explain xkcd - User contributions [en]

1659: Tire Swing

2020-01-10T13:41:29Z

SmartAlec105: Added info on how tires are recycled.

{{comic
| number = 1659
| date = March 23, 2016
| title = Tire Swing
| image = tire_swing.png
| titletext = If we find one of those tire dumps, the next time he tries to get his truck back we can just retreat and let him have it.
}}

==Explanation==
In this comic, [[Science Girl]] and another girl have just completed a [https://damnyoulittlerock.files.wordpress.com/2011/11/img_5457.jpg tire swing]: A common makeshift {{w|swing (seat)|swing}} is created by hanging a car {{w|tire}} from a length of rope, typically tied to the branch of a tree as in the comic. The other girl might at first look like she has hair like [[Megan]] but not quite as she is revealed upon zoom in to have curly hair. That they are rather small kids can be seen from the size of the tire compared to them. (They could be the same as the girls in the last panel of [[1580: Travel Ghost]]).

In the second panel of this comic Science Girl muses that there are huge [http://www.dailymail.co.uk/news/article-2337351/Worlds-biggest-tyre-graveyard-Incredible-images-Kuwaiti-landfill-site-huge-seen-space.html tire dumps] filled with nothing but old tires that have no use. In the last panel, Science Girl continues that maybe they should use a tire from such a dump next time they make a tire swing. The presumption is that perhaps they used a brand new tire, or a tire from some other source. This is confirmed by the other girl's response (and also by the title text, see below) which makes it clear that the tire they used was in fact stolen from a guy's vehicle. The last reply from Science Girl suggests the victim put up a fight and they had to take the tire by force. So these two small girls actually fought an adult man over his truck and won the fight.

Vehicle tires have a limited lifespan. The natural end of their life is when the pattern of raised treads on the circumference of the tire, which promote traction on wet roads, are worn down to a point where they are no longer effective enough, or after 6-10 years (sunlight causes the rubber to degrade, so the tire becomes prone to cracking and unsafe, even if it appears to be in good condition). Tires can also become damaged in other ways, such as puncture.

{{w|Tire recycling|Used tires}} are a notable ecological problem for a number of reasons (e.g. their size, the quantity produced, their relatively short lifespan, and the fact that they are difficult and slow to break down and contain a number of components that are ecologically problematic). A tire swing represents a functional use for otherwise useless old tires. The amount of tires (it is estimated that 259 million tires are discarded annually) makes them attractive targets for recycling. More than half of used tires are ultimately simply burned for their fuel value (which prevents them from sitting in landfills indefinitely, but this may even be worse as it releases otherwise locked up carbon thus releasing this into the atmosphere and making {{w|global warming}} even worse). Some steel mills that use electric arc furnaces will mix shredded tires with their scrap when charging the furnace for both the carbon value and fuel value, in place of the coal that would otherwise be used.

The comic is thus clearly [[Randall|Randall's]] attempt to draw attention to this huge ecological problem, as he so often before has done with other climate change/global warming related comics. (Climate change, especially global warming, is a [[:Category:Climate change|recurring theme]] in xkcd). So while this is not the joke of the comic, it could be the point of it.

He also suggests another way to use old tires. It should be noted that used tires are not necessarily safe to use as a kids' toy as they could become sharp/frayed along the edges and stones and other hard/sharp objects may have become stuck in the tires (even going all the way through), during its life span, or worn thin enough to tear apart mid-swing (when the stresses on the swing material would be at their peak). So tires bought for use as a swing may even be made from a new tire, but not necessarily of the same solid type as those used for cars. Used tires reused for a swing should be inspected for the problems mentioned above.

The title text goes further, suggesting that they actually stole the victim's entire truck - possibly just to harvest the tire needed for the swing - and that he unsuccessfully attempted to recover the truck, so they probably did fight him. He put up enough of a fight that they do not wish to fight him again (so he at least survived). Further, since the girls expect him to try again (maybe recovering the truck with only three tires), they apparently still have the truck. One of the girls suggests that if they could find one of these tire dumps, then they could take a tire from there, make a new swing, and then just walk or run away from the truck when the guy comes back, letting him have it if he really wants it so bad.

The reason Science Girl made this swing could be that she wishes to become a {{w|cosmologist}} as a reference back her meeting a cosmologist on a tire swing in [[1352: Cosmologist on a Tire Swing]].

Note that {{w|Calvin and Hobbes}} which have often been [[:Category:Calvin and Hobbes|referenced in xkcd]] has done the same to Calvin's father as the girls did to the guy (though without the violence) in a [http://assets.amuniversal.com/bcb737d0b98e013340c2005056a9545d similar comic].

This was the first of two Wednesday's in a row where Randall used two children to make a reference to an environmental issue, the second being [[1662: Jack and Jill]] about {{w|hydraulic fracturing|fracking}} also with Science Girl.

==Transcript==
:[Science Girl and a girl with long curly hair, are standing under a large leafless tree as Science Girl adjusts a tire swing hanging from the largest of the branches of the tree. The tire hangs so high that the small girls only reach up to just above the center of the tire which has a diameter of more than half the height of the girls.]
:Science Girl: OK, looks good.

:[Zoom in on the girls so only the tire swing can be seen, and nothing of the tree. They both look at the tire.]
:Science Girl: I read that there are these huge dumps everywhere full of millions of old tires that no one knows what to do with.

:[Same setting but Science Girl looks up at the tree (outside the frame).]
:Science Girl: We should use one of those next time.
:Curly haired girl: Yeah. That guy was real mad.
:Science Girl: I would ''not'' want to fight him again.

{{comic discussion}}



[[Category:Comics featuring Science Girl]]
[[Category:Climate change]]

2251: Alignment Chart Alignment Chart

2020-01-06T21:36:50Z

SmartAlec105: Better definition of a phase diagram. Improved explanation of phase diagram alignment.

{{comic
| number = 2251
| date = January 6, 2020
| title = Alignment Chart Alignment Chart
| image = alignment_chart_alignment_chart.png
| titletext = I would describe my personal alignment as "lawful heterozygous silty liquid."
}}

==Explanation==
{{incomplete|Created by a [[User:DgbrtBOT|TRUE NEUTRAL BOT template]]. Needs explanations of each alignment chart, and probably some editing for clarity.}}

"Alignment" and "alignment charts" come from the the tabletop game ''{{w|Dungeons & Dragons}}''. Every character has an {{w|Alignment (Dungeons & Dragons)|alignment}}, which very roughly identifies their tendencies. The most widely used alignment system was introduced in the ''{{w|Dungeons & Dragons Basic Set}}'' in 1977 and has been reused in many (but not all) subsequent editions of the game. This system uses two perpendicular axes, each divided into three levels (for a total of nine categories). The two axes are:
* Lawful/neutral/chaotic: this axis says whether a character is strongly devoted to, indifferent about, or categorically opposed to following established rules.
* Good/neutral/evil: this axis says whether a character is generally inclined to commit good deeds or evil deeds.

In this system, the "lawful" attribute is independent from the "good" attribute. Lawful alignment means that a character is committed to a set of rules, which can refer to actual established laws, or to something like a rigid personal code, a set of traditions, or a chain of command, while a chaotic alignment means that a character has no interest in those, and may actively oppose them. The good vs evil scale is generally based on a character's concern for the lives and well-being of others, a good character will actively seek to help others and prevent harm, while an evil character will have no such concern and may actively harm others. Being 'good' is assumed to be independent of being 'lawful'. For example, a character who actively breaks laws to help those who are unjustly imprisoned or oppressed would be be considered to be "chaotic good". In both cases, a neutral alignment can indicate a character's indifference to a concept, or that their commitment is conditional, or that they consciously seek to balance both sides. A character with the "neutral neutral" alignment is called a true neutral.

An alignment chart is a grid that divides the alignments, usually for the purpose of putting descriptions or particular characters on it. Alignment charts are frequently used as a [https://knowyourmeme.com/memes/mcdonalds-alignment-chart meme template], where humorous or absurdist things are organized into different alignments. In addition to the "classic" Dungeons and Dragons alignment chart, there are a number of variant alignment charts in use as meme templates. Many keep the three-by-three grid structure but replace the lawful-neutral-chaotic and good-neutral-evil axes with descriptions.

This comic claims to be a meta-alignment chart, where nine "alignment charts" are themselves sorted into the nine Dungeons and Dragons alignments, following the use of alignment charts to humorously classify abstract concepts. However, these "alignment charts" are mostly diagrams used in academic classifications, which are being treated as if they were blank meme templates. There are two levels of absurdity here: first, the idea of using these diagrams to classify things they were never intended for, and second, the conflation of chaos as a physics concept and an assigned moral weights as it applies to each of these classification systems.

The title text describes Randall's alignment as "lawful heterozygous silty liquid" which references the true neutral, neutral good, lawful good, and lawful neutral charts in the Alignment Chart Alignment Chart. Lawful is the left side of an alignment chart, heterozygous is the top right or bottom left of a Punnet Square, silty is the bottom right of a soil chart, and liquid is the top right of a phase diagram. As such, the title test describes Randall's alignment as between Lawful Neutral and Neutral Good on this chart.

{| class="wikitable"
!Alignment
!Chart
!Explanation
|-
|Lawful Good
|{{w|Soil texture|Soil chart}}
|This chart shows the USDA classification of soil types by their relative proportions of sand, clay and silt. The chart is a ternary diagram (very common in geology), so soils with more clay plot towards the upper corner, soils with more sand to the bottom left, and soils with more silt to the bottom right. This chart has been used humorously as an alignment chart ([https://www.reddit.com/r/PrequelMemes/comments/8wakd4/anakin_soil_reference_chart/ for example]) and may have been the inspiration for Randall to use scientific diagrams as alignment charts. In addition to being Lawful Good, this grid cell is also the upper left cell of the chart and will be read first, making it a good place to put this chart as a "jumping off point".
|-
|Neutral Good
|{{w|Punnett square}}
| Punnet squares are a visual method of determining what traits an organism might have based on the traits of the organism's parents. It relies on the principle that a trait is either dominant (indicated with capital letters) or recessive (indicated with lowercase letters). The exact combination of dominant or recessive genes that a child organism receives from their parents determines their traits. It is important to understand the terms "heterozygous", "homozygous" …” These refer to the pairs of alleles in an organism’s genotype, indicating mixed or same alleles, respectively. Randall later uses “heterozygous” in the title text. Note that it is possible for a phenotype to be expressed the same between some heterozygotes and homozygotes, e.g., persons with genotypes heterozygous ”Aa” and homozygous “AA” will both express blood type A.
Therefore, the Punnett Square is a good chart because it is both a simple and true geometric predictor of inheritance, but it tends to neutral because of complicating factors such as polygenic inheritance; these and other factors will cause genotypic frequency to deviate from expected 1:2:1 patterns.
|
|-
|Chaotic Good
|{{w|IPA vowel chart with audio|IPA vowel chart }}
|This chart shows the relationship between different vowels according to the {{w|International Phonetic Alphabet}}. As different vowel sounds are created by changes in different parts of the mouth, it can be considered chaotic.
|-
|Lawful Neutral
|Phase diagram
|A {{w|phase diagram}} shows the equilibrium phases of matter present for a particular temperature, pressure, and composition. The diagram included is a unary phase diagram of a typical material that has a solid, liquid, and gas phase depending on the temperature and pressure for a fixed composition. Phase diagrams are useful for understanding how a material may change as its conditions change. For example, the air pressure of Mars is such that there is no temperature at which liquid water can exist in equilibrium. Water exists as ice until the temperature reaches a point where it sublimates directly into steam.

Phase diagrams follow the laws of thermodynamics and concern themselves with the order in which things ''should'' be, so they are inherently lawful.
|-
|True Neutral
|Alignment chart
|All alignment charts are neutral unless humans contaminate them.
|-
|Chaotic Neutral
|CIE chromaticity diagram
|The {{w|chromaticity}} diagram is typically used to help determine a color temperature given the typical RGB intensities of light. Low color temperatures tend to be associated with 'softer' lights that are easier on the eyes, whereas 'higher' color temperatures are associated with 'harder' light that are perceived as brighter. Given that color temperature as defined by the chromaticity diagram has nothing to do with the actual color temperature of a blackbody as defined by Physics, it is chaotic. Also, the official specification for CIE is behind a paywall and defined by private organizations, making it more chaotic.
|
|-
|Lawful Evil
|Political compass
|Political Compass [https://www.politicalcompass.org/] separates out left-right thinking into economic and social political thought. For example, Gandhi and Stalin supposedly both had similar economic perspectives (collectivist) but radically different social perspectives (authoritarian vs libertarian).

As politicians make the laws, this is inherently lawful. Attempting to represent all politics in terms of two very general axes is a gross oversimplification, which is likely why it is listed as evil.

Like the USDA soil chart, the political compass has actually been [https://knowyourmeme.com/memes/political-compass used as an alignment chart], largely to mock the original political compass chart.
|-
|Neutral Evil
|{{w|QAPF diagram|QAPF rock diagram}}
|This diagram is used to classify coarse-grained felsic (low magnesium and iron) igneous rocks by the relative volumes of the minerals quartz, alkali feldspars, plagioclase feldspars, and feldspathoids in the rock. It consists of two ternary diagrams - quartz and feldspathoid minerals cannot coexist (they will react to form feldspars) so only three of these components will be in any given rock. Rocks in the upper triangle of the diagram contain quartz, with rocks with more quartz plotting closer to the top, while rocks in the lower triangle contain feldspathoids, with rocks with more feldspathoids plotting lower. Rocks closer to the left corner of the diagram contain more alkali feldspar and rocks closer to the right corner contain more plagioclase feldspar. The field on the diagram for granite is labeled in the comic, but each area outlined on the diagram has it's own rock name (monzonite, syenite, granodiorite, etc.). All the rocks that the QAPF diagram is used to classify look superficially like granite, but their chemistry, mineralogy, and origin differ.
The QAPF diagram and the names of the more obscure rock types on it can be somewhat arcane, which may be why it is considered evil here.
|-
|Chaotic Evil
|Omnispace classifier
|The other eight diagrams shown in this comic, squished together into one, with the shapes of the diagrams corresponding to those of the originals. Probably self-referential humour, in that the diagram created for this comic is considered to be chaotically evil.
|}

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

{{comic discussion}}



[[Category:Charts]]
[[Category:Biology]]
[[Category:Physics]]
[[Category:Geology]]
[[Category:Language]]
[[Category:Fiction]]
[[Category:Politics]]

2251: Alignment Chart Alignment Chart

2020-01-06T16:54:31Z

SmartAlec105: This is not water. Water has a negative slope between the solid and liquid phase.

{{comic
| number = 2251
| date = January 6, 2020
| title = Alignment Chart Alignment Chart
| image = alignment_chart_alignment_chart.png
| titletext = I would describe my personal alignment as "lawful heterozygous silty liquid."
}}

==Explanation==
{{incomplete|Created using the [[User:DgbrtBOT|BOT template]]. Needs explanations of each alignment chart, and probably some editing for clarity.}}

"Alignment" and "alignment charts" come from the the tabletop game ''{{w|Dungeons & Dragons}}''. Every character has an {{w|Alignment (Dungeons & Dragons)|alignment}}, which is a sort of a personality archetype or general description of morality. The most widely used alignment system was introduced in the ''{{w|Dungeons & Dragons Basic Set}}'' in 1977 and has been reused in many (but not all) subsequent editions of the game. This system uses two perpendicular axes, each axis having three words; the alignment of a particular character is a combination of one word from each axis (for a total of nine categories). The two axes are:
* Lawful/neutral/chaotic: this axis says whether a character is strongly devoted to, indifferent about, or categorically opposed to following the rule of the law.
* Good/neutral/evil: this axis says whether a character is generally inclined to commit good deeds or evil deeds.
For example, a character's alignment can be "chaotic neutral". Being classified as "chaotic" means they're very prone to acting on emotions, they don't care what is allowed and what is prohibited, and their actions often go against things like tradition and chain of command. Being classified as "neutral" (on the second axis) means that their deeds and character are not strongly good nor evil; either they have a balance of both, or they rarely do anything that can be clearly labelled as one or the other. There are nine possible alignments - any combination of the two axes is allowed. A character with the "neutral neutral" alignment is called a true neutral.

The use of the term chaotic in a personality alignment context is different to the term in a physics concept. In physics, {{w|chaos theory|chaos}} refers to unpredictable outcomes following emergent behaviours that are sensitive to small changes in underlying conditions. Similarly, lawful can be considered to follow deterministic physical behaviours. Hitting pool balls with a pool cue is deterministic, it follows the deterministic Newtonian laws of motion. Hitting your opponent with a pool cue is chaotic, the end state of the ensuing brawl is unpredictable.

An alignment chart is a grid that divides the alignments, usually for the purpose of putting descriptions or particular characters on it. Alignment charts are frequently used as a [https://knowyourmeme.com/memes/mcdonalds-alignment-chart meme template], where humorous or absurdist things are organized into different alignments. In addition to the "classic" Dungeons and Dragons alignment chart, there are a number of variant alignment charts in use as meme templates. Many keep the three-by-three grid structure but replace the lawful-neutral-chaotic and good-neutral-evil axes with others, such as [https://knowyourmeme.com/memes/gay-bi-lesbian-distinguished-functional-disaster distinguished-functional-disaster vs. gay-bi-lesbian] and [https://knowyourmeme.com/memes/edgy-depressed-dumbass-bitch-thot-bastard edgy-depressed-dumbass vs. bitch-thot-bastard]. Some alignment charts use other systems of classification, like the [https://knowyourmeme.com/memes/mcdonalds-alignment-chart McDonald's alignment chart], which is a {{w|Ternary_plot|ternary diagram}}, a way of plotting data points by the relative proportions of three components in them on a triangular plot.

This comic claims to be a meta-alignment chart, where nine "alignment charts" are themselves sorted into the nine Dungeons and Dragons alignments, following the use of alignment charts to humorously classify abstract concepts. However, these "alignment charts" are mostly diagrams used in academic classifications, which are being treated as if they were blank meme templates. There are two levels of absurdity here: first, the idea of using these technical scientific diagrams to classify things they were never intended to, like fictional characters or how people bag their bread, and second, the conflation of chaos as a physics concept and an assigned moral weights as it applies to each of these classification systems.

{| class="wikitable"
!Alignment
!Chart
!Explanation
|-
|Lawful Good
|{{w|Soil texture|Soil chart}}
|This chart shows the USDA classification of soil types by their relative proportions of sand, clay and silt. The chart is a ternary diagram (very common in geology), so soils with more clay plot towards the upper corner, soils with more sand to the bottom left, and soils with more silt to the bottom right. This chart has been used humorously as an alignment chart ([https://www.reddit.com/r/PrequelMemes/comments/8wakd4/anakin_soil_reference_chart/ for example]) and may have been the inspiration for Randall to use scientific diagrams as alignment charts. In addition to being Lawful Good, this grid cell is also the upper left cell of the chart and will be read first, making it a good place to put this chart as a "jumping off point".
|-
|Neutral Good
|{{w|Punnett square}}
| (quote from wikipedia article, but should have been obvious. Oh, yeah - we're all tech nerds, not biologists!) "The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach. The diagram is used by biologists to determine the probability of an offspring having a particular genotype. The Punnett square is a tabular summary of possible combinations of maternal alleles with paternal alleles.[1] These tables can be used to examine the genotypical outcome probabilities of the offspring of a single trait (allele), or when crossing multiple traits from the parents. The Punnett square is a visual representation of Mendelian inheritance. It is important to understand the terms "heterozygous", "homozygous" …” These refer to the pairs of alleles in an organism’s genotype, indicating mixed or same alleles, respectively. Randall later uses “heterozygous” in the title text. Note that it is possible for a phenotype to be expressed the same between some heterozygotes and homozygotes, e.g., persons with genotypes heterozygous ”Ao” and homozygous “AA” will both express blood type A.
So, the Punnett Square is a good chart because it is both a simple and true geometric predictor of inheritance, but it tends to neutral because of complicating factors such as polygenic inheritance; these and other factors will cause genotypic frequency to deviate from expected 1:2:1 patterns.
|
|-
|Chaotic Good
|{{w|IPA vowel chart with audio|IPA vowel chart }}
|This chart shows the relationship between different vowels according to the {{w|International Phonetic Alphabet}}. As different vowel sounds are created by changes in different parts of the mouth, it can be considered chaotic.
|-
|Lawful Neutral
|Phase diagram
|A {{w|phase diagram}} shows the temperature and pressure points where a material changes phase. The diagram included is of an unknown material that has a solid, liquid, and gas phase. Phase diagrams are useful as the relationship is not always linear. For example, the air pressure of Mars is such that there is no temperature at which liquid water can exist. Water exists as ice until the temperature reaches a point where it sublimates directly into steam.

Phase diagrams follow the laws of physics, so are inherently lawful.
|-
|True Neutral
|Alignment chart
|All alignment charts are neutral unless humans contaminate them.
|-
|Chaotic Neutral
|CIE chromacity diagram
|The {{w|chromacity}} diagram is typically used to help determine a color temperature given the typical RGB intensities of light. Low color temperatures tend to be associated with 'softer' lights that are easier on the eyes, whereas 'higher' color temperatures are associated with 'harder' light that are perceived as brighter. Given that color temperature as defined by the chromacity diagram has nothing to do with the actual color temperature of a blackbody as defined by Physics, it is chaotic. Also, the official specification for CIE is behind a paywall and defined by private organizations, making it more chaotic.
|
|-
|Lawful Evil
|Political compass
|Political Compass [https://www.politicalcompass.org/] separates out left-right thinking into economic and social political thought. For example, Gandhi and Stalin supposedly both had similar economic perspectives (collectivist) but radically different social perspectives (authoritarian vs libertarian).

As politicians make the laws, this is inherently lawful. Attempting to represent all politics in terms of two very general axes is a gross oversimplification, which is likely why it is listed as evil.

Like the USDA soil chart, the political compass has actually been [https://knowyourmeme.com/memes/political-compass used as an alignment chart], largely as a mockery of it.
|-
|Neutral Evil
|{{w|QAPF diagram|QAPF rock diagram}}
|This diagram is used to classify coarse-grained felsic (low magnesium and iron) igneous rocks by the relative volumes of the minerals quartz, alkali feldspars, plagioclase feldspars, and feldspathoids in the rock. It consists of two ternary diagrams - quartz and feldspathoid minerals cannot coexist (they will react to form feldspars) so only three of these components will be in any given rock. Rocks in the upper triangle of the diagram contain quartz, with rocks with more quartz plotting closer to the top, while rocks in the lower triangle contain feldspathoids, with rocks with more feldspathoids plotting lower. Rocks closer to the left corner of the diagram contain more alkali feldspar and rocks closer to the right corner contain more plagioclase feldspar. The field on the diagram for granite is labeled in the comic, but each area outlined on the diagram has it's own rock name (monzonite, syenite, granodiorite, etc.). All the rocks that the QAPF diagram is used to classify look superficially like granite, but their chemistry, mineralogy, and origin differ.
The QAPF diagram and the names of the more obscure rock types on it can be somewhat arcane, which may be why it is considered evil here.
|-
|Chaotic Evil
|Omnispace classifier
|The other eight diagrams shown in this comic, squished together into one, with the shapes of the diagrams corresponding to those of the originals. Probably self-referential humour, in that the diagram created for this comic is considered to be chaotically evil.
|}

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

{{comic discussion}}



[[Category:Charts]]