* Mastodon does not support file transfer. You can only upload images, and ''not'' even all image formats—webp is not supported. Some other ActivityPub servers support file upload, but then it's not Mastodon.
* IRC also doesn't support file transfer afaik.
* Mastodon and SMS don't require a central server
* Discord, Reddit, and Slack doesn't have user-run instances
* Discord doesn't have builtin games last time I checked. The games are by the bots,

I don't know about Slack, but pretty much all of Discord and Reddit is user-run/moderated instances.
:That slash is doing a lot of work there. [[Special:Contributions/172.69.34.31|172.69.34.31]] 06:57, 17 November 2022 (UTC)

"IRC itself is a teleconferencing system, which (through the use of the client-server model) is well-suited to running on many machines in a distributed fashion. A typical setup involves a single process '''(the server) forming a central point''' for clients (or other servers) to connect to, performing the required message delivery/multiplexing and other functions." – J. Oikarinen, D. Reed; Internet Relay Chat Protocol; RFC 1459; May 1993. Emphasis added. [[Special:Contributions/172.71.154.158|172.71.154.158]] 01:45, 17 November 2022 (UTC)

Notably, Mastodon ''eschews'' file transfer - audio specifically - for fear of enabling piracy (issue #7495). Tumblr would have a more comprehensive version of file transfer.
[[Special:Contributions/172.71.146.136|172.71.146.136]] 03:17, 17 November 2022 (UTC)

IRC has (X)DCC for File Transfers and for it's centralisation it depends on the deployment, the original network that became EFNet (Eris-Free Network) doesn't have a central server, but things like Libera and OFTC have centralised services for authentication and servers maintained by only one organisation. Btw for games on the fediverse (which Mastodon is part of) Misskey includes some, sadly they're centralised. [[User:Lanodan|Lanodan]] ([[User talk:Lanodan|talk]]) 03:40, 17 November 2022 (UTC)

Tumblr does have group chats. They're publicly viewable by anyone, but only people in the group can send messages, so I think they still count as group chats.

It appears we are all having a [[386]] moment watching Randall finally be wrong about something. How dare he?! [[Special:Contributions/172.70.111.30|172.70.111.30]] 05:37, 17 November 2022 (UTC)
: Nobody wants to put this train wreck into the explanation, but someone has to. I'm guessing we're waiting for further corrections just in case.
[[Special:Contributions/172.69.34.31|ki172.69.34.31]] 06:57, 17 November 2022 (UTC)

Discord did add games recently: https://discord.com/blog/server-activities-games-voice-watch-together
[[User:Spenc|Spenc]] ([[User talk:Spenc|talk]]) 07:28, 17 November 2022 (UTC)

He also just left out Matrix entirely, y'know I'm starting to think this isn't a serious comparison. --[[Special:Contributions/172.70.250.193|172.70.250.193]] 07:42, 17 November 2022 (UTC)

Not sure what built-in would mean, but Slack has plenty of games you can install on it as an admin [[Special:Contributions/172.70.162.223|172.70.162.223]] 09:52, 17 November 2022 (UTC)

2548: Awful People

2021-11-30T13:21:50Z

172.70.162.223: /* Explanation */ I think this is more poetic. Or is it merely more prosaic? Either way, I consciously rejected "...to be slain", for my edit, though YMMV.

{{comic
| number = 2548
| date = November 29, 2021
| title = Awful People
| image = awful_people.png
| titletext = Hm, this burger place has a couple of good reviews, but LakeSlayer7 says he got food poisoning there and everyone should try this other place down by the lake instead.
}}

==Explanation==
{{incomplete|Created by a NORMAL PEER (DEFINITELY NOT A TROLL BOT, TRUST ME, I PROMISE) - Please slay this comment when editing this lake. Do NOT try that burger place with the good reviews.}}

Megan and Cueball are having a conversation about social media. Megan relates a negative comment she got from a stranger about her taste in movies. The twist is that it turns out the person criticizing her was a murderer. Although this does not inherently negate his taste in movies, it does free Megan from the burden of weighing his opinions equally to her own.{{citation needed}}

The title-text mentions the “LakeSlayer7” which is clearly a reference to the "Lake Slayer" in the comic. They mention that a burger joint in town is unsatisfactory, and that the reader should come to a place “by the lake” instead, which might be (and probably is) a plot to lure people to the lake and to be slayed.

In many "[[918: Google+|social]]" and "[[997: Wait Wait|news]]" sites there is a tendency to surface [[258: Conspiracy Theories|negative content]]. This can be [[1111: Premiere|editorial intent]], [[2237: AI Hiring Algorithm|naive algorithms]], or [[1390: Research Ethics|both]], attempting to induce rage to drive "engagement". "Review" sites can exhibit a [[1098: Star Ratings|bias]] in either direction, with minutiae [[937: TornadoGuard|burying]] valid feedback.

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

:[Cueball and Megan are having a conversation while walking.]
:Cueball: The Internet makes it easy to be a jerk and forget the person we're talking to is a human.
:Megan: Yeah...
:Megan: But it also makes us see messages from awful people and assume they come from normal peers.

:[Closeup on Megan. Above Megan is a picture of a "reply" post from a man with sunglasses. The post has a title above it.]
:Megan: Recently I got a mean reply from a stranger. It was minor but it really got to me.
:Post title: Replies to "Favorite Movie"
:Post: Every group has one person who likes that movie, and it's the friend they all secretly hate.

:[Blondie as a news anchor behind a desk. There is a picture of the man with sunglasses with "Arrested" under his name. His picture is next to a picture of a house with "Breaking" above it. Megan's dialogue appears above the picture, but she herself is not shown in this panel.]
:Megan: Then the next week I saw that guy on the news. He was an actual murderer!

:[Megan and Cueball standing next to each other.]
:Megan: I can't believe I spent a week stressed out that my taste in movies wasn't shared by the East Valley Strangler.
:Cueball: Yeah, at ''least'' wait for a second opinion from the Lake Slayer.

{{comic discussion}}
[[Category:Comics featuring Blondie]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Social networking]]

2545: Bayes' Theorem

2021-11-23T16:36:32Z

172.70.162.223: /* Explanation */ Salt to taste.

{{comic
| number = 2545
| date = November 22, 2021
| title = Bayes' Theorem
| image = bayes_theorem.png
| titletext = <nowiki>P((B|A)|(A|B)) represents the probability that you'll mix up the order of the terms when using Bayesian notation.</nowiki>
}}

==Explanation==
{{incomplete|Created by <nowiki> P(d/dx x^x|P(d/dx|x^x))) </nowiki> - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

{{w|Bayes' theorem}} describes the probability of an event, given knowledge of conditions related to the event. It is typically used to update the probability that a starting condition occurred, given an outcome. This can reveal unintuitive results when the probability involved is very small. For example, when testing a large number of people for a rare disease, even a fairly accurate test will produce more false positives than the number of people actually afflicted with the disease, and hence a positive result is more likely to be false than true.
{| class="wikitable"
|| || Tested positive || Tested negative || Total
|-
|| Affected || 0.1% || 0.0% || 0.1%
|-
|| Unaffected || 0.9% || 99% || 99.9%
|-
|| Total || 1% || 99% || 100%
|}
For example, if a test has a 100% sensitivity (all those infected receive a positive result) and a 99% specificity (1% of the uninfected also appear to be so), the interpretation of a positive test depends on the prevalence (percentage of affected). In the example case, the prevalence is 0.1%, so that when the test result is positive (left column) the subject is unaffected nine time out of ten. Although this would be a very performant test (functionally useful), given the relative prevalences involved the chances are that it will produce overwhelmingly false positives.

For this same example, the Bayesian formula gives : P( Affected | Positive ) = P( Positive | Affected ) * P( Affected ) / P( Positive ) = 100% * 0.1% / 1% = 10% and P( Unaffected | Positive ) = P( Positive | Unaffected ) * P( Unaffected ) / P( Positive ) = 0.9009% * 99.9% / 1% = 90%

In this comic, a teacher is presenting a problem which the students are supposed to use Bayes' theorem to solve. However, the off-panel student knows that they are studying Bayes' theorem, so they use that prior knowledge to guess the usual answer to such problems. The punch line is the caption - The student doesn't need to do the calculation because they're familiar with questions involving Bayes' theorem and how they often present the counter intuitive result to illustrate the importance of prevalence to the calculation.

There is perhaps also a self-referential situation here where the student has updated their prior probabilities a number of times for whether the answer was "Yes" to a question involving Bayes' Theorem. If their method of answering "Yes" to every such question has succeeded every time before then by Bayes' theorem they will have a lot of justification to continue to do until they start getting it wrong. The prevalence of Bayes Theorem questions that require the answer "No" might be small enough that this doesn't happen in any small number of times and so they learn nothing of the false-positive rate until that point in time. This could be interpreted as a criticism of Bayesian Statistics which may treat a judgement as well justified (e.g. getting the question right) despite lacking a clear understanding of mechanism (e.g. basing your answer to the question on the numbers provided).

The title text refers to the mathematical definition of Bayes' theorem: P(A | B) = P(B|A) * P(A) / P(B). Here, P(A|B) represents the probability of some event A occurring, given that B has occurred. This is often referred to as "the probability of A given B". It can be hard to remember if P(A|B) means probability of A given B, or if it's B given A, especially when talking about the probability of an earlier cause given a later effect. Randall's joke is based on this difficulty. Here P((B|A)|(A|B)) is meant to be read as the probability that you ''write'' (B|A) given that the correct expression is (A|B), which makes it the probability that you got the order of the notation mixed up.

==Transcript==
:[Miss Lenhart is pointing with a pointer, held in her right hand, to a white-board with tables, what looks like formulae and lots of other unreadable text. She looks toward her off-panel class, from where a voice replies to her question.]
:Miss Lenhart: Given these prevalences, is it likely that the test result is a false positive?
:Off-panel voice: Well, this chapter is on Bayes' Theorem, so yes.

:[Caption below the panel]:
:Sometimes, if you understand Bayes' Theorem well enough, you don't need it.

==Trivia==
*When this comic came out, the title text was only "P((B", and the comic itself linked to [https://xkcd.com/2545/A) A)] or [https://xkcd.com/A) A)] (depending on where the comic was viewed from) and the "Black Lives Matter" image in the header was replaced by "(A", but this was quickly corrected.
**See this [https://web.archive.org/web/20211122212442/https://xkcd.com/2545/ archived] version.
*It turns out that it is the notation that messes with the home page as it also messes with this wiki.
**In this [https://www.explainxkcd.com/wiki/index.php?title=2545:_Bayes%27_Theorem&oldid=221182 version] of this page, the [https://www.explainxkcd.com/wiki/index.php?title=2545%3A_Bayes%27_Theorem&type=revision&diff=221182&oldid=221181 correct title text] has been entered, but it still looked the same so everything from behind the first "|" fails to show.
**Now this has [https://www.explainxkcd.com/wiki/index.php?title=2545%3A_Bayes%27_Theorem&type=revision&diff=221183&oldid=221182 been fixed] using the <nowiki><nowiki></nowiki> format.
***Seems like [[Randall]] made an exploit on himself like [[Mrs. Roberts]] did in [[327: Exploits of a Mom]].
***This is extra funny since [[Blondie]], is both sometimes used for Mrs Roberts and for Miss Lenhart from this comic.

{{comic discussion}}

[[Category:Comics featuring Miss Lenhart]]
[[Category:Statistics]]

2541: Occam

2021-11-12T20:22:28Z

172.70.162.223: /* Explanation */ And I wrongly enclosed!

{{comic
| number = 2541
| date = November 12, 2021
| title = Occam
| image = occam.png
| titletext = Oh no, Murphy just picked up the razor.
}}

==Explanation==
{{incomplete|Created by a BOT THAT ONLY CREATES ALL PAGES NOT MENTIONING ITSELF - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic conflates three conceptual approaches. {{w|Occam's Razor}}, {{w|Russell's Paradox}} and {{w|Murphy's Law}}.

Occam would suggests that explanations that do not add unnecessary assumptions (the 'simplest') should be your position until proven otherwise. The 'razor' conceptually cuts away those alternative explanations, to leave just whatever is currently most valid.

Russell postulates, in one analogy of it, the paradoxical situation in which a barber is expected to shave (with an in-universe razor) all men in his town who do not shave themselves. The question is whether he must/must not thus shave himself.

In the titletext, Murphy is invoked as the expectation (sometimes known as Sod's Law) that if anything can go wrong, in any given circumstance, it will. Shaving with a {{w|Straight razor|cut-throat razor}} has failure modes including one explained by the name.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[One panel. Megan and Cueball walking.]

Megan: The simplest explanation is that Occam shaves the barber.

{{comic discussion}}

2540: TTSLTSWBD

2021-11-11T12:13:52Z

172.70.162.223: /* Explanation */ An organ "living" in its own right has connotations to be avoided. That change required its "function" to be rephrased for rhetoric flow reasons. It's a good job the "pulled/pushed" bit didn't mention an operation at all... ;)

{{comic
| number = 2540
| date = November 10, 2021
| title = TTSLTSWBD
| image = ttsltswbd.png
| titletext = Tomorrow's sessions will be entirely devoted to sewing machine rotary hooks.
}}

==Explanation==
{{incomplete|Created by a BOT THAT SEEMS LIKE IT SHOULDN'T WORK BUT DOES. Do NOT delete this tag too soon.}}

[[Cueball]] is standing at a [[1661: Podium|lectern]], addressing a large crowd. He is describing the program of some event, listing the different topics that will be covered. These appear to be random, but the caption gives the punchline: it is a conference on things that seem like they shouldn't work but do.

By "things that seem like they shouldn't work", it means things that you wouldn't expect to be able to function at all.

{{w|Organ transplantation}}, where a functioning organ is pulled from a (possibly dead) person and put into another person where it will continue to operate, is not a simple process, and a lot of things could go wrong and make it not work. Nevertheless, humanity’s medical knowledge is advanced enough that organ transplantation is a widely accepted and largely effective life-saving procedure.

{{w|Airship|Airships}}, or dirigibles, are big,{{citation needed}} have a metal envelope, and look pretty heavy,{{citation needed}} but are able to be held aloft by the lighter than air gas inside.

{{w|Gyroscope|Gyroscopes}}, where a spinning disk will tend to keep its orientation in space despite the movement of the structure around it, can be counterintuitive even to those who understand the physical principles. This weirdness has been previously referenced in [[332: Gyroscopes]].

{{w|Butterfly|Butterflies}} fly with an unusual fluttering behaviour, which works in part due to the notoriously complex principles of fluid dynamics. This is not as intuitively understandable as the flight of larger creatures such as birds.

The title text refers to {{w|Rotary hook|rotary hooks}} on sewing machines, which are a complicated, and complicated looking, mechanism, to the extent that they feel they need a whole day to cover them.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball stands at a lectern gesturing with one hand held out, speaking to an audience. A banner hangs on the wall with the acronym "TTSLTSWBD" displayed in large text, with illegible smaller text under it.]
:Cueball: Next we have a session on organ transplants and another on airships.
:Cueball: Then lunch, then we'll have one on gyroscopes and one on butterflies.
:[Caption below panel:]
:The first annual conference on Things That Seem Like They Shouldn't Work But Do

{{comic discussion}}

434: xkcd Goes to the Airport

2021-10-26T11:43:24Z

172.70.162.223: /* Explanation */ Added a sentence to the end of the paragraph about lockpicking.

{{comic
| number = 434
| date = June 9, 2008
| title = xkcd Goes to the Airport
| image = xkcd_goes_to_the_airport.png
| titletext = Under three ounces, but it stains panties.
}}

==Explanation==
The various characters of [[xkcd]] cause problems at the airport due to their various quirks.

*[[Beret Guy]] and [[Megan]] are lost, following each other in a loop. Beret Guy displays his obsession with baked goods as he also does in later comics: [[442: xkcd Loves the Discovery Channel]] and [[452: Mission]].

*[[Cueball]] tries to carry a {{w|Lock picking|lockpick set}} (a tool able to unlock doors without the original key) through security. The security guard tells Cueball that he has to come with him, but Cueball wants to tell the guard about "this hacker girl" before going with the guard (interestingly Cueball doesn't resist the arrest at all so long as he can tell his story). This may be spoofing the incidents where someone has been manipulated into smuggling drugs or other contraband by a romantic interest they met on the Internet. Alternatively, it may reference the fact that lockpicking is a common hobby among hackers, suggesting that Cueball's interest in the girl led to his current interests in hacking, lockpicking or both. The hacker girl could be [[Elaine]] from the [[:Category:1337|1337-series]].

*On the plane, Cueball has been instructed to disable the wireless transmission functionality of his device. Many airlines require passengers to disable {{w|Mobile phones on aircraft|mobile phones on aircraft}} as well as other radio transmitting devices, because they may interfere with the radio-based navigation and communication equipment of the aircraft. However, his laptop is running Linux, and he doesn't know how to change the wireless settings; he's reading the {{w|Man page|manual}} for the program that controls the wireless radio. This is probably not an ideal situation, as the airplane is about to take off. Man pages were also referenced in [[293: RTFM]]. Much later, a plane was again linked to a man page in [[912: Manual Override]].

*[[Black Hat]] tries to carry a container of liquid through security. According to US law, the maximum amount of liquid that can be taken onto a plane in a container is three ounces (89 ml), a security measure taken to prevent terrorists from taking explosives onto planes. When the guard has doubts about the amount of liquid in the vial, Black Hat implies that the liquid is actually blood from a churchmouse. This is referred to later in [[526: Converting to Metric]], which claims that a fieldmouse has much less blood than that. The guard is visibly uncomfortable and clearly does not want to deal with the issue any further.

The title text continues off the final panel, saying that there are less than three ounces of blood in a churchmouse, but it "stains panties," an undesirable scenario. However, this undesirable scenario is paralleled by the implied undesirable scenario of a terrorist attack due to explosive liquids, the possibility of which caused the law. The title text seems to parody the prospect of an explosion with the relatively insignificant staining of panties, a term for women's underwear. This may also be a menstruation joke.

==Transcript==
:[Standing outside the Airport. There is a sign saying "Airport" and a plane in the background.]
:Megan: Okay, what airline?
:Beret Guy: I'm following you.
:Megan: ...I'm following you.
:Beret Guy: I assumed we were walking to the bakery.
:Megan: You always assume that!

:[Presumably the security checkpoint. The Security guy is digging through Cueball's bags.]
:Security guy: Lockpicks? These are... illegal, actually. Where did you get them?
:Cueball: Oh man, it all started with this hacker girl.
:Security guy: You need to come with-
:Cueball: Sure, sure. But man, let me tell you about her!

:[On a plane. Cueball is on a laptop.]
:Announcement: If your device has a "Transmit" function, please disable it.
:Cueball: Okay - hang on, I'm halfway through the iwconfig man page.

:[Security checkpoint. Security guy is examining a vial of dark liquid.]
:Security guy: Sir, is this container under three ounces?
:Black Hat: Not sure, how much blood is there in a churchmouse?
:Security guy: . . .Why don't you just go.

{{comic discussion}}
[[Category:Comics featuring Beret Guy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Megan]]
[[Category:Linux]]
[[Category:Food]]
[[Category:Man pages]]
[[Category:Comics with blood]]