explain xkcd - User contributions [en]

Talk:2766: Helium Reserve

2023-04-22T12:39:43Z

Darthpoppins:

So, uh... is the reason he can't say it out loud because he inhaled it all and the squeaky voice would give it away? [[User:LtPowers|LtPowers]] ([[User talk:LtPowers|talk]]) 12:34, 22 April 2023 (UTC)

That was my first thought. [[User:Darthpoppins|Darthpoppins]] ([[User talk:Darthpoppins|talk]]) 12:39, 22 April 2023 (UTC)

Talk:2722: Etymonline

2023-01-10T00:46:22Z

Darthpoppins:

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)

2632: Greatest Scientist

2022-06-13T23:57:34Z

Darthpoppins: /* Explanation */ another spelling correction

{{comic
| number = 2632
| date = June 13, 2022
| title = Greatest Scientist
| image = Greatest Scientist.png
| titletext = "Ow! One of the petri dishes I left on the tower railing fell and hit me on the head. Hey, that gives me an idea..."
}}

==Explanation==
{{incomplete|Created by HISTORY'S WURST SCIENTIST - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic pretends that many (6 by my count) of history's greatest scientists were the same person, and says that this person was the greatest scientist in history. A combination of 6 of the greatest scientists ever would most likely be the greatest scientist ever.{{Citation needed}}

These scientists are most likely {{w|Galileo Galilei}}, {{w|Benjamin Franklin}}, {{w|Alexander Fleming}}, {{w|Ivan Pavlov}}, {{w|Eratosthenes}}, and {{w|Isaac Newton}}

Humorously combining multiple science experiments into one was also a punchline in [[1584: Moments of Inspiration]].
{| class="wikitable"
|+ List of experiments in the comic
|-
! Experiment in comic !! Experiment in reality !! Meaning !! Scientist
|-
| The Leaning Tower of Pisa || {{w|Galileo}} conducted [https://en.wikipedia.org/wiki/Galileo%27s_Leaning_Tower_of_Pisa_experiment an experiment] at the Leaning Tower of Pisa to measure whether the rate at which objects fall is dependent on weight or is consistent. || Galileo found that objects with different weights still fall at the same rate, disproving Aristotle's theory which purported the opposite. However, {{w|Viviani}} had already discovered this.|| {{w|Galileo Galilei}}
|-
|While flying a kite into a distant thunderstorm, where lightning || In June 1752, Benjamin Franklin performed his famous {{w|Kite experiment}}, where he attached a conductive wire to a kite, and flew it near a thunderstorm. Attached to the kite was a key, which was further attached to a {{w|leyden jar}} || While the kite was not hit by lightning, "Franklin did notice that loose threads of the kite string were repelling each other and deduced that the Leyden jar was being charged" This is sometimes considered the discovery of the fact that lightning contains/is electricity. || {{w|Benjamin Franklin}}.
|-
| caused two mouldy petri dishes to fall || In August 1928, Alexander Fleming put ''S. aureus'' into multiple petri dishes, and then left to go on holiday/vacation. On September 3, he returned and found that one plate had mould on it. This plate was the only one that did not have ''S. aureus'' bacteria in it. He later repeated this experiment, and the result was confirmed. {{w|History_of_penicillin#The_breakthrough_discovery|Wikipedia link}} || The mould that Alexander Fleming had discovered produced Penicillin, an antibiotic. This was the first time that a substance had been discovered that could ''Reliably'' treat bacterial infections, and had a huge effect on medicine across the world. || {{w|Alexander Fleming}}
|-
| Onto a bell next to a salivating dog, || [https://www.simplypsychology.org/pavlov.html In 1902 Ivan Pavlov conducted a study on dog reflexes] he gave dogs food, and rang a bell. When the dog saw the food, it started salivating. Eventually, ringing the bell made the dog salivate as the dog associated the bell ringing with food. Pavlov also performed other, less humane experiments on other dogs. || This was the discovery of {{w|classical conditioning}}, where a stimulus is paired with an unrelated other thing, through repeated exposure. The subject will eventually react to the unrelated thing like the stimulus, instinctively. This is an example of taught reflexes, where a subconsious reaction like a reflex or instinct is taught. || {{W|Ivan Pavlov}}
|-
| whose shadow angle determined the circumference of The Earth. || |In the 200s BCE, the greek philosopher Eratosthenes {{w|Earth's_circumference#Eratosthenes|measured the circumference of the Earth.}} While his exact method had been lost to time, A simplified version remains: At high noon on the summer solstice in a Alexandria, the sun was almost directly overhead. This was confirmed with a sundial. 5,000 stadia away in Seyene, at the same time, the angle of the sun was measured with another sundial. The angle of the sun could then be converted into degrees away on Earth's surface. Some simple division and multiplication could then yield the circumference of the Earth. || This was one of the first, if not the first, measurement of the Earth's circumference with any accuracy. The distance Eratosthenes calculated for the circumference of Earth was 250,000 stadia. This estimate was either 2.4% low or 0.8% high compared to modern knowledge, depending on whether he used Greek or Egyptian Stadia. || {{w|Eratosthenes}}
|-
| (Title text) fell and hit me on the head. Hey, that gives me an idea... || Sir Isaac Newton is a very famous scientist, who discovered/invented a lot of important things, including {{w|Calculus}} and that white light can be split. His most famous discovery, however, was how {{w|gravity}} works. The story goes that while contemplating things in his garden, {{w|Isaac_Newton#Apple_incident|an apple fell on Newton's head}}. Rather than brushing it off, he wondered what ''exactly'' caused the apple to fall. This lead him to investigate gravity and celestial motion, eventually publishing ''{{w|Philosophiæ Naturalis Principia Mathematica}}'', or simple ''principa'' || Gravity is important {{Citation needed}}, so understanding gravity and its effects was, and still is, very important. || Sir {{w|Isaac Newton}}
|}

==Transcript==
{{incomplete transcript |Please change this comment when editing this page. Do NOT delete this tag too soon.}}

:[Caption below the panel:]
:History's greatest scientist was probably that one who measured the shadow of the Leaning Tower of Pisa while flying a kite into a distant thunderstorm where lightning caused two moldy Petri dishes to fall onto a bell next to a salivating dog whose shadow angle determined the circumference of the Earth.

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

2632: Greatest Scientist

2022-06-13T23:53:26Z

Darthpoppins: /* Explanation */ Corrected spelling errors.

{{comic
| number = 2632
| date = June 13, 2022
| title = Greatest Scientist
| image = Greatest Scientist.png
| titletext = "Ow! One of the petri dishes I left on the tower railing fell and hit me on the head. Hey, that gives me an idea..."
}}

==Explanation==
{{incomplete|Created by HISTORY'S WURST SCIENTIST - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic pretends that many (6 by my count) of history's greatest scientists were the same person, and says that this person was the greatest scientist in history. A combination of 6 of the greatest scientists ever would most likely be the greatest scientist ever.{{Citation needed}}

These scientists are most likely {{w|Galileo Galilei}}, {{w|Benjamin Franklin}}, {{w|Alexander Fleming}}, {{w|Ivan Pavlov}}, {{w|Eratosthenes}}, and {{w|Isaac Newton}}

Humorously combining multiple science experiments into one was also a punchline in [[1584: Moments of Inspiration]].
{| class="wikitable"
|+ List of experiments in the comic
|-
! Experiment in comic !! Experiment in reality !! Meaning !! Scientist
|-
| The Leaning Tower of Pisa || {{w|Galileo}} conducted [https://en.wikipedia.org/wiki/Galileo%27s_Leaning_Tower_of_Pisa_experiment an experiment] at the Leaning Tower of Pisa to measure whether the rate at which objects fall is dependent on weight or is consistent. || Galileo found that objects with different weights still fall at the same rate, disproving Aristotle's theory which purported the opposite. However, {{w|Viviani}} had already discovered this.|| {{w|Galileo Galilei}}
|-
|While flying a kite into a distant thunderstorm, where lightning || In June 1752, Benjamin Franklin performed his famous {{w|Kite experiment}}, where he attached a conductive wire to a kite, and flew it near a thunderstorm. Attached to the kite was a key, which was further attached to a {{w|leyden jar}} || While the kite was not hit by lightning, "Franklin did notice that loose threads of the kite string were repelling each other and deduced that the Leyden jar was being charged" This is sometimes considered the discovery of the fact that lightning contains/is electricity. || {{w|Benjamin Franklin}}.
|-
| caused two mouldy petri dishes to fall || In August 1928, Alexander Fleming put ''S. aureus'' into multiple petri dishes, and then left to go on holiday/vacation. On September 3, he returned and found that one plate had mould on it. This plate was the only one that did not have ''S. aureus'' bacteria in it. He later repeated this experiment, and the result was confirmed. {{w|History_of_penicillin#The_breakthrough_discovery|Wikipedia link}} || The mould that Alexander Fleming had discovered produced Penicillin, an antibiotic. This was the first time that a substance had been discovered that could ''Reliably'' treat bacterial infections, and had a huge effect on medicine across the world. || {{w|Alexander Fleming}}
|-
| Onto a bell next to a salivating dog, || [https://www.simplypsychology.org/pavlov.html In 1902 Ivan Pavlov conducted a study on dog reflexes] he gave dogs food, and rang a bell. When the dog saw the food, it started salivating. Eventually, ringing the bell made the dog salivate as the dog associated the bell ringing with food. Pavlov also performed other, less humane experiments on other dogs. || This was the discovery of {{w|classical conditioning}}, where a stimulus is paired with an unrelated other thing, through repeated exposure. The subject will eventually react to the unrelated thing like the stimulus, instinctively. This is an example of taught reflexes, where a subconsious reaction like a reflex or instinct is taught. || {{W|Ivan Pavlov}}
|-
| whose shadow angle determined the circumference of The Earth. || |In the 200s BCE, the greek philosopher Eratosthenes {{w|Earth's_circumference#Eratosthenes|measured the circumference of the Earth.}} While his exact method had been lost to time, A simplified version remains: At high noon on the summer solstice in a Alexandria, the sun was almost directly overhead. This was confirmed with a sundial. 5,000 stadia away in Seyene, at the same time, the angle of the sun was measured with another sundial. The angle of the sun could then be converted into degrees away on Earth's surface. Some simple division and multiplication could then yield the circumference of the Earth. || This was on of the first, if not the first, measurement of the Earth's circumference with any accuracy. The distance Eratosthenes calculated for the circumference of Earth was 250,000 stadia. This estimate was either 2.4% low or 0.8% high compared to modern knowledge, depending on whether he used Greek or Egyptian Stadia. || {{w|Eratosthenes}}
|-
| (Title text) fell and hit me on the head. Hey, that gives me an idea... || Sir Isaac Newton is a very famous scientist, who discovered/invented a lot of important things, including {{w|Calculus}} and that white light can be split. His most famous discovery, however, was how {{w|gravity}} works. The story goes that while contemplating things in his garden, {{w|Isaac_Newton#Apple_incident|an apple fell on Newton's head}}. Rather than brushing it off, he wondered what ''exactly'' caused the apple to fall. This lead him to investigate gravity and celestial motion, eventually publishing ''{{w|Philosophiæ Naturalis Principia Mathematica}}'', or simple ''principa'' || Gravity is important {{Citation needed}}, so understanding gravity and its effects was, and still is, very important. || Sir {{w|Isaac Newton}}
|}

==Transcript==
{{incomplete transcript |Please change this comment when editing this page. Do NOT delete this tag too soon.}}

:[Caption below the panel:]
:History's greatest scientist was probably that one who measured the shadow of the Leaning Tower of Pisa while flying a kite into a distant thunderstorm where lightning caused two moldy Petri dishes to fall onto a bell next to a salivating dog whose shadow angle determined the circumference of the Earth.

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

2624: Voyager Wires

2022-05-25T20:51:55Z

Darthpoppins: /* Explanation */ spelling edit

{{comic
| number = 2624
| date = May 25, 2022
| title = Voyager Wires
| image = voyager_wires.png
| titletext = Also, they're getting increasingly worried that someone will accidentally hit the 'retract' button, and that the end of the cable thrashing around as it winds up could devastate the Earth's surface.
}}

==Explanation==
{{incomplete|Created by a WIRE CUT BECAUSE OF BUDG- are you there houston? it's me v----ger, you'll never guess what I found! Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic claims that the Voyager probes communicate with NASA though ridiculously long copper wires, when in reality they use radio waves.{{citation needed}} These wires would have to be continuously lengthened as the probes travel away from Earth. Supposedly, because of "high copper prices and budget constraints," they may not be able to afford to lengthen the wires much longer. If this occurred, they would have to either cut the wires or let them break, which would prevent any further communication with the probes. As mentioned earlier, however, they actually use radio waves, not long copper wires, so this will not actually happen.

If copper wires were dragged by the Voyager probes, the resulting wire would slow down the probes by drag, but be perfect space elevators for lightweight spacecraft.
Of course, since the Earth spins, the wires would also spool around the Earth, slowing the probes down even further. Clearly, this is not a good idea.{{citation needed}}

This doesn't even factor in how the Earth, in its rotation around the sun, will drag these copper wires in a circular orbit leading the wires through the sun at least once per year. The difference between the melting point of copper and the average core temperature of the sun has not yet been established by reproducible experiment, but is believed to be incompatible with the high quality required for signal transmission.

The consequence of a cable between a craft in space and a planetary location being suddenly retracted was recently demonstrated in the first episode of the Apple TV series {{w|Foundation}}. It didn't end well for anyone.

====Alternate Explanation====
When Randall Munroe states that Voyager 1 and 2 are cabled to the Earth by copper wires, his assertion deserves serious consideration.{{citation needed}}

The primary explanation, above, takes the position that this comic is ridiculously wrong.{{citation needed}} But the insertion of several "citation needed" links suggests that the explanation's position is weak.{{citation needed}}

The comic's author, Randall Munroe,{{citation needed}} is well attested as a competent scientist,{{citation needed}} for example see the citations in the [https://en.wikipedia.org/wiki/Randall_Munroe Wikipedia Randall Munroe page]. His books, cited in that same Wikipedia article,{{citation needed}} offer well-researched easy to understand discussions of science and of everyday phenomena.{{citation needed}} Trust him.{{citation needed}}

(For completeness, see another Wikipedia article, [https://en.wikipedia.org/wiki/Disinformation Disinformation]. In its subsection ''Strategies for spreading disinformation'', strategy number 4 is "Directly Sharing Disinformation".{{citation needed}} That is mentioned here only because the top header at the xkcd web site states it is a webcomic of romance, '''sarcasm,''' math, and language.){{citation needed}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[There is an image of a space probe, presumably one of NASA's Voyager probes, with a long wire connecting it to a ball, presumably earth. To the left, there is a second wire, which goes offscreen. Below, there is a caption.]

Caption: "Sad news: Due to high copper prices and budget constraints, NASA may finally have to cut the wires that they've been spooling out to communicate with Voyager 1 and 2."
{{comic discussion}}

2614: 2

2022-05-02T23:19:03Z

Darthpoppins: Spelling correction

{{comic
| number = 2614
| date = May 2, 2022
| title = 2
| image = 2.png
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.
}}

==Explanation==
{{incomplete|Created by 6b6t.org - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

The comic contains examples of scientific notation. Plain numbers are common in all math. A number in superscript to the right of a letter or combination of letters may denote the mass number of an atom and hence specifies an isotope, while a number in subscript may be the atomic number. A number in superscript to the right of a number or letter may in math be an exponential, and in most contexts a referral to a footnote. A number in subscript to the right may denote the amount of an atom in a chemical formula, while two numbers separated by semicolon may refer to one specific element of the matrix if the subscript follows the name of the matrix.

This demonstrates the different ways in which the number 2 can be typeset in various scientific fields.

The number 2 on its own is regular math. The dotted box represents any character. The number 2 as a superscript means take the second power (i.e., square whatever precedes it) in physics or regular math. The number 2 as a subscript can be used, in chemistry, to show how many atoms of a particular element are present in a molecule. A subscript 2,2 shows the second element on the second row of a matrix. The number 2 in parenthesis is the argument to a function (or something else{{citation needed}} in group theory). A symbol centred underneath another symbol is normally reserved for doing summations, where the big symbol is a capital sigma, or other combinations of operations; it does not make sense to have a single number there, as indicated in the alt text.

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

[An apparently scientific expression:]
2 [superscript:] 2 [subscript:] 2 [normal text:] an empty box [superscript:] 2 [subscript:] 2;2 [normal text:] (2) [beneath the last 2:] 2

{{comic discussion}}

2592: False Dichotomy

2022-03-11T17:50:28Z

Darthpoppins: /* Explanation */

{{comic
| number = 2592
| date = March 11, 2022
| title = False Dichotomy
| image = false_dichotomy.png
| titletext = There are two types of dichotomy: False dichotomies, true dichotomies, and surprise trichotomies.
}}

==Explanation==
{{incomplete|Created by the only alternative to a bot - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

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

:White Hat: That's a false dichotomy!
:Cueball: Yes, but we have to embrace false dichotomies, because the only alternative is cannibalism.

{{comic discussion}}

2548: Awful People

2021-11-30T00:17:14Z

Darthpoppins: /* Explanation */

{{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 (Maybe) - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

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

2527: New Nobel Prizes

2021-10-12T02:09:13Z

Darthpoppins: /* Explanation */

{{comic
| number = 2527
| date = October 11, 2021
| title = New Nobel Prizes
| image = new_nobel_prizes.png
| titletext = They've endowed a separate prize in Physiology or Medicine or Stopping Dr. Adams.
}}

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

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Megan stands at a podium on a stage, facing right. Behind her is a screen showing eight Nobel Prizes. Ponytail is approaching the front of the stage while waving.]
:Megan: And all eight Nobel Prizes for the Discovery of New Nobel Prizes have been awarded to...
:Megan: ''*sigh*''
:Megan: ...Doctor Adams, '''''again''''', for the discovery of two new Prizes.
:Ponytail: Thank you, thank you!

:[Caption below frame:]
We don't know how she started this and now we can't figure out how to stop her.

{{comic discussion}}

Talk:2346: COVID Risk Comfort Zone

2020-08-14T21:03:22Z

Darthpoppins:

The current text seems more like a comment than an explanation. [[User:Darthpoppins|Darthpoppins]] ([[User talk:Darthpoppins|talk]]) 21:03, 14 August 2020 (UTC)

2304: Preprint

2020-05-08T23:40:15Z

Darthpoppins: Replaced "much" with "many", since "applications" is a countable plural.

{{comic
| number = 2304
| date = May 9, 2020
| title = Preprint
| image = preprint.png
| titletext = DOWNSIDES: Adobe people may periodically email your newsroom to ask you to call it an 'Adobe® PDF document,' but they'll reverse course once they learn how sarcastically you can pronounce the registered trademark symbol.
}}

==Explanation==
{{incomplete|Created by an ADOBE® PDF DOCUMENT. Explain the different terminology used by the newscaster, expand upon benefit points. Do NOT delete this tag too soon.}}

This comic is about how media reports non-peer-reviewed papers. The newscaster depicted is attempting to report breaking news based on information in a study; however, the study in question has not been formally published. This leads to uncertainty on the part of either the newscaster or her scriptwriters as they try to determine how to refer to this study, represented here by alternative introduction lines being scribbled out.

Randall suggests that, instead of explaining that the paper was in preprint, or unpublished or submitted to a preprint server and not peer-reviewed, the newscaster could simply say it was a PDF, and lists several benefits of doing so:
* The use of terms such as "preprint" makes statement about its publication status, which might be based on inaccurate information or even be in the process of changing as the news goes out; in contrast, proclaiming it to be a PDF is an unambiguously factual statement.
* Referring to the PDF directly also prevents individuals from making assumptions that the one responsible knows and has verified what they're doing - or, in contrast, that the information is automatically false based on the grounds that it hasn't yet been officially published.
* The comic finishes with a jab at the PDF format itself, proclaiming that no ordinary person would ''voluntarily'' choose a PDF file as their medium of communication.

The title text makes fun of the official name for a PDF file. Since so many applications can create and even edit PDF files, implying a connection with Adobe every time someone talks about one is preposterous, and one could sarcastically pronounce the registered trademark symbol to show contempt for the fact that it is a registered trademark.

If you want to lend extra legitimacy to the "was probably prepared by a professional" point, mention that it was created using LaTeX, the only file extension more trustworthy than PDF (see [[1301: File Extensions]]).

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

[A newscaster is sitting at a desk. Several of her opening sentences are scribbled over, indicating revisions to her script.]

:Newscaster (scribbled out): According to a new preprint…
:Newscaster (scribbled out): …An unpublished study…
:Newscaster (scribbled out): According to a new paper uploaded to a preprint server but which has not undergone peer review...
:Newscaster: According to a new PDF…
:Inset graphic: Breaking ''NEWS''
:Caption: Benefits of just saying "a PDF":
:* Avoids implications about publication status
:* Immediately raises questions about author(s)
:* Still implies "this document was probably prepared by a professional, because no normal human trying to communicate in 2020 would choose this ridiculous format."

{{comic discussion}}

Talk:2301: Turtle Sandwich Standard Model

2020-05-01T22:46:47Z

Darthpoppins:

This is the first time I have had a chance to see the comic early enough to make a meaningful contribution to the explanation, but this time I have no idea whatsoever what the comic is about! [[User:Moosenonny10|Moosenonny10]] ([[User talk:Moosenonny10|talk]]) 20:32, 1 May 2020 (UTC)

Looks like it is referencing the standard model of elementary particles. The title text mentions four of the quarks(top,bottom,charm,strange) [[Special:Contributions/162.158.106.150|162.158.106.150]] 20:38, 1 May 2020 (UTC)

Disagree with DgbrtBOT that this is primarily to do with genetics. I agree that it's about the standard model. Up, down, charmed and strange. It may 'because I'm dumb', but even I'm not that dumb.
:I agree that this is not about genetics. The usual Mendelian diagram has the same traits in both dimensions. Maybe he didn't make the particle physics connection because that has more than 4 boxes. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 21:52, 1 May 2020 (UTC)

I added a bit about the physics part of it, but it can definitely use more information! [[User:ChunyangD|ChunyangD]] ([[User talk:ChunyangD|talk]]) 20:52, 1 May 2020 (UTC)

Randall missed an obvious physics/turtle joke "turtles all the way down" reference here [[Glenn Strycker]] 4:56pm CDT 1 May 2020

If this really is about genetics, which I question, it seems likely that most people who haven't studied genetics would find the use of genetics jargon to be less than helpful in an explanation.[[User:Darthpoppins|Darthpoppins]] ([[User talk:Darthpoppins|talk]]) 22:46, 1 May 2020 (UTC)

2238: Flu Shot

2019-12-07T10:44:07Z

Darthpoppins: /* Explanation */

{{comic
| number = 2238
| date = December 6, 2019
| title = Flu Shot
| image = flu_shot.png
| titletext = "Wait, how often are you getting bitten by snakes? And why are you boiling water?" "Dunno, the CDC people keep showing up with complicated questions about the 'history of the property' and 'possible curses' but I kinda tune them out. At least one of them offered me the flu shot."
}}

==Explanation==
{{incomplete|Created by a FLU VIRUS. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

In this comic, Megan tells Cueball that she got a {{w|flu shot}}, which is a vaccine to prevent getting the {{w|common flu}}. She then goes on to claim she doesn't have to worry about being bitten by bats, but the worry with being bitten by bats is rabies, not the flu. This implies she got the two confused. Then, she goes on to claim to now be immune to other abnormal stuff, such as poison ivy, snake venom, contaminated water, and computer viruses.

The flu shot consists of inactivated viruses from three different strains of the flu, which are those judged by the {{w|World Health Organization}} (WHO) to most likely be in wide circulation in the following flu season. Because the influenza virus comes in many strains and mutates rapidly, the flu shot is generally less than 60% effective at preventing flu infections; this is a positive effect for health outcomes, but it's not exactly what most people think of as "immunity", especially compared to e.g. the 97% effectiveness of the MMR vaccine against measles and rubella, and it will certainly not prevent harm from coming to Megan by the other sources of infection or poison she mentions (except to the extent that all of these things will be even worse for her if she is also sick with the flu):

* '''{{w|Rabies}}''' is a viral disease that causes brain inflammation, which in turn causes symptoms including aggression, fear of water, and violent uncontrollable limb movements. It can be carried by almost any vertebrate animal, but bats, raccoons, and wild dogs are the stereotypical carriers. There is a rabies vaccine, but it is generally only administered to pets and humans who work extensively with animals.
* '''{{w|Poison ivy}}''' is a vine which produces an oil, {{w|urushiol}}, which chemically reacts with membrane proteins on the skin cells it contacts, which in turn tricks the immune system into attacking those cells. Some people are not affected by poison ivy, but as it is an allergic reaction, people often become more sensitive to poison ivy upon repeated exposure. There is no known vaccine or other permanent preventative treatment against urushiol sensitivity, although there are several creams that can be applied in advance of expected poison ivy exposure to reduce the risk of contacting the chemical.
* '''Sunburn''' is caused by exposing the skin to high levels of ultraviolet radiation, such as by playing outside in noontime sun for an hour or two without clothing or sunscreen. Repeatedly getting sunburned can increase the risk of skin cancer later in life. As ultraviolet radiation is a form of electromagnetic energy, it cannot be vaccinated against, although some humans have greater tolerance for UV radiation due to melanin production in their skin. Stimulating melanin production through controlled exposure to UV radiation is called "{{w|sun tanning}}", although this is generally done for cosmetic rather than medical purposes, and the effect will fade over time if UV doses are reduced.
* '''{{w|Snake venom}}''' is not one single compound, but several proteins and molecules produced by venomous snakes to inject into prey. Different snakes' venoms have different effects, so there is no single vaccine or antivenom for all snake bites, but {{w|antivenom}}s are produced by a process similar to vaccination. Small doses of venom are injected into host animals, such as horses, to provoke an immune response; the resulting antibodies are then stored to be injected into snakebite victims, where they will bind up and inactivate the toxic proteins and mark them for disposal by the immune system.
* '''Untreated water''' may be contaminated by bacteria, protozoa, parasites, and chemical pollutants. Boiling water will kill off any biological contaminants, which will prevent food-borne diseases such as {{w|cholera}}, {{w|dysentery}}, and {{w|giardiasis}}. In developed areas of the world (which presumably most of the XKCD characters live in), boiling water is generally not necessary due to municipal water treatment, but if those treatment facilities are interrupted by a disaster, the government may advise residents to boil their water before drinking it. This is likewise advised for people living or traveling in less-developed areas, like backpackers or farmers. Some of these diseases can be prevented by vaccines, but because there are so many microscopic life-forms in water, it is not possible to vaccinate against all of them.
* '''{{w|Computer viruses}}''' are computer programs that spread through networks via infected devices, attachments, and websites. They can cause harm directly by taking up computer cycles and network bandwidth, but nowadays they often perform other tasks for their creators, such as exfiltrating financial information or encrypting files and demanding ransom for the keys. Computer viruses can be recognized and blocked or deleted by software that scans incoming files and links against known computer virus patterns, which is analogous to vaccination, but there is no vaccine that can be administered to Megan which would protect her computer.

In the title text, Cueball asks Megan why she is subject to all of the above maladies. She responds that some members of the {{w|U.S. Centers for Disease Control}} (CDC) have evidently speculated that Megan is subject to all of the above maladies due to a curse on her property. In many works of fiction, building over sacred or desecrated ground (such as the stereotypical "ancient Indian burial ground", mentioned by Megan back in [[782: Desecration]]) results in curses befalling the builders and/or occupants of such properties, although usually those curses express themselves in more fantastical ways, such as disruptive {{w|poltergeists}} or re-animating the dead.

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

:Megan (walking into frame from the left): Yesss, I got my flu shot.
:Cueball (off panel): Nice! I got mine a few weeks ago.
:Cueball: Immunity buddies!

:Megan (spreading her arms wide): Now I can finally get bitten by all the bats I want!
:Cueball: No, that's rabies, that's not what—

:(closeup of Megan's head)
:Megan: I'll be able to roll and play in the poison ivy without a care in the world!
:Cueball (off screen): Why would you do that even if the shot ''did''—

:Megan (flexing her arms): No more slathering on sunscreen. No more rushing for antivenom after a snakebite. And now I can stop wasting time boiling contaminated water before drinking it!

:Megan (running off toward the left): Gonna click on every URL in every email I get, even the ones with IP addresses and weird Unicode in them!
:Cueball: You know what, sure, go for it.

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Biology]]
[[Category:Animals]]

1839: Doctor Visit

2017-05-20T22:25:40Z

Darthpoppins: /* Explanation */

{{comic
| number = 1839
| date = May 19, 2017
| title = Doctor Visit
| image = doctor_visit.png
| titletext = According to these blood tests, you're like 30% cereal.
}}

==Explanation==
{{incomplete|Created by a BOT - Edited by a human. Needs more humans.}}
[[Cueball]] is visiting his doctor [[Ponytail]], apparently for a general medical checkup.

While there is nothing wrong with him medically, the doctor wonders why he has continued to work for many years despite his body parts' individual fragility. Compared to man-made structures - like the USB cables mentioned by Ponytail, which quickly begin to fray - it's surprising that the body can survive for so long while sustaining so much wear and tear. Actually the body gets stronger and more fit the more it is used (an example of antifragility[https://en.wikipedia.org/wiki/Antifragility]), in contrast to USB cables, which tend to wear out with use.

Ponytail specifically mentions his eyes which are so fragile and exposed. Yet most people go through a whole life with both eyes intact, although the vision itself may be impaired. The human reflexes and the shape of the skull around the eyes has a lot to do with the fact that it is possible to protect such fragile structures for a lifetime.

Ponytail also remarks that the body is composed of high pressure fluids (particularly blood, intracellular and extracellular fluids) and intricate parts (like the nervous system and the heart). If the fluids stopped flowing or the intricate parts stopped working, the entire body would fail, killing Cueball.

It should be noted that the human body is constantly replacing dead/injured cells and proteins. In a young human body, everything in the body is continually refurbished, and nothing is able to become old enough to deteriorate unintentionally; this requires a constant supply of energy and nutrients to keep this process going. As the body ages, these self-repair mechanisms eventually slow and can no longer keep up with the required repairs; this manifests as the various symptoms of old age (wrinkled skin, graying and balding hair, worsening eyesight and hearing, etc.)

USB cables are built to withstand far more wear and tear than the human body. But while this makes them tougher than blood vessels on the outset, they inevitably fray and fail faster than blood vessels because they lack the self-repair mechanisms of organic material.

The doctor's final remark is that Cueball is mainly made from dissolved bread, which is true from the perspective that the food (bread) he eats is digested in his alimentary system, absorbed into his bloodstream and used as nutrients for growth and repair.

This is taken further in the title text, where she states that the blood tests reveal he is 30% {{w|cereal}}.

All things taken into consideration, we don't actually have any confirmation that Ponytail is a real doctor. As Randall has stated before, [[699: Trimester|anybody can just buy a lab coat]]. Although Ponytail's answer in the final panel lacks [[1644: Stargazing|the usual "I have no idea" or equivalent non-answer]], so it's still somewhat possible she's a real doctor having an existential episode.

==Transcript==
:[Cueball is seated on an medical examination table while Ponytail stands dressed in a doctor's coat holding a file in her right hand.]
:Cueball: Everything look good?
:Ponytail: I don't get how your body has been moving around for years and still works at all. My USB cables fray after like a month.

:Ponytail: Your heart has been pumping for decades without pausing for even a few minutes.
:Ponytail: And your ''eyes!'' They're so fragile and exposed!

:[Zoom in on Cueball gazing at his palms.]
:Ponytail (off-panel): You're full of all these high-pressure fluids and intricate parts that could kill you in seconds if they stopped working!

:[Zoom out again to the entire scene.]
:Cueball: ...can you just tell me whether I'm healthy?
:Ponytail: Yeah, you're fine.
:Ponytail: Which is weird, given that your body is basically made from dissolved bread.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

1839: Doctor Visit

2017-05-20T22:24:38Z

Darthpoppins: /* Explanation */

{{comic
| number = 1839
| date = May 19, 2017
| title = Doctor Visit
| image = doctor_visit.png
| titletext = According to these blood tests, you're like 30% cereal.
}}

==Explanation==
{{incomplete|Created by a BOT - Edited by a human. Needs more humans.}}
[[Cueball]] is visiting his doctor [[Ponytail]], apparently for a general medical checkup.

While there is nothing wrong with him medically, the doctor wonders why he has continued to work for many years despite his body parts' individual fragility. Compared to man-made structures - like the USB cables mentioned by Ponytail, which quickly begin to fray - it's surprising that the body can survive for so long while sustaining so much wear and tear. Actually the body gets stronger and more fit the more it is used(an example of antifragility[https://en.wikipedia.org/wiki/Antifragility]), in contrast to USB cables, which tend to wear out with use.

Ponytail specifically mentions his eyes which are so fragile and exposed. Yet most people go through a whole life with both eyes intact, although the vision itself may be impaired. The human reflexes and the shape of the skull around the eyes has a lot to do with the fact that it is possible to protect such fragile structures for a lifetime.

Ponytail also remarks that the body is composed of high pressure fluids (particularly blood, intracellular and extracellular fluids) and intricate parts (like the nervous system and the heart). If the fluids stopped flowing or the intricate parts stopped working, the entire body would fail, killing Cueball.

It should be noted that the human body is constantly replacing dead/injured cells and proteins. In a young human body, everything in the body is continually refurbished, and nothing is able to become old enough to deteriorate unintentionally; this requires a constant supply of energy and nutrients to keep this process going. As the body ages, these self-repair mechanisms eventually slow and can no longer keep up with the required repairs; this manifests as the various symptoms of old age (wrinkled skin, graying and balding hair, worsening eyesight and hearing, etc.)

USB cables are built to withstand far more wear and tear than the human body. But while this makes them tougher than blood vessels on the outset, they inevitably fray and fail faster than blood vessels because they lack the self-repair mechanisms of organic material.

The doctor's final remark is that Cueball is mainly made from dissolved bread, which is true from the perspective that the food (bread) he eats is digested in his alimentary system, absorbed into his bloodstream and used as nutrients for growth and repair.

This is taken further in the title text, where she states that the blood tests reveal he is 30% {{w|cereal}}.

All things taken into consideration, we don't actually have any confirmation that Ponytail is a real doctor. As Randall has stated before, [[699: Trimester|anybody can just buy a lab coat]]. Although Ponytail's answer in the final panel lacks [[1644: Stargazing|the usual "I have no idea" or equivalent non-answer]], so it's still somewhat possible she's a real doctor having an existential episode.

==Transcript==
:[Cueball is seated on an medical examination table while Ponytail stands dressed in a doctor's coat holding a file in her right hand.]
:Cueball: Everything look good?
:Ponytail: I don't get how your body has been moving around for years and still works at all. My USB cables fray after like a month.

:Ponytail: Your heart has been pumping for decades without pausing for even a few minutes.
:Ponytail: And your ''eyes!'' They're so fragile and exposed!

:[Zoom in on Cueball gazing at his palms.]
:Ponytail (off-panel): You're full of all these high-pressure fluids and intricate parts that could kill you in seconds if they stopped working!

:[Zoom out again to the entire scene.]
:Cueball: ...can you just tell me whether I'm healthy?
:Ponytail: Yeah, you're fine.
:Ponytail: Which is weird, given that your body is basically made from dissolved bread.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]