FDR

Explanation:
The United States Naval base at Pearl Harbor, Hawaii was attacked in 1941 , and is credited with starting the United States' involvement in World War II. The then US president, Franklin D. Roosevelt (FDR), issued a speech to the American people which begins with the line "Yesterday, December 7th, 1941, a date which will live in infamy... ". Whenever Randall writes "December" he feels compelled to complete the line, a mistake which is visible in this comic.
This may be a parody of a more common type of error in which people writing dates during January (particularly early in the month) accidentally write the previous year instead of the current one because the previous year number is an established pattern while the new one is a recent change.
The title text confuses the date of the northern hemisphere summer solstice (June 21st) with the date of the 365 Crete earthquake that happened on July 21st 365AD.  The earthquake had a magnitude of at least 8.0 which caused widespread destruction across the Eastern Mediterranean.  Then it mentions Guy Fawkes Night , the anniversary of the famous failed attempt to bomb Parliament on the night of November 5th, 1605. The latter event is immortalized in the rhyme "remember remember, the fifth of November, the gunpowder, treason, and plot", the former event less so.
Randall also may be suggesting that Roosevelt implied the degree of "infamy" of an event can be measured by how long its date is remembered. Pearl Harbor resulted in 2,458 deaths and obviously extensive damage to a military base and fleet. It has been remembered 77 years, thus far. The earth quake of 365AD resulted in an estimated 230,000 killed and numerous cities severely damaged or destroyed. Randall states it was remembered for a few centuries. The Gunpowder Plot resulted in the death of a couple of conspirators and no notable damage. It has been remembered, at least in song, for "over 400 years".
[Close-up of a form. Each field has a label (the first is assumed) and a handwritten entry. The name and country are each half visible. The numeral "4" has been only partially written before being scratched out.] [ NAME ] Randall Munroe DATE Dec 7, 194 12, 2018 COUNTRY United States
[Caption below the frame:] FDR was so good at speeches that I spend a whole month each year writing the date wrong.


arXiv

Explanation:
arXiv is a free online repository of electronic preprints of scientific papers in various fields, particularly in physics, math, and computer science. Scientists typically publish "preprint" versions of journal articles to arXiv, which are free to publish to and read. In this comic Megan remarks that academic journals must have a hard time getting by since their primary revenue is from researchers who pay to publish articles and readers who pay for subscriptions. Her remark seems to assume that arXiv must be a recent development, perhaps similar to the Sci-Hub project which began in 2011. However, Ponytail informs her that the arXiv project has been around since the 1990s (1991 to be exact).
After a panel of Megan looking contemplative, she remarks that that does not make sense at all. After all, why would publishing companies be able to make money from something that is free online? Ponytail tries to stop her from freaking out, so that her outrage does not inform others about the current arrangement and thus ruin the system. She uses the term " jinx ", which in common usage means to affect negatively by speaking about, to imply that this system is one that could break down if discussed.
Ponytail expressing confusion about the continued existence of scientific journals previously happened in 2025: Peer Review .
The title text refers to another project that is invaluable for internet research, the Internet Archive ( link to it here ). Internet Archive is a public archive of information, including public domain books and music. Internet Archive runs the Wayback Machine , an archive of backups of web pages all over the Web at various times that can be used to see past versions of a page, even if that site has since shut down. Internet Archive accepts submissions of any type of information, including new backups of web pages and newly-made public domain content. The title text argues that these two projects are so useful, yet make so little economic sense, that, if they did not exist, we would dismiss them as ideas that would never be viable. In addition, as "arXiv" is intended to be pronounced the same as "archive", both sites have URLs with a common pronunciation.
[Megan and Ponytail are standing together. Megan is talking to Ponytail.] Megan: Wait, all the papers in your field are posted as free PDFs on arXiv? That must be killing big science journals, since they charge such huge subscription/publication fees.
[Ponytail responds with her arms wide, palms up.] Ponytail: Nah, we’ve been doing it since the 90s and nobody seems to care.
[Megan contemplates, speechless.]
[Megan slightly raises her arms and Ponytail puts up a hand to shush her.] Megan: That makes no sense at all!! Ponytail: Shhh, you’ll jinx it!


History Department

Explanation:
In this comic Ponytail is a representative of the history department, which might be a department of a university or other organisation. She presents the year report of 2018. In this, she explains, the department has fully analyzed over four months of history. In the meantime, due to the passage of time, another year of history has been added to their workload (implied to be the year spanning between the current meeting and the previous one). This presents a cycle in which the department would only be able to keep up if they could analyze, within a one year period, more than or exactly one year of history.
A department in a business, such as the finance department, is typically required to keep up with their own workload and complete an entire year's worth of workload every year.  A business that fails to manage this minimum would almost certainly fail: bills would not get collected, invoices would not get paid, employees would not get paid, etc.  A history department fails to follow this model in two very important ways.  First, the subject of history cannot be fully processed.  New discoveries change what we know about certain time periods.  Even current events cannot be fully processed, as future events will cause historians to see connections in things not previously thought to be connected.  Second, the standard model for history departments focuses on specific eras or specific subjects for the purpose of explaining the events to students.  History departments do not process years, but instead process the subject so that it stays relevant to the understanding of the current student body.
There are, however, long running historical projects that have suffered this very problem. An example is the Histoire littéraire de la France which began publication in 1733 with a volume covering up to the year 300. By 1995 over 40 volumes had been published, but the historical account had only reached the 14th century. The volumes for the 14th century had taken 130 years to produce. Although over the 250 years of the project publication had been proceeding faster than time elapsed, the proliferation of literary content following the dawn of printing in the 15th century is likely to cause the project to slip further into reverse.
The title text further expands this problem by indicating the discovery of a new era of history that had previously gone un-analyzed, which would have added more undiscovered history than it removed. The 1750s decade is possibly a reference to the adoption of the Gregorian Calendar by the British Empire .
Randall previously mentioned that history is huge in 1979: History .
Events in the dates listed:
June – The Serbians from Vojvodina start a rebellion against the Hungarian government. June 2–June 12 – The Prague Slavic Congress brings together members of the Pan-Slavism movement. June 17 – The Austrian army bombards Prague , and crushes a working class revolt. June 21 – Wallachian Revolution of 1848 : The Proclamation of Islaz is made public, and a Romanian revolutionary government led by Ion Heliade Rădulescu and Christian Tell is created. June 22 – The French government dissolves the national workshops in Paris, giving the workers the choice of joining the army or going to workshops in the provinces. The following day, the June Days Uprising begin in response. July – The Public Health Act establishes Boards of Health across England and Wales . July 5 – The Hungarian national revolutionary parliament starts to work. July 19 – Women's rights – Seneca Falls Convention : The 2-day Women's Rights Convention opens in Seneca Falls, New York and " Bloomers " are introduced at the feminist convention. July 26 – The Matale Rebellion breaks out, against British rule in Sri Lanka . July 29 – Young Irelander Rebellion : A nationalist revolt in County Tipperary , against British rule, is put down by the Irish Constabulary . August 6 – HMS Daedalus reports a sighting of a sea serpent. August 14 – American President James K. Polk annexes the Oregon Country , and renames it the Oregon Territory as part of the United States. August 17 – Yucatán officially unites with Mexico. August 24 – The U.S. barque Ocean Monarch is burnt out off the Great Orme , North Wales , with the loss of 178, chiefly emigrants. August 28 – Mathieu Luis becomes the first black member to join the French Parliament , as a representative of Guadeloupe .
[Ponytail is standing behind a lectern holding a hand up indicating the presentation screen next to her with a list of time periods. The screen has a string ending in ring, attached to it, to pull it down.] Ponytail: 2018 was a productive year for the history department - we were able to fully analyze over four months of history. Ponytail: Unfortunately, over that same period, an entire year of new history was produced. Ponytail: I'm afraid we're falling behind.
[Presentation:] Studied November 1833 April 19-22, 1979 May 21-25, 585 BCE June-August 1848 May 16, 2001


Rocket Launch

Explanation:
This comic was posted on a week with a notably high number of rocket launches .  Originally, there were to be four orbital rocket launches from the United States on December 19, 2018 (the publish date for the comic), which would have tied with the prior record for number of orbital rocket launches in one day.  While these launches were ultimately delayed, breaking the event, the comic was doubtless under production by then.
Only some of the steps listed are actually typical.
Liftoff The traditional start of a launch, when the rocket leaves the ground.  The engines will typically have been ignited a short time before, often one-by-one in a specifically engineered sequence to reduce shock stress on the rocket, but need to throttle up to produce enough thrust to overcome the rocket's weight.  Some launch pad configurations physically restrain the rocket (at least to some degree) until the engines are known to produce the required thrust then the rocket is released (e.g. by pyrotechnically crushing restraining bolts such as in NASA Space Shuttle configuration, or by hydraulic actuators opening a sturdy "clamp", such as in SpaceX Falcon 9 configuration).  "Liftoff" refers to the moment this happens, making the rocket lift off the ground. Max-Q : Peak aerodynamic stress. A rocket accelerates from the moment it leaves the ground.  The faster a rocket goes, the bigger volume of air it pushes through per second - but the higher a rocket goes, the thinner the air.  (Before liftoff, the rocket is not moving, and thus is not pushing through air.  Once in orbit, there is essentially no air to push through, so the rocket is not pushing through air.  Between those two times, the rocket is pushing through some amount of air, the exact amount increasing before Max Q and decreasing after Max Q.)  "Max Q" is the moment where these two factors produce a maximum, and is the point where the rocket's structure must withstand the most air pushing back against it. Booster separation Rockets are designed in stages , so they do not have to carry the empty fuel tanks all the way to orbit.  (Carrying any mass to orbit is expensive, so the more that can be dropped off earlier, the better.) Two or three stages are typical.  "Booster separation" marks the point where the first of these stages (the " booster "), its fuel expended, is typically ejected. Max-CB: Highest chance of collision with Care Bears . This is entirely fictitious.  Care Bears are fictitious characters, which have a toy line, television series, and movies.  The existence of a basketball sneaker named the "Nike Air Force Max CB" may or may not be relevant. Main stage separation See "booster separation" above.  This marks the point where the second stage (the "main stage") is ejected. GPS silenced so it will stop saying "Make a U-turn" Again, this is fictional.  While some rockets do make use of signals from the Global Positioning System ("GPS"), no rockets are known to use the navigational devices that incorporate GPS readers and street maps, providing directions - often with optional text-to-speech - along the Earth's surface.  Some such devices are notorious for getting confused in extreme situations (such as the high Mach numbers that rockets achieve); constantly uttering "make a U-turn" would be one such confusion, and any device in such a confused state might well be silenced for being more annoying than helpful.  Navigation of this nature is neither necessary nor useful on a rocket, which will have its entire route from ground to orbit computed before launch, and piloting typically left entirely to computers given the precise timing required. Reunification (of boosters) Another fictional step.  Discarded stages fall back into the Earth's atmosphere, either hitting the ground (or, more often, water) or burning up because of the heat-up resulting from high compression of air in front of them while re-entering thick layers of atmosphere at extreme speed.  The booster and main stage would not be on a course to come anywhere near each other, and would not have enough fuel to change their course (running out of fuel being why they were discarded in the first place).  Even if they did, landing for reuse (as SpaceX has attempted , often successfully) would be far more likely than a mid-air reunion. Pilot panics, copilot takes command after struggle Another fictional step.  Astronauts are not the sort of people who panic easily, nor struggle with their crewmates.  More importantly, in any modern rocket the "pilot" is not a human being, but a computer incapable of panic [ citation needed ] (as in the human emotion).  It is possible that part of the flight computer could fail, causing redundant failsafes to take over, but the process could not correctly be described as a "struggle", and in any case this sort of failure is uncommon enough that it is not part of a "typical" rocket launch. Pursuit phase Fictional.  This assumes the (nonexistent) reunified booster would have enough fuel to pursue the top stage of the rocket, and a reason to do so.  See "Reunification".  This might be a reference to Pursuit guidance . The comic indicates that a fight ensues with only one of the pair continuing to orbit. Inter-stage dogfight Fictional.  See "Pursuit phase".  A dogfight is an aerial battle between fighter aircraft, conducted at close range.  This step claims that the rocket booster and the top stage of the rocket engage in a battle. Winner proceeds to space Fictional.  As noted above, in a real rocket launch there is no dogfight of which there can be a "winner". A careful reading would note that the bottom stage "wins" by default; in contrast, in a real (orbital) rocket launch, the top stage typically proceeds to space.
The title text refers once again to the Care Bears franchise. The Care Bears live in a castle made of clouds, called Care-a-Lot Castle , so the comic claims that NASA aims to avoid launching into their castle, but sometimes cannot avoid hitting "stray" Care Bears. That being said, the point about the strike has a basis in truth; at the speeds a rocket moves, impact with something roughly the size and weight of a human (or a Care Bear) has the potential to be catastrophic. If something should threaten to connect with the rocket, the best that the humans involved can do is hope for a glancing blow with a part of the rocket sturdy enough to endure the impact.
[The major stages of a rocket launch are shown, with the rocket trajectory indicated by dotted lines. Each stage is annotated with a description and an arrow. A title above the image reads 'Outline of a typical rocket launch'.]
[A rocket with two boosters is shown at the bottom left hand corner of the image taking off from a launch pad on the ground, surrounded by clouds of smoke.] Liftoff
[The rocket ascends vertically] Max-Q: Peak aerodynamic stress
[Separation of the two external booster rockets is shown, with the main rocket continuing to ascend vertically with a slight rightward tilt and the two boosters curving off to the right.] Booster separation
[The main rocket stage starts to curve over to the right.] Max-CB: Highest chance of collision with care bears
[Separation of the second rocket stage. Main rocket heads right, whilst second booster stage curves downward to meet trajectory of first booster stages.] Main stage separation
[Main rocket continues towards the right.] GPS silenced so it will stop saying "make a U-turn"
[First and second stage booster rocket trajectories meet and become a single trajectory heading upwards and right.] Reunification
[Trajectory of main rocket wobbles slightly.] Pilot panics, copilot takes command after struggle
[Booster stage rockets continue to head upwards and right towards the main rocket trajectory.] Pursuit phase
[Main rocket and booster stage trajectories meet and cross three times.] Inter-stage dogfight
[The trajectory for one of the stages ends in an explosion.]
[The remaining trajectory, indicated with dashed-lines and question marks, continues towards the right and off the edge of the page.] Winner proceeds to space


Schwarzschild's Cat

Explanation:
This comic is primarily a wordplay joke about the Schwarzschild radius , or the distance from a black hole corresponding to the event horizon .The Schwarzschild radius for a given body is the limit to which a given mass can be shrunk down before it becomes a black hole - the Schwarzschild radius also represents the event horizon of this newly-created black hole. The event horizon, in turn, is the limit from which nothing can leave a black hole; not even light. The joke is that, apparently, smaller cats are cuter, and there is a limit below which a sufficiently small cat (but larger than zero) will approach infinite cuteness, in a similar pattern to the way time's rate for an observer will approach infinity, the closer they get to the event horizon of a black hole.
It's also an oblique reference to the Schrödinger's cat thought-experiment, since the names (Erwin) "Schrödinger" and (Karl) "Schwarzschild" are somewhat similar and both men were early 20th-century physicists who exchanged ideas with Albert Einstein. However, the actual comic doesn't bring up quantum superposition .
The title text makes two allusions. First, it alludes to what happens when an object falls into a black hole. From an outside observer's point of view, such objects appear to slow down and take an infinite amount of time to cross the event horizon due to the time dilation of General relativity . The object's photons become increasingly red-shifted, fading as they lose energy to the black hole's gravity well. The scientific consensus suggests that from the falling object's point of view, it should continue to experience time and cross the Schwarzschild radius, but that event is unobservable from the outside (hence the term "event horizon").
Second, the title text is a play on the Cheshire Cat from Alice in Wonderland, which slowly fades from view until only its grin remains.
Randall previously discussed the superiority of tiny mammals in 1682: Bun , and drew graphs relating to the perceived cuteness of cats in 231: Cat Proximity .
[A graph is shown. The x-axis is labeled "Cat size" and the y-axis, "Cat cuteness". Parallel to and a short distance from the y axis is a dashed line the same length as the y-axis line, representing a vertical asymptote; the space between the y axis and the dashed line is labelled "Critical Limit". Graphed is a function coming down from infinity, starting close to the dashed line; it then levels off and does not reach zero on-screen. At the top end of the graph is the text "Schwarzschild's Cat" and an arrow pointing upwards outside of the graph.]


Christmas Eve Eve

Explanation:
This year's Christmas comic was posted on December 24, 2018, the Christmas Eve of 2018.
The evening or day preceding a special day such as a holiday is often referred to as the eve of that day (derived from the same word from which we get evening ). Thus December 24 is Christmas Eve. Some people extend this and call December 23 "Christmas Eve Eve," as Christmas Eve is itself a noted holiday. The day before that would be "Christmas Eve Eve Eve," adding one "Eve" for each night before Christmas morning, although the increasing extension leads to each additional "Eve" being continuously less common.
Cueball notes the general idea, and Megan acknowledges it. Cueball follows by naming December 24 as Christmas Eve, December 25 as Christmas, and then mentions that the following day is his favorite. Megan's "Oh no" implies that she knows what Cueball will say next.
Since December 26 is the 364th day before Christmas (when the following year is not a leap year, which was correct in 2018 when the comic was released), it follows that it is "Christmas" followed by "Eve" 364 times.
Megan finds listening to Cueball recite this unacceptable. As such, she announces that she will not give him gifts, taking the extra step of returning the gifts she'd already bought. As Christmas presents in America are first handed out on Christmas Day's morning (unless the giver and recipient are aware in advance they will be unable to meet in person on that day; Megan's presence on Christmas Eve indicates this is not a threat), she has not given it to him yet.
The title text refers to the Boxing Day holiday celebrated the day after Christmas in the UK and many parts of the former British Empire. Although the exact origin of the name is unknown, it is believed to be in reference to the Alms Box placed in areas of worship to collect donations to the poor, which was then opened right after Christmas. Most Americans don't know this and make jokes about how it refers to the sport of boxing . In this title text we can presume Cueball was punched (or boxed ) after his litany of 364 Eve s, to which he replies, "Oh, so that's why they call it Boxing Day." As this is a pun of groan-inducing triviality, he receives another punch .
[Cueball with his arms out is talking with White Hat and Megan. In Cueball's long last remark the letters get smaller from line to line.]
Cueball: Today is Christmas Eve. Yesterday was Christmas Eve Eve. Megan: Uh huh... Cueball: Of course, tomorrow is Christmas. And then, my favorite... Megan: Oh no. Cueball: ...Christmas Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve  Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve Eve! Megan: I'm returning the presents I got you.
11 14 14 14 15 16 17 17 18 20 21 22 24 25 27 30 32 27 364 total! The first line also has Christmas along with the 11 eves, and do take up more space than the 14 eves below. The last line is only partially filled, with 4 eves from the line above on each side (so room for more than 35, probably 40, eves in one line with that font size.) The first three lines with 14 eves becomes clearly shorter, before more is added almost in every line after this, except two lines with 17 each.


Feathered Dinosaur Venn Diagram

Explanation:
Translated plainly, this comic reads "People who don't think feathered dinosaurs sound scary have never tried to fight an ostrich."
This comic is a jab at people who dismiss the idea feathered dinosaurs sound scary.  Adding feathers to a reptile can trigger a cognitive dissonance; people today see feathers and think of harmless birds. However, the ostrich and a few other avian species, which are feathered dinosaurs ( 1211: Birds and Dinosaurs ) are in fact deadly.  The diagram points out that anyone who has tried to fight an ostrich would be scared of a dinosaur with feathers, and anyone who thinks a feathered dinosaur doesn't sound scary has never tried to fight one.  The two groups of people are exclusive because the two circles do not overlap.
Ostriches are not typically considered scary or dangerous because its appearance is comical or awkward to most people; they are also herbivorous and not typically aggressive, choosing to use its great speed to outrun predators rather than fight them. In reality, however, ostriches are much larger than a human and will attack when cornered or when their family is threatened; their powerful legs can kick hard enough to kill lions and other predators, and their feet are equipped with large claws which can disembowel a human. Thus, the actual experience of fighting an ostrich would quickly convince any human that survives the experience that ostriches (and by extension other feathered dinosaurs) are, in fact, scary.
The title text refers to " Volunteer Boy ", a kid in the beginning of Jurassic Park who dismisses a raptor fossil as a "six-foot turkey". Dr. Grant uses a fossil of a raptor talon to imply that a raptor would slice open his belly and eat him while he's still alive. This scares the kid into respecting the raptor.  The title text theorizes that if he didn't get that pep talk, and continued to think of dinosaurs as "six-foot turkeys", then he would grow up to make some of the contested sequels in the franchise. Raptors play a central role throughout the series of movies, with some even being trained by a raptor handler like dogs.
Technically , the diagram is an Euler diagram , rather than a Venn diagram . A Venn diagram shows all possible combinations of two or more sets, including those with no elements, and so all of the regions must intersect in all possible combinations. An Euler diagram only depicts the non-empty combinations, and therefore does not have this constraint. However, this is a technicality, and many people use the words interchangeably.
[The comic shows a rectangular panel containing two circles, side by side and not intersecting. A caption is underneath each circle.] [Left circle caption:] People Who Don't Think Feathered Dinosaurs Sound Scary [Right circle caption:] People Who Have Tried To Fight An Ostrich


Million, Billion, Trillion

Explanation:
Much like comic 558 , this comic addresses the difficulty ordinary people have with large numbers. Though most if not all people intuitively understand the difference between one object and two objects, or one object and ten objects, or even one object and a hundred objects, as numbers increase most people's ability to innately conceive of the numbers being discussed decreases remarkably quickly. When numbers reach the millions and the billions, and especially the trillions, most people don't truly process the numbers at all, and instead conceive of them as some version of a drastically-oversimplified concept such as "very big." Where comparing one to ten is simple, comparing "very big" to a different "very big" can prove extremely challenging, and will certainly require non-intuitive, conscious thinking.
The comic represents this challenge by providing a graph which represents Randall 's intuitive conception of the values of various very large numbers, and said conception's misalignment with reality. Though some trends reflect the real value of the numbers on the graph, i.e. 100 million larger than 10 million larger than 1 million and 1 billion larger than 1 million, the curve is far from the linear (exponential on the log-scaled axes) path it should take, with 1 billion being intuitively understood as less than 100 million, based, presumably, on the fact, easily comprehended on an intuitive level, that 100 is larger than 1 , and therefore the presence of 100 in 100 million places it at a higher value than the 1 in 1 billion would place the latter. In reality, of course, 1 billion is ten times larger than 100 million, but the comic deals not with actual reality, but with the perception of reality  of these numbers before conscious thought is applied .
The most interesting parts of the graph, and the parts where the disconnect between intuition and reality becomes clearest, are the dashed sections labeled with question marks, the one between 100 million and 1 billion, the other between 100 billion and 1 trillion. Here two competing intuitive understandings compete for dominance. On the one hand, the intuitive understanding described above, with 100 trumping 1, would see the curve taking a sharp downturn. On the other hand, the path from 100 million to 1 billion is paved with such numbers as 500 million, 700 million, and 900 million, all of which would theoretically be seen intuitively as larger than 100 million, thanks to the fact that 9 is greater than 7, and 7 greater than 5, and so on, bending the curve up rather than down. These two conflicting intuitions leave Randall with no single intuitive path for the two dashed sections, leading to their dashed and questioned state.
The comic's caption and title highlight another problem surrounding the intuitive grasping of large numbers: the flaws in the English words used for them. For instance, nothing about the word "million" suggests smallness relative to the word "billion" on an intuitive scale. This unintuitive language contributes greatly to the "100 trumps 1" intuitive fallacy described above.
The title text references a highly relevant disconnect between the long and short scales of large numbers .
For all English speakers, and for most languages, 1 million constitutes 1,000 thousands, or, less ambiguously, 10^6. However, this is the last of the consensus numbers, and the definition of what should be the "next step" varies depending on how each country's language evolved.
In other words, 1 billion objects in a country using the short-scale would be 1,000 million objects in a country using the long-scale; at the "next step", 1 trillion in the short-scale would be named 1 billion in the long-scale, despite the fact that the number of objects has remained the same. This difference between languages using the short-scale and the long-scale often causes confusion when translating articles with large numbers in them, as translators sometimes fail to change between short-scale and long-scale schemes, wrongly translating large numbers to incorrect values.
The fact that such a staggering difference of terminology was able to exist and be almost completely unknown to many supports Randall's point about the failure of human intuition in the discussion of extremely large numbers.
[A graph with Y-axis labeled “Perceived size of number” and X-axis labeled “Actual size of number (log scale)”.] [The line graph shows points that are labeled with the following numbers from “1 million” to “100 trillion”:]
[ Points on graph: ]
1 million [ (2, 1.5) ] 10 million [ (3, 3.5) ] 100 million [ (4, 4.8) ] 1 billion [ (5, 2.8) ] 10 billion [ (6, 4.4) ] 100 billion [ (7, 5.3) ] 1 trillion [ (8, 4.3) ] 10 trillion [ (9, 5.1) ] 100 trillion [ (10, 5.6) ]
[The perceived size increases between most numbers, but decreases between 100 million and 1 billion, and between 100 billion and 1 trillion. The decreases are shown as dashed lines labeled “?”, in contrast to the solid unlabeled lines between the increases. The increases and decreases in perceived size become smaller as the numbers grow in actual size.] [Caption below the panel:] Talking about large numbers is hard


Consensus New Year

Explanation:
In this New Year comic , Randall is proposing a compromise for when to celebrate, or recognize, New Year's Day .  These celebrations traditionally take place at the stroke of midnight between Dec. 31st and Jan. 1st, at the local time of the event's location.  With "Consensus New Year", these celebrations would happen at the same time, world over, and would be at exactly 1:30 pm EST (6:30 pm UTC ).  At this time, about half the world's population would be in 2018 local time and the other half would be in 2019.  This is due to the various time zones throughout the world, and the graph is based on the proportion of the population in these zones.
This is based on the assumption that the entire world uses the same calendar system.  Randall's graph shows the year starting on the same day for the entire world.  While the Gregorian calendar is used as the civil calendar in most countries of the world, the Eastern Orthodox churches uses the Julian calendar, on which the year will begin 13 days later, and the year (as of December 2018-January 2019) is 1440 on the Muslim calendar and 5779 on the Hebrew calendar. Other countries have the same New Year as the Gregorian calendar but count years differently; for example, 2019 is the year 108 in Taiwan and 2562 in Thailand.
The Wiktionary entry for " consensus " includes multiple definitions, including these two meanings:
In an attributive grammar structure, a noun is placed before another noun to assign an attribute to it.  When "consensus" is used this way, it's a statistical term which means the average projected value of the modified noun.
Randall properly uses this first definition for both the title of the comic and the graph itself, where the graph represents the average projected value of the percentage of the world population reaching the new year at any given time.
Randall may be purposefully misusing the second definition of the word "consensus" to reflect the common misuse of the term consensus for the practice of majority vote .
In scenarios involving group decision-making, consensus means that all or almost all members of the group will accept the decision.  Depending on how it is done, this generally results in a slower decision-making process due to discussion, but decisions that many more people are happy with.  Consensus can scale to large groups of people using approaches such as the spokescouncil model to speed dialogue. By this definition, Consensus New Year happens at one of the last four time zones as the last to "agree" enter 2019, so (nearly full consensus definition) 4:00 am, 5:00 am, 6:00 am, or (full consensus definition) 7:00 am EST on January 1, 2019.
Consensus lies in contrast to majority vote, where a decision passes when over 50% of the people desire it.  Majority vote is used in most current large democracies and is what most people are familiar with.  It is quick to describe and implement, but can result in polarized political parties and a stark lack of minority rights, unless enough people develop concern for the issues that they are tempered with constitutions and logrolling .
The leftmost horizontal axis label (10am EST Dec 31st) was an error. The point marked as 0% should be 5am EST (see table below).
Additionally, some of the lines are shown with a slope, which is inaccurate. Since sun time is not used anywhere, a correct graph line would only consist of horizontal and vertical lines.
[A graph labeled “Percentage of the world's population living in 2019” with Y-axis markers at 0%, 50%, and 100%, and X-axis markers at 10:00 AM EST Dec 31st, 1:30 PM EST, 7:00 PM EST, Midnight EST, 3:00 AM EST Jan 1st, and 7:00 AM EST.] [The line graph shows the percentage increasing from 0 to 100% in several steps, with 50% reached at 1:30 PM EST.]
[Caption below the panel:] Consensus New Year: as of 1:30PM Eastern Time (6:30PM UTC) a majority of the world's population will be living in 2019.
Randall has mislabeled the leftmost point of the graph: the Earth's earliest time zone ( UTC+14:00 ) should have the midnight at 5:00 AM EST rather than 10:00 AM EST. The number of one-hour increments on the x-axis does not match Randall's label.


Reminders

Explanation:
In this comic, Cueball is using an email client program on a laptop, which is a popular tool for communicating by email with others.
In recent years, many email clients have started implementing helpful warnings and reminders to catch common human mistakes and ease the process of communication. One such feature, demonstrated in this comic, is that many clients will now warn you if you've mentioned an attachment in your email but haven't actually attached anything, a common error people make when emailing.
This has gotten to the point where email clients are increasingly stepping in to help with social obligations too; for example, reminding you if you've left an email unanswered for too long, or that someone is celebrating a birthday today and should be congratulated. With the increasing availability of social data and advances in machine learning, these features have the potential to become very sophisticated, to the point that they can effortlessly make social inferences and connections that might have slipped a human user's mind.
Such features are meant to be helpful aids, but have led people to be worried about privacy issues, or about how "smart" technology is becoming. However, in this comic, Cueball (likely representing Randall himself) has come to the uncomfortable realization that technology is now easily surpassing his own ability to maintain social relationships with other people, by being more aware of his friends' social lives than he is. He is disturbed by how unwittingly unconscientious he has become.
The title text suggests that the problem of keeping up a baseline level of interest in other people's lives eventually solves itself; implying, somewhat darkly, that if you don't put in even the bare minimum effort to keep up, you'll end up with fewer friends as some get annoyed by your lack of interest in their lives.
[Cueball at his desk using a laptop.] Laptop: You got this email six days ago. Do you want to follow up? Cueball: Oh, right, I should do that. [Cueball types on laptop.] *type type* Laptop: Did you forget the attachment? Cueball: Oops, yes. Laptop: Today is the recipient's birthday. Did you want to mention that? Cueball: Wait, it is?
[Caption below the panel:] These reminders make me uncomfortable, not because computers are getting too smart, but because it reminds me how often I fall short of even baseline levels of conscientiousness.


Short Selling

Explanation:
Shorting stocks (short selling stocks) is a stock market practice. If we think of normal investing where we buy into a stock as betting on the stock rising in value then shortselling is a corresponding betting on a stock to fall in value. This inverse procedure is accomplished by getting the stock on a loan or "front" basis to begin with, then selling the stock that isn't actually owned, so that when the stock loses value you're able to pay back a lower amount and keep the difference. We could say someone takes a risk because they believe that a certain stock's price is going to drop.  The risk-taker borrows stock from someone, and then sells the stock that they've just borrowed, keeping the money from the sale. They then owe that stock to the lender. But the risk-taker believes that they will be able to buy the same stock back on the stockmarket later on at a lower price, and then give it to the lender to replace what they borrowed.  If everything goes according to plan and the stock drops in price, the risk-taker will walk away with a profit.  Of course, if things don't go according to plan and the stock rises in price instead, the risk-taker winds up losing money, because they have to buy back the stock for more than they sold it.
Cueball asks Ponytail to explain shorting stocks.  Ponytail starts out with a fairy tale story that falls apart almost before she even starts.
The process of short selling a stock functions similarly to the initial parts of the story. The major steps in normal shorting are described here alongside the analogous (sort of) parts of the story:
An investor decides that stock S is likely to decrease in value, and wants to make money from this difference. Stock S is currently selling for $5, but the investor believes it will drop in value to $1 or $2 in the near future. The person in the story is going to have a child, and believes that the child will be worth one or two magic beans. They have been offered a price of five beans for the child, and they see this as a benefit.
The investor finds a person willing to allow them to borrow stock S now. This is usually done through a broker. The investor then sells the stock they borrowed, adding $5 to their account. They plan on waiting until stock S is selling for $1, then buying it again. They will have made $4 in profit, and can return the stock they borrowed. The parent in the story sells the rights to their child for five beans because their child is worth one or two beans to them, so they will end up making a profit of three or four beans.
Stock S does not decrease in price, but increases dramatically to $200. The investor has promised to return the stock within a specific timeframe, and they must do this or they will be in violation of various laws and contracts. They can wait in the hopes that the value will drop again, but they will eventually have to buy the stock for the new price of $200. They will lose $195 on this transaction. The child is born, and the parent involved decides that they love the child. They would put a valuation of this child at two hundred magic beans, and would prefer not to turn the child over to the witch. They have no choice, however, as they have formerly agreed to do this.
This part of the story somewhat matches the process of short selling a stock, except that there is a convenient market for buying and selling stocks at a common price, while a network of witches buying children or a method of valuing them does not exist. [ citation needed ]
Ponytail's version does not make exact analogies to the process of short selling. The first major difference occurs when  the parent sells a child they haven't had yet to a witch.  Like short selling, the parent is selling something they don't own.  But unlike short selling, the parent is selling something that doesn't exist yet. The somewhat broken analogy breaks further when Ponytail says the parent now is going to fight the witch instead of paying the witch with the child.  There is no legal option to "fight" the other person if a shorted stock or call-writing strategy fails. You simply lose money.
Our now definitely broken analogy breaks down even further (if possible) by sending the kid up the beanstalk to fight the giant - a giant that Ponytail says represents high interest rates.  Interest rates have nothing to do with shorting stocks.  (Technically they can, but the short seller would have / should have calculated that when determining if their investment strategy would work.) In addition, it is not possible for the investor, on their own, to fight interest rates that are harming their strategy, as those rates are set by lenders and are based on the credit worthiness of the borrower, the stated use case for the funds, and the nation's government's monetary policy.
Cueball comments that the analogy is rapidly losing its value to him.  Ponytail fires back with the comment that he should have shorted her advice before asking for it, thus making a profit. The decreased helpfulness of her wisdom is analogous to the decreased value of a shorted stock price. She once again proves that she lacks the knowledge of how short selling functions, or at least the knowledge to explain it, as her advice does not have a price to anyone, was presumably given to Cueball for free, and cannot be traded.
Her story appears to be based on plot elements of multiple fairy tales. It begins by mixing up the story of Rapunzel with Jack and the Beanstalk .
In one version of Rapunzel a Father breaks into a witch's garden to steal the Rapunzel plant for his pregnant wife. The Witch catches him and agrees to let him go and not punish him in exchange for the child.
In one version of the " Jack and the Beanstalk " fairy tale story, Jack sells a cow for magic beans.  His mother, thinking the beans are fake, is angry with Jack.  Jack plants the beans and a magic beanstalk grows up into the clouds.  Jack climbs the beanstalk and explores the land above the clouds.  He finds the home of a cruel giant and proceeds to steal from the giant.  The giant discovers the theft and chases Jack back down the beanstalk.  Jack reaches the bottom of the beanstalk first and cuts the beanstalk down.  The giant falls to his death, and Jack uses his stolen wealth to take care of himself and his mother.
The combination of the two stories is similar to the story from the musical " Into the Woods ," in which a Father sneaks into the Witch's garden to steal vegetables, then trades his soon to be born child for the vegetables, but also steals beans in the process.
The title text is actually the most useful part of this comic when it comes to investment advice.  The witch (the broker) is offering the father (short seller) 20 magic beans now if the father/short seller buys all of the analogies (stocks) later.  However, multiple witches/stock brokers trick multiple people into this strategy.  Since every father/seller now needs the same analogies/stocks, and multiple witches need the exact same complete set of analogies, a bidding war erupts and it's impossible to please all the witches.  The "winner" pays a much higher price than expected (limiting how much of a win it really is).  And the losers wind up either dead or enslaved (bankrupt). In the stock market the corresponding phenomenon is known as a short squeeze , hence Cueball's comment. However, if the witches implement this strategy by discussing among themselves to orchestrate the phenomenon, it would be in violation of various trading regulations, and brokers rarely have a reason to hope for their clients to go bankrupt.
[Cueball and Ponytail are walking together, talking.] Cueball: I don't understand shorting stocks. Ponytail: It's like when you promise your firstborn to a witch for five magic beans.
[Ponytail close up] Cueball (off-panel): Is that a common– Ponytail: She's a sucker, right? You know your awful kid will be worth one or two beans at best .
[Ponytail and Cueball stopped, facing each other] Ponytail: But then it turns out you love your kid, a love worth 200 beans! You can't afford that loss! Ponytail: There's only one way out: Ponytail: You gotta fight the witch.
[Ponytail and Cueball stopped, facing each other] Ponytail: So you send your kid up the beanstalk to battle the giant, who represents interest rates. Cueball: This analogy is getting less helpful by the minute. Ponytail: If only you'd somehow shorted my wisdom before you asked.


Marsiforming

Explanation:
Terraforming is the (so far only suggested) process of changing a planet, usually to make it more habitable for humans or other Earth life. A very common example is Mars , which is known to harbour water ice and believed to have previously been warm enough to have liquid water. Normally, plans for terraforming try to adjust temperatures to be compatible with liquid water, and an atmosphere containing significant amounts of oxygen but little carbon dioxide. The word Terra is the Latin name for Earth , so terraforming would be "Earth Forming".
In this comic Cueball is suggesting doing the opposite: change Earth to be more like Mars, i.e. extremely dry, cold, and with a very thin atmosphere, approximately 1/160 of Earth's surface pressure. In addition, Mars has no magnetic core, so it is possible that Cueball wants to remove the magnetic field from Earth. The comic title combines Mars with Forming (with a linking "i") to create the new word Marsiforming.  He is having trouble getting the enthusiastic response to his proposal that he expects.
The title text provides examples of how this could improve things: preserving Martian life (a proposed reason to terraform Mars would be to provide a second planet to preserve Earth life at the cost of destroying any potential [undiscovered] Martian organisms, so by marsiforming Earth, we would provide a second planet to preserve Martian life, if there is any life on Mars), needing fewer interplanetary launches (no need to leave this planet's atmosphere in order to visit itself, and Martians who might otherwise need to return to their home planet could instead settle on Earth), and making it easier to field-test Mars rovers (field-test means to test in the environment of actual use, which would readily be available on Earth). While the second and third items would indeed be advantages, and the first would be as well if Mars has developed life, they are severely outweighed by the fact that most life on Earth, including humans, would die.
Unstated in the comic are the extreme costs such a proposal would incur, which would surely be grounds for rejection.  Between the thin atmosphere, harsh solar radiation, and other changes, Earth would become uninhabitable for most life currently on Earth, most notably humans.  Almost all humans value the continued existence of the human race far more than Martian exploration [ citation needed ] (if nothing else, it is for the benefit of humans that Mars is being explored, so exterminating the human race would render the benefits moot).
There are known extremophile species that would survive underground on Mars.  If similar life is hiding on Mars, marsiforming the Earth would benefit their possible eventual interplanetary efforts.  There is an existing project to begin experimental terraforming on Mars by nurturing some of our extremophile species on it.
[Cueball is on a stage giving a presentation, with a diagram behind him. The diagram shows Earth and Mars side-by-side, along with some writing below the two.] Cueball: Earth and Mars may look different now, but with some orbiting mirrors and atmospheric adjustments, we could change that.
[Caption below the panel:] I'm having trouble selling people on my proposal to terraform Earth to resemble Mars.


Mattresses

Explanation:
Cueball is talking to Ponytail about his mattress, in what appears to be just a casual conversation.  Cueball suddenly offers to take any questions from listeners, as though the conversation were part of a podcast; this confuses Ponytail. The subtitle explains that Randall has heard so many advertisements for certain products on podcasts that he can't discuss them without feeling as though he's in a podcast himself.
Podcasts are typically audio-only programs available online, which frequently generate income through advertisements. Ads are often read by the podcast host. Hosts will often include segues or personal anecdotes to further reduce the "topical whiplash" caused by abruptly switching subjects from that of the podcast to an unrelated brand plug, and back.
In 2018, many podcasts (or at least many podcasts that Randall listens to) contained ads by Casper or Helix Sleep (both mattress brands), MeUndies or Tommy John (both underwear brands), and Stamps.com (an internet-based mailing/shipping service).
The title text refers to "The War To Sell You A Mattress Is An Internet Nightmare" , about the pressures companies put on reviewers, and the legal battle between a mattress review site that makes money through affiliate sales, and a mattress company, which was unhappy with a review. Since saying anything unfavorable about mattresses might open one to legal action, the title text author opted to avoid them entirely.  However, that could be seen as an endorsement of sleeping on the floor, thus requiring a disclaimer. It also references the way that podcast hosts will often note when they intentionally or unintentionally endorse a product sponsor in an attempt to remain transparent about their financial supporters.
[Cueball and Ponytail are talking to each other] Cueball: ...It's firmer than my old mattress, which I thought I wouldn't like, but it's actually really nice. Ponytail: Cool, maybe I should get one. Cueball: Now let's take some listener questions! Ponytail: What?
[Caption below the panel:] I can't talk about mattresses, underwear, or the Post Office anymore without feeling the urge to segue back into a podcast.
The image was originally posted as an indexed image with only a 3-color map (white, black, and grey), leading to graphical artifacts in place of a smooth blur between black and white. Most of Randall's comic images are indexed images with over 200 different grayscale colors. The original image can be seen here .


Thor Tools

Explanation:
In Norse mythology, Thor is the name of a god of thunder and lightning. His signature weapon is a magic hammer called Mjölnir . In popular culture Thor might be best known for his role in Marvel comics and films , which his appearance here seems to be referencing.  In the Marvel Cinematic Universe movie, Avengers: Infinity War, Thor also wields an axe named Stormbreaker.
Although this hammer was historically a weapon, this comic interprets it as it would more commonly be interpeted today -- as a tool.  The comic is listing various hand tools in order of utility and viability as Thor's weapon, besides his actual, enchanted hammer. Hammers are heavy, blunt, and can do large amounts of damage to an opponent, whereas a hand plane is sharp, but only in one place, and will only inflict surface wounds.
Some of these tools require power, which would generally require Thor to stay near an outlet or keep a battery charging, such as the circular saw, or Dremel. However, being the god of lightning may allow him to circumvent this, by producing electricity for the direct current (D.C.) tools, although he would need an inverter to convert the lightning (D.C.) to alternating current (A.C.) for the tools requiring it. Thor would also need compressed air for the nail gun or jackhammer, only allowing Thor so many shots before reloading the air tank at an outlet, or via a concentrated wind storm.
The nail gun and staple gun would also require nails or staples respectively to function as a weapon. Although Mjölnir is believed to return to Thor if thrown, it's not clear how a similar system could work with nails and staples.
The usefulness of the nail gun as a weapon might depend on whether it was an older one that can be bump-fired or a newer one that requires a separate trigger pull for each nail.
In the title text, Randall writes that the order of the axis label should be reversed, making the plane the best tool and Mjölnir the worst.  Considering that the title of the comic is "Thor Tools" ("tools", instead of "weapons"), the argument seems to be that a hammer is less useful than the rest, by seeing them as tools and not as weapons.
A few other interpretations of this could be:
The title may be a reference to Gary Larson's The Far Side comic, Cow Tools . The comic depicted a cow next to a set of crude tools, and was famous for no one understanding it.
All shown tools are explained below:
Hammer A hammer is a tool consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object . Thor was a hammer-wielding god and produced the lighting by using this tool. A war hammer was an actual blunt weapon used for combat in medieval times, and is the original Thor's attribute. There exists a variety of craftsman's hammers designed for specific purposes which can be used as weapons of opportunity to various degrees, depending on the tool's size, weight and material. Axe An axe or just ax is another old human tool used to split and cut wood, but it also was used as a dangerous weapon in the medieval times. The battle-axes of old were of considerably different design than the woodworking ones, being lighter and having thinner and wider blades. A woodworking axe, though not designed for combat, could be a formidable weapon of opportunity. Notably, this tool is placed slightly below the hammer, possibly indicating Randall's thoughts on Thor's axe, 'Stormbreaker' which features in the Marvel films. (Note: In Norse mythology Thor is depicted exclusively with a hammer rather than an axe). Claw hammer A claw hammer is a hammer tool primarily used for driving nails into other objects, but also for pulling nails from them. This item seems a bit redundant in the presence of a general hammer on the axis, but could be seen as more scary because it has a pointed, curved and split back head (used for pulling nails). In fact, the usefulness of its back head for combat is debatable at least. On the other hand, it is smaller and lighter than some other craftman's hammers, and less scary than a true war hammer, so its place on the axis may be justified. Circular saw A circular saw is using a, mostly electric powered, fast-revolving toothed disc to cut materials. A stationary version is called a table saw but the figure of Thor drawn above presents him using a lighter hand-held version making a buzzing sound. Since the power of the saw is far beyond the human power it is quite a dangerous tool and could be fatal to the user himself. However, it would be rather unwieldy in combat, as it is quite heavy and bulky. Also, electric circular saw would be limited by its cord length, however cordless (battery-operated) saws exist today. This item could be a mock reference to a common trope in horror movies or computer games, when a chainsaw (not a circular saw) is used a weapon. Shovel A shovel is also a historic tool. It can be used to dig into the ground, move snow or dirt, harvest, and much more. Because it has a relatively thin, sharp metal blade at the end of a pole, it can be used as a weapon of opportunity. Indeed, a small (sometimes foldable), sturdy spade was and still is a standard issue item for an infantryman in some countries, intended mainly for entrenching work, but also usable as a weapon – and the soldiers are trained to use it as such, sometimes to a high skill, specifically among special forces. It is rumored that Russian Spetznaz operators are specifically trained to use their spades as throwing weapons. It is therefore more useful in combat than a circular saw – but may be seen as less scary. Jackhammer A jackhammer is a power tool used to drill and crush hard but brittle materials like stone, concrete etc. It has heavy body with a protruding shaft that makes hard and rapid back-and-forth (and optionally also rotary) movements that drive an implement (a drill, a chisel etc.) into the worked material. Like the circular saw jackhammer is a tool that is powered far beyond single human capabilities. Most jackhammers are very heavy and can be reasonably used only in a facing-down position to work on floors, pavements and other near-horizontal surfaces, nullifying combat application. However, since Thor is purportedly very strong, he may be able to hold it horizontally for some combat... Socket wrench A handle attached to a socket wrench is mostly used to tighten bolts or nuts. But since it is quite heavy and resembles a hammer it could also be used in a similar fashion. It may be a self-reference to comic 538 . Bolt cutters Bolt cutters are cutters with very long handles, typically 2 or 3 feet long, and comparatively tiny jaws. The length of the handles provides the user enough mechanical advantage to sheer through things like bolts, chain links, and lock shackles. Although this tool can cut some fairly tough objects, its usefulness in combat is limited – as far as the cutting action goes at least. On the other hand they are quite heavy and can be used as a blunt weapon. Hacksaw A hacksaw is a type of hand saw with very small teeth. Hacksaws are well suited to cutting materials like metal and plastic, where the larger teeth of a wood saw would tend to bind or damage the material around the cut. Hacksaw blades are fairly unlikely to seriously injure people, though a hacksaw may be useful against metal baddies like Ultron. Nail gun A nail gun is a tool for driving nails or other fasteners into various materials ranging from soft wood to hard concrete by a single powerful "shot" to the nail being driven. There are models powered by compressed air, electricity (several types of mechanisms) or explosive charges similar to firearm ammunition (most often compatible with .22 Short blank cartridges). They are normally used by slightly pushing the "nozzle" against an object, disengaging a safety nose contact mechanism, and pulling the trigger. These are quite dangerous tools and can be potentially modified – by removing safety mechanisms – to act similarly to a handgun, shooting nails as high-speed projectiles. Its place in the middle of the axis seems not right compared to the work hazard level of other tools placed left of it. If safety mechanisms are left intact, a nail gun would need to be used in close combat by pressing it against an opponent which would make it difficult to apply, but if applied successfully it would inflict grievous wounds. Staple gun A staple gun is a tool used to drive staples (C-shaped pieces of hard wire) into relatively soft materials such as wood, plastics and light masonry in order to fix something to them. There exist spring-loaded hand-operated staple guns as well as power ones utilizing either electricity or compressed air. The power discharged during staple action is a lot less than that of a nail gun and would inflict minor skin wounds at most. If one manages to eject a staple into the air (not against an object) it won't travel very far. A figure of Thor is drawn above the axis showing him using a staple gun this way, with staples falling short onto the ground. The gun held by Thor makes kachunk sounds characteristic for a spring-loaded version of the tool. Coping saw A coping saw is a hand saw with a thin replaceable blade and is used to cut curves and shapes in wood or other relatively soft materials.  While it could produce a surface wound and draw blood, a person would generally not stand still long enough to be seriously hurt by being sawed at by a coping saw, plus they could bend or break the blade relatively easily. Screwdriver (flat) A (flat) screwdriver is a metal rod with a handle, flattened and ground at the other end to form a fairly sharp but short edge perpendicular to the rod. It is normally used to drive screws into a material, by putting the edge into a groove on the screw's head and turning it while pressing firmly. It is not very dangerous normally, but many people have cut their fingers while driving screws in, or sometimes whilst using it incorrectly to unscrew a bolt . It could potentially be used as a stabbing weapon similarly to a dagger, but much less effectively, or alternatively the heavy handle may be used as a bludgeon, though the smooth rod would be difficult to grip. Some nations seem to regard it so much dangerous as to ban its possession in public along knives. Ball-peen hammer Like a regular hammer, a ball-peen hammer has a flat head designed to hammer things like nail.  However instead of the "claw" a regular carpenter's hammer has to pull out nails, it has a second head that is shaped like a ball and which is used to bang surfaces such as sheet metal directly.  A ball-peen hammer is probably the smallest of traditional hammers, and usually used for more delicate work.  Thor's Hammer has two flat surfaces for pounding (no claw), so a ball peen might be like a smaller Thor's Hammer and could be pretty deadly in his hands.  The ball part would probably not be any more or less effective than the flat part, except it might bounce or deflect off some surfaces where a flat one might not. Screwdriver (Phillips) Similar to a flat screwdriver, but with a cross-shaped tip, designed to drive screws with matching cross-shaped heads.  While a Phillips screwdriver could potentially be used as an improvised weapon to stab or strike like a flat screwdriver, the blunter, cross shape is less likely to inflict cutting injury, likely leading to its lower position on the list. Awl An awl is a hand tool, basically a rather short, thin, sharp (sometimes curved) spike with a handle. It is used for punching holes through soft material (leather, fabrics) or to mark points or lines on wood or metal to assist further work such as cutting or drilling. In a pinch, it could be used as a stabbing weapon like a dagger, but a screwdriver is more sturdy for such purpose. Digital Caliper Digital calipers are an instrument for precisely measuring the dimensions of small objects. Typically, digital calipers can measure inner diameters, outer diameters, and depth. The reason they are considered more formidable than Dremels and planes is likely how surprisingly sharp the calipers are. They need to be sharp to make accurate measurements, but it is not uncommon for people to cut themselves while using a digital caliper. Dremel Dremel is a brand name (often used in a generic sense) of small rotary power tools that can be used in precise work involving small objects such as engraving, milling, drilling, grinding, cutting, polishing etc. It consists of a relatively small and lightweight body housing a high-speed electric motor driving a shaft equipped with a chuck . Various implements can be fixed to the chuck – drills, milling cutters of various shapes, small cutting disks, grinding stones, brushes, soft polishing disks etc. Typically the tool is used handheld against an object held in a vice. It can also be mounted in a stand with a flexible shaft attached, at the other end of which an implement is fixed in a chuck, allowing for still more precise work. A Dremel would be rather useless in combat, effecting in superficial wounds only. It could be seen as a baby circular saw, therefore much less scary and placed much more to the right of the scale. However, it is still a heavy object with a firm grip, and could plausibly be wielded as a bludgeon, making it slightly more effective than a plane. Plane A hand plane is a tool for shaping wood using muscle power to force the cutting blade over the wood surface.  It is designed to scrape layers of wood off the surface.  While a plane does have a sharp edge and can cause painful injuries if misused, its awkward shape and the small size of the cutting edge would make it impractical to wield and nearly useless as a combat weapon, even for bludgeoning.  A hand plane could plausibly be used as a particularly brutal torture device on a restrained victim, but as Thor is typically depicted as an honorable and heroic character it is unlikely that he would use one in this manner. Could also mean an actual plane that is meant to fly. Most likely to be used as a thrown projectile or, since Thor can fly using Mjölnir, he can use the plane to fly as well.
[A wide image is shown in a single frame.] Hand tools Thor could have ended up with [Below is a small centered horizontal line with arrows at both ends, labeled "Best" to the left and "Worst" on the right.]
[The rest of the image shows an other horizontal line in the middle, also with arrows at both ends, covering the full width. Items are marked by a dot with a text above or below, and sometimes a figure wearing a winged helmet, above the line, uses a tool mentioned below:] Hammer Axe Claw hammer Circular saw [Above, the winged helmet guy uses a circular saw:] Bzzzz zzzz Shovel Jackhammer Socket wrench [Above, the winged helmet guy spins the socket of a socket wrench with a tiny sound.] Bolt cutters Hacksaw Nail gun Staple gun [Above, the winged helmet guy fires staples into the ground in front of him:] Kachunk kachunk Coping saw Screwdriver (flat) Ball-peen hammer Screwdriver (Phillips) Awl Digital Caliper Dremel [Above, the winged helmet guy shows a running Dremel to the left:] Bzzzzz Plane


Magnetic Pole

Explanation:
Over the last couple of months, Earth's magnetic fields have been shifting rapidly . Although the magnetic fields do move regularly, the current shift has been unexpected and unprecedented. As many location systems are reliant on the magnetic fields to function, the accuracy of such tools is being shifted beyond the maximum acceptable error.
Locational and navigational systems use the magnetic field, combined with a model of field behavior, to do fancy math and pop out data. Because of the rapid shifts, a new model was scheduled to be created; however, the model has been considerably delayed by the US government shutdown ,
As shifts occur, the error of geopositional data will increase until a new model is released. The effect is especially pronounced as you move toward the poles.
Cueball is saying that because of the currently published magnetic declination data being slightly incorrect, his schooners (old merchant sailing ships) may go off-course and crash on shoals . This is to illustrate how magnetic pole shift doesn't actually affect many people's daily lives.  Modern ships' navigation systems do not rely on magnetic pole location – in contrast to old vessels which mostly used a compass .
Since the movement is only about two-fifths of a degree, it wouldn't cause much disruption for Cueball or require him to adjust anything about his lifestyle, but since the speed of the change has been steadily increasing over the past few years, it may mean we are heading for a geomagnetic reversal in the next few decades, something very exciting indeed. During a magnetic reversal, the poles wouldn't just switch places; several different poles would form and interact chaotically, and it's likely that one of them would end up close enough to where Randall lives to cause auroras to become more common at some point during the transition.
In the title text, Randall mentions that there are reasons people could be concerned, but says that they would be more than made up for by newly being able to experience mid-latitude auroras. Since auroras occur between 10° and 20° from the magnetic poles, the migration of the poles to middle latitudes would cause the auroras to occur there as well; since more people live at middle latitudes than in the Arctic and Antarctic Circles, and since auroras are considered aesthetically attractive, the psychological benefits of the drifting poles might more than make up for the technical difficulties it causes.
[White Hat and Cueball are talking to each other. White Hat has a cellphone in his hand, while Cueball is raising his hands in the air in mock exasperation.] White Hat: I just read that the Earth's North magnetic pole is drifting rapidly. Cueball: Oh no! I must update our declination tables post haste, lest our merchant schooners run aground on the shoals!
[Caption below the panel:] I like when the Earth's magnetic field does weird stuff, because it's a huge, cool, urgent-seeming science thing, but there's nothing I personally need to do about it.


Missal of Silos

Explanation:
This comic plays on the similarity in name between missile silos, places where long range weapons are deployed, and the missal of Silos, an old document residing in Spain .
In Christianity , a missal is a priest 's book of instructions , texts and music for the proper celebration of Mass . The Missal of Silos is an 11th-century missal from the Abbey of Santo Domingo de Silos in northern Spain ; it is famous for being the oldest known paper document in Europe, written at a time when the usual writing material was parchment .
Missile silos are often thought to be the first targeting priority in event of a nuclear strike, in hopes of preventing retaliation.  If one was searching for potential nuclear missile targets, the Missal of Silos could conceivably be returned as a result of a fuzzy search for "missile silos", and be made a target.
Fuzzy, or approximate, string matching is a technique used for searching text for sequences of characters similar to a given sequence.  Normal string matching would only find results that matched the search exactly (searching for " missile " would find only occurrences of " missile ").  Fuzzy string matching instead finds results that are "close enough" by some metric (searching for " missile " would find " missile " but also close variants like " missal " or " missel ").  Fuzzy string matching is often used in search engines, as typos, misspellings, and inexact searches are common.
Cheyenne Mountain is a mountain in Colorado , which houses an underground military compound (aptly named the Cheyenne Mountain Complex ) designed to withstand a nuclear strike and host to the North American Aerospace Defense Command . Cheyenne, Wyoming , on the other hand, is the capital of Wyoming . The residents of Cheyenne, Wyoming would prefer their town not to be the target of a nuclear attack because of confusion with Cheyenne Mountain. [ citation needed ] However, Cheyenne, Wyoming is likely a listed target because of the nearby 90th Operations Group at Francis E. Warren Air Force Base operating Minuteman III ICBMs from missile silos.
There have been several comics with nuclear weapons as a part of the plot. See for instance 1655: Doomsday Clock , where several other comics are mentioned in the explanation.
[A passage from the Wikipedia page for Missal of Silos is shown, with underlined heading and with links in the text in blue font. The last line is partly cut off by the comics panel, but can be read.] Missal of Silos From Wikipedia, the free encyclopedia The Missal of Silos is the oldest known paper document created in the Christian West; it is 11th century in date. [1] The missal is held in the library of the Monastery of Santo Domingo de Silos near Burgos, Spain . It is one of a number of liturgical manuscripts...
[Caption below the panel:] Spain would like to remind everyone not to use fuzzy string matching in their nuclear strike target lists.


Models of the Atom

Explanation:
This comic humorously describes the changing view of what an atom is.  This has happened so much it seems that we never really knew what we are looking at, and there have been many competing theories aside from the mainstream ones we are taught in school.  He lists major depictions in the history of our understanding of an atom, and adds a few humorous ones in to poke fun at how diverse, contentious, and in retrospect often foolhardy, this history has been.
Small hard ball model
The first model shown, in 1810, is said to be a "small hard ball model." Around this time, John Dalton published his textbook A New System of Chemical Philosophy which linked existing ideas of atomic theory and chemical reactivity to produce a combined law of multiple proportions which proposed that each chemical element is comprised of a single unique type of atom, and introduced the concept of molecular weight . Dalton's theories form the basis of what is known today as stoichiometry , which underpins chemical reactivity. As atoms were considered at this time to be the smallest possible division of matter the scientific community thought of them as "hard round balls" of different sizes; thus the name described here. The "small hard ball" model is still commonly used when teaching and discussing chemical molecules which do not require the level of detail provided by more advanced models, with atoms represented as small, hard, round balls connected by sticks representing chemical bonds.
Plum pudding model
In the late 19th and early 20th centuries, the study of these "atom" things faced a crisis: where would the newly discovered " electrons " go? In 1904, physicist J. J. Thomson , who discovered electrons, had an idea: maybe the electrons were small point charges moving around in a big mass of positive charge. This was the " plum pudding model ", the second model on the comic, called this because people imagined the positively charged mass as a " plum pudding ". (The title text references Thomson (although misspelled as "J.J. Thompson") as well, along with the humorous observation that plum puddings themselves are made of atoms.) The problem with this approach is that same charges generally repel, resulting in the more mobile or unbalanced charges forming a surface shell around the others, attempting to escape, rather than being content to being randomly distributed among them.
Tiny bird model
There were many competing ideas in the formative years of what-are-atoms-made-of-ology; Randall makes up a 1907 "tiny bird model," which he suggests might have fit well in the relative chaos of the period. In this model, four birds surround the small hard ball at equal distances to one another. Two of them are singing and the other two are not and all birds are opposite to their identical bird. The non-singing birds balance the singing birds like electrons and protons. This model might be mocking the strange and sometimes illogical models that were presented for the shape of an atom.
Rutherford model
The tentative winner in the battle was the model of Thomson's student Ernest Rutherford , who discovered from electrostatic scattering experiments that the positive charge seemed to be concentrated in the center of the atom, and proposed his Rutherford model , or "planetary model", in 1911, where electrons orbit a very concentrated positive charge. This model has often been compared to the orbit of the planets around the sun, with the electrostatic attraction of the electrons and protons shaping the orbits, rather than gravity.  This is the fourth model in the comic.
Bohr model
The Rutherford model could not explain the discrete spectral lines in absorption and emission spectra. It also did not explain why electrons did not spiral in to the nucleus. Niels Bohr patched the model up by proposing that electrons could only exist in distinct "energy levels" at discrete distances from the nucleus.  The 1913 " Bohr model ", the fifth model shown here, was part of beginning quantum mechanics.  Physics behaves differently at the small scale of atoms than the large scales we are more familiar with.
Nunchuck model
Randall facetiously suggests a " nunchuck model", the sixth model shown, of a packet of protons swinging a packet of electrons around.  One can imagine a handle filled with electrons bonded by the strong nuclear force to a chain made of neutrons, bonded again by the strong nuclear force to a handle made of protons.  The heavier protonic handle acts loosely as an orbital center as the electron-filled opposite handle swings wildly around it, attempting to resolve its electrostatic attraction within the restraints of its chain.
Chadwick model
The next refinement was in the structure of the nucleus.  Note that at this time, nobody thought of splitting up the nucleus into protons and neutrons . But pretty soon people noticed that protons and neutrons existed; James Chadwick , who discovered the neutron, figured that the atom had a nucleus of neutrons and protons, along with a bunch of electrons orbiting around it in a Bohrish manner. This is what the layman today often thinks of as an atom, and is the seventh model shown here.
538 model
The eighth model shown is a made up "538 model," in 2008. FiveThirtyEight is a statistical analysis website that gained fame in 2008 for predicting every race but 2 correctly in the US presidential election and predicting every state and Obama's win in the 2012 election. Unlike most other media and polling institutes it saw a rather high probability of 29% for Trump to win the 2016 election by summing up the uncertainties in all the battle states. It has since been known for making mathematical models for everything; the model jokingly suggests that 538 has modeled and presumably made predictions about the atom. The pie chart shows the statistical composition of neutrons, protons and electrons, 38%, 31%, and 31% respectively. This could either be the average of a massive body with several isotopes or represent gallium-69, the most abundant isotope of gallium , with 31 protons, 31 electrons and 38 neutrons. FiveThirtyEight has previously been mentioned in several xkcd comics, including in 477: Typewriter , 500: Election , 635: Locke and Demosthenes , 1130: Poll Watching , 1779: 2017 , and 2002: LeBron James and Stephen Curry .  It's appropriate to list the 538 model as a precursor to the quantum model, as it is a step towards considering the likelihood of different quantities of subatomic particles to be in different volumes of space, rather than considering them as strictly kinematic particles.  The comic moves this development into 2008 in support of this joke, when it was actually made much earlier.
Quantum model
But is the Chadwick model what scientists endorse today? No! The theory of electromagnetism says that accelerated charges, like the electrons circling, would lose energy emitted as electromagnetic waves and would quickly orbit into the nucleus. Bohr only postulated that this would not happen, but his model could not explain why. Another problem [ citation needed ] is that atoms, even the hydrogen atom are not flat - which they would be, if a single electron orbited in a circular or elliptical trajectory (the circular motion of charge results in a magnetic moment; Otto Stern and Walter Gerlach showed that independent from the direction of the measurement the angular momentum - for certain elements - always has the maximum positive or negative value, i.e. not only the radius, but also the angular momentum is quantized - and never zero. You cannot 'look at' the atom from above and 'see' the orbital circle. It always 'seems', as if you 'looked' from the side and would measure the full magnetic dipole. Stern and Gerlach actually saw the spin of an electron of the silver atom instead of the angular momentum, which is according to quantum mechanics 0).
Today (i.e. actually since 1926, 29 years after the discovery of the electron) physicists subscribe to a quantum model, which is the ninth model shown here. Instead of electrons with definite location and momentum (~speed), the parts of the atom are described by probability fields of possible locations and momentums. The changes in momentum probability normally cancel each other out, so there is no electromagnetic radiation. This is very abstract, and in the last model, the model is postulated to get so abstract that it is just a "small hard ball surrounded by math" model, the last model shown. This then is remarkably similar to the model we started out from, the "small hard ball model" (without the math).
“Small hard ball surrounded by math” model
The picture for the "small ball surrounded by math" depicts a circle with several numbers around it. While the numbers seem to symbolize the "surrounding math" in a general sense, some of them suggest constants used in actual mathematical equations or other numbers related to the quantum model.  The shapes and densities of the atomic orbitals are calculated with the Schrödinger equation , which is complex and difficult to solve. For this reason atoms are generally precisely considered in only very simple simulations, and the details of interactions of many atoms at large scales that form our daily lives are incredibly hard to precisely understand and predict on an atomic level.  It comes down to "these roundish things we call atoms are moving around in these approximate ways obeying this complex equation with too many numbers involved in most situations to accurately model, so let's use a different, empirically derived formula that describes the behavior of the system in general."
This model is probably a reference to the mathematical universe hypothesis and, as a striking case of prescience , may be seen as a prediction of April 2020’s Wolfram Physics Project .
[Heading:] Models of the Atom over time
[What follows is a progression of depictions of atoms.]
[A ball.] 1810 Small hard ball model
[A 'pudding' inside of which there are electrons.] 1904 Plum pudding model
[A ball, with four birds perched on it and two of them singing.] 1907 Tiny bird model
[A ball with electrons orbiting chaotically, in all directions, around it.] 1911 Rutherford model
[A ball with electrons circling around it.] 1913 Bohr model
[A nunchuck swinging, with the left stick filled with protons and the right stick filled with electrons.] 1928 Nunchuck model
[A nucleus with protons and neutrons, with electrons circling around it like the Bohr model.] 1932 Chadwick model
[A pie chart. 38% is allocated to neutrons, 31% to protons, and 31% to electrons.] 2008 538 model
[A nucleus with clover-like orbitals around it and surrounded by two outer partly dashed circles.] Today Quantum model
[A ball surrounded with numbers.] Future "Small hard ball surrounded by math" model


Technical Analysis

Explanation:
There are two recognized methods to attempt to predict the stock market, each with its own pros and cons:
Random Walk theory suggests that neither of these methods are particularly useful at predicting the future of the stock market (see link for a funny story about dart throwing monkeys).
The theoretical value of a stock is its net present value , which is the sum of all its future earnings, with earnings in the future discounted appropriately to account for the time value of money . Because these earnings are never fully predictable, traders may have different ideas about the true value of a stock, and buy the stock if they believe the currently offered prices are particularly low, or sell it when the prices are high.
Technical analysis, however, does not even attempt to understand the earnings of the stock, instead focusing on the shapes and patterns that result from traders making their moves. While there is a human behavioral component to stock trading, it is not clear that one can extract much information from the shapes of stock charts. To the extent it does work, a substantial part of its success may be simply an artifact of the herd behavior of traders who engage in technical analysis, a zero-sum game.
The comic displays a stock price chart , annotated with labels which purport to be technical analysis. These labels are nonsense from the perspective of technical analysis, but do accurately describe the graph itself: " allegro " (a musical term used to set the tempo at the beginning of a score), " prologue " (an introductory section of a play, book, or similar), " lumbar support" (the thing in a chair shaped to better support your back), "bathtub" (possibly a reference to the so-called " Bathtub curve "), " uptalk " (a speech pattern). One label celebrates that "these two points define a line! Promising signal." (In geometry, any two points define a line.)
The shape of the chart is similar to the exponential behavior of cryptocurrencies when they are successful, where price (positional height on the chart) roughly increases while volatility (height of the bars or candles themselves, and of the peaks and troughs, on the chart) does the same.  Technical analysis used to be an esoteric domain held by well-paid stock analysts, but as cryptocurrency has spread, and as financial companies have made it easier for members of the public ("retail investors", as opposed to "institutional investors") to engage in investment trading, people from all walks of life have begun staring at charts like this.
The title text is a quote from James Tobin (from his 1984 paper On the efficiency of the financial system ) that raises a question of very talented people building systems to make themselves a lot of money without actually accomplishing anything worth money. The quote was about the stock market and high speed traders in particular. It comments on the 'financialization' of the economy, where activities like speculation and abstracted financial products have become an increasingly large part of the economy, as opposed to investment in productive industry.
Interestingly, this comic appeared the day after Oxfam reported that the world's 2,200 billionaires had added 12% to their wealth in 2018, while the 3.8 billion people comprising the poorest half of the world's population had lost 11%. Perhaps this prompted what appears to be Randall's jab at those whose business is merely making money.
[A series of red and green box-and-whisker plots form a line that starts in the bottom left corner of the image and wiggles up to the top right corner, with a series of peaks and troughs that resemble a typical stock market diagram. The diagram is annotated with lines, arrows and text.]
[Title in top left corner] The basics of technical analysis
[A roughly horizontal section with mostly green boxes:] Allegro
[A horizontal bracket encompasses the next three sections] Prologue
[Slope becomes slightly negative. Mostly red boxes, bordered with a black line above and below:] Decline
[A roughly horizontal section with mostly green boxes, bordered with a black line above and below:] Doldrums
[Line curves upwards with mostly green boxes, with a dashed black line below:] Spline
[Three green boxes at minor peaks in the line are circled and indicated with arrows:] [Hmm!]
[A section with slight positive slope and a mixture of red and green boxes, with a solid black line below:] Lumbar support
[Slope increases. All green boxes, with a black line through the centre:] Renewal
[A sharp upwards incline, with two large green boxes:] Hark! The cliffs!
[Two black dots and a dashed black line connect two major peaks:] These two points define a line! Promising signal
[Inside trough between two major peaks is a roughly drawn black triangle:] Bathtub
[Slope becomes negative, mostly red boxes with a black line through the centre:] Declination
[At the lowest point of the trough:] Inflection
[Slope becomes positive, mostly green boxes with a black line through the centre:] Uptalk
[Slight negative slope, with large error bars. Mixture of red and green boxes. One red box is marked with an arrow:] Yikes!
[Negative slope, all red boxes. Gap between two central boxes is circled:] Wrong!
[Line rises then falls. Mixture of red and green boxes with non-parallel dashed black lines above and below:] If I add some lines here I can convince myself I'm doing something more than just seeing patterns in a graph of a random walk.
[Positive slope, all green boxes with a black line through the centre:] Slope!
[One error bar on a green box is circled:] Could be an omen?
[Arrow indicating peak:] Red + Green = Christmas!
[Positive slope, all green boxes with a wiggly black arrow through the centre. A separate arrow points off the edge of the page:] Likely to continue forever


Internet Archive

Explanation:
The Internet Archive is a project that is invaluable for internet research. It is a public archive of information, including public domain books and music. It also runs the Wayback Machine , an archive of backups of web pages all over the Web at various times that can be used to see past versions of a page, even if that site has since shut down. The Internet Archive accepts submissions of any type of information, including new backups of web pages and newly-made public domain content.
Ponytail and Cueball first remark upon how weird the concept of the Internet Archive is, commenting that it would seem like an implausible concept if not for the fact that it already existed.
This revisits a point that Randall made in 2085: arXiv : in the title text for that comic, he wrote,
Both arXiv and archive.org are invaluable projects which, if they didn't exist, we would dismiss as obviously ridiculous and unworkable.
Our culture has an overarching theme of equating profit with success, so when efforts succeed due to inherent public benefit, this can often yield surprise.
They then become more philosophical, and wonder about invaluable systems that are maintained by a just a few individuals, meaning that they could disappear if any of those people stopped doing what they were doing. They relate this to the function of the human body , which does contain many systems whose function and inner workings are unknown to the average person.
Again, as in 2085: arXiv , the two try not to "jinx things" by drawing attention to the improbability of this system working perfectly. In arXiv, when Megan exclaims that being able to post research papers as free PDFs on arXiv "makes no sense at all", Ponytail responds, "Shhh, you'll jinx it!" Here, Cueball tells Ponytail, "Probably best not to think about it."  This is ironic as the inclusion of this information in a popular comic like xkcd is drawing attention to it.
As an example of "invaluable systems maintained by just a few individuals", the title text refers to the " npm left-pad incident ", a 2016 incident where a package for the npm package manager was removed from the software library by its author. As this particular package was used by many projects, both directly and indirectly, this caused a severe disruption in the software world. Randall is relieved that cases like this do not occur more frequently. This topic appears to stay on his mind for a while, since 2347: Dependency covers a similar theme.
[Ponytail and Cueball are walking to the right.] Ponytail: The Internet Archive is so weird. If it didn't exist, it would sound totally implausible. Cueball: Seriously.
[Ponytail and Cueball continue walking to the right.] Cueball: Do you ever worry about how reliant we are on systems that someone happens to maintain for some reason but which could disappear at any time?
[Ponytail and Cueball are seen in silhouette from a distance.] Ponytail: Yeah - the same thing freaks me out about having a body. Cueball: I know, right?? I don't even know what half these parts do ! Ponytail: And yet if they stop, we die! Cueball: Probably best not to think about it.


Midcontinent Rift System

Explanation:
Recently, USA politics has caused polarization of the public. [1] It is said to be “split” in two camps (liberal, mostly loyal to the Democratic Party , and conservative, mostly loyal to the Republican Party ). Here Black Hat is trying to get elected to some sort of federal office in the at the time upcoming 2020 elections by promising he will actually split America in two. His presentation illustrates, using a giant crowbar, the completion of the Midcontinent Rift , which is a large crack that started to form about 1.1 billion years ago, but failed to completely sever the continent. Around the same time, the rift was also mentioned in "How To", Chapter 9: How to build a lava moat.
It is unclear why anyone would vote for such a thing, but people directly affected (the Midwest) are likely to vote against Black Hat . While Black Hat and his campaign advisor Ponytail speak of weakness in the Midwest, they are talking about two different things: Black Hat refers to the physical weakness of the North American Plate in the Midwest due to the geological rift which he thinks could be exploited by a large enough crowbar, while Ponytail is referring to a political weakness for Black Hat’s campaign in the Midwest due to the likely-unpopular proposal (different regions of the US have different voters and populations who have different priorities and stances, so candidates and their campaigns’ platforms will likely be more popular in some regions and less popular in others).  In this case a successful or attempted completion of the rift would likely result in the destruction of millions of houses, buildings, and other man-made structures, not to mention the deaths of many humans (if proper evacuation were not fully implemented and enforced) as well as millions of animals that could not be evacuated.  The proposal would also cause huge economic impacts; the Midwest produces a significant proportion of America’s food supplies and hosts important economic centres, such as Chicago and Cleveland.  So the popularity among those directly or even indirectly affected is likely quite low.  The successful passing of a highly destructive measure such as this would generally involve more direct and overwhelming compensation of the many interests that would otherwise be harmed, to incentivize them to vote against their present livelihood.
The title text is a pun. A wedge issue is a controversial issue which splits apart a demographic group. It is often introduced to create controversy within an opponent’s base so that if the opponent takes any position on the issue, half the voters will desert the opponent. Here the joke is that the “wedge issue” is an actual wedge to split apart the United States. It could potentially be a wedge issue, as while most people would oppose such a measure, some people could be convinced that it would benefit certain Midwestern cities by making them port cities, which would result in an economic boom and make trade easier if those cities weren't destroyed. Also, some die-hard liberals living outside the Midwest might favor the destruction of the Midwest because it tends to vote conservative. Ponytail seems to state that Black Hat's proposal is only unpopular in the Midwest.
[A map of North America shows the Midcontinent Rift System as a red line curving through the Great Lakes and down through the midwestern United States.] 1.1 billion years ago, the North American continent began to split in half.
[Black Hat stands at a lectern with a "Vote 2020" sign on it. He gestures to an image of the globe with a giant crowbar inserted in the rift with an arrow indicating applying pressure to widen the rift.] Black Hat: We don’t know why it stopped.  If elected, I vow to finish the job.  Thank you.
[Ponytail, Black Hat, Megan, and Cueball walk to the right away from a set of stairs. Cueball is looking at a phone and Ponytail is looking at a device or paper with writing on it.] Ponytail: Great job up there. Black Hat: Thanks!  How are my polling numbers? Ponytail: Well, I’m seeing some weakness in the Midwest. Black Hat: So am I.  So am I.