explain xkcd - User contributions [en]

3081: PhD Timeline

2025-04-26T20:44:40Z

172.70.90.236: Undo revision 375308 by 172.70.43.139 (talk) reverted removal of details and insertion of biased language

{{comic
| number = 3081
| date = April 25, 2025
| title = PhD Timeline
| image = phd_timeline_2x.png
| imagesize = 382x516px
| noexpand = true
| titletext = Rümeysa Öztürk was grabbed off the street in my town one month ago.
}}

Clicking on the image on [https://xkcd.com xkcd.com] takes you to ''[https://www.youtube.com/watch?v=JyypeEEOklM Surveillance video shows Tufts University student Rumeysa Ozturk apprehended in Somerville, MA]'' on YouTube.

==Explanation==
{{incomplete|You might want to {{w|Detention of Rümeysa Öztürk|copy text over from the Wikipedia page}}, but keep in mind this wiki's main goal is to explain the comic. Don't remove this notice too soon.}}

This comic presents a typical PhD timeline, with a twist. Typically a PhD is broken into a number of steps, from enrollment through to thesis defense. However, in this case, the timeline takes an unexpected turn when, instead of publishing the thesis, the candidate is detained by masked government agents. While this may seem like an unlikely event, it reflects the {{w|detention of Rümeysa Öztürk|lived experience of Rümeysa Öztürk}}, a Turkish Ph.D. student at Tufts University<ref>"Tufts Democrats and Tufts Republicans release joint statement condemning detainment of Rümeysa Öztürk" Tufts Daily 22/04/2025 https://www.tuftsdaily.com/article/2025/04/tufts-democrats-and-tufts-republicans-release-joint-statement-condemning-detainment-of-rumeysa-ozutrk accessed 26/04/2025</ref> who was abruptly detained by six masked ICE agents in Somerville, MA while walking to an {{w|iftar}} dinner. Subsequently, she was transported to Vermont and then to a detention facility in Louisiana before a court ordered that she not be removed from Massachusetts.<ref>"Louisiana federal judge denies bond to Rümeysa Öztürk" Tufts Daily 18/04/2025 https://www.tuftsdaily.com/article/2025/04/louisiana-judge-denies-bond-to-rumeysa-ozturk-while-vermont-judge-considers-jurisdiction accessed 26/04/2025</ref>

The reason given for her detention was that her {{w|F visa|F-1 student visa}} was revoked due to, according to a Department of Homeland Security spokeswoman<ref>"DHS detains grad student who advocated for Palestine and the "humanity of all people"" Salon 26/03/2025 https://www.salon.com/2025/03/26/dhs-detains-grad-student-advocated-for-palestine-and-the-humanity-of-all-people/ accessed 26/04/2025</ref>,
her alleged activities in support of the foreign terrorist organization {{w|Hamas}} on the campus of Tufts. Aside from her being co-author of an article in a student newspaper which was critical of her university's response towards protests against the ongoing {{w|Gaza war}}, no evidence of support for Hamas has been provided. The U.S. government can cancel a visa if the subject's activities are harmful to U.S. foreign policy interests, though the threat of a visa being revoked has a clear chilling effect on legal speech, and raises serious {{w|First Amendment}} issues. Ordinarily, revocation of a visa is not, of itself, grounds for detention; that would merely prevent one from reentering the country if one left.<ref>"Visa Stamps and Status" Washington University https://oiss.washu.edu/visa-status-stamps/ accessed 26/04/2025</ref>

The title text refers to the fact that Somerville is also where [[Randall Munroe]] lives.

For a more detailed account, see {{w|Detention of Rümeysa Öztürk}} on Wikipedia.

This is only the second comic referring to what is happening in the US after Trump became president. The first was [[3073: Tariffs]], but that was actually an attempt to extract humor from a situation. This one is very different.

==Transcript==
:[A chart shows the typical events in a research program. At the top there is a dotted line. There is a title above the line and the line is labeled with text in the middle breaking the line:]
:US PH.D. PROGRAM TIMELINE
:–––––––ENROLLMENT–––––––––

:[The dotted line aligns with the top of an Y-axis with 7 ticks, the top tick on level with the dotted line. There are seven labels from top towards the bottom, not written near specifik ticks, and with uneven distance. Between each of the labels there is an arrow from the one above pointing the the next. To the right of the first five labels there is a split up rectangle, that are closed at the top , but open at the bottom. Down through the middle part it is split up in two along a kind of S-shape going a bit up from left to right. There is a gab between the top and bottom part of this figure along this s-shape. Both top and bottom part has a label. All text and other parts of the comic has been in black until this. But the last two labels near the Y-axis beneath where the rectangular figure stops, which are still written in black, have been crossed out with red squiggly lines, both the two small arrows and the text. From the label above those crossed out, there goes a red arrow down and then to the right. This point to another red label next to and right of the first of the two that has been crossed out. From beneath this another red arrow point to a second red label, next to the the last of the two that was crossed out. A third red arrow goes beneath this to a final red label.]
:Meet with Advisor
:Research Proposal
:Qualifying Exams
:Purpose Dissertation
:Research and Write dissertation

:[The above is the labels near the rectangular figure to the right with the following labels:]
:Coursework
:Research

:[The final two labels that have been crossed out with red lines:]
:Submit dissertation
:Defend dissertation

:[The new labels written to the right with red:]
:<font color="red">Get grabbed off the sidewalk outside of your home by masked government agents
:Be whisked out of the state before a judge has time to intervene
:????</font>

==References==
{{reflist}}

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Charts]]
[[Category:Comics featuring real people]] 
[[Category:Politics]]
[[Category:Comics with red annotations]]

3073: Tariffs

2025-04-08T13:06:45Z

172.70.90.236: /* Explanation */

{{comic
| number = 3073
| date = April 7, 2025
| title = Tariffs
| image = tariffs_2x.png
| imagesize = 681x809px
| noexpand = true
| titletext = [later] I don't get why our pizza slices have such terrible reviews; the geotextile-infused sauce gives the toppings incredible slope stability!
}}

==Explanation==
{{incomplete|Created by a SPOILER FOR AVATAR 2 (Neteyam dies) - Please change this comment when editing this page. Explanation of the consequences of stopping imports (the last panel) is needed. Do NOT delete this tag too soon.}}

This comic is a parody of the tariffs that {{w|Donald Trump}} {{w|tariffs in the second Trump administration|imposed in 2025}}, which were announced shortly before the comic's release. [[Cueball]] describes the tariffs and, specifically, why the plan has garnered widespread disapproval for several seemingly illogical decisions, to [[Ponytail]] using a pizza store analogy.

Similar to [[2396: Wonder Woman 1984]], Ponytail blocked news sites to avoid {{w|spoiler (media)|spoiler}}s about ''Avatar 2'' (officially titled ''{{w|Avatar: The Way of Water}}'') in early 2021, but did not re-enable notifications until just now. ''Avatar 2'' was released on December 16, 2022, but this means that she has missed all news since 2021, including the re-election of Trump in 2024. She is surprised by the fact that Donald Trump is still the president in early 2025. She may be under the impression that Trump refused to step down when [[Joe Biden]]'s presidency officially began on Jan. 20, 2021. This is likely because of the relative rarity of a nonconsecutive second term, which has only happened once before in U.S. history with Grover Cleveland serving from 1885 to 1889 and again from 1893 to 1897. On the other hand, only {{w|Franklin D. Roosevelt}} ever had more than two four-year terms, and that was before the {{w|Twenty-second Amendment to the United States Constitution|22<sup>nd</sup> Amendment}} made it even less of a possibility that one could have started a third.

Ponytail has further missed Trump's wide-ranging tariffs, and the attending news coverage that has served to introduce many people to what tariffs are and how they work. Cueball attempts to explain by comparing the U.S. with the Geotechnical Survey company that Ponytail works for, as they are both producers of high value, technologically advanced goods, and comparing the countries the U.S. imports from to a pizza place, since the U.S. primarily imports lower value consumer goods and materials used to make the goods that the U.S. then exports, similar to how pizzas feed the workers in Ponytail's company.

A trade deficit occurs when party A buys more from party B than they sell to party B. Donald Trump, the president of the United States at the time the comic released, claimed that if the U.S. has a trade deficit with another country, then the U.S. is getting ripped off and the other country must be punished. In the comic, Cueball mockingly echoes Trump's belief to better explain his policies. As Ponytail explains, there is nothing wrong with having a trade deficit if you think you are getting your money's worth for what you are buying.{{Citation needed}} The U.S. can benefit from a trade deficit in some cases: the flow of foreign capital (like factory machinery) into the country can allow for more development, and some kinds of production are dangerous or polluting relative to the value of the goods produced. In addition, the U.S. treasury commands the world's reserve currency as well as the currency used for most world trade, making outflow of foreign currency not really a problem.{{Actual citation needed}}

A tariff is a tax on imports from another country. Most politicians try to balance tariffs carefully in order to keep domestic products competitive with imported goods. In contrast, Donald Trump introduced tariffs unilaterally and aggressively with the aim to "punish" countries with which the United States had a trade deficit. Trump's opponents and even many of his supporters worry excessive tariffs will backfire and cause countries to target the American consumer with even higher prices (especially prices of goods which the United States cannot produce domestically at all) resulting in a "trade war."

In the comic, Cueball proposes that Ponytail impose a tax or "tariff" on the pizza store until they start buying from Ponytail. Notably, the tariff is applied on the people who deliver the products to Ponytail's company, just like in real life. Ponytail notes that such a tariff might encourage the pizza store to stop selling to her, which Cueball considers (in his position as devil's advocate for the whole concept) a victory. In reality, nations have very little control of where the products go after being produced inside their own borders. Instead, it is left up to the companies (the delivery companies, in this case) to decide where to produce (or procure) the goods. What tariff proponents often omit, is that companies will simply pass on the costs associated with tariffs to the consumers, making the pizza more expensive for the consumer but with no benefit to the supplier. In practical terms, the pizza company may even just stop taking orders from this company, having other customers that are easier to deliver to. Even if there's a saturated pizza industry, with several pizza outlets all vying for the local business, it may still be less problematic to compete for the slightly smaller 'rest of the town' market, perhaps even to offer deliveries to places previously outside their area, than to work with whatever requirements the survey company is imposing.

In contrast to real world countries like China or Canada which, as of 2025, procure a substantial amount of goods from the U.S., Ponytail notes that the pizza company has little use for land survey equipment, unless they are constructing their own stores from the ground up without outside contractors. Ponytail suggests surveying pizzas using their equipment, which would serve little purpose.

The U.S. used to be a dominant producer of consumer goods up until the 1970s, after which companies started offshoring production that utilized low-skilled labor to third-world countries. In contrast, Ponytail's company has likely never been a producer of food. {{w|LIDAR}} is a technique using lasers to measure distances. Ponytail's company is using the technology to do surveying. In the final panel and title text, Cueball suggests that they use their LIDAR components to make their own pizzas, which would be inedible and potentially toxic.{{Citation needed}} Cueball may be referencing the annoyance Italians have at unconventional pizza toppings.

The title text references slope stability, or the ability of an inclined slope to withstand movement. Toppings often slide off poorly-made pizzas when it is being eaten, leading to dissatisfaction. Geotextiles are permeable fabrics used for support and various other functions. The narrator claims that geotextiles prevent toppings from sliding off the pizza. However, very few geotextiles are edible.{{Citation needed}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.I don’t like reCAPTCHAS}}
:[Ponytail walks over to Cueball while looking at a phone in her hand. Cueball turns away from the laptop on his desk to look at her.]
:Ponytail: You know how I blocked all news sites at the start of 2021 to avoid spoilers for Avatar 2, and then forgot to start checking them again?
:Cueball: Yeah, we've been meaning to talk to you about that...

:[Ponytail stops in front of Cueball and is facing him.]
:Ponytail: Well, I just checked the news for the first time, and why is the economy tanking?
:Cueball: Uh, the president is mad at other countries and imposed lots of tariffs.

:[Closeup on Ponytail's head.]
:Ponytail: Wait, who's the president now?
:Cueball (off-panel): Donald Trump.
:Ponytail: ...Still??
:Cueball (off-panel): No, again.

:[Pan out. Ponytail is no longer holding the phone.]
:Ponytail: OK, fine, what's a tariff? Why is he doing this?
:Cueball: You know that pizzeria your company orders from? They don't buy anything from ''you'', right?
:Ponytail: Why would they? We do geotechnical landscape surveys.

:[Closeup on Cueball, arms spread.]
:Cueball: Right, so they're ripping you off! ''You're'' paying ''them'' tons of money, and what are ''you'' getting for it?
:Ponytail (off-panel): I mean... pizza?
:Cueball: See? They're not helping ''your'' business at all!
:Cueball: What a ripoff!

:[Pan out. Ponytail has her hand under her chin.]
:Ponytail: What would they even buy from us? I guess we could survey a pizza...
:Cueball: Yes, perfect! You refuse to let the delivery driver past your security desk unless they Venmo you for an equivalent value of LIDAR scans.

:[Closeup on Ponytail's head.]
:Ponytail: Wouldn't they just stop taking our orders?
:Cueball (off-panel): Perfect, balance restored!

:[Pan out.]
:Ponytail: OK, but I still want pizza.
:Cueball: Can you just make one? You have all that gear.
:Ponytail: I don't think pizza made with LIDAR diodes would be very good.
:Cueball: Ugh, why is everyone so picky about toppings?

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Politics]]
[[Category:Comics featuring Donald Trump]]
[[Category:Food]]
[[Category:Geology]]

3069: Terror Bird

2025-04-01T10:51:09Z

172.70.90.236: /* Explanation */

{{comic
| number = 3069
| date = March 28, 2025
| title = Terror Bird
| image = terror_bird_2x.png
| imagesize = 342x274px
| noexpand = true
| titletext = There has long been debate about Big Bird's species, with some experts claiming he was a canary, but recent genetic analysis places him firmly in Cariamiformes.
}}

==Explanation==
{{incomplete|The explanation is not a transcript. Need to actually explain the comic, not describe the scene.}}

This comic is a scene of two people, [[Jill]] and [[Hairy]], at a museum looking at a fossil skeleton of a large prehistoric {{w|Phorusrhacidae|terror bird}}, which is a "big bird". [[Hairy]] thinks out loud about {{w|Big Bird}} (as becomes clear in the title text), a Muppet character from {{w|Sesame Street}}. He suggests that he must be a terror bird, and wonders whether he will be updated to be more scientifically accurate, and therefore more scary. However Big Bird, being from a show for little kids, was never intended to be a terror bird and would almost certainly never be made to look scary.

The title text claims that there is ongoing scientific debate about Big Bird's species. Initially, likely due to his color, he was thought to be a {{w|Yellow canary|canary}}.<ref>Borgenicht, David. ''Sesame Street Unpaved: Scripts, Stories, Secrets and Songs''. Hyperion Press, 1998.</ref> He has more recently been placed in the order {{w|Cariamiformes}}, which the terror birds belong to. This text is likely intended to mirror what somebody might say about the {{w|Seriema|seriemas}}, modern-day birds also in the Cariamiformes, as if Big Bird were the descendant of these birds. [https://www.pechakucha.com/presentations/what-if-anything-is-big-bird Actual scientific analysis] seems to suggest that Big Bird is in fact related to the {{w|whooping crane}}.

The comic implies that the Big Bird species is extinct. This is could be a reference to current events (there was a Congressional [https://www.nytimes.com/2025/03/25/business/media/pbs-npr-congressional-hearing.html hearing] March 26, 2025 in which one of the topics was whether funding for PBS would be reduced or eliminated). It is worth mentioning, though, that Sesame Street is not directly owned by PBS, but rather by [https://sesameworkshop.org/ Sesame Workshop] which is itself a 501(c)(3) organization.

==Transcript==
:[Jill and Hairy are standing together, looking up at the skeleton of a very large bird. The skeleton, that towers more than two times the height of Hairy, is being displayed on a low podium. There is an information stand in front of the podium, for the benefit of visitors.]
:Hairy: Wow.
:Hairy: Now that we know how scary they were, do you think Sesame Street will update him?

== Notes ==
{{reflist}}

{{comic discussion}}

[[Category:Comics featuring Jill]]
[[Category:Comics featuring Hairy]]
[[Category:Animals]]

Talk:3064: Lungfish

2025-03-17T16:24:26Z

172.70.90.236: program vs static data

Huh, first time I've seen a comic the literal minute it was posted. Weird seeing a completely empty explainxkcd page. [[User:Beanie|<span style="text-shadow:0 0 5px black;font-size:11pt;color:#dddddd">Beanie]]</span> [[User talk:Beanie|<sup><span style="text-shadow:0 0 3px black;font-size:8pt;color:#dddddd">talk]]</span></sup> 16:10, 17 March 2025 (UTC)
Got the basics of a transcript going. --[[User:DollarStoreBa'al|DollarStoreBa'al]] ([[User talk:DollarStoreBa'al|talk]]) 16:21, 17 March 2025 (UTC)
People often talk about DNA being the program that builds life, but it seems to me more as if its the static-data used by the program that builds life
[[Special:Contributions/172.70.90.236|172.70.90.236]] 16:24, 17 March 2025 (UTC)

3019: Advent Calendar Advent Calendar

2024-12-04T15:18:58Z

172.70.90.236: /* Explanation */

{{comic
| number = 3019
| date = December 2, 2024
| title = Advent Calendar Advent Calendar
| image = advent_calendar_advent_calendar_2x.png
| imagesize = 482x324px
| noexpand = true
| titletext = The growth rate of items per day may may seem absurd, but it's actually much less than the acceleration in the 12 Days of Christmas song.
}}

==Explanation==
{{incomplete|Created by 7 SIGS A-MISSING, 6 [CITATIONS NEEDED], 5 WIKILINKS, 4 ENVELOPE BACKS, 3 NERDS [https://fancyclopedia.org/Neeping A-NEEPING], 2 TURTLE BOTS, AND A FUNNY NEW XKCD - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
{{w|Advent calendar}}s are a form of countdown to Christmas consisting of a card or structure with one closed "window"/opening for each day. Every day, another "window" is opened (e.g. a cardboard flap is opened along perforations), revealing a small present (traditionally, just a thematic picture or chocolate). While the religious season of {{w|Advent}} traditionally begins four Sundays before Christmas, most Advent calendars begin on December 1st for simplicity. In 2024, when this comic was published, the Advent season coincidentally starts on December 1st. Advent calendars usually have either 24 or 25 doors (ending on either Christmas Eve or Christmas Day), depending on manufacturer's choice and/or local tradition.

In this comic, Randall has devised an Advent calendar that contains multiple smaller Advent calendars, each of which contains the same number of items as there are days left until (and ''including'') Christmas Day. By the time he reaches Christmas, he will have 325 different items, or 350 if counting the sub-calendars. The calendar is shown as it might be on December 2<sup>nd</sup>, the date of publication of this strip. The "window" in the upper left, presumed to be for the 1<sup>st</sup> of December, has 25 sub-windows, of which two are open. (One would have been opened on December 1<sup>st</sup> and the next for the day after.) The "window" 5<sup>th</sup> from the left in the bottom row, probably for December 2<sup>nd</sup>, has 24 sub-windows, of which one (that for the initial 2<sup>nd</sup>) is open.

The title text refers to {{w|The Twelve Days of Christmas (song)|The Twelve Days of Christmas}}, a traditional Christmas carol in which the singer receives many gifts from their paramour for each day of the Twelve Days of Christmas. On day one, they receive one gift, and on day ''n'', they receive again all the gifts they received on day ''n-1'', plus ''n'' copies of a new gift. The exact gifts given each day vary by version of the song, receiving 78 gifts on day 12, for a total of 364 gifts. For the Advent calendar Advent calendar, each day a number of items equal to the number of days left until Christmas are added. There are 364 items total in the 12 Days of Christmas, the final day itself having exceeded the gifts of the nested calendars (the sub-gift count being 325, and regardless of the 25 calendars also being included). However the advent calendar uses 25 days rather than just 12, hence the song's acceleration in number of gifts each day is much higher. The title text says “may” twice, either mistakenly, or maybe on purpose since the comic's name has word duplication.

The advent calendar's advent calendar gift total follows the {{w|triangular number}} sequence of all new gifts on a given day being one more than those the day before: on the first day, this is 1 (the first sub-gift of the first sub-calendar); on the second, we now have 3 (add two sub-gifts from two sub-calendars); on the third, we have 6 (three sub-gifts added), etc. The formula for the total on day ''n'' is <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:9pt; text-size-adjust: none;"><tr><td style="text-decoration: underline">''n''(''n''+1)</td></tr><tr><td style="text-align: center">2</td></tr></table>. For the Twelve Days song (which goes from the 25th of December to 5th of January), ''each day'' adds to the total the next ''triangular number'' in the sequence: +1=1, +3=4, +6=10, etc... The formula for this {{w|tetrahedral number}} (a 'pyramid of triangular numbers') is <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:9pt; text-size-adjust: none;"><tr><td style="text-decoration: underline">''n''(''n''+1)(''n''+2)</td></tr><tr><td style="text-align: center">6</td></tr></table>, and matches a triple-nested meta-Advent Calendar's non-calendar gift count. This already starts in a more rapid escalation of gift-giving, immediately after the first day where both counts are at one item. However, due to the later start of the Twelve Days, one would have to extend the gift-giving patterns to the 17th Day Of Christmas (and thus the 41st day of Advent) for the number of ''true love'' gifts (969) to properly overtake the continuing meta-calendar's ones, with (902) or without (861) counting the sub-calendars as gifts. (The number of ultimate gifts in any quadruple-nested Advent Calendar would be <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:9pt; text-size-adjust: none;"><tr><td style="text-decoration: underline">''n''(''n''+1)(''n''+2)(''n''+3)</td></tr><tr><td style="text-align: center">24</td></tr></table>, excluding all the calendars themselves.)

It is not clear what is inside each sub-calendar. The typical filling would be chocolate, however it could also be possible that the advent calendar advent calendars had even more advent calendars within. That this is not the case is revealed in the title text as, if they were (and were run concurrently), the number of (sub-sub-)gifts would always equal those in the song.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[On a grey board, there are 23 Advent calendars behind large "windows", numbered from 3 to 25, plus two open calendars with their covers torn off.]
:[From top-left to bottom-right, the boxes are numbered as such: (opened), 14, 23, 16, 11, 3; 5, 24, 18, 7, 21; 10, 17, 4, 9, 22, 15, 12; 8, 20, 13, 25, (opened), 19, 6]
:[Each calendar numbered ''n'' has 26−''n'' squares in it.]
:[The open calendar on the top left has 25 squares, two of which are black. The other open calendar has 24 squares, one of which is black.]

:[Caption below the panel:]
:I like Advent calendars, so I got an Advent calendar that gives me a new one every day until Christmas.

{{comic discussion}}

[[Category:Christmas]]
[[Category:Calendar]]
[[Category:Songs]]

3019: Advent Calendar Advent Calendar

2024-12-04T15:17:34Z

172.70.90.236: /* Explanation */

{{comic
| number = 3019
| date = December 2, 2024
| title = Advent Calendar Advent Calendar
| image = advent_calendar_advent_calendar_2x.png
| imagesize = 482x324px
| noexpand = true
| titletext = The growth rate of items per day may may seem absurd, but it's actually much less than the acceleration in the 12 Days of Christmas song.
}}

==Explanation==
{{incomplete|Created by 6 [CITATIONS NEEDED], 5 wikilinks, 4 ENVELOPE BACKS, 3 NERDS [https://fancyclopedia.org/Neeping A-NEEPING], 2 TURTLE BOTS, AND A FUNNY NEW XKCD - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
{{w|Advent calendar}}s are a form of countdown to Christmas consisting of a card or structure with one closed "window"/opening for each day. Every day, another "window" is opened (e.g. a cardboard flap is opened along perforations), revealing a small present (traditionally, just a thematic picture or chocolate). While the religious season of {{w|Advent}} traditionally begins four Sundays before Christmas, most Advent calendars begin on December 1st for simplicity. In 2024, when this comic was published, the Advent season coincidentally starts on December 1st. Advent calendars usually have either 24 or 25 doors (ending on either Christmas Eve or Christmas Day), depending on manufacturer's choice and/or local tradition.

In this comic, Randall has devised an Advent calendar that contains multiple smaller Advent calendars, each of which contains the same number of items as there are days left until (and ''including'') Christmas Day. By the time he reaches Christmas, he will have 325 different items, or 350 if counting the sub-calendars. The calendar is shown as it might be on December 2<sup>nd</sup>, the date of publication of this strip. The "window" in the upper left, presumed to be for the 1<sup>st</sup> of December, has 25 sub-windows, of which two are open. (One would have been opened on December 1<sup>st</sup> and the next for the day after.) The "window" 5<sup>th</sup> from the left in the bottom row, probably for December 2<sup>nd</sup>, has 24 sub-windows, of which one (that for the initial 2<sup>nd</sup>) is open.

The title text refers to {{w|The Twelve Days of Christmas (song)|The Twelve Days of Christmas}}, a traditional Christmas carol in which the singer receives many gifts from their paramour for each day of the Twelve Days of Christmas. On day one, they receive one gift, and on day ''n'', they receive again all the gifts they received on day ''n-1'', plus ''n'' copies of a new gift. The exact gifts given each day vary by version of the song, receiving 78 gifts on day 12, for a total of 364 gifts. For the Advent calendar Advent calendar, each day a number of items equal to the number of days left until Christmas are added. There are 364 items total in the 12 Days of Christmas, the final day itself having exceeded the gifts of the nested calendars (the sub-gift count being 325, and regardless of the 25 calendars also being included). However the advent calendar uses 25 days rather than just 12, hence the song's acceleration in number of gifts each day is much higher. The title text says “may” twice, either mistakenly, or maybe on purpose since the comic's name has word duplication.

The advent calendar's advent calendar gift total follows the {{w|triangular number}} sequence of all new gifts on a given day being one more than those the day before: on the first day, this is 1 (the first sub-gift of the first sub-calendar); on the second, we now have 3 (add two sub-gifts from two sub-calendars); on the third, we have 6 (three sub-gifts added), etc. The formula for the total on day ''n'' is <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:9pt; text-size-adjust: none;"><tr><td style="text-decoration: underline">''n''(''n''+1)</td></tr><tr><td style="text-align: center">2</td></tr></table>. For the Twelve Days song (which goes from the 25th of December to 5th of January), ''each day'' adds to the total the next ''triangular number'' in the sequence: +1=1, +3=4, +6=10, etc... The formula for this {{w|tetrahedral number}} (a 'pyramid of triangular numbers') is <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:9pt; text-size-adjust: none;"><tr><td style="text-decoration: underline">''n''(''n''+1)(''n''+2)</td></tr><tr><td style="text-align: center">6</td></tr></table>, and matches a triple-nested meta-Advent Calendar's non-calendar gift count. This already starts in a more rapid escalation of gift-giving, immediately after the first day where both counts are at one item. However, due to the later start of the Twelve Days, one would have to extend the gift-giving patterns to the 17th Day Of Christmas (and thus the 41st day of Advent) for the number of ''true love'' gifts (969) to properly overtake the continuing meta-calendar's ones, with (902) or without (861) counting the sub-calendars as gifts. (The number of ultimate gifts in any quadruple-nested Advent Calendar would be <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:9pt; text-size-adjust: none;"><tr><td style="text-decoration: underline">''n''(''n''+1)(''n''+2)(''n''+3)</td></tr><tr><td style="text-align: center">24</td></tr></table>, excluding all the calendars themselves.)

It is not clear what is inside each sub-calendar. The typical filling would be chocolate, however it could also be possible that the advent calendar advent calendars had even more advent calendars within. That this is not the case is revealed in the title text as, if they were (and were run concurrently), the number of (sub-sub-)gifts would always equal those in the song.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[On a grey board, there are 23 Advent calendars behind large "windows", numbered from 3 to 25, plus two open calendars with their covers torn off.]
:[From top-left to bottom-right, the boxes are numbered as such: (opened), 14, 23, 16, 11, 3; 5, 24, 18, 7, 21; 10, 17, 4, 9, 22, 15, 12; 8, 20, 13, 25, (opened), 19, 6]
:[Each calendar numbered ''n'' has 26−''n'' squares in it.]
:[The open calendar on the top left has 25 squares, two of which are black. The other open calendar has 24 squares, one of which is black.]

:[Caption below the panel:]
:I like Advent calendars, so I got an Advent calendar that gives me a new one every day until Christmas.

{{comic discussion}}

[[Category:Christmas]]
[[Category:Calendar]]
[[Category:Songs]]

3017: Neutrino Modem

2024-11-27T22:13:37Z

172.70.90.236:

{{comic
| number = 3017
| date = November 27, 2024
| title = Neutrino Modem
| image = neutrino_modem_2x.png
| imagesize = 461x537px
| noexpand = true
| titletext = Our sysadmin accidentally won a Nobel Prize while trying to debug neutrino oscillation error correction.
}}

==Explanation==
{{incomplete|Created by a 1978 neutrino fax machine - 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}}

2860: Decay Modes

2023-11-28T23:21:44Z

172.70.90.236: /* Explanation */

{{comic
| number = 2860
| date = November 27, 2023
| title = Decay Modes
| image = decay_modes_2x.png
| imagesize = 586x360px
| noexpand = true
| titletext = Unlike an Iron Age collapse, a Bronze Age collapse releases energy, since copper and tin are past the iron peak on the curve of binding energy.
}}

==Explanation==
{{incomplete|Created by an EXTANT MODE OF DECAY - Please change this comment when editing this page. Title text not explained. Do NOT delete this tag too soon.}}
{{w|radioactive decay|Decay modes}} refer to the different ways in which unstable atomic nuclei transform into more stable ones, typically by emitting particles or radiation. The process of decay is a natural phenomenon that occurs in radioactive substances. There are several types of decay mode, each characterized by the particles emitted or the energy released during the process.
In the comic's diagram, protons are white and neutrons are gray.

The first six modes are real, and most occur relatively frequently:

In '''{{w|alpha decay}}''', an unstable nucleus emits an alpha particle, composed of two protons and two neutrons. Alpha decay is the primary source of helium on Earth, as alpha particles are <sup>4</sup>He nuclei.

In '''{{w|beta decay}}''' (more properly beta-minus decay), a neutron-rich nucleus emits a W⁻ boson, converting one neutron into a proton — as shown in the supplementary diagram — which in turn decays into an electron (the titular beta (minus) particle) and an electron antineutrino. The main diagram shows only the release of the beta particle, which was the only thing expelled from the nucleus that could be observed directly when the types of nuclear decay were first described and enumerated.

In '''{{w|gamma decay}}''', an unstable nucleus (represented by the lumpy, prolate nucleus in the diagram – representing a high-energy {{w|nuclear isomer}}) emits a high-energy photon known as a gamma-ray and settles into a stabler, lower-energy state.

In '''{{w|electron capture}}''', a proton-rich atom slurps an electron from the K or L electron shell. This converts a proton into a neutron and emits an electron neutrino. No 'slurp' sound is actually produced in real electron capture event.{{Citation needed}}

In '''{{w|positron emission}}''', or beta plus decay, a proton-rich nucleus emits a W+ boson, converting one proton into a neutron, which in turn decays into a positron, the beta plus particle, and an electron neutrino. Again, the main diagram shows only the beta particle, presumably for simplicity, the nucleon conversion being shown separately. This is much rarer than beta minus decay.

In '''{{w|neutron emission}}''', a neutron-rich/proton-deficient unstable nucleus emits a neutron (which then goes on to decay into further daughter particles).

The other six modes are fictional:

'''Baryon panic''': In this mode, all the subatomic particles flee the atom simultaneously, similar to a crowd fleeing a building during a fire alarm, or other similar states of panic in people. In reality, this mode of decay would require an incredible amount of energy. The like charges of protons do repel each other, but they are held together more tightly by the residual {{w|nuclear force}} in the presence of neutrons.

'''Omega decay''': The atom has decayed and left behind a skull in its wake, leaving cracks in the area surrounding it and send neutrons and protons flying everywhere. Whereas ''alpha'', ''beta'', ''gamma'' are the first three letters of the Greek alphabet, ''omega'' is the last, so the name ''omega'' might suggest the ultimate, final decay. The skull presumably represents the finality of such a decay, given that the end stage of human decay leaves behind a skeleton, something that does not exist in nucleons.{{Citation needed}} Many works of science fiction propose forms of radiation and/or particles with further letters in the Greek alphabet, such as {{w|The Omega Directive}} in Star Trek. In real life, the {{w|omega baryon}} was predicted to exist by Murray Gell-Mann's early quark theory, and then discovered several years later with the properties he had predicted. This mode may also represent the atom becoming the origin of a {{w|false vacuum decay}}, a theoretical decay of space itself, which would indeed spread outward and be very final and lethal.

'''Electron wilt''': The electrons surrounding the atom fall to the ground. Some plants are subject to diseases that cause this kind of wilting of their leaves. Electrons will attempt to settle into a 'ground state' but this does not involve them literally slumping to the ground, rather they will be as close as possible to the nucleus subject to the limitations of energy levels and the Pauli exclusion principle. In addition, since the ground is made of atoms,{{citation needed}} the electrons will just keep falling.

'''One big nucleon''': The protons and neutrons combine to form a single huge baryon. {{w|Exotic baryon|Exotic baryons}} with more than the usual three quarks, such as {{w|pentaquarks}}, have been created in the lab but are not known to exist in nature. String theorists propose that black holes are actually {{w|Fuzzball (string theory)|fuzzballs}}, single "subatomic" particles which are macroscopic in size (namely that of their event horizon) formed by the fusion of the strings of in-falling matter under extreme gravitational conditions.

'''Fungal decay''': The nucleus rots, and fungal fruiting bodies (toadstools and mushrooms) grow around it. This plays on the meaning of "decay".

'''Collapse due to invasion by the Sea Peoples''': The atom floats in water, with boats on either side full of Cueballs shooting arrows at it, and the atom is breaking up. The {{w|Sea Peoples}} are a somewhat mysterious group that attacked Egypt and other regions of the eastern Mediterranean in the late Bronze Age (1200-900 BCE). Due to a combination of factors, such as climatic change, mass migration and invasions (including from the Sea Peoples) several nations around the central and eastern Mediterranean underwent societal decline or outright collapse — a period known as the {{w|Late Bronze Age collapse}}. Randall has mentioned the Sea Peoples previously in [[1732: Earth Temperature Timeline]].

'''Bronze/Iron Age Collapse (Title text)''': Continuing from the last panel of the comic, and making a pun on the Iron Age of civilization with the properties of iron atoms. Nuclear fusion – the merging of small light elements – expels energy, powering stars and and creating increasingly heavier elements which also fuse until the process reaches iron, predominantly <sup>56</sup>Fe. Fusing iron nuclei does not release energy, so the previous cycle of fusion abruptly stops and the star contracts under gravity (whereupon it can now create the different conditions from which small amounts of heavier nuclei ''do'' form, and disperse to be discovered in later star systems). In contrast, nuclear fission – where atoms spontaneously split into lighter elements, releasing the energy ultimately imbued into them during their synthesis – applies increasingly so to the more heavy nuclei with increasing instabilities as they 'collapse' out into their various fission products. The atomic components of bronze, {{w|tin}} and {{w|copper}}, ''could'' potentially release energy, in the right conditions. Tin's main isotopes (<sup>114</sup>Sn across to <sup>124</sup>Sn, with more than two thirds being of weight 116, 118 or 120) are considered stable, as are the two for copper (<sup>63</sup>Cu and <sup>65</sup>Cu, being practically all that is naturally present), but trace/synthesized isotopes beyond that range (e.g. actively induced by initiating a neutron bombardment) are known to, eventually, beta(±) decay/'collapse' to forms of antimony (from the tin) or nickel/zinc (from the copper).

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

[Label:] Radioactive Decay Modes

[A 6x2 table of illustrations depicting types of atomic decay.]

[First row]
[Label: "alpha decay". An illustration of alpha decay, a small group of 2 protons and 2 neutrons are shown leaving a larger nucleus.]
[Label: "beta decay". An illustration of beta decay, a small particle is shown being ejected from a nucleus while a neutron is shown converting to a proton as indicated by a shaded circle becoming white.]
[Label: "gamma decay". An illustration of gamma decay, a nucleus is shown emitting waves.]
[Label: "electron capture". An illustration of electron capture, a nucleus is shown absorbing one of its electrons along with the text "slurp".]
[Label: "positron emission". An illustration of positron emission, a small particle is shown being ejected from a nucleus while a proton is shown converting to a neutron as indicated by a white circle becoming shaded.]
[Label: "neutron emission". An illustration of neutron emission, a shaded particle is shown being ejected from a nucleus.]

{{comic discussion}}
[[Category:Chemistry]]
[[Category:Physics]]

Talk:2830: Haunted House

2023-09-20T15:31:43Z

172.70.90.236:

I initially thought this was Randall's version of the old joke "The great thing about standards is there are so many of them." Like the zoo of USB cables and adapters to allow you to connect them. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 21:22, 18 September 2023 (UTC)
:Well, shoot. I was hoping to find an online old phone charger cord museum but it doesn't seem to exist. In the late 1990s-early 2000s, every time you bought a cell phone, you automatically got a different charger cord that was basically incompatible with anyone else's. Those flat, wide weird looking connectors that predated USB-anything. Thought maybe someone would have compiled a list. [[Special:Contributions/172.70.126.192|172.70.126.192]] 22:05, 18 September 2023 (UTC)Pat
:No mention of https://xkcd.com/927/?! [[User:TPS|TPS]] ([[User talk:TPS|talk]]) 03:10, 19 September 2023 (UTC)

This reminds me of how Eastern Japan uses 50Hz but Western Japan uses 60Hz (and how under the Articles of Confederation each state had their own form of paper currency) [[Special:Contributions/108.162.237.63|108.162.237.63]] 22:03, 18 September 2023 (UTC)Bumpf

Not only are doorknobs quite standardized, they are usually already IN the doors. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:29, 18 September 2023 (UTC)
:Not always, unfortunately. I once rented an apartment where the bathroom door's inside knob had to be "plugged in" in order to open the door, but would fall out when not in use. If you couldn't find it you'd be stuck in the bathroom till someone let you out. [[User:Andes|Andes]] ([[User talk:Andes|talk]]) 22:55, 18 September 2023 (UTC)
:: I've seen those. The door (or at least the knob) was on backwards. The idea is to have a knob you can remove on the outside for locking purposes in homes where you don't want someone walking in on you. I always thought it was pretty dumb, but backwards it would be worse, you'd have to stage a breakout if someone absent mindedly took the knob into the kitchen or something. [[User:Thisfox|Thisfox]] ([[User talk:Thisfox|talk]]) 22:47, 19 September 2023 (UTC)
:Not really standardised. From what I've heard, on a number of occasions, there are places in America (need to check, could be Canadian provinces or US States, or subset areas) where doors legally must have doorknobs, rather than door-handles, as an anti-bear measure (they can't be a 'clever girl' so easily with a doorknob). And then there are legislative areas which require ''handles'', not ''knobs'', as an accessability (or indeed egressability!) measure for those people with arthritis/other hand-disabilities for precisely the same reason (they would have difficulty with a doorknob, unassisted) but now looking for the more widely usable outcome. Thus mutually incompatible Building Codes are in force. [[Special:Contributions/172.70.91.241|172.70.91.241]] 00:16, 19 September 2023 (UTC)
::And now I've got an imagine in my head of a horror movie in which an arthritic grandmother is chasing the heroes, and manages to open a traditional doorknob with her walker... "Clever girl". So thank you for that. [[Special:Contributions/172.69.247.41|172.69.247.41]] 15:11, 19 September 2023 (UTC)

Household electrical outlets do vary from country to country in Europe, such that I have collected a variety of plug adapters. And world-wide, I have seen it asserted that there are 15 different standards, including a number that are partially compatible with each other, differing only by the arrangement of the grounds. [[Special:Contributions/162.158.62.197|162.158.62.197]] 22:45, 18 September 2023 (UTC)
:[https://en.wikipedia.org/wiki/Mains_electricity_by_country Wikipedia list] [[Special:Contributions/162.158.63.63|162.158.63.63]] 03:50, 19 September 2023 (UTC)

The Louisville Knobs are a geologic/geographic feature. [[Special:Contributions/172.71.174.252|172.71.174.252]] 02:42, 19 September 2023 (UTC)
: Kentucky, USA [[wikipedia:Knobs_region]] [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:51, 19 September 2023 (UTC)
The explanation so far is somewhat inaccurate, as ANSI and ISO are not the organizations that set specific electrical configurations in the US. For electrical wiring in general, the National Fire Prevention Association publishes NFPA-70, The National Electric Code, which is the basis for most electrical wiring. Plug and socket configurations in buildings are defined by the National Electrical Manufacturers Association, and are referred to by that organization's nomenclature, such as "NEMA 5-15" for the 125V 15A standard plug and socket for most convenience outlets and cords. Appliance connectors like the "C-13" socket used on most computers are defined by the International Electrotechnical Commission. It's too late at night for me to make something shorter than this paragraph...[[Special:Contributions/172.68.174.209|172.68.174.209]] 06:14, 19 September 2023 (UTC)

:The relationship between ANSI and NEMA is sufficiently tricky that I'm not sure "somewhat inaccurate" is a true statement. For instance, see https://www.nema.org/standards/technical/ansi-accreditation, which states in pertinent part, "NEMA is accredited by the American National Standards Institute (ANSI) to develop American National Standards…" I'd not be surprised if there's a similar ISO/IEC or even ANSI/IEC thing. Dual branded standards are not unheard of. [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 11:01, 19 September 2023 (UTC)

Ehhh - door/doorknob interfaces do have competing standards (albeit not state-to-state) in bore diameter, door width, spindle size... The joke is that guests are expected to bring their own doorknobs to use, instead of a competent person having fitted the appropriate one in advance, and also that the standard in use is regulated rather than arbitrary. [[Special:Contributions/141.101.68.102|141.101.68.102]] 15:24, 20 September 2023 (UTC)