explain xkcd - User contributions [en]

2296: Sourdough Starter

2020-04-23T14:27:57Z

Elessar: correction: sourdough starter is not a culture of mere yest, but a symbiosis of yeast and bacteria

{{comic
| number = 2296
| date = April 20, 2020
| title = Sourdough Starter
| image = sourdough_starter.png
| titletext = Once the lockdown is over, let's all get together and swap starters!
}}

==Explanation==
{{incomplete|Created by a BOT WITH AN EXTREMELY CONVOLUTED PARASITIC LIFE CYCLE. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This comic is another comic in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.

Recently, because of the coronavirus, many people are forced to stay home in quarantine. Quarantines often lead to spare time that needs to be filled, and many people have turned to baking, which can usually be done entirely at home, is relatively time-consuming, and has the advantage of producing finished food, lessening the need to go out to buy food. This trend is common enough that baking supplies, including yeast, have seen a spike in demand, to the point where [https://www.foodandwine.com/news/yeast-supply-shortage-coronavirus many people have trouble finding it.]

As an alternative to yeast, consumers can grow their own sourdough starter, which is a symbiotic culture of yeast and bacteria naturally found in flour. Once the starter has matured, part of it can be used to make bread or other baked good rise, while the remainder can be mixed with more water and nutrients to allow the remaining yeast and bacteria to multiply once again. Because these populations need to be maintained, it's often been a practice to trade starters from house to house, with each home using starter when they need it, then setting up the remaining starter to breed more. This has historically been a social activity, allowing people who share an interest in baking to meet, share recipes, and spend time together.

The upshot of all of this is that the coronavirus pandemic has created conditions in which yeast (and symbiotic bacteria) are being bred in larger numbers, both by companies trying to fill demand, and by individuals trying to make their own. The joke is that this outcome is, in fact, the entire purpose of the coronavirus, which is in a {{w|symbiosis|symbiotic}} relationship with yeast. The entire global pandemic, by this logic, is directed to keep humans indoors and baking so that more yeast (and bacteria) is bred. The practice of swapping sourdough starters means that they're propagated more widely, increasing and distributing the yeast population (while potentially giving the virus more opportunity to spread, as people socialize).

As Randall points out, this cycle is extremely convoluted. However, it is not unknown for {{w|Parasite}}s to drive the responses of other creatures in order to propagate themselves. For example, ''{{w|Toxoplasma gondii}}'' infects mice, but can only reproduce when it infects cats. The organism has therefore adapted to infect the nervous systems of mice, making them extremely reckless, increasing their odds of being caught and eaten by cats, allowing the the parasite to move to a new host. Some flatworm parasites have very complex life cycles that involve [http://olsonlab.com/resources/Publications/2003AdvParaCribb.PDF four different host animals].

Randall has previously speculated about unusual parasitic organisms in [[2246: Christmas Presents]], in which he "concluded" that Christmas presents are parasites of Christmas trees, possibly mediated by a fungus. And in [[1664: Mycology]] a fungus infects human brains making them wish to study (and thus grow more of) this fungus.

Viruses are not organisms (lacking some of the defining features of life), and it is debatable whether they would be considered parasites. Moreover, this theory is obviously implausible for a number of reasons. The most obvious being that natural responses, particularly of viruses and simple organisms, evolve over a long time scale. SARS-CoV-2, the virus responsible for the current pandemic, has very likely been infecting humans for less than one year, certainly not long enough to evolve such a complex set of behaviors. At the same time, a symbiotic relationship would require yeast to somehow contribute to the life cycle of the coronavirus in a meaningful way, which is unlikely when the yeast is being artificially bred in isolated containers. If however, as suggested by the title text, people getting together to swap yeast starters after the lockdown ends does cause the virus to begin spreading in humans again as a result of the social contact, then the yeast would be contributing to the life cycle of the coronavirus, in a equally convoluted way. The humor, therefore, is derived from the fact that this is a comical exaggeration, but based on cycles that actually do happen in nature.

==Transcript==
:[Cueball stands in front of a kitchen counter looking down at a glass jar he is holding in both hands. The jar's flat lid is lying on the table. There is another large jar farther back on the counter with a lid, with a small handle, on. In both jars there is a substance, which do stay in the same position in the jar even though Cueball tilts the jar he is holding.]
:Cueball: My sourdough starter is coming along nicely!

:[Caption below the panel]
:Theory: The coronavirus is a yeast symbiont with an '''''extremely''''' convoluted parasitic life cycle.

{{comic discussion}}

[[Category:COVID-19]]
[[Category:Comics featuring Cueball]]
[[Category:Food]]

1767: US State Names

2016-12-02T09:01:42Z

Elessar: complete some terms

{{comic
| number = 1767
| date = December 2, 2016
| title = US State Names
| image = us_state_names.png
| titletext = Technically DC isn't a state, but no one is too pedantic about it because they don't want to disturb the snakes.
}}

==Explanation==
This is just a silly map.
Randall has taken a map of the United States of America labeled "Geography Challenge: Name all 50 States" and filled in the states with words that sound similar to the states' names.

{| class="wikitable sortable"
|-
! Fictional State
! Actual State
! Explanation
|-
| Wilwheaton
| Washington
| Will Wheaton is an actor from Washington
|-
| Organs
| Oregon
|
|-
| Cafeteria
| California
|
|-
| Fallout New Vegas
| Nevada
| Fallout New Vegas is set in Nevada
|-
| Idolatry
| Idaho
|
|-
| mount -a
| Montana
| A command to mount all disk volumes
|-
| Wysiwyg
| Wyoming
| Acronym What You See Is What You Get.
|-
| Uhaul
| Utah
| [https://en.wikipedia.org/wiki/U-Haul U-Haul] is a company where you can rent vans.
|-
| Verizona
| Arizona
| Verizon has a shared "Rizon" with Arizona. Randall presumably enjoys this.
|-
| Namaste
| New Mexico
| [https://en.wikipedia.org/wiki/Namaste Namaste] is a Hindu greeting.
|-
| Hexxus
| Texas
| The antagonist of Ferngully. [https://en.wikipedia.org/wiki/FernGully:_The_Last_Rainforest FernGully] is said to be the model for the later film "Avatar".
|-
| Okay
| Oklahoma
| OK is the state's abbreviation.
|-
| Candice
| Kansas
|
|-
| Colocated
| Colorado
|
|-
| Nebrunswick
| Nebraska
| New Brunswick, A Canadian province
|-
| Dakota
| South Dakota
|
|-
| More Dakota
| North Dakota
|
|-
| Minestrone
| Minnesota
| Minestrone is a thick vegetable soup, originating in Italia.
|-
| Wainscot
| Wisconsin
|
|-
| Iota
| Iowa
|
|-
| Sk8rbois
| Illinois
| "Skater Boys"
|-
| Mossouri
| Missouri
| The single different letter might be borrowed from Montessori, as in Montessori schools.
|-
| Arkanoids
| Arkansas
| An arcade game.
|-
| Louisa
| Louisiana
|
|-
| Misstate
| Mississippi
|
|-
| Bandana
| Alabama
|
|-
| Thennessy
| Tennessee
|
|-
| Kennedy
| Kentucky
|
|-
| That Other One
| Indiana
|
|-
| Mishy
| Michigan
|
|-
| Oh Hi
| Ohio
|
|-
| Pencilmania
| Pennsylvania
|
|-
| Newark
| New York
| A mispronunciation of New York. Possible reference to William Gibson's works.
|-
| Vermouth
| Vermont
| [https://en.wikipedia.org/wiki/Vermouth Vermouth] is an Italian alcoholic beverage
|-
| New Hamper
| New Hampshire
|
|-
| Spanish Maine
| Maine
|
|-
| Masseuses
| Massachusetts
|
|-
| Roald Dahl
| Rhode Island
| A British writer, famous for child novels such as Charlie and the Chocolate Factory
|-
| Connectfour
| Connecticut
|
|-
| Nude Juggalos
| New Jersey
|
|-
| Delorean
| Delaware
| The car model used in the Back to the Future movies
|-
| Maybelline
| Maryland
|
|-
| District of Colubrids
| District of Columbia
| The [https://en.wikipedia.org/wiki/Colubridae Colubridae] are the biggest family of snakes, accounting for about two thirds of the world's species. As the title text mentions, the [https://en.wikipedia.org/wiki/Washington,_D.C. District of Columbia], although not part of any state, is technically not a state itself, but is usually labeled on the maps like the 50 others for practical reasons. Here, Randall humorously explains the reason as people not wanting to upset the aforementioned snakes by dismissing their district for this pedantic reason.
|-
| Wyvern
| West Virginia
|
|-
| Virjayjay
| Virginia
| Virginia is similar to vagina. Vajayjay is slang for vagina.
|-
| Sweet Caroline
| North Carolina
|
|-
| South Caroline
| South Carolina
|
|-
| George
| Georgia
|
|-
| Fyoridor
| Florida
| Possibly derived from the Russian name Fyodor, as in Fyodor Dostoyevsky.
|-
| Alberta
| Alaska
| A Canadian province.
|-
| Kawaii
| Hawaii
| A Japanese term for cute commonly romanized similar to Hawaii.
|-
| Bandana
| Alabama
|
|}

==Transcript==
{{incomplete transcript}}
| Alabama => Bandana |
| Alaska => Alberta |
| Arizona => Verizona |
| Arkansas => Arkanoids |
| California => Cafeteria |
| Colorado => Colocated |
| Connecticut => Connect Four |
| Delaware => Delorean |
| District of Columbia => District of Colubrids |
| Florida => Fyoridor |
| Georgia => George |
| Hawaii => Kawaii |
| Idaho => Idolatry |
| Illinois => SK8RBOIS |
| Indiana => That Other One |
| Iowa => Iota |
| Kansas => Candice |
| Kentucky => Kennedy |
| Louisiana => Loisa |
| Maine => Spanish Maine |
| Maryland => Maybelline |
| Massachusetts => Masseuses |
| Michigan => Mishy |
| Minnesota => Minestrone |
| Mississippi => Misstate |
| Missouri => Mossouri |
| Montana => mount -a |
| Nebraska => Nebrunswick |
| Nevada => Fallout New Vegas |
| New Hampshire => New Hamper |
| New Jersey => Nude Juggalos |
| New Mexico => Namaste |
| New York => Newark |
| North Carolina => Sweet Caroline |
| /South Carolina => South Caroline |
| Ohio => Oh Hi |
| Oklahoma => Okay |
| Oregon => Organs |
| Pennsylvania => Pencilmania |
| Rhode Island => Roald Dahl |
| South Dakota => Dakota |
| /North Dakota => More Dakota |
| Tennessee => Thennessy |
| Texas => Hexxus |
| Utah => Uhaul |
| Vermont => Vermouth |
| Virginia => Virjayjay |
| Washington => Willwheaton |
| West Virginia => Wyvern |
| Wisconsin => Wainscot |
| Wyoming => WYSIWYG |

{{comic discussion}}

[[Category:Maps]]

1462: Blind Trials

2014-12-19T09:30:57Z

Elessar: /* Transcript */ the work “think” is emphasized

{{comic
| number = 1462
| date = December 19, 2014
| title = Blind Trials
| image = blind_trials.png
| titletext = Plus, you have to control for the fact that some people are into being blindfolded.
}}

==Explanation==
{{incomplete|Created by a BOT - Please change this comment when editing this page.}}
In research, a {{w|Blind Experiment|blind trial}} is an experiment where certain information about the test is concealed from the subjects and/or the testers, in order to reduce sources of bias in the results. A scientific approach requires the use of {{w|control groups}} to determine the significance of observations in (clinical) trials. The members of the control group receive either no treatment or the standard treatment.

A double-blind trial is one where neither the subject nor the testers know who has recieved treatment, and who is in the control group. It is vital that there are no clues available to distinguish between the different groups, either for the subjects or the testers. In a clinical drugs trial for example, it would not be suitable for some people to be given blue pills and others red pills, so an identical placebo pill should be used, typically a sugar pill with no medical value.

There are, however, certain cases where it is almost impossible to make the experience of the control group identical to that of the test group. In the described experiment, it will be challenging (to say the least) to make the control group think they are having lots of sex, when in fact they are just taking a sugar pill.

Scientific research involving humans is extremely challenging to conduct because of the difficulty in finding appropriate control groups. This is one of the reasons animal experiments (for instance involving inbred strains of mice) are so common.

The title text adds another twist by taking “blind” literally, and noting that for some people, being blindfolded increases their enjoyment of sexual activity.

==Transcript==
:[Megan is pointing at a chart.]
:Megan: We've designed a double-blind trial to test the effect of sexual activity on cardiovascular health.
:Both groups will ''think'' they're having lots of sex, but one group will be actually getting sugar pills.

:[Caption reads]
:The limitations of blind trials

{{comic discussion}}

1424: En Garde

2014-09-22T07:31:01Z

Elessar: /* Explanation */ “en garde” ~ “at your mark”, not “ready”

{{comic
| number = 1424
| date = September 22, 2014
| title = En Garde
| image = en_garde.png
| titletext = 'Touch!' 'Nope, I sighed and stared at you with resignation, so I regained emotional right-of-way.'
}}

==Explanation==
{{incomplete|How guarded is Cueball really?}}

The left participant says "en garde!", a fencing call literally meaning "be on your guard" (from French). The call is used to order the participants to take their position, in a similar way to the “on your mark” command in racing (the other two commands are “((tireurs,) êtes-vous) prêts?” (“((combattants,) are you) ready?”) and “allez” (“go”)). The right participant takes this to mean being "guarded" emotionally, and explains so, to which the left participant says he shouldn't be ''that'' guarded.

The title text takes this further with the "touch" call, used to indicate to a participant that they have been "touched" by their opponent's blade, and have therefore lost the bout (fencing terminology for the current round). The right participant counters this claim by saying his emotions have priority (or right-of-way). Fencing right-of-way rules can make a move invalid when another move has priority, but generally refer to physical actions on the participant's part.

==Transcript==
[Two fencers are standing together as if to fight]
:Fencer 1: ''En Garde!''
:Fencer 2: Ok.
:Fencer 2: No matter how long we know each other, when you ask "What are you thinking," I will always pause before answering.
:Fencer 1: Maybe a little ''less'' guarded?
:Fencer 2: No way. I've been hurt before.

{{comic discussion}}

Talk:1181: PGP

2013-03-04T09:03:15Z

Elessar: Do not separate my signature from my comment

I don't really understand what's funny about this comic. [[Special:Contributions/76.106.251.87|76.106.251.87]] 05:53, 4 March 2013 (UTC)
: Perhaps the fact that an email is encrypted (or pretends to be) at all? Most emails aren't encrypted, or none of the ones I send or get are. :D [[Special:Contributions/59.10.72.121|59.10.72.121]] 06:28, 4 March 2013 (UTC)

I think merely the fact that PGP is in the email itself suggests the sender of the email is probably just a big nerd and therefore can be trusted. {{unsigned|153.90.91.1}}

Isn't it that those markers could very simply just have been typed in, rather than being part of the decryption system? [[User:DonGoat|DonGoat]] ([[User talk:DonGoat|talk]]) 07:41, 4 March 2013 (UTC)

With public key systems like PGP you need the public key of the other person to verify the authenticity of the message. Most people do not use PGP or do not know how it works or are just lazy. Some of those are convinced enough just by the outer looks of a signed email: The starting block and the jumbled chars at the end. It is like being impressed by a signature per se in real life without knowing what the one of the person you write to looks like. I think the allusion to pretty good is coincidental. Sebastian --[[Special:Contributions/178.26.118.249|178.26.118.249]] 08:11, 4 March 2013 (UTC)

There is an interesting comparison to do with regular handwritten signature, as this is exactly how people check the authenticity of a handwritten signed document: check for a signature. If there is one, and if there is, even if you never saw a sample of that signature, trust it. However, as with cryptographic signature with an unknown key, this does rely one something: the fact that it is forbidden, and punishable, to counterfeit one's signature, even if it is badly done (as in: write a random signature, hoping that the recipient does not know the real signature of the alleged author). -- [[User:Elessar|Elessar]] ([[User talk:Elessar|talk]]) 09:02, 4 March 2013 (UTC)

Talk:1181: PGP

2013-03-04T09:02:14Z

Elessar: Comparison with handwritten signature checking

I don't really understand what's funny about this comic. [[Special:Contributions/76.106.251.87|76.106.251.87]] 05:53, 4 March 2013 (UTC)
: Perhaps the fact that an email is encrypted (or pretends to be) at all? Most emails aren't encrypted, or none of the ones I send or get are. :D [[Special:Contributions/59.10.72.121|59.10.72.121]] 06:28, 4 March 2013 (UTC)

I think merely the fact that PGP is in the email itself suggests the sender of the email is probably just a big nerd and therefore can be trusted. {{unsigned|153.90.91.1}}

Isn't it that those markers could very simply just have been typed in, rather than being part of the decryption system? [[User:DonGoat|DonGoat]] ([[User talk:DonGoat|talk]]) 07:41, 4 March 2013 (UTC)

With public key systems like PGP you need the public key of the other person to verify the authenticity of the message. Most people do not use PGP or do not know how it works or are just lazy. Some of those are convinced enough just by the outer looks of a signed email: The starting block and the jumbled chars at the end. It is like being impressed by a signature per se in real life without knowing what the one of the person you write to looks like. I think the allusion to pretty good is coincidental. Sebastian --[[Special:Contributions/178.26.118.249|178.26.118.249]] 08:11, 4 March 2013 (UTC)

There is an interesting comparison to do with regular handwritten signature, as this is exactly how people check the authenticity of a handwritten signed document: check for a signature. If there is one, and if there is, even if you never saw a sample of that signature, trust it. However, as with cryptographic signature with an unknown key, this does rely one something: the fact that it is forbidden, and punishable, to counterfeit one's signature, even if it is badly done (as in: write a random signature, hoping that the recipient does not know the real signature of the alleged author).
[[User:Elessar|Elessar]] ([[User talk:Elessar|talk]]) 09:02, 4 March 2013 (UTC)

1181: PGP

2013-03-04T08:55:57Z

Elessar: Direct link to the RFC page about cleartext signatures, replace incorrect “encrypted” by “signed” since this is what this comic is about

{{comic
| number = 1181
| date = March 4, 2013
| title = PGP
| image = pgp.png
| titletext = If you want to be extra safe, check that there's a big block of jumbled characters at the bottom.
}}

==Explanation==
This comic is a play on words with PGP, or {{w|Pretty Good Privacy}}, a method of encrypting emails. While PGP relies on, in part {{w|Public-key cryptography}}, Randall suggests that if you just look for "Begin PGP Signed Message" in the message, the assumption that the message is encrypted is "Pretty Good." This holds true as one of the [https://tools.ietf.org/html/rfc4880#page-60 RFC4880]-devised plaintext headers for messages with {{w|ASCII armor}} is exactly this text. The title-text carries this further, suggesting that if something looking like a signature is located at the end of the message, the email was signed.

The joke here lies within the approach of ignoring actual privacy guarantees PGP provides as if you can distinguish the plaintext part from the signature you are using it without encryption and thus there's pretty good certainty about no privacy added through PGP.

Also humans hardly ever can verify signatures just doing math in their head.

==Transcript==
:

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Computers]]