explain xkcd - User contributions [en]

Talk:2956: Number Line Branch

2024-07-10T03:24:48Z

172.70.210.103: reply

Is it significant that the branch point is close to the value of π? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:28, 8 July 2024 (UTC)
:I was thinking the same thing, but decided it was probably nothing worth mentioning - probably just an arbitrary starting point. *Possibly* referencing the strange appearance of π but I doubt it. Anything can be significant if you believe hard enough, anyway.--[[Special:Contributions/162.158.158.60|162.158.158.60]] 20:30, 8 July 2024 (UTC)
How does adding a new branch to a railway line reduce congestion? Isn't this more like a highway? [[Special:Contributions/141.101.105.47|141.101.105.47]] 23:30, 8 July 2024 (UTC)
:Read about the 2nd avenue subway. [[Special:Contributions/172.70.111.168|172.70.111.168]] 02:22, 9 July 2024 (UTC)

What is "thrembo"? [[User:AndroidTheLucario|Your favorite aura doggo]] ([[User talk:AndroidTheLucario|talk]]) 04:12, 9 July 2024 (UTC)
: I think the whole section can be removed. The point is to explain the comic, not to describe what is seen (unless it's relevant for the explanation, which, so far, seems not be the case). "Various symbols" should cover it. [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 06:35, 9 July 2024 (UTC)

The symbols seem well chosen TBH, I can totally see how they substitute for 4, 5, 6, 7, 8 [[Special:Contributions/162.158.146.32|162.158.146.32]] 14:42, 9 July 2024 (UTC)
:Except that, according to the title text, they should be 4, 8, 16, 32, 64. [[Special:Contributions/172.71.242.159|172.71.242.159]] 15:59, 9 July 2024 (UTC)
::I think that the express train travels on the regular number line, so I think the second branch parallels the regular number line. Thus, 4, 5, 6, 7, 8. [[User:Sarah the Pie(yes, the food)|Sarah the Pie(yes, the food)]] ([[User talk:Sarah the Pie(yes, the food)|talk]]) 02:11, 10 July 2024 (UTC)

Mathematicians been there, done that: https://en.wikipedia.org/wiki/Non-standard_model_of_arithmetic
Although a nonstandard model of the integers can't branch by Peano axioms. [[Special:Contributions/172.71.160.71|172.71.160.71]] 15:08, 9 July 2024 (UTC)
:Hold my beer! [Prompts Claude 3.5 Sonnet to create a non-standard model of arithmetic. Tentacled one sleeps. Ph'nglui mglw'nafh Cthulhu. Accept this new soul. [[Special:Contributions/172.70.210.103|172.70.210.103]] 03:24, 10 July 2024 (UTC)

Personally I would have branched off between 9 and 10, and had single character symbols for 10, 11, 12, 13, 14, and 15 so that you could do base 16 without having to use letters. Randell just lacks vision. [[User:Andyd273|Andyd273]] ([[User talk:Andyd273|talk]]) 15:12, 9 July 2024 (UTC)
:Letters are single character symbols! I think he should extend the number line with all the letters, getting to 36 (z) before needing any new symbols[[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 21:46, 9 July 2024 (UTC)

2307: Alive Or Not

2024-04-22T19:17:40Z

172.70.210.103: /* Things ranked as alive */

{{comic
| number = 2307
| date = May 15, 2020
| title = Alive Or Not
| image = alive_or_not.png
| titletext = Computer viruses currently fall somewhere between prions and fire.
}}

==Explanation==
There is no universally-accepted definition of "{{w|life}}"; {{w|Life#Definitions|all definitions}} thus far proposed have either excluded some things commonly understood to be alive or included some things commonly understood to not be alive. Take reproduction, a trait commonly assumed to be essential and unique to life; by this definition, anything which cannot reproduce (including {{w|mules}}, {{w|worker bees}}, and postmenopausal women) would be considered nonliving, while anything which can duplicate itself (including {{w|computer viruses}}, {{w|3D printers|advanced 3D printers}}, and {{w|fire}}—see below) would be considered alive.

Many more elaborate definitions of life have been attempted over the decades. Some common additional factors include:

* {{w|Homeostasis}}, the ability to control an internal environment to maintain a constant state;
* {{w|Metabolism}}, converting nutrients into energy and building blocks for growth, reproduction, and so on;
* {{w|Adaptation}} through heredity and natural selection; and
* Responding to the environment.

Despite all of this, the only definite definition of "life" is "something everyone agrees is alive" - and even then, that’s also indefinite because of the further ambiguity of what counts as part of “everyone”. This comic attempts to rank several types of things by how likely people are to perceive them as "alive". As there is a debate as to whether viruses are alive or not, [[Randall]] has taken a side, and may spark debate, by putting viruses above the alive line.

Given that this comic was released during the early days of the [[:Category:COVID-19|COVID-19]] pandemic, viruses are for sure on Randall's mind, given that most comics more than a month before this one was about COVID-19. And this comic is most likely inspired by this, and the previous comic [[2306: Common Cold]], where the cold viruses are definitely alive, and afraid.

=== Things ranked as alive ===

* '''Animals (normal)'''
* '''Animals (weird ones like jellyfish and coral)''': Randall's categorization of animals as "normal" or "weird" can be seen as a simplified version of the {{w|Great chain of being}}, a philosophical framework in which humans are seen as the most "advanced" form of life, followed by a divine or otherwise justified hierarchy of progressively lesser life-forms (mammals, birds, fish, lizards, insects, and so on). Categorizing weird animals was already done in [[1587: Food Rule]]. Corals may be considered as lying between animals and fungi because corals, like, fungi and plants, are {{w|Sessility (motility)|sessile}}, i.e., they "grow" in one place. Jellyfish are not sessile, but {{w|Cnidaria#Basic_body_forms|many jellyfish are very similar to corals}} in different generations. The more unlike ourselves that creatures are, the more incomprehensible their 'lives' are to casual inspection - whilst being definitely alive and officially members of the Animal Kingdom, {{w|Sponge#Coordination of activities|some creatures}} can be very weird indeed.
* '''{{w|Fungi}}''': Fungi represent a unique lineage of eukaryotic, mostly multicellular organisms. Although historically studied by botanists specializing in the sub-discipline "mycology", modern scholarship places fungi in the "opisthokont" lineage, which contains both the animals and the fungi. Fungi, like animals, cannot make complex organic molecules from carbon dioxide, and must consume organic molecules as food to survive. Like plants, fungi are typically unable to move on their own. The various types of fungi include mushrooms, yeasts, rusts, smuts, and molds. Fungi evolution is also referenced in [[1749: Mushrooms]].
* '''{{w|Plant}}s''': Those often green<sup><nowiki>[</nowiki>{{w|Viridiplantae|citation needed}}<nowiki>]</nowiki></sup>, often leafy things outside your current isolation dwelling, sometimes inside, next to the window. They are primarily distinguished from other eukaryotes by being able to use photosynthesis to convert water, carbon dioxide and energy from light into sugar and free oxygen.
* '''{{w|Slime mold}}s''': Slime molds are eukaryotic single-celled organisms (so "more advanced" than bacteria). In the "plasmodial" slime molds, the "single cell" may expand to spread across several feet of territory, and weigh several pounds, while the "cellular" slime molds are most notable for their occasional congregation into macro-sized colonies which can appear to move as a single creature. It's interesting that Randall ranks them as "less alive" than fungi (which they were once thought to be), especially given some of their curious behaviors (e.g. [https://www.theguardian.com/cities/2014/feb/18/slime-mould-rail-road-transport-routes optimizing transportation networks] when presented with a collection of food flakes and obstacles).
* '''{{w|Bacteria}}''': Bacteria are one of two groups of prokaryotes, meaning cells that do not contain a nucleus and rarely harbor membrane-bound organelles. A small portion of Bacteria are pathogenic, but most are actually harmless. Bacteria's ability to convert raw materials into nutrients available for other living things makes them essential to other living things.
* '''{{w|Archaea}}''': Archaea (understandably misspelled as ''Archea'' by Randall) is a {{w|domain (biology)|domain}} of organisms, which do not fall under eukaryotes or bacteria. They are single-celled organisms that lack a nucleus, and were initially thought to be ancient lineages of bacteria (i.e. ''archaeobacteria'') found in extreme environments similar to the early Earth, which is probably why Randall ranks them as "less alive" than bacteria. However, it is now known that they live pretty much everywhere that regular bacteria do, and that they have very distinct biochemistry from bacteria; they are actually more closely related to eukaryotes (i.e. slime molds and up) than bacteria are.
* '''{{w|Virus}}es''': Viruses are infectious agents consisting of a genome surrounded by a protein or lipid shell. When a virus contacts a cell, it delivers its genome inside the cell which causes the cells' reproductive machinery to create more viruses. Since viruses are incapable of reproducing without the aid of larger cells, [https://www.google.com/search?q=are+viruses+alive it is often debated] whether or not they are actually alive. Randall has ranked viruses as "alive" but on the lowest possible rung of such; indeed, many biologists say [https://askabiologist.asu.edu/questions/are-viruses-alive viruses fall in a gray area], or that [https://www.sciencedirect.com/science/article/pii/S1369848616300103 the question is arbitrary and non-scientific]. By another criterion life on Earth is defined by the presence of extremely long molecules that can be replicated (copied). Every organism above viruses contains both DNA and RNA. Viruses only contain either RNA or DNA. Nothing below here contains any (biologically active) DNA or RNA. This comic came out the day after [[2306: Common Cold]], where cold virus was anthropomorphized and was asking humans to stop with all their hand washing when the [[:Category:COVID-19|COVID-19]] pandemic is over. Thus those viruses where definitely alive. Maybe that comic inspired this one.

===Things ranked as not alive===
* '''{{w|Prions}}''': Prions are misfolded proteins that cause other proteins to misfold. They are most famously the cause of various brain diseases such as "{{w|mad cow disease}}", and may be involved in Alzheimer's disease. Similarly to viruses, prions require something else to replicate, but unlike viruses, they do not possess a nucleic-acid genome or any other means of carrying heritable information, and they do not alter the cell's production machinery, but rather interact with proteins which are already made. In that sense, they're more like a particularly tricky kind of metabolic waste product or pollution.
* (from title text) '''{{w|Computer virus}}es''': A piece of code which hijacks computer systems to replicate itself, named by analogy to biological viruses. Strictly speaking, they're just a particular encoding of information, usually stored in electromagnetic media (although there's no reason one couldn't be stored on punch cards). Randall ranks them as "''currently''" more alive than fire, because they do carry "genetic" information (which anti-virus programs can be programmed to look for, analogous to immunity) and some are capable of modifying themselves to adapt to new environments, but less alive than prions because they only operate within information systems. However, if viruses became more intelligent, or a virus were able to e.g. hijack an electronics factory to start making flash drives and memory cards that carry the virus's code, then perhaps it might move up in the hierarchy.
* '''{{w|Fire}}''': Fire is a common example of something which meets many common definitions for life; it grows, reproduces by spreading seeds (sparks), and consumes energy and excretes waste (ashes and smoke) by the same net chemical process as respiration. However, while fire can be a necessary part of the life cycle of other organisms (e.g. redwood trees), it does not maintain a constant environment within itself, nor does it perform {{w|anabolism}}, the construction of larger molecules from smaller ones. Respirating life-forms use helper molecules to moderate the oxidation reaction into small steps to produce useful units of energy, rather than letting it all happen at once to produce heat.
* '''{{w|Clouds}}''': Random shapes taken by clouds may resemble animals and other objects, but arguably they are not alive in any sense. Things like tornadoes and hurricanes, on the other hand, can meet some definitions of life: they maintain homeostasis, actively seek and consume energy, and occasionally reproduce. Cf. ''Fire'' above.
* '''{{w|Fossils}}''': Fossils are the petrified remains of once-living organisms, so in that sense they are more connected to life than "regular rocks", and some may hold DNA that could theoretically be used to clone the fossilized life-form.
* '''{{w|Rocks}} shaped like faces''': Humans have an extremely advanced capability for seeing patterns, and one of the most powerful patterns we seek is {{w|Face perception|faces}}, so much so that we see faces even where they don't exist (a common form of {{w|pareidolia}}). Humans instinctively anthropomorphize any object which vaguely resembles a face as having a sense of attention and mood, and so a rock shaped like a face would likely be treated differently than a rock not shaped like a face. Randall does not distinguish between rocks intentionally carved to look like faces (such as the famous {{w|Moai}} sculptures) or rocks that happen to look vaguely like faces under the right lighting conditions (such as the famous {{w|Face on Mars}}.)
* '''Regular {{w|rocks}}''': Modern taxonomy originates from Carl Linnaeus, who categorized all objects on Earth as animals, plants (often stated as "''vegetable''" in quiz games like Twenty Questions), or minerals. Minerals are most obviously not alive, although some cultures and works of fiction have creatures that turn to stone and will return later to life, and some people keep {{w|Pet Rock|rocks as "pets"}}.

Interestingly, the vertical line linking the categories extends beyond both the most-alive and least-alive things, making one wonder what Randall might think is more alive than "normal animals" or less alive than "regular rocks". In the latter direction an explanation might be that shortly before this comic the scientific press wrote about heat-resistant bacteria that live in the desert and slowly eat regular rocks generating their own water in this process making even the sand in the desert partially alive.

==Transcript==
:[A chart consisting of vertical line, with 14 dots and a horizontal dashed dividing line drawn across the list a bit below the middle. Each dot has a label to the right of the line with a line pointing to the dot they belong to. Above and below the dividing line is a label with a broad arrow pointing up above and down below.]
:Up arrow: Alive
:Down arrow: Not alive

:[Dot labels from top to bottom above the dashed line:]
:Animals (Normal)
:Animals (Weird ones like jellyfish and coral)
:Fungi
:Plants
:Slime molds
:Bacteria
:Archea
:Viruses

:[Dot labels from top to bottom below the dashed line:]
:Prions
:Fire
:Clouds
:Fossils
:Rocks shaped like faces
:Regular rocks

{{comic discussion}}

[[Category:Charts]]
[[Category:Biology]]
[[Category:Geology]]
[[Category:Mycology]]

2900: Call My Cell

2024-02-29T06:27:09Z

172.70.210.103: /* Explanation */ wlink

{{comic
| number = 2900
| date = February 28, 2024
| title = Call My Cell
| image = call_my_cell_2x.png
| imagesize = 509x222px
| noexpand = true
| titletext = 'Hey, can you call my cell?' '...I'm trying, but it says this number is blocked?' 'Ok, thanks, just checking.'
}}

==Explanation==
{{incomplete|Created by THIS GUY'S BOT - feel free to elaborate on any and all points. Do NOT delete this tag too soon.}}

When a person cannot find their cell phone, it is not uncommon to ask a friend to call the phone in question. This will set off the device's ring tone, and - assuming the device is not on silent - play the ringtone, making it easier to find.

At first, [[Black Hat]] appears to have misplaced his cell phone, as he asks [[Cueball]] to call it. However, when Cueball does call Black Hat's cell, it is revealed to be on his person. He then makes a show of ''annoyance'' that Cueball is calling him, sends the call to voicemail, and leaves. From this, it can be inferred that Black Hat was simply trying to demonstrate that he doesn't ''want'' Cueball to call him, showing another of his ''[[72: Classhole|classhole]]'' tendencies.

The title text is a similar situation. But instead Black Hat demonstrates that he has {{w|Call blocking|blocked Cueball's number}} so he is unable to reach him.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Black Hat, with his finger raised, walks in from the right, and comes next to Cueball]
:Black Hat: Hey, can you call my cell?

:[Cueball, holding his phone, calls Black Hat. Black Hat looks at his back pocket which is ringing.]
:Black Hat: Oh, one sec.
:''Ring''

:[Cueball, still holding his phone, looks at Black Hat. Black Hat is looking to the right and holding his phone.]
:Black Hat: Ugh, it's ''this'' guy.
:Phone: ''Send to voicemail''

:[Cueball, still holding his phone, watches as Black Hat exits the frame to the right.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Phones]]

Talk:2891: Log Cabin

2024-02-07T19:52:25Z

172.70.210.103:

"''The odd part about it is the bottom right corner, which appears to be infinitely recursive copies..''"
The whole right side is the left side, shrunk and recursed. Each iteration rotated 90 degrees. [[User:PRR|PRR]] ([[User talk:PRR|talk]]) 19:49, 7 February 2024 (UTC)
This is a LOGarithmic spiral [[Special:Contributions/172.70.210.103|172.70.210.103]] 19:52, 7 February 2024 (UTC)NickM

2887: Minnesota

2024-01-31T19:11:29Z

172.70.210.103: /* Explanation */ add question

{{comic
| number = 2887
| date = January 29, 2024
| title = Minnesota
| image = minnesota_2x.png
| imagesize = 673x260px
| noexpand = true
| titletext = In addition to 'squishy', after reviewing my submitted intraplate ground motion data, the National Geodetic Survey has politely asked me to stop using the word 'supple' so often when describing Midwestern states.
}}

==Explanation==
{{incomplete|Created by A SLOWLY EXPANDING CANADIAN-IOWAN INVASION - Please change this comment when editing this page. Do NOT delete this tag too soon. What does "post-glacial rebound" mean?}}

[[Hairy]], [[Ponytail]], and [[Cueball]] are in a business meeting of an unknown nature, but one which (it transpires) is unrelated to either geography, geology or geopolitical boundaries. Hairy asks if anyone has any other concerns, a common enough question to ask when trying to ensure that nobody at the meeting has still something to say that had not already been covered directly by the agenda or the resulting discussions.

Cueball voices an opinion on Minnesota. Due to the {{w|post-glacial rebound}} present in Minnesota, this US state is apparently slowly decreasing in size. The humor comes from the fact that this may be a genuine concern by Cueball, but is completely unrelated to the topic of the meeting nor even a very significant problem even in more relevant circles. And yet Cueball clearly finds it important enough that "all meetings should be about Minnesota" until the 'problem' is solved. Not only is the minor decrease of Minnesota size not really a 'problem' that has any practical significance, there is also no way to prevent this{{citation needed}}.

The title text implies that Cueball has also brought this issue up to the {{w|National Geodetic Survey}}; rather than commenting on his data or findings, they have simply requested that he stop using suggestive language in his papers ("supple" and "squishy" are sometimes used, especially in erotic literature, to describe certain body parts).

The Midwestern states, particularly in areas like the {{w|New Madrid Seismic Zone}}, are subject to the movement of tectonic plates well within a tectonic plate boundary. While these areas are typically less active than boundary zones, they can still experience significant seismic activity. The flexible way the Earth's crust in these regions responds to tectonic stresses – gently stretching and flexing over centuries in response to deep stresses – could imaginatively be described as "supple."

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

:[Hairy standing in front of Ponytail and Cueball, who are sitting behind a desk]
:Hairy: Does anyone have any other concerns?
:Cueball: I'm concerned that Minnesota is getting shorter.

:[A map of Minnesota beside Cueball, with arrows pointing from the northern and southern borders towards the middle]
:Cueball: Because of post-glacial crust rebound, the northern border is moving toward the southern border. It's less than an inch a decade, but I still don't like it.
:Cueball: Minnesota shouldn't be squishy.

:[Hairy again standing in front of Ponytail and Cueball at the desk. Ponytail is looking at Cueball, whose finger is now raised in the air, gesturing]
:Hairy: Okay. Does anyone have any concerns related to the topic of this meeting?
:Cueball: All meetings should be about Minnesota until we resolve this.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Ponytail]]
[[Category:Geology]]
[[Category:Geography]]

2671: Rotation

2022-09-12T23:13:25Z

172.70.210.103: /* Explanation */ image from 2658

{{comic
| number = 2671
| date = September 12, 2022
| title = Rotation
| image = rotation.png
| titletext = It's okay, we can just feed the one-pixel image into an AI upscaler and recover the original image, or at least one that's just as cool.
}}

==Explanation==
{{incomplete|Created by an AI upscaler - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Another of Randall's [[:Category:Tips|Tips]], this tip claims that rotating a phone and taking a screenshot too many times will cause an image to disappear into nothingness, and warns the user against doing so. This is funny because while camera phone users are unlikely to do this, they are usually less aware of the optimal resolution for their intended purposes than they could be. A phone's "auto-rotation" feature will automatically rotate an image to the fit the current phone's orientation based on {{w|accelerometer}}s.

[[Image:World lines and world sheet.svg|thumb|200px|{{w|String theory}} describes the {{w|worldline}}s of point-like particles as {{w|worldsheet}}s of "closed strings," forming a topological foam.]]

For a fuller explanation of the concepts involved, including {{w|Planck units}}, often associated with the topological {{w|quantum foam}} of {{w|string theory}}, please see [https://www.youtube.com/watch?v=pUF5esTscZI this CGP Grey video.] For an explanation of topological string theory, see [[2658: Coffee Cup Holes]].

The title text refers to producing photographically likely higher resolution images from lower resolutions, an active area of current research.

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

[A phone in portrait orientation shows an image. It is then rotated, showing the image smaller with bars in landscape orientation, then the next phone is in portrait showing the entire screen of the previous rotated sideways, shrinking it every time. The labels show the decreasing size of the original image as it goes through successive rotations.]

"9 rotations: original image is smaller than a pixel."

"25 rotations: original image is smaller than an atom."

"101 rotations: original image is smaller than the Planck length, at which the concept of distance may break down."

Bottom caption: "Phone tip: don't rotate and screenshot an image too many times or it will become lost in the quantum foam of the universe."

{{comic discussion}}
[[Category:Tips]]
[[Category:Smartphones]]