https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&user=162.158.203.38&feedformat=atomexplain xkcd - User contributions [en]2024-03-29T15:50:20ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=2774:_Taxiing&diff=3128012774: Taxiing2023-05-10T21:09:56Z<p>162.158.203.38: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 2774<br />
| date = May 10, 2023<br />
| title = Taxiing<br />
| image = taxiing_2x.png<br />
| imagesize = 399x431px<br />
| noexpand = true<br />
| titletext = I don't understand why anyone would pay full price for a flatbed truck rental when you can buy 'DETOUR' signs online for like $10.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a STOLEN WATERBED TRUCK - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
In this comic, [[Cueball]] is acquiring an airplane by directing it with orange lights sticks onto a ramp that will take it up onto a trailer, so he can drive away with it. And he thus wonders why anyone would buy a plane, when those glow sticks can be bought cheaply on the internet.<br />
<br />
{{w|Aircraft marshalling|Marshallers}} stand on the runway and use "glowing wand things" to direct planes around while they are taxiing. Cueball is using glowing wand things to hijack a plane and direct it into a trailer, where it will presumedly be locked up and taken somewhere else with the plane claimed. The caption claims that paying "full price" for an airplane (buying one normally) is ridiculous when the wand things that allow you to direct planes to where you want them to go are about $30 online.<br />
<br />
This may be illegal.{{citation needed}}<br />
<br />
The title text mentions doing a similar thing, but with detour signs rather than glow wands and flatbed trucks rather than planes. It seems Cueball used this tactic to obtain the truck he is loading the airplane onto.<br />
<br />
==Transcript==<br />
:[Cueball is waiving two orange sticks in the air, one in each hand. They are glowing as indicated with small orange lines all around the orange part. The handle he holds them by is black. Cueball is pointing one stick to the left where, behind him, is a ramp that extends beyond the panel. The other stick is held up in front of his face and he looks up onto the front end of a large plane. Only a small part of the plane is visible, mainly the very tip with just a bit of the window into the cockpit shown. The underside of the tip is gray, the rest is white with the window in black.]<br />
:Cueball: ...Keep going...<br />
:Cueball: ...Slightly left...<br />
:Cueball: ...Okay, good...you're lined up with the ramp...<br />
:Cueball: ...Now pull forward slowly up onto the trailer...<br />
<br />
:[Caption below the panel:]<br />
:I don't understand why anyone would pay full price for an airplane when you can buy those glowing wand things online for like $30.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics with color]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Aviation]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=1559:_Driving&diff=2984621559: Driving2022-11-09T14:55:14Z<p>162.158.203.38: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 1559<br />
| date = August 3, 2015<br />
| title = Driving<br />
| image = driving.png<br />
| titletext = Sadly, it probably won't even have enough gas to make it to the first border crossing.}}<br />
<br />
==Explanation==<br />
A {{w|self-driving car}} is a car that requires no human interaction to navigate streets to a destination. Thus, when [[Black Hat]] places a rock that weighs "as much as a small adult" into the car's seat, he begins the process of fooling the car into thinking it has an occupant when it does not. His purpose in doing so appears to be to send the car to {{w|Anchorage}}, {{w|Alaska}}, which is presumably quite far from where Black Hat and [[Cueball]] are standing, thus taking the car far away from its owner with relatively little effort on the part of Black Hat. This is yet another evil prank from xkcd's resident [[classhole]].<br />
<br />
The title text references the fact that driving to Alaska from the [[2394: Contiguous 41 States|contiguous lower 41 states]] requires two border crossings, once into {{w|Canada}} from the mainland, and once from Canada into Alaska. The car apparently begins some distance from the Canadian border, since it will likely run out of gas before reaching Canada. The title text expresses regret about this probable failure; perhaps Randall was looking forward to the encounter between the border guards and the vehicle's "occupant." However, even if the car does not get to Anchorage, Black Hat will have created a serious problem for its owner who will have to report the car as stolen.<br />
<br />
Shortly after this comic appeared, Tesla released footage of a robotic charger that can [http://www.bbc.co.uk/news/technology-33794085 connect itself to a Tesla automatically.] If this kind of technology becomes common then a self-driving electric car might be able to make a transcontinental journey without human intervention.<br />
<br />
At the time of the release of this comic there were no places where self-driving cars were for sale to individuals. However, several corporate-owned test cars are frequently seen on public roads (such as those operated by Google among others). {{w|Google_driverless_car|Nevada, Florida, California and Michigan}} were the first states to allow the testing of self-driving cars on public roads, and this legality is quickly spreading to many other states, as well as several countries in Europe. Alternatively, Randall might be setting this comic in an idyllic near future, wherein you could drive all over the country (and Canada) with these cars!<br />
<br />
It could have been [[Beret Guy|Beret Guy's]] car - see [[1493: Meeting]]. Self-driving cars are a [[:Category:Self-driving cars|recurring topic]] on xkcd.<br />
<br />
==Transcript==<br />
:[Black Hat, carrying a rock, is walking toward Cueball, leaving a trail of sand.]<br />
:Black Hat: Would you guess this weighs as much as a small adult?<br />
:Cueball: What?<br />
:Cueball: Uh, probably.<br />
<br />
:[Black Hat walks past Cueball who turns to look after him.]<br />
:Black Hat: Great!<br />
<br />
:[Black Hat has walked out of the frame. Cueball is looking in the direction he left in. Several noises and voices are coming from off-panel.]<br />
:Off-panel: <nowiki>*</nowiki>Thump*<br />
:Car voice (off-panel): ''Please fasten your seatbelt.''<br />
:Off-panel: <nowiki>*</nowiki>click*<br />
:Black Hat (off-panel): Take me to Anchorage, Alaska.<br />
:Car voice (off-panel): ''Navigating''<br />
:Off-panel: <nowiki>*</nowiki>slam*<br />
<br />
:[Black Hat walks back in the panel towards Cueball.]<br />
:Car driving off:''Vrrrrrrrrrrrr<small>rrrr<small>rrrrr<small>rr</small></small></small>''<br />
:Black Hat: I love self-driving cars.<br />
:Cueball: ...Whose car was that?<br />
:Black Hat: Dunno, but they shouldn't have left it running.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Black Hat]]<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Self-driving cars]]<br />
[[Category:Sabotage]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2519:_Sloped_Border&diff=2974242519: Sloped Border2022-10-23T20:37:41Z<p>162.158.203.38: /* Transcript */ Maybe instead "...are in a posture of...", but while "postured" is correct, it has a more common alternative word-for-word replacement.</p>
<hr />
<div>{{comic<br />
| number = 2519<br />
| date = September 22, 2021<br />
| title = Sloped Border<br />
| image = sloped_border.png<br />
| titletext = "The slope will be 74° at ground level." "Okay, I think we can hack together a ... wait, why did they specify ground level? It's 74° everywhere, right? ... Oh no, there's a whole section in the treaty labeled 'curvature.'"<br />
}}<br />
<br />
==Explanation==<br />
<br />
Every country has land and sea {{w|international borders}} that demarcate the extent of their territory and their legal jurisdiction. These borders are established through law, treaty, or consensus. Establishing an international border is maintained by present-day customs, immigration, and security checks. Some countries (like {{w|Cyprus}}) have established a {{w|buffer zone}} outside of their international border in order to gain additional protection during a conflict, and most countries have an offshore {{w|Exclusive Economic Zone}} in order to preserve exclusive proprietorship of marine resources such as oilfields and fishing grounds. <br />
<br />
In this comic, Cueball and Blondie have established a "sloped" international border through a treaty. Usually borders are perpendicular to the ground{{citation needed}} so that all the air(space) above the ground belongs to the same country. This is called {{w|Air sovereignty}}. Thus it suffices to define the border on the earth surface, as 1D lines across the curved 2D surface. The precise definition is that a line from the center of the Earth through the point of the border is drawn. Sloped terrain is immaterial to the border of the air sovereignty which is still vertical, even if not perpendicular to the terrain. <br />
<br />
If the borders were sloped (with respect to the horizontal ground level) an airplane would need to know its precise height to decide if another country's jurisdiction currently applies. With the help of the {{w|Global Positioning System}} this would be in principle possible, although the height information of GPS is less reliable. (It might be possible to program a computer to use altitude data from the airplane's altimeter along with latitude and longitude data from the GPS and a relevant ground relief database to make an accurate determination.)<br />
<br />
Most countries would not agree to a border that cuts into their airspace and shrinks their territory as the altitude increases; most cases of countries losing area have come about as a result of trying to avert, or losing, an armed conflict. It is entirely possible that Cueball's country has compelled Blondie's country to accept its demands, of which the redrawn border is one. Alternatively, Cueball's country may be deliberately reducing its own airspace purely because it will cause problems.<br />
<br />
There is at least one famous case of a border being affected by elevation: the Franco-Swiss border bisects the staircase of the {{w|Hotel Arbez}}. Hence, although part of the upper floor is geographically in France, the entire floor is Swiss territory, because it is only accessible through Switzerland.<br />
<br />
The mathematical computation for an angled air sovereignty seems relatively straight-forward at low level and could be expressed with a single line of code or a single equation, although the people acting on the information are likely unfamiliar with code and equations and likely use tools with completely no support for sloped borders. The mention of curvatures in the title text may reveal some emergent problems that need accounting for. <br />
<br />
A totally straight line drawn far enough upwards at an angle will find the surface of the Earth curving away beneath it (not even considering terrain undulations) and the angle to the local vertical will reduce as it continues, tending towards vertical as you head towards infinite altitude.<br />
<br />
Alternately (although it seems this is not the case) the profile of the sloped border may be assumed to remain at a constant angle to the shifting vertical, in which case it describes a certain {{w|Logarithmic spiral|form of spiral}} (which will eventually loop around the earth).<br />
<br />
A third option is that it gains altitude at a constant rate, with respect to the passage of land measured on its surface track, to form a {{w|Archimedean spiral|different spiral}}, in which case it will still loop around the Earth but at an angle that increasingly tends towards horizontal.<br />
<br />
While the comic doesn't mention this, such a boundary should probably also extend underground, in the opposite direction. (The straight-line version, if implemented, will eventually reach a depth at which it is tangential to the radius and then rise back through the surface an equal distance further around the planet.) This would then impact, at practical depths for such things, planning rights for property foundations and, at deeper levels, mining rights for minerals.<br />
<br />
Practically, an upper-limit to a nation's claim (somewhat below satellites, e.g. the Karman Line) and a lower limit (well before reaching the Earth's mantle) will prevent many of these complications, together with intersections with other (probably vertical) 'territorial volume' borders that will supercede in any compound claims to ownership. - However, it is still ''very important'' to specify exactly which curve (i.e. with respect to what) the boundary is designed to be respecting.<br />
<br />
"GIS" refers to {{w|geographic information system}}, a set of tools and methods for capturing, analyzing and presenting spatial and geographic data. While altitude is already an (optional) element in the blocks of information, people developing these systems would be inconvenienced by the additional requirements demanded by the border described in the comic.<br />
<br />
It is possible this comic is inspired by such boundary disputes as the {{w|Beaufort_Sea#Border_dispute|Beaufort Sea 'wedge'}} which, while in this case perpendicular to the surface, suffers from alternative interpretations of how to extend it from the shoreline out towards international waters.<br />
<br />
==Transcript==<br />
:[Cueball and Blondie are standing on a podium. They are holding a document together between them, filled with unreadable text. On either side of the podium are two informational graphics each on a stand. They are placed a bit behind the back side of the podium. The graphic to the left shows a cross-sectional view of a non-vertical border, shown as a dotted line going up between Cueball and Blondie, who both are standing on the ground. The angle is indicated and noted, and the line tilts towards Blondie's side. The graphic on the right shows a skewed perspective of a similar setup of the non vertical border, shaded so what is behind it becomes gray. There are also some lines on this plane to indicate where it is. It almost looks like a window, but people can move through it. There are also two more persons than on the left, Megan, who is on the same side of the border as Cueball, and another Cueball-like guy standing next to Blondie. Megan is entirely on Cueball's side of the plane, but the other three are positioned so they are intersected by the 'shaded plane' of the border, with the effect that some or most of their bodies are beyond the sloped boundary, in the gray area, but not all. Cueball and Blondie are posed in a mutual greeting across this border, as the others look on.]<br />
:Cueball: With this treaty, we are proud to announce the creation of the world's first '''''sloped''''' international border!<br />
:Angle: 74°<br />
<br />
:[Caption below frame:]<br />
:If I'm ever put in charge of a country, I'm going to spend all my time trying to think of new ways to make life a nightmare for GIS people.<br />
<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Comics featuring Blondie]]<br />
[[Category:Comics featuring Megan]]<br />
[[Category:Multiple Cueballs]]<br />
[[Category: Geography]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2687:_Division_Notation&diff=2971932687: Division Notation2022-10-20T18:45:08Z<p>162.158.203.38: /* Transcript */</p>
<hr />
<div>{{comic<br />
| number = 2687<br />
| date = October 19, 2022<br />
| title = Division Notation<br />
| image = division_notation_new_2x.png<br />
| imagesize = 235x310px<br />
| noexpand = true<br />
| titletext = Science tip: Scientists hardly ever use the two-dot division sign, and when they do it often doesn't even mean division, but they still get REALLY mad when you repurpose it to write stuff like SALE! ALL SHOES 30÷ OFF!<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a GROUP OF SCHOOLCHILDREN DIVIDED AMONGST THEMSELVES. Do NOT delete this tag too soon.}}<br />
<br />
This comic pokes fun at some of the ways to write the {{w|Division (mathematics)|division}} operation in math. In this comic, [[Randall]] has used A as the dividend (the number being divided) and B as the divisor (the number that A is divided by). Division is the fourth simplest arithmetic operation in mathematics, after addition, subtraction, and multiplication.[https://plato.stanford.edu/entries/principia-mathematica/#PartIVRelaArit]<br />
<br />
The first two of the seven notations shown are the {{w|division sign}} (÷) and the {{w|long division}} notation used for {{w|short division}} and {{w|long division}} in beginning arithmetic. (Note: division typography is only used in some countries, and there are [https://en.wikipedia.org/wiki/Long_division#Notation_in_non-English-speaking_countries different notations in the non-English speaking world]). These methods of division are often used by school children because the ÷ sign is what most people use when first learning division, and the short division format is usually the first algorithm learned for dividing arbitrary dividends, typically starting with the easier abbreviated short division form.<br />
<br />
The expression on the third line, A/B, is the way division is usually written in software code. The four simple arithmetic operations in programming usually are +, -, *, /. This line was not in the [[media:division_notation_2x.png|first version]] of the comic. This is most commonly seen in regular mathematics as it somewhat saves space, and is easy to type with the slash key. Additionally, it uses standard {{w|ASCII}} characters instead of sophisticated notation. A notable exception is {{w|APL_(programming_language)|APL}}, which uses an idiosyncratic character set modeled after traditional arithmetic.<br />
<br />
The expression on the fourth line, <sup>A</sup>/<sub>B</sub>, is how division is usually written by hand. It is nearly identical to the fraction notation that follows, but the diagonal line allows each number to be bigger while still fitting into a single line of text. It takes more effort to type with this notation; however, the Unicode character sets provide some specific fractions such as ⅓ as well as some superscript and subscript characters, so someone familiar with it might use it to write fractions such as ²²⁄₇.<br />
<br />
The fifth notation is the way division is written in science: <table style="display: inline-table; line-height: 0.6em; vertical-align: middle; font-size:7pt; text-size-adjust: none;"><tr><td><u>A</u></td></tr><tr><td>B</td></tr></table>, i.e. the dividend on the top of the expression, over the divisor on the bottom with a horizontal line seperating them. This is how a {{w|Fraction|fraction}} would be written. It has the advantage of clearly separating the numerator and denominator when they are longer expressions, such as polynomials, without needing to add parentheses. This format is mostly used in written and professionally typeset math, as it can't be typed without something like {{w|MathML}}, {{w|LaTeX}} or HTML tables.<br />
<br />
The sixth, "fancy," notation uses a negative exponent. The exponent -1 is equivalent to {{w|Multiplicative inverse|reciprocation}}. It can be used to keep an entire division expression on one line. Note that AB<sup>-1</sup> is equal to <sup>A</sup>/<sub>B</sub> only if A and B are in a commutative ring (and B has an inverse). If A and B are, for example, matrices, AB<sup>-1</sup> is not the same in general as B<sup>-1</sup>A (and the notation <sup>A</sup>/<sub>B</sub> is never used in this case as it would be ambiguous).<br />
<br />
The AB<sup>-1</sup> format is also often used to express physical units.<br />
<br />
The final form of notation declares a function. The writer defines a new function, F, that takes in the parameters A and B, before listing out the function's definition (trailing off in increasingly smaller text). Randall warns the reader they should escape while they still can, because both the function itself and the math environment as a whole are going to get relatively tedious. Integer division can be defined in terms of multiplicative inequalities and the remainder, or modulo ('%' in Python), operator. This situation is likely to occur in many sorts of algebra, where one might have to define what "division" means for two elements of a mathematical object such as a group, ring, or magma. One example would be an object G, such that, for two elements A and B of G, "A divided by B" is defined as an element C such that CB=A, or alternatively as an element C such that BC=A. These definitions will differ if multiplication in G is not commutative. Furthermore, if such a C is not unique, the function F(A,B) will need to include a method to select a unique value for "A divided by B" for each A and B. Thus, the F(A,B) in the comic might not even refer to a uniquely defined operation, but simply to the property of a function F(A,B) that is a valid division operation on G, given some definition of division. You were warned.<br />
<br />
The title text discusses how the division sign (÷) has fallen out of favor in most professional contexts (the ISO-80000 guidelines even specify the symbol "should not be used") yet has resisted all efforts to repurpose it as a new function. Specifically, it pokes fun at how similar the division sign is to a percent sign. A scientist might be really mad at the use of the division sign as an alternative to a percent sign not just because it is the wrong symbol in that context, but also because of the tedium of modern consumerist practices.<br />
<br />
==Transcript==<br />
{{incomplete transcript| Really should have descriptions instead of 'span styles'... Consider giving it descriptive labels intead (or at least as well as)... Do NOT delete this tag too soon.}}<br />
:<u>Division notation</u><br />
:A÷B <br />
:B⟌A Schoolchild.<br />
:A/B Software engineer.<br />
<span style="display:inline-flex;flex-direction:column;vertical-align:middle;"><br />
<span>A</span><br />
<span style="border-top:1px solid">B</span><br />
</span> Scientist<br />
:AB<sup>-1</sup> Fancy scientist.<br />
:F(A, B) such that F(G)= (text getting smaller) Oh no, run<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Math]]<br />
[[Category:Science]]<br />
[[Category:Programming]]<br />
[[Category:Science tip]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2685:_2045&diff=2968072685: 20452022-10-15T16:33:25Z<p>162.158.203.38: Undo revision 296804 by 108.162.241.51 (talk)</p>
<hr />
<div>{{comic<br />
| number = 2685<br />
| date = October 14, 2022<br />
| title = 2045<br />
| image = 2045_2x.png<br />
| imagesize = 350x457px<br />
| noexpand = true<br />
| titletext = "Sorry, doctor, I'm going to have to come in on a different day--I have another appointment that would be really hard to move, in terms of the kinetic energy requirements."<br />
}}<br />
<br />
==Explanation== <br />
{{incomplete|Created by a GIGANTIC NUCLEAR FURNACE (THE SUN) - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
The characters are talking about upcoming total {{w|solar eclipses}}. Partial solar eclipses are fairly frequent (2–5 per year), but total eclipses are less frequent (about every 18 months), and most of them will not be in convenient locations for a particular set of people. Cueball seems to be talking about total eclipses visible in much of North America: {{w|Solar eclipse of April 8, 2024|April 8, 2024}} and {{w|Solar eclipse of August 12, 2045|August 12, 2045}}. (There's also a {{w|annular eclipse}} on October 14, 2025.) Making plans for eclipses is awkward given the uncertainty present for anything else far in the future, such as whether the attendees will have children by then, and even whether another scheduling program will catch on and replace Google Calendar.<br />
<br />
Black Hat claims he can't make it, as he has "a thing" on August 12, 2045. Events for that far in the future usually have not yet been scheduled for a precise date{{Citation needed}}, and this combined with the fact that Black Hat remembers this date without checking implies that this could be another of his grand and sinister plans... or he just doesn't want to go.<br />
<br />
The title text is someone cancelling a medical appointment to see the eclipse. The eclipse is hard to move because that would require hastening or delaying it by moving the Earth, Moon or Sun, any of which would require vast amounts of energy.{{Citation needed}} People also don't often schedule doctor's appointments decades in advance.{{Citation needed}} This was published a year before the next eclipse so, if you're someone who plans things a year in advance this serves as a reminder to put it on your calendar.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
:[Cueball, a friend also drawn as Cueball, Danish, and Black Hat are standing together. Danish is looking at her phone.]<br />
:Cueball: ...And then after the one in 2024, there's another on August 12, 2045.<br />
:Friend: We're in! We can invite our kids, assuming we have any.<br />
:Danish: I'll create an event. Do you think we'll still be using Google Calendar in 2045?<br />
:Black Hat: Sorry, I'd love to make it, but I have a thing that day.<br />
<br />
:Caption: It's weird making plans for eclipses.<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Multiple Cueballs]]<br />
[[Category:Comics featuring Danish]]<br />
[[Category:Comics featuring Black Hat]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2169:_Predictive_Models&diff=2954922169: Predictive Models2022-09-25T14:48:33Z<p>162.158.203.38: Two little girls are wrestling and they kick each other in the genitals</p>
<hr />
<div>{{comic<br />
| number = 2169<br />
| date = June 28, 2019<br />
| title = Predictive Models<br />
| image = predictive_models.png<br />
| titletext = WE WILL ARREST THE REVOLUTION MEMBERS [AT THE JULY 28TH MEETING][tab] "Cancel the meeting! Our cover is blown."<br />
}}<br />
<br />
==Explanation==<br />
<br />
<br />
{{w|Predictive text}} is a feature on many systems where as you type the system automatically suggests likely words or phrases to follow what you have written to that point. For instance, if you type "I'm heading" the system may suggest "home" or "back" as likely words to follow. Predictive systems usually use prior input to generate their predictions, so if you frequently type "Totally amazing!" the system will suggest "amazing!" every time you type "totally" even if you actually want to type "totally true" sometimes.<br />
<br />
In the comic, [[Cueball]] is using predictive text to uncover a plot against his organization/government, but instead of using only his personal input, the system is using input from ''all'' users. By typing in an obscure phrase related to revolution and a meeting, he gets the predictive text algorithm to display where and when the next supposedly secret meeting will be held based on other users input. This works because it is unlikely that anyone else other than revolutionaries would be typing this phrase, thus the only data the algorithm has to predict from is the actual message from the revolutionaries on their next meeting. The caption of the comic is pointing out that systems which use prior input for predictive purposes in this way can end up leaking information that might otherwise be considered private. (However, this method may produce outdated information. On June 29, 2019, typing in Google "Long live the revolution. Our next meeting will be at" gave the predicted completion "long live the revolution. our next meeting will be at comic con 2018", which would not be useful information to anyone looking for revolutionaries, because Comic-Con 2018 was already over.)<br />
<br />
The title text shows the revolutionaries using the same technique. By typing in "We will arrest the revolution members" they are hoping that the algorithm will suggest the time and date of their planned arrest, since no one other than the authorities would be typing in that phrase. Pressing the key [tab] to autocomplete that text produces "WE WILL ARREST THE REVOLUTION MEMBERS [AT THE JULY 28TH MEETING]", and the revolutionaries then say "Cancel the meeting! Our cover is blown." The revolutionaries have apparently made the serious mistake of holding secret meetings on regular, predictable dates (such as the 28th day of each month, the last date guaranteed to exist in any month of the Gregorian Calendar), and the authorities have successfully figured this out, either through the predictive-text attack or by other means.<br />
<br />
Both examples assume that the revolutionaries and the authorities would be talking about very secret information in the clear on a network accessible to their adversaries. In the real world people engaged in sensitive activities would communicate via code, encryption, or both, or would do so through what they believe to be secure channels. There is still the danger of secret information leaking via non-secret channels, however. <br />
<br />
{{w|Side-channel attack|Side-channel attacks}} use information gained from the implementation of a system to deduce supposedly protected information. A famous example occurred in World War II. The Germans kept tank production figures a secret, but they gave items like engine blocks sequential serial numbers. The Allies wanted to know exact tank production figures, so they solved the {{w|German tank problem}} by using statistical methods to analyze the distribution of these numbers on captured vehicles. They were able to predict tank production figures extremely accurately, to the point they predicted 270 tanks in a month when 276 were actually built. Thus the secret information on tank production leaked.<br />
<br />
Some systems require frequent password change, in an effort to limit danger from a password being discovered. However, people respond by choosing passwords in patterns, so it is easy to predict what subsequent passwords will be, given old ones, thus defeating the purpose of requiring frequent changes.[https://www.troyhunt.com/passwords-evolved-authentication-guidance-for-the-modern-era/ Passwords Evolved: Authentication Guidance for the Modern Era]<br />
<br />
Although the comic title is "Predictive Models", the term {{w|Predictive modelling}} usually refers to computer programs that try to predict outcomes from data aggregation, such as reviewing health records to identify people most at risk from certain diseases based on weight, prior injuries, etc., before testing directly for the diseases themselves. This is similar to but not precisely like the example in the comic, since predictive text is using direct input to predict further input, while predictive modelling is using related input (such as make and model of a car along with driver acceleration patterns) to predict a different output (such as likelihood of a crash). Both predictive text and predictive modelling could leak information as the comic suggests, however. <br />
<br />
Predictive text and the possibility to leak unintended information has been parodied on xkcd before in [[1068: Swiftkey]].<br />
<br />
==Transcript==<br />
:[A naked girl with dick and balls kiscks another girl in the balls. Above him is the text she starts wrestling along with what the predictive text tool suggests, the latter in grey text. The TAB at the end is in a small frame.]<br />
:Cueball typing: Long live the revolution. Our next meeting will be at<span style="color:gray">| the docks at midnight on June 28 [tab]</span><br />
:Cueball: ''Aha, found them!''<br />
<br />
:[Caption below the panel:]<br />
:When you train predictive models on input from your users, it can leak information in unexpected ways.<br />
<br />
==Trivia==<br />
*On its original release, the alt text was bugged. The full text would not display in certain browsers, and clicking the comic takes you to this page: [https://xkcd.com/%5BAT%2520THE%2520JULY%252028TH%2520MEETING%5D%5Btab%5D <nowiki>https://xkcd.com/[AT%20THE%20JULY%2028TH%20MEETING][tab]</nowiki>], which only shows "404 Not Found". <br />
**The anchor actually contains invalid HTML <nowiki><a href=" [AT THE JULY 28TH MEETING][tab] "Cancel the meeting! Our cover is blown.""></nowiki>. This would suggest that [[Randall]] didn't intend this behaviour.<br />
**The image and alt text were later corrected, long before July 28th, 2019, further implying it was a simple mistake on Randall's part.<br />
*Some browsers, only show the first part of the title text "WE WILL ARREST THE REVOLUTION MEMBERS." For example Firefox version 66 Windows does this, evidently some versions of Firefox and chrome do likewise on GNU/Linux, also Windows 10 Microsoft Edge<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:Comics featuring Cueball]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=Talk:2671:_Rotation&diff=294695Talk:2671: Rotation2022-09-12T22:41:46Z<p>162.158.203.38: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
For extra credit: Waht is the resolution of the phone screen? [[Special:Contributions/172.71.94.135|172.71.94.135]] 18:59, 12 September 2022 (UTC)<br />
<br />
:IMHO 400px. Note SMALLER. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 19:53, 12 September 2022 (UTC)<br />
<br />
:From the image you can assume an 9/20 aspect ratio. Assuming each rotation reduces the image dimensions by that fraction after 9 rotations the dimensions would be reduced 1322 times so the resolution would be something between 1322x595 pixels (anything less than that would made it require 8 rotations or less) to 2935x1321 pixels (anything beyond that would require 10 rotations or more). 1600x720 or 2400x1080 maybe? Applying the same formula for the phone width and assuming atoms are typically around 100 picometers across then the phone width is close to 4.67 cm, too small, but maybe that's because rounding. In the other hand that formula does not work with Planck length at all: using it the phone width would be 1.69 meters. If you assume a width of 7 cm and 97 rotations you get pretty close to Planck length, but the comic says 101, not 97. Something is wrong with my calculations, I don't know what. [[Special:Contributions/162.158.63.160|162.158.63.160]] 21:03, 12 September 2022 (UTC)<br />
<br />
This seems like it could actually be really cool. Can anyone do this and put the picture here as an example? Also, if possible, include an AI upscale of the one pixel. [[Special:Contributions/172.69.90.83|172.69.90.83]] 19:07, 12 September 2022 (UTC)<br />
<br />
There's a '''minor''' counting error: instead of pointing to the 9th rotation, the 'nine rotations' statement points to the 8th as the first phone has no rotations.[[Special:Contributions/172.70.90.77|172.70.90.77]] 19:10, 12 September 2022 (UTC)<br />
<br />
Anyone getting a 404? Seems like the comic has disappeared. EDIT: ...aaaand it's back. [[Special:Contributions/172.70.100.54|172.70.100.54]] 19:34, 12 September 2022 (UTC)<br />
<br />
Just putting https://www.codeguru.com/multimedia/rotate-a-bitmap-image/ here. [[Special:Contributions/172.69.134.131|172.69.134.131]] 20:12, 12 September 2022 (UTC)<br />
: Microsoft C#, and not the original HAKMEM or Smalltalk 80? Please! You might as well be using C++: https://docs.microsoft.com/en-us/windows/win32/api/wingdi/nf-wingdi-plgblt [[Special:Contributions/162.158.166.173|162.158.166.173]] 20:21, 12 September 2022 (UTC)<br />
:: I see your trivial software squabble, and raise one peer reviewed open access article citation: https://link.springer.com/article/10.1007/s10648-010-9144-5 [[Special:Contributions/172.69.22.5|172.69.22.5]] 22:03, 12 September 2022 (UTC)<br />
:::I'll see your humorously ambiguous reference, and raise you a slightly more on-topic chapter encompassing both: https://journalspress.com/LJRHSS_Volume17/208_The-Geometric-Progression.pdf [[Special:Contributions/162.158.166.125|162.158.166.125]] 22:10, 12 September 2022 (UTC)<br />
<br />
Tiktok [[Special:Contributions/108.162.246.68|108.162.246.68]] 20:40, 12 September 2022 (UTC)<br />
<br />
Where would the rotated photograph bar be on [[1909: Digital Resource Lifespan]]? [[Special:Contributions/172.70.211.50|172.70.211.50]] 22:14, 12 September 2022 (UTC)<br />
<br />
Doing this with an jpeg does the same. When rotating an image and saving it the lossy compression will lose more pixels. This makes it more blurry each step. [[Special:Contributions/162.158.203.38|162.158.203.38]] 22:41, 12 September 2022 (UTC)</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=Talk:2636:_What_If%3F_2_Countdown&diff=287376Talk:2636: What If? 2 Countdown2022-06-23T11:57:22Z<p>162.158.203.38: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
I've started the table to explain all the calendar entries. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 00:19, 23 June 2022 (UTC)<br />
<br />
Is the dog minutes calculation backwards? 777,777 dog minutes should be 777,777 x 7 human minutes, which is over 10 years. Randall seems to be dividing instead of multiplying. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 00:36, 23 June 2022 (UTC)<br />
: No - 1 human year = 7 dog years; 1 dog year = 1/7 human year; 1 dog minute = 1/7 human minute; 777,777 dog minutes = 111,111 human minutes. [[Special:Contributions/172.70.90.173|172.70.90.173]] 11:32, 23 June 2022 (UTC)<br />
<br />
First entry is probably mistake by Randall, e^pi would give value of 84.5 [[Special:Contributions/162.158.203.38|162.158.203.38]] 11:57, 23 June 2022 (UTC)</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=Talk:2633:_Astronomer_Hotline&diff=287029Talk:2633: Astronomer Hotline2022-06-15T15:17:48Z<p>162.158.203.38: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
Someone really needs to check on the bot. This is the second day in a row where I have had to begin the article! [[User:SqueakSquawk4|SqueakSquawk4]] ([[User talk:SqueakSquawk4|talk]]) 13:06, 15 June 2022 (UTC)<br />
<br />
The fact that this is the Astronomer Helpline seems like commentary on the frequency with which astronomers are asked about mysterious objects, and/or the fact that astronomers (who tend to spend a lot of time looking at the sky) rarely report seeing unidentified objects. It could also be noted that calling fireflies a UFO would technically be accurate, as they are objects which are flying that the observers apparently could not readily identify. [[Special:Contributions/172.71.82.121|172.71.82.121]] 13:36, 15 June 2022 (UTC)<br />
<br />
Title text probably referes to [https://en.wikipedia.org/wiki/Periodical_cicadas Periodical cicadas] that appears every 17 years.<br />
[[Special:Contributions/172.71.98.99|172.71.98.99]] 13:58, 15 June 2022 (UTC)<br />
<br />
As someone from a country without fireflies, is "Ground Stars" a normal word for fireflies or a joke? (similar to how planets are "wandering stars", so to an astronomer everything is a star, similar to [[2017: Stargazing 2]]) [[User:Sqek|Sqek]] ([[User talk:Sqek|talk]]) 14:17, 15 June 2022 (UTC)<br />
:A joke. [[Special:Contributions/172.70.115.4|172.70.115.4]] 14:54, 15 June 2022 (UTC)<br />
<br />
The second last paragraph is extremely confusing. Someone should fix it. [[Special:Contributions/162.158.203.38|162.158.203.38]] 15:17, 15 June 2022 (UTC)</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2627:_Types_of_Scopes&diff=2849392627: Types of Scopes2022-06-01T15:53:48Z<p>162.158.203.38: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 2627<br />
| date = June 1, 2022<br />
| title = Types of Scopes<br />
| image = types_of_scopes.png<br />
| titletext = An x-ray gyroscope is used to determine exactly which toppings they included in the pita.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
-scope is an ending for words denoting an instrument used for viewing or examination. It comes from the Ancient Greek word for "examine, inspect, look to or into, consider". There are many such words in the English language.<br />
<br />
''Electron microscopes'', ''electron telescopes'' and ''radio telescopes'' are special forms of microscopes and telescopes, respectively. This comic explores what you could do with a hypothetical "electron ___-scope" and "radio ___-scope" for other words also ending in -scope (namely: periscope, stethoscope, kaleidoscope, gyroscope and horoscope). The definition of the word itself ("regular ___-scope") is also given.<br />
<br />
The third column often plays on different meanings of the word ''radio:'' 1) related to radiation and 2) a device for receiving radio communication or broadcasts.<br />
<br />
{| class="wikitable"<br />
|+ What the words could mean according to the comic<br />
|-<br />
! Word !! Regular !! Electron ___ !! Radio ___<br />
|-<br />
| Microscope || || ''Really exists'' || Simply a microscope for looking at your radio.<br />
|-<br />
| Telescope || || ''Really exists'' || ''Really exists''<br />
|-<br />
| Periscope || || ||<br />
|-<br />
| Stethoscope<br />
|| A medical device for listening to sounds made by a patient's body, for example the heart. Has a disc-shaped resonator that is placed against the patient's skin.<br />
|| If the resonator is emitting electromagnetic radiation, it could burn the skin due to its close proximity.<br />
|| Normally, the sounds are transmitted to an earpiece that the examiner wears. There are also recording stethoscopes. A radio stethoscope would transmit the sound either directly via radio waves, or send it to a radio station such as NPR where it could then be broadcasted. <br />
|-<br />
| Kaleidoscope || || ||<br />
|-<br />
| Gyroscope || || ||<br />
|-<br />
| Horoscope<br />
|| In common usage, predictions or advice given based on the position of stars and planets. Often believed to be unscientific junk.<br />
|| Predictions on the position of a particle (such as an electron).<br />
|| Predictions or advice given based on the radiation emitted by exploding stars or galaxies. <br />
|}<br />
<br />
The title text makes a pun on "gyroscope" and the Greek foods {{w|Gyros}} and {{w|Pita}}.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
{{comic discussion}}</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2627:_Types_of_Scopes&diff=2849292627: Types of Scopes2022-06-01T15:29:35Z<p>162.158.203.38: /* Explanation */</p>
<hr />
<div>{{comic<br />
| number = 2627<br />
| date = June 1, 2022<br />
| title = Types of Scopes<br />
| image = types_of_scopes.png<br />
| titletext = An x-ray gyroscope is used to determine exactly which toppings they included in the pita.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
-scope is an ending for words denoting an instrument used for viewing or examination. It comes from the Ancient Greek word for "examine, inspect, look to or into, consider". There are many such words in the English language.<br />
<br />
''Electron microscopes'' and ''radio telescopes'' are special forms of microscopes and telescopes, respectively. In this comic, Randall muses what an "electron ___-scope" and "radio ___-scope" could be for other words also ending in -scope (namely: periscope, stethoscope, kaleidoscope, gyroscope and horoscope). The definition of the word itself ("regular ___-scope") is also given.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
{{comic discussion}}</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2614:_2&diff=2320462614: 22022-05-03T07:40:41Z<p>162.158.203.38: Undo revision 232041 by 108.162.245.69 (talk)</p>
<hr />
<div>{{comic<br />
| number = 2614<br />
| date = May 2, 2022<br />
| title = 2<br />
| image = 2.png<br />
| titletext = It's like sigma summation notation, except instead of summing the argument over all values of i, you 2 the argument over all values of 2.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by 2 squared - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}<br />
<br />
This demonstrates the different ways in which the number 2 can be typeset in various scientific fields.<br />
<br />
The dotted box represents any character (presumably a letter or bigram of letters). All the other notation consists only of the digit 2, in various fashions with occasional additional punctuation, and labelled as to what the 'purpose' might normally be of any particular element(s) as indicated, with respect to the general term, in the following fashions:<br />
;Regular Math<br />
:Precedes the term. "2x" indicates two times the value of ''x'' in normal {{w|algebra|algebraic}} use that should be familiar for many people.<br />
;Physics<br />
:A preceding superscript. "<sup>2</sup>H" would indicate the particular {{w|isotope}} of Hydrogen with the atomic weight of two, i.e. deuterium, which is most often encountered when working with the atomic level of matter where the total number of neutrons and protons in the atom is important.<br />
;Chemical Physics<br />
:A preceding subscript, "<sub>2</sub>He" indicates the atomic number of an atom, which is the number of protons it contains, and thus a guide to the number of electrons its unionised form usually has and hence meaningful in its potential chemical interactions with other atoms. This should be invariant for any particular named element, but is usually given simultaneously with the presuperscripted mass number where it can be indicative of the applicable nuclear physics.<br />
;Regular Math or Footnotes<br />
:A trailing superscript is typical of a {{w|Exponentiation|power value}}, in this case "x²" would be ''x'' multiplied by a second copy of itself, and a fairly typical mathematical standard.<br />
:Additionally, superscripted numbers are one common way to mark words in a line of text in a way to refer to a {{w|Note (typography)|footnote}}, typically placed at the bottom of the page, with additional information that would not be appropriate or easily comprehendable to edit into the main text itself. The ambiguity between footnotes and exponents was used in [[1184: Circumference Formula]]<br />
;Chemistry<br />
:A trailing subscript is used in chemistry to indicate a multiple of the element (or group of elements, in brackets) in a {{w|chemical formula}}. "H<sub>2</sub>O" indicates two hydrogen atoms bond with a single oxygen atom in a molecule of water.<br />
;Matrices!<br />
:Extending the trailing subscript with a comma-separated value usually indicates a multidimensional array (e.g. establishing a 2-by-2 square of numbers, or this particular position in such an array), which is in the realms of {{w|Matrix (mathematics)|matrix mathematics}}. This is a little bit beyond 'everyday algebra' for many people, as seemingly indicated by the exclamation of the mere mention of matrices!<br />
;The Physicists Are At It Again<br />
:This label encompases a mark that turns the prior comma into a semicolon, as part of the trailing subscript. This is a common notation for the {{w|Covariant derivative}} of a tensor field, which is commonly used in the mathematics of general relativity.<br />
;Either High School Math Function or Incomprehensible Group Theory<br />
:The number 2 in parentheses that follow a term would normally be the argument to a {{w|Function (mathematics)|function}}, e.g. "f(2)", which means that you should take the value (in this case 2) and find the result if manipulated by the predefined function ''f''. It is generally taught as part of algebraic mathematics already described, i.e. at {{w|Secondary school|High School}}.<br />
:In {{w|group theory}}, however, the number 2 in parentheses could indicate a cyclic subgroup or ideal generated by two or a special case of cycle notation for elements of symmetry groups used to mean an element that keeps 2 fixed. This may be somewhat beyond high-school level.<br />
;Oh no. Whatever this is, it's cursed.<br />
:A symbol centered underneath another symbol is normally reserved for doing summations, where the big symbol is &Sigma;, or some other operation applied to a sequence of numbers.<br />
:It does not make sense to have a single number there, as indicated in the alt text. As with [[2529: Unsolved Math Problems|other things]] in Randall's comic universe, the explanation for this particular anomaly is that it is 'Cursed'.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
[An apparently scientific expression:]<br />
<br />
[normal text:] 2 [superscript behind the box:] 2 [subscript behind the box:] 2 [an empty box with a dotted outline] [superscript:] 2 [subscript:] 2;2 [normal text:] (2) [smaller and beneath the last 2:] 2<br />
<br />
;[Captions above the numbers]<br />
:[with an arrow pointing to the first 2:] Regular Math<br />
:[with an arrow pointing to the behind superscript 2:] Physics<br />
:[with an arrow pointing to the regular superscript 2:] Regular math or footnotes<br />
:[with an arrow pointing to (2):] Either high school math functions or incomprehensible group theory<br />
<br />
;[Captions below the numbers]<br />
:[with an arrow pointing to the behind subscript 2:] Chemical Physics<br />
:[with an arrow pointing to the regular subscript 2:] Chemistry<br />
:[with an arrow pointing to a grey circle around ";2":] The physicists are at it again<br />
:[with an arrow pointing to a smaller grey circle inside the other circle that leaves out the dot of the semicolon:] Matrices!<br />
:[with an arrow pointing to the 2 below the 2:] Oh no. Whatever this is, it's cursed.<br />
<br />
{{comic discussion}}<br />
[[Category:Math]]<br />
[[Category:Physics]]<br />
[[Category:Chemistry]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=Talk:2609:_Entwives&diff=230799Talk:2609: Entwives2022-04-20T15:56:28Z<p>162.158.203.38: </p>
<hr />
<div><!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--><br />
<br />
This seems like one of the earliest-released comics in recent history [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 14:00, 20 April 2022 (UTC)<br />
<br />
There seemed to be two versions of the title text; on mobile, there is a youtube link visible, but this is not present on my chrome desktop view [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 14:05, 20 April 2022 (UTC)<br />
<br />
The mouseover text in android devices is this youtube link - [[https://www.youtube.com/watch?v=mt2qCjL6-n4]] https://www.youtube.com/watch?v=mt2qCjL6-n4 [[User:DefectedWBC|DefectedWBC]] ([[User talk:DefectedWBC|talk]]) 14:18, 20 April 2022 (UTC)<br />
<br />
Is LotR the lowest scoring major motion picture on the {{w|Bechdel test}}? [[Special:Contributions/172.70.206.95|172.70.206.95]] 14:37, 20 April 2022 (UTC)<br />
<br />
Unlikely, depending on how you define major motion picture.<br />
<br />
As pointed out in YouTube’s comment section, the video seems to be a joke, not ''actually'' the only female interaction in the films. [[User:Chortos-2|Chortos-2]] ([[User talk:Chortos-2|talk]]) 14:49, 20 April 2022 (UTC)<br />
<br />
Gender imbalance among readers and viewers of lotr as well. [[Special:Contributions/172.70.230.53|172.70.230.53]] 14:51, 20 April 2022 (UTC)<br />
<br />
In response to Chortos-2 comment, I would think a slight edit for accuracy along the following lines -- instead of "a video showing" change to "a video that purports to show". As they discuss, the point still stands, but the added accuracy would hurt, would it? [[Special:Contributions/172.70.114.251|172.70.114.251]] 15:39, 20 April 2022 (UTC)newbie<br />
<br />
I feel like it's weird that nobody's brought up that this is an Ent comic on 4/20. For context, reddit.com/r/trees (the weed subreddit) has an in joke where they call themselves ents, basically. [[User:Bazzherb|Bazzherb]] ([[User talk:Bazzherb|talk]]) 15:44, 20 April 2022 (UTC)<br />
<br />
So who is the third hobbit supposed to be? --[[Special:Contributions/162.158.203.38|162.158.203.38]] 15:56, 20 April 2022 (UTC)</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2601:_Instructions&diff=2297772601: Instructions2022-04-05T22:10:19Z<p>162.158.203.38: /* Explanation */ The code is running (being executed), not "compiling".</p>
<hr />
<div>{{comic<br />
| number = 2601<br />
| date = April 1, 2022<br />
| title = Instructions<br />
| image = instructions.png<br />
| imagesize = 500px<br />
| titletext = Happy little turtles<br />
}}<br />
*To experience the interactivity of this comic, visit the {{xkcd|2601|original comic}}.<br />
{{TOC}} <br />
==Explanation==<br />
{{incomplete|Created by the LOGO OF A HAPPY LITTLE TURTLE - now that the full comic has been completed, an explanation of that is necessary. Do NOT delete this tag too soon.}}<br />
This is the 12th [[:Category:April fools' comics|April fools' comic]] released by [[Randall]]. The previous April fools' comic was [[2445: Checkbox]], which was released on Thursday, April 1st, 2021.<br />
<br />
When loading the comic just a small dot is shown, a {{w|radio button}} (or option button). Usually, there would be more than one to give the user options. Once it has been selected it cannot be deselected. Once pressed the [https://www.explainxkcd.com/wiki/images/2/20/2601_Instructions_Radio_on.png button turns blue] and this starts the real part of this April fool's comic.<br />
<br />
The comic consists of an [https://xkcd.com/2601/radio.mp3#t=0 audio file]. The speech is a mix of [[#Index of facts|facts about turtles]] and coding instructions in {{w|Logo_(programming_language)|LOGO}}. When executed, the instructions draw an xkcd comic. The audio file is 9 hours and 7 minutes long.<br />
<br />
[[File:xkcd 2601 finished comic animation.gif|thumb|200px|200px|Click to view the animation of the code running to create the picture, also from GitHub.]]<br />
*See the [[#The Resulting Image|resulting comic]] below.<br />
**And see how it is [https://www.explainxkcd.com/wiki/images/0/05/xkcd_2601_finished_comic_animation.gif animated here].<br />
**This has been compiled by [https://github.com/theinternetftw/xkcd2601#transcription-complete theinternetftw on Github].<br />
*The transcript of the quotes (the non-code) can be found here [[2601: Instructions/Audio Transcript]].<br />
*Images of the dynamic changes and other pictures relating to this comic can be found here [[2601: Instructions/Images]].<br />
<br />
Once the voice begins to describe the instructions (hence the title) it is possible to mute the audio by pressing a [https://www.explainxkcd.com/wiki/images/2/20/2601_Instructions_Radio_on.png muted button] at the bottom right of the screen. This fades into view when the radio button is pushed. Pressing it will change the button to a [https://www.explainxkcd.com/wiki/images/7/78/2601_Instructions_Radio_on_muted.png non muted loudspeaker]. These were the same buttons that were in the previous April fool's comic [[2445: Checkbox]]. That was the first xkcd [[:Category:Comics with audio|comic with audio]], and thus these were two April fools' comics with audio in a row, and these are the only comics with audio. In the Checkbox comic, the mute buttons meaning are reversed, so the sound is on when the loudspeaker is shown and muted when the mute button is shown. It could be another layer to the April fool's joke or just an error by Randall.<br />
<br />
The [https://www.explainxkcd.com/wiki/images/archive/e/e3/20220402201427%21instructions.png image originally displayed] on this page was of a small turtle crawling in the center where the radio button is in the real comic. That was the image that would be downloaded by web crawlers like explain xkcd's bot, as it is what was placed here on xkcd: https://imgs.xkcd.com/comics/instructions_2x.png. This is of course not the real comic, which cannot be downloaded in that manner. <br />
<br />
The "turtle" is a key concept in Logo, a programming language especially designed to teach programming to children in an easy way. The turtle in the logo is the cursor. Programming commands move the turtle, drawing a line as it goes. Of course, listening to hours of instructions, including the speech-synthesized reading of source code, is not an easy way to code or draw a picture.{{cn}}<br />
<br />
In addition, at [https://xkcd.com/2601/radio.mp3#t=32817 the end of the audio] the voice says:<br />
<blockquote><br />
"I even talk to turtles at times, but you need to understand LOGO to appreciate the great, great things that have been created. We spend so much of our life typing, looking, but never ever seeing."<br />
</blockquote><br />
<br />
The title text alludes to {{w|Bob Ross}}'s catchphrase "happy little trees" in ''{{w|The Joy of Painting}}'', a PBS TV show in which Ross leads the viewer through the painting of a nature scene. The audio file itself is also presented in the style of ''The Joy of Painting''; it begins with greeting the viewer and introducing the color palette to be used (just one color, in this case, as Logo and all computer monitors of the time were monochrome). The speaker then reads out some helper functions to be used in programming the scene, which is more analogous to Ross's palette of paints (titanium white, carmine red, etc.) along with words of encouragement as each is completed. The functions are DIST, to calculate the {{w|Euclidean distance}} between two points, LERP, to perform {{w|linear interpolation}}, MIX to average two numbers (with LERP), and CUBIC to draw {{w|cubic Hermite spline}}s. From there, the speaker alternates between sketching parts of the scene and offering more words of encouragement, mixed in with turtle facts.<br />
<br />
Transcribing the audio into text was organized as a [https://github.com/theinternetftw/xkcd2601 project on github].<br />
<br />
This is not the first time that Randall made an interactive comic where turtles played a big part, see [[1416: Pixels]]. In this, he jokes with the idea of turtles all the way down, which is [https://xkcd.com/2601/radio.mp3#t=10403 also mentioned] in the audio file. He also made a comic simply called [[889: Turtles]].<br />
<br />
===Unique header text===<br />
This comic has a [[xkcd_Header_text#Unique_header_text|unique header text]], see [[xkcd_Header_text#Instructions|the details here]]. The header is:<br />
:"Today's comic was created with [https://twitter.com/fadinginterest Patrick], [https://twitter.com/Aiiane Amber], [https://twitter.com/chromakode @chromakode], [https://twitter.com/dyfrgi Michael], [https://twitter.com/wirehead2501 Kat], [https://twitter.com/xDirtyPunkx Conor], [https://twitter.com/zigdon @zigdon], and [https://twitter.com/bstaffin Benjamin Staffin]."<br />
The header had not changed [[xkcd_Header_text#2022-01-31_-_What_if.3F_2|since the promotion]] of the new ''what if? 2'' book.<br />
<br />
==Trivia==<br />
*If you have scripts disabled, you will just see a picture of a [https://www.explainxkcd.com/wiki/images/archive/e/e3/20220402201427%21instructions.png little turtle] which is not interactive.<br />
<br />
==Transcript==<br />
:[The comic consists of one radio button, a small circle in the center of a large white panel. It is interactive. When pressing the radio button (selecting it), it turns blue. The second the radio button is pressed a more than 9-hour long audio file of coding instructions begins to play, and a mute button appears in the bottom right corner. It fades slowly into full opacity. Pressing this button will change it to a loudspeaker. It toggles whether there is sound playing or not. It is not possible to shut down the audio by pressing the radio button. Once selected it cannot be deselected as there is only this one option.]<br />
<br />
:[Covered by the radio button is an image of a turtle crawling from left to right, with a dotted line trailing behind it, indicating its movement. This image can only be seen by looking in the place where images for xkcd are usually placed on xkcd.]<br />
<br />
:'''[To read a transcript of the audio file go here: [[2601: Instructions/Audio Transcript]].]'''<br />
<br />
==The Resulting Image==<br />
[[File:xkcd 2601 finished picture.png|800px]]<br />
<br />
===Explanation of the image===<br />
<br />
The image drawn by the Logo program is a depiction of {{w|Bob Ross}} standing in front of a canvas, on which he has painted "a happy little tree, holding up a happy little world". However, unlike his usual "happy little trees", the tree depicted is not a small pine, but rather a gargantuan {{w|World Tree}} growing from the back of a giant {{w|World Turtle}}, on which a {{w|Flat Earth}} rests. (The "happy little world" does bear several small pines more typical of his style.)<br />
<br />
Near the middle of the world, a Cueball sits while listening to the radio, perhaps tuning in to the same transmission that generated the image. Closer to the reader, a turtle is shown walking around, leaving dotted-line tracks behind it, suggestive of the Logo turtle. The dotted-line tracks spell out "TY", shorthand for "thank you".<br />
<br />
At the far left of the image, a robot and human are drawn next to a turtle which has flipped onto its back. The robot declares, "Poor thing!" while the human says "I'll help". This is a reference to the "empathy tests" employed to distinguish humans from androids in ''{{w|Do Androids Dream of Electric Sheep?}}'' and its film adaptation ''{{w|Blade Runner}}''. As part of the test, the listener is asked to imagine being in the desert, flipping a tortoise onto its back, and refusing to turn it back over, while their eyes are monitored for signs of emotional response (or lack thereof). In this case, the robot expresses sympathy for the turtle and the human declares that he will turn it back over. (Although the robot is very clearly distinguishable from a human being.)<br />
<br />
===Transcript of the image===<br />
:[A man with large hair and a beard is holding an artist's palette with five patches of paint in one hand and a paintbrush in the other. He looks upon his canvas, where he has painted a large painting.]<br />
:Painter: A Happy little tree <br />
:Painter: Holding up a happy little world.<br />
<br />
:[The painting contains lots of stuff. Among others, is a robot that sees Cueball bending down to lift a turtle that is on its back. They talk:]<br />
:Robot: Poor thing"<br />
:Cueball: I'll help<br />
<br />
:[In the top right corner, there is a dotted line forming a semi-circle around the corner. Inside this are the words:]<br />
:Vacuum decay<br />
<br />
:[There are no other words in the image. The image includes:] <br />
In the sky: <br />
* Mars, including: <br />
** A Mars rover (appears to be Curiosity or Perseverance), which is examining a turtle<br />
** A small rover (appears to be Sojourner)<br />
* The JWST (James Webb Space Telescope)<br />
* The ISS transiting the sun<br />
* A winged figure (likely Icarus) transiting the sun<br />
* Saturn<br />
* A moon of Saturn, with both Cueball and a tiny turtle<br />
* A constellation in the shape of a turtle<br />
* A constellation in the shape of a kite (or a tetrahedron)<br />
* A constellation that appears to be the little dipper (Ursa Minor) stacked inside the big dipper (Ursa Major), resembling a [[:wikipedia:lemon squeezer|lemon squeezer]], next to an object that appears to be half a lemon.<br />
* Cueball playing tennis with incoming meteors<br />
* A rocket<br />
* Birds<br />
<br />
On top of the tree: <br />
* Cueball listening to a radio<br />
* Ponytail holding a balloon<br />
* Megan looking over the edge<br />
* A turtle who may have walked a path in the shape of the letters "T" and "Y"<br />
* A squirrel<br />
* A rabbit<br />
* Two happy little trees<br />
* Mountains in the background, one of which seems to have a gigantic Egg on its top and stairs leading to it, which is likely a reference to the video game {{w|The Legend of Zelda: Link's Awakening}}.<br />
<br />
Under the tree: <br />
* Beret guy looking out of a window in the tree<br />
* Blondie standing at the base of the tree<br />
* Ponytail in a balloon, throwing out an anchor<br />
* A helicopter with a stegosaurus tail (Thagomizer)<br />
* Glass ball ornaments hanging from the tree <br />
<br />
:[The rest just needs to be written out in detail...]<br />
<br />
==Index of facts==<br />
{| class="wikitable"<br />
|Merriam-Webster defines a turtle as a noun.<br />
|https://xkcd.com/2601/radio.mp3#t=569<br />
|-<br />
|Here are some interesting notes from interesting facts about turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=962<br />
|-<br />
|Over a great many years, I have taken a great interest in the land turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=973<br />
|-<br />
|One of the interesting points about turtles is their great variety of foods.<br />
|https://xkcd.com/2601/radio.mp3#t=1415<br />
|-<br />
|in the pen and in five minutes it is surrounded by the turtles,<br />
|https://xkcd.com/2601/radio.mp3#t=1976<br />
|-<br />
|when I found one of the large turtles had caught and disemboweled, the very large toad,<br />
|https://xkcd.com/2601/radio.mp3#t=2648<br />
|-<br />
|I have seen turtles eating at 11:00 at night<br />
|https://xkcd.com/2601/radio.mp3#t=2655<br />
|-<br />
|the youngest of turtles I have ever had seems to take to the same food as the adults<br />
|https://xkcd.com/2601/radio.mp3#t=3506<br />
|-<br />
|I made friends with a turtle yesterday and he gave me his phone number.<br />
|https://xkcd.com/2601/radio.mp3#t=4283<br />
|-<br />
|Running away is slow as compared to this turtle propulsion.<br />
|https://xkcd.com/2601/radio.mp3#t=4522<br />
|-<br />
|Occasionally one can see a turtle dragging another one along<br />
|https://xkcd.com/2601/radio.mp3#t=5370<br />
|-<br />
|I have never known a land turtle to bite<br />
|https://xkcd.com/2601/radio.mp3#t=5382<br />
|-<br />
|Some people have turtles in their cellars believing that they catch rats and mice.<br />
|https://xkcd.com/2601/radio.mp3#t=5853<br />
|-<br />
|I believe that these turtles died because they were exhausted<br />
|https://xkcd.com/2601/radio.mp3#t=5879<br />
|-<br />
|and mice might be kept away by the noise made by the turtle making its endless<br />
|https://xkcd.com/2601/radio.mp3#t=6151<br />
|-<br />
|But doubt whether a turtle could catch a rat or a mouse<br />
|https://xkcd.com/2601/radio.mp3#t=6158<br />
|-<br />
|In this, the turtles would enjoy themselves<br />
|https://xkcd.com/2601/radio.mp3#t=6437<br />
|-<br />
|How about some interesting things in 10 facts about marine turtles from the WWF UK.<br />
|https://xkcd.com/2601/radio.mp3#t=6622<br />
|-<br />
|There are seven species of marine turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=6628<br />
|-<br />
|Marine turtles were around more than 100<br />
|https://xkcd.com/2601/radio.mp3#t=6632<br />
|-<br />
|These days, scientists recognize seven species of marine turtle,<br />
|https://xkcd.com/2601/radio.mp3#t=6638<br />
|-<br />
|turtles do not have teeth.<br />
|https://xkcd.com/2601/radio.mp3#t=6890<br />
|-<br />
|Turtle shells are made of over 50 bones fused together.<br />
|https://xkcd.com/2601/radio.mp3#t=7064<br />
|-<br />
|The first few years of a marine turtle's life are known as the lost years.<br />
|https://xkcd.com/2601/radio.mp3#t=7352<br />
|-<br />
|Marine turtle species vary greatly in size.<br />
|https://xkcd.com/2601/radio.mp3#t=7654<br />
|-<br />
|Wales holds the world record for the largest marine turtle ever found<br />
|https://xkcd.com/2601/radio.mp3#t=7675<br />
|-<br />
|1000 marine turtle hatchlings make it to adulthood.<br />
|https://xkcd.com/2601/radio.mp3#t=8216<br />
|-<br />
|turtles seem to prefer red, orange, and yellow food.<br />
|https://xkcd.com/2601/radio.mp3#t=10106<br />
|-<br />
|I'm beginning to suspect it's turtles all the way down<br />
|https://xkcd.com/2601/radio.mp3#t=10403<br />
|-<br />
|marine turtles can migrate incredibly long distances.<br />
|https://xkcd.com/2601/radio.mp3#t=10623<br />
|-<br />
|Marine turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=11365<br />
|-<br />
|move the turtle<br />
|https://xkcd.com/2601/radio.mp3#t=11788<br />
|-<br />
|Here are some more interesting bits from interesting facts about turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=11913<br />
|-<br />
|several occasions with the turtle still in c.<br />
|https://xkcd.com/2601/radio.mp3#t=12612<br />
|-<br />
|there is an artist in the bottom of everybody<br />
|https://xkcd.com/2601/radio.mp3#t=12934<br />
|-<br />
|The number laid by a turtle varies<br />
|https://xkcd.com/2601/radio.mp3#t=15403<br />
|-<br />
|I have also observed one turtle laying its eggs<br />
|https://xkcd.com/2601/radio.mp3#t=15411<br />
|-<br />
|I had the pleasure of seeing six little baby turtles come out<br />
|https://xkcd.com/2601/radio.mp3#t=16167<br />
|-<br />
|The turtle commenced to dig at six p.m.<br />
|https://xkcd.com/2601/radio.mp3#t=16753<br />
|-<br />
|Five days later a second turtle dug these eggs out arid,<br />
|https://xkcd.com/2601/radio.mp3#t=16760<br />
|-<br />
|personally. I do not believe that the turtle digging out.<br />
|https://xkcd.com/2601/radio.mp3#t=16768<br />
|-<br />
|turtles a year factoid. Actually just statistical error,<br />
|https://xkcd.com/2601/radio.mp3#t=16972<br />
|-<br />
|average person paints zero turtles per year<br />
|https://xkcd.com/2601/radio.mp3#t=16976<br />
|-<br />
|turtles. Georg who lives in cave and eats over 10,000 each day<br />
|https://xkcd.com/2601/radio.mp3#t=16980<br />
|-<br />
|The young turtles when they make their emergence at the end of three months,<br />
|https://xkcd.com/2601/radio.mp3#t=17234<br />
|-<br />
|Do you know what A sea turtle's favorite sandwiches?<br />
|https://xkcd.com/2601/radio.mp3#t=17526<br />
|-<br />
|Just ask the next sea turtle you meet.<br />
|https://xkcd.com/2601/radio.mp3#t=17536<br />
|-<br />
|Here are some interesting observations from odd facts about turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=17639<br />
|-<br />
|It has been said that the turtle,<br />
|https://xkcd.com/2601/radio.mp3#t=17647<br />
|-<br />
|In many ways. The turtle is one or the strangest of living things,<br />
|https://xkcd.com/2601/radio.mp3#t=17943<br />
|-<br />
|But the turtle in all his varieties in all his ways is a most mysterious animal.<br />
|https://xkcd.com/2601/radio.mp3#t=17961<br />
|-<br />
|Your turtle is neither fish, flesh nor fowl.<br />
|https://xkcd.com/2601/radio.mp3#t=17979<br />
|-<br />
|a little turtle<br />
|https://xkcd.com/2601/radio.mp3#t=18667<br />
|-<br />
|there is none so tenacious of life as the turtle<br />
|https://xkcd.com/2601/radio.mp3#t=18986<br />
|-<br />
|Leave the turtle apparently undisturbed<br />
|https://xkcd.com/2601/radio.mp3#t=18992<br />
|-<br />
|Just as soon as a baby turtle emerges from the egg off he scuttles down to the sea.<br />
|https://xkcd.com/2601/radio.mp3#t=19273<br />
|-<br />
|The young turtle feeds unmolested while his armor undergoes the hardening process<br />
|https://xkcd.com/2601/radio.mp3#t=19306<br />
|-<br />
|whatever the young sea turtle eats and wherever he eats it<br />
|https://xkcd.com/2601/radio.mp3#t=19628<br />
|-<br />
|the turtle is free from all danger<br />
|https://xkcd.com/2601/radio.mp3#t=19915<br />
|-<br />
|interferes with the turtle<br />
|https://xkcd.com/2601/radio.mp3#t=19924<br />
|-<br />
|Cool facts about turtles from Deutsche Welle.<br />
|https://xkcd.com/2601/radio.mp3#t=20499<br />
|-<br />
|There is a reason why turtles look a little prehistoric.<br />
|https://xkcd.com/2601/radio.mp3#t=20506<br />
|-<br />
|Luckily for the turtles, they're burrowing and water-dwelling habits.<br />
|https://xkcd.com/2601/radio.mp3#t=20527<br />
|-<br />
|While a turtle's lifespan largely depends on the species,<br />
|https://xkcd.com/2601/radio.mp3#t=20926<br />
|-<br />
|A typical pet turtle can make it to anywhere between 10 and 80 years.<br />
|https://xkcd.com/2601/radio.mp3#t=20935<br />
|-<br />
|Researchers think some turtles could even be hundreds of years old.<br />
|https://xkcd.com/2601/radio.mp3#t=20949<br />
|-<br />
|There are currently 356 known species of turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=21629<br />
|-<br />
|There are sea turtles, leatherback turtles, snapping turtles,<br />
|https://xkcd.com/2601/radio.mp3#t=21642<br />
|-<br />
|pond turtles, soft-shelled turtles, and of course tortoises,<br />
|https://xkcd.com/2601/radio.mp3#t=21646<br />
|-<br />
|Not all turtles or tortoises<br />
|https://xkcd.com/2601/radio.mp3#t=22175<br />
|-<br />
|but all tortoises or turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=22177<br />
|-<br />
|technically all tortoises are in fact turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=22181<br />
|-<br />
|But the main difference between turtles and<br />
|https://xkcd.com/2601/radio.mp3#t=22192<br />
|-<br />
|while most turtles live in or near water<br />
|https://xkcd.com/2601/radio.mp3#t=22198<br />
|-<br />
|Some turtles are vegetarians<br />
|https://xkcd.com/2601/radio.mp3#t=22405<br />
|-<br />
|Most turtles are actually omnivores but a few species<br />
|https://xkcd.com/2601/radio.mp3#t=22409<br />
|-<br />
|Not to the fearsome-looking alligator turtle<br />
|https://xkcd.com/2601/radio.mp3#t=22421<br />
|-<br />
|Even water-dwelling turtles will dig their nests<br />
|https://xkcd.com/2601/radio.mp3#t=22805<br />
|-<br />
|No species of turtle sticks around to raise their young.<br />
|https://xkcd.com/2601/radio.mp3#t=22814<br />
|-<br />
|A turtle's gender is determined by temperature<br />
|https://xkcd.com/2601/radio.mp3#t=23005<br />
|-<br />
|A turtle's gender is determined after fertilization.<br />
|https://xkcd.com/2601/radio.mp3#t=23010<br />
|-<br />
|If the turtles eggs incubate below 27.7 degrees Celsius,<br />
|https://xkcd.com/2601/radio.mp3#t=23015<br />
|-<br />
|turtles tend to give birth to more females<br />
|https://xkcd.com/2601/radio.mp3#t=23037<br />
|-<br />
|Sea turtles are known for their amazing ability to return<br />
|https://xkcd.com/2601/radio.mp3#t=23182<br />
|-<br />
|turtles can navigate their way at sea by<br />
|https://xkcd.com/2601/radio.mp3#t=23190<br />
|-<br />
|turtles have strong underwater eyesight.<br />
|https://xkcd.com/2601/radio.mp3#t=23618<br />
|-<br />
|Although sea turtles are famous for their internal GPS<br />
|https://xkcd.com/2601/radio.mp3#t=23629<br />
|-<br />
|Six out of seven turtle species are classified as<br />
|https://xkcd.com/2601/radio.mp3#t=23919<br />
|-<br />
|How about some interesting facts from turtle facts by Alina Bradford.<br />
|https://xkcd.com/2601/radio.mp3#t=24214<br />
|-<br />
|turtles are reptiles with hard shells that protect them from predators.<br />
|https://xkcd.com/2601/radio.mp3#t=24221<br />
|-<br />
|Turtles live all over the world in almost every type of climate<br />
|https://xkcd.com/2601/radio.mp3#t=24233<br />
|-<br />
|the turtle order<br />
|https://xkcd.com/2601/radio.mp3#t=24479<br />
|-<br />
|turtle,<br />
|https://xkcd.com/2601/radio.mp3#t=24874<br />
|-<br />
|turtles spend most of their lives in water.<br />
|https://xkcd.com/2601/radio.mp3#t=25251<br />
|-<br />
|Sea turtles rarely leave the ocean except to lay eggs in the sand.<br />
|https://xkcd.com/2601/radio.mp3#t=25260<br />
|-<br />
|Freshwater turtles live in ponds and lakes<br />
|https://xkcd.com/2601/radio.mp3#t=25266<br />
|-<br />
|With so many different types of turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=25760<br />
|-<br />
|The largest sea turtle species is the leatherback turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=25765<br />
|-<br />
|The largest freshwater turtle in North America is the alligator snapping turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=25788<br />
|-<br />
|The Yangtze giant softshell turtle is the largest softshell turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=25799<br />
|-<br />
|A turtle's shell is a modified rib cage and part of its vertebral column<br />
|https://xkcd.com/2601/radio.mp3#t=26177<br />
|-<br />
|All the thoughts of a turtle are turtles and of a rabbit rabbits.<br />
|https://xkcd.com/2601/radio.mp3#t=26401<br />
|-<br />
|So let's try to think like a turtle<br />
|https://xkcd.com/2601/radio.mp3#t=26406<br />
|-<br />
|Many turtles are able to retract their heads and feet into their shells,<br />
|https://xkcd.com/2601/radio.mp3#t=26450<br />
|-<br />
|turtles are placed in the two sub-orders based on the method of retraction.<br />
|https://xkcd.com/2601/radio.mp3#t=26455<br />
|-<br />
|Sea turtles have lost the ability to retract their heads<br />
|https://xkcd.com/2601/radio.mp3#t=26472<br />
|-<br />
|turtles are very adaptive and can be found on every continent except Antarctica.<br />
|https://xkcd.com/2601/radio.mp3#t=26676<br />
|-<br />
|Most turtle species are found in southeastern North America and South Asia.<br />
|https://xkcd.com/2601/radio.mp3#t=26681<br />
|-<br />
|sea turtles can be found in the coral triangle.<br />
|https://xkcd.com/2601/radio.mp3#t=26844<br />
|-<br />
|what do you get if you cross a turtle with a giraffe,<br />
|https://xkcd.com/2601/radio.mp3#t=26976<br />
|-<br />
|a turtleneck<br />
|https://xkcd.com/2601/radio.mp3#t=26981<br />
|-<br />
|The African helmeted turtle is the most common turtle in Africa,<br />
|https://xkcd.com/2601/radio.mp3#t=27157<br />
|-<br />
|roti island. Snake-necked turtles are found only on Rhode island.<br />
|https://xkcd.com/2601/radio.mp3#t=27221<br />
|-<br />
|turtles are not social creatures<br />
|https://xkcd.com/2601/radio.mp3#t=27393<br />
|-<br />
|while they typically don't mind if there are other turtles around them,<br />
|https://xkcd.com/2601/radio.mp3#t=27396<br />
|-<br />
|Most turtles are active during the day,<br />
|https://xkcd.com/2601/radio.mp3#t=27405<br />
|-<br />
|turtles are not silent creatures.<br />
|https://xkcd.com/2601/radio.mp3#t=27537<br />
|-<br />
|Most turtles are omnivores.<br />
|https://xkcd.com/2601/radio.mp3#t=27961<br />
|-<br />
|musk turtles eat mollusks,<br />
|https://xkcd.com/2601/radio.mp3#t=27968<br />
|-<br />
|The cooter turtle is mostly vegetarian<br />
|https://xkcd.com/2601/radio.mp3#t=27973<br />
|-<br />
|and the green sea turtle only eats grasses and algae.<br />
|https://xkcd.com/2601/radio.mp3#t=27976<br />
|-<br />
|The alligator snapping turtle lures in fish with its tongue<br />
|https://xkcd.com/2601/radio.mp3#t=28293<br />
|-<br />
|crayfish and other turtles.<br />
|https://xkcd.com/2601/radio.mp3#t=28313<br />
|-<br />
|All turtles lay eggs.<br />
|https://xkcd.com/2601/radio.mp3#t=28483<br />
|-<br />
|No species of turtle nurtures their young<br />
|https://xkcd.com/2601/radio.mp3#t=28493<br />
|-<br />
|turtles reach the age to mate at different times.<br />
|https://xkcd.com/2601/radio.mp3#t=28762<br />
|-<br />
|Male and female turtles intertwined their tails so<br />
|https://xkcd.com/2601/radio.mp3#t=29117<br />
|-<br />
|sea turtles travel from the ocean to lay eggs on beaches.<br />
|https://xkcd.com/2601/radio.mp3#t=29387<br />
|-<br />
|sea turtles lay around 110 eggs in a nest<br />
|https://xkcd.com/2601/radio.mp3#t=29392<br />
|-<br />
|Though the flatback turtle only lays 50 at a time<br />
|https://xkcd.com/2601/radio.mp3#t=29396<br />
|-<br />
|the temperature of the sand affects the sex of the turtle.<br />
|https://xkcd.com/2601/radio.mp3#t=29661<br />
|-<br />
|Too many sea turtle females are being born<br />
|https://xkcd.com/2601/radio.mp3#t=29673<br />
|-<br />
|according to the sea turtle. Conservancy<br />
|https://xkcd.com/2601/radio.mp3#t=29679<br />
|-<br />
|Many turtle species are listed as threatened,<br />
|https://xkcd.com/2601/radio.mp3#t=29984<br />
|-<br />
|I even talked to turtles at times<br />
|https://xkcd.com/2601/radio.mp3#t=32815<br />
|}<br />
===Sources===<br />
* Merriam-Webster, "Turtle" https://www.merriam-webster.com/dictionary/turtle <br />
* Forest And Stream, January 1916, p. 764: "Interesting Facts About Turtles"—"A Little Nature Study by a Scientist that will Interest Old and Young Naturalists Alike"—"By Randle C. Rosenberger M.D., Professor of Hygiene and Bacteriology, Jefferson Medical College, Philadelphia, Pa." https://www.biodiversitylibrary.org/item/281932#page/8/mode/1up <br />
* "Top 10 Facts About Marine Turtles", https://www.wwf.org.uk/learn/fascinating-facts/marine-turtles <br />
* "Odd facts about turtles", Christian observer, May 11th, 1919 <br />
* "World Turtle Day: 10 cool facts about turtles" from Deutsche Welle, 22 May 2020, by Ineke Mules https://www.dw.com/en/turtles-tortoises-difference-facts/g-53260454<br />
* "Turtle Facts" by Alina Bradford, published October 02, 2015, https://www.livescience.com/52361-turtle-facts.html<br />
<br />
<br />
{{comic discussion}}<br />
<br />
[[Category:April fools' comics]]<br />
[[Category:Interactive comics]]<br />
[[Category:Dynamic comics]]<br />
[[Category:Comics with animation]] <!-- the mute button fading in --><br />
[[Category:Comics with color]] <!-- pushing the radio button --><br />
[[Category:Comics with audio]]<br />
[[Category:Animals]]</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=File:xkcd_2601_finished_comic_animation.gif&diff=229776File:xkcd 2601 finished comic animation.gif2022-04-05T22:09:03Z<p>162.158.203.38: The code is not compiling (or being compiled), it is running (or being executed).</p>
<hr />
<div>== Summary ==<br />
The animation of the code read out in xkcd 2601 running in LOGO.<br />
<br />
== Licensing ==<br />
{{XKCD file derived}}</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=2552:_The_Last_Molecule&diff=2222712552: The Last Molecule2021-12-09T06:54:31Z<p>162.158.203.38: Undo revision 222270 by 172.70.210.3 (talk)</p>
<hr />
<div>{{comic<br />
| number = 2552<br />
| date = December 8, 2021<br />
| title = The Last Molecule<br />
| image = the_last_molecule.png<br />
| titletext = Biology is really struggling; they're barely at 93% and they keep finding more ants.<br />
}}<br />
<br />
==Explanation==<br />
{{incomplete|Created by a FRUSTRATED BIOLOGIST - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br />
<br />
There are an infinite number of ways to arrange atoms into molecules, and chemistry is the study of the interaction of subatomic particles, atoms, and molecules, not simply the cataloging of all specimens of molecule.<br />
<br />
This is reminiscent of biology's focus on previous centuries on simply cataloging the species on Earth.<br />
<br />
Further, the goal of science is not to "complete" a field, but to understand it better and better. No scientific field, with the possible exception of optics, is considered fully understood.<br />
<br />
Putting Biology at 93% and Physics at 98% is patently absurd. As mentioned in the comic, we don't even know how many kinds of ants there are yet. When J.B.S Haldane, founder of the field of population genetics, was asked what could be inferred about the creator from the creation, he reportedly said, "He has an inordinate fondness for beetles". Insects aside, fundamental and important problems such as what genes promote which traits, the nature of cognition, and the mechanism behind several diseases remain complete mysteries. We know less about our own ocean floor than we do about the surface of Mars. Needless to say, Biology is nowhere close to 93% solved. As for Physics, questions such as "what the actual hell is dark matter?" and "how do we unify the four fundamental forces?" and "how do we make nuclear fusion possible on earth?" and "how fast does light travel in one direction?" make it clear that the field still has a long, long way to go.<br />
<br />
==Transcript==<br />
{{incomplete transcript|Do NOT delete this tag too soon.}}<br />
<br />
[Ponytail is presenting on a stage. To the top-center of the slide displays "Chemistry" at a circled "100% complete", then to the left is "Biology" at "93% complete" and to the right is "Physics" at "98% complete". The bottom of the slide shows the [[Wikipedia:structural formula|structural formula]] of a molecule captioned "The last one", along with a few smaller captions around it drawn as squiggles.]<br />
<br />
Ponytail:<br />
<br />
:With the discovery of the last molecule, I'm pleased to announce that chemistry is finally complete.<br />
<br />
:Best of luck to our competitors in their race for second place.<br />
<br />
{{comic discussion}}</div>162.158.203.38https://www.explainxkcd.com/wiki/index.php?title=193:_The_Perfect_Sound&diff=218062193: The Perfect Sound2021-09-15T16:48:14Z<p>162.158.203.38: Fix Wikipedia link</p>
<hr />
<div>{{comic<br />
| number = 193<br />
| date = December 6, 2006<br />
| title = The Perfect Sound<br />
| image = the_perfect_sound.png<br />
| titletext = Oh, what a pity, can't you understand...<br />
}}<br />
<br />
==Explanation==<br />
This comic relates to the song "{{w|Mickey_(Toni_Basil_song)|Mickey}}", performed in 1982 by one-hit-wonder {{w|Toni Basil}}. The lyrics, as well as the instrumentation of the song, were in fact rather simple, being a perfect example of {{w|Bubblegum pop|bubblegum pop}} in the early 1980s.<br />
<br />
In the comic, however, the song is introduced as a musical masterpiece. [[Cueball]] points out the opening sequence to his friend and states that it should be considered art. When the chorus sets in and the song unfolds its lyrical brilliancy, his friend has no other comment to make except that there must be something wrong with Cueball.<br />
<br />
Cueball's actions might be seen as a critical approach towards over-interpreting music. The comic's title, as well as the stereo setup depicted, could perhaps also denote a sidesweep on {{w|audiophiles}}.<br />
<br />
The title text parodies a line from the song and links it with the incomprehension of Cueball's friend.<br />
<br />
==Transcript==<br />
:[Cueball and his friend are listening to music on a stereo.]<br />
:Cueball: I'm telling you, listen right here to the sets of rising notes following the opening section.<br />
:Friend: Uh huh.<br />
:[Cueball indicates stereo.]<br />
:Cueball: And then right here, the transition into the chorus. <u>This</u> is music. This is <u>art</u>!<br />
:[Cueball dances along with the music.]<br />
:Stereo: Oh Mickey, you so fine, you so fine you blow my mind, hey Mickey! *clap* *clap* Hey Mickey!<br />
:Friend: There's something wrong with you.<br />
<br />
{{comic discussion}}<br />
[[Category:Comics featuring Cueball]]<br />
[[Category:Music]]</div>162.158.203.38