explain xkcd - User contributions [en]

2675: Pilot Priority List

2022-10-25T11:08:17Z

172.70.86.48: /* Explanation */ Maybe a better example can be found (e.g. flight-surface loss, midflight), but link was to a UFIT incident. Removing the link removes its explanatory power.

{{comic
| number = 2675
| date = September 21, 2022
| title = Pilot Priority List
| image = pilot_priority_list_2x.png
| imagesize = 369x548px
| noexpand = true
| titletext = CELEBRATE: Serve passengers tiered cakes shaped like the airspace class diagram
}}

==Explanation==

The [https://elevate-aviation.com/blog/pilots-priority-checklist "ANC" Pilot Priority Checklist] is a list of three guidelines, sorted by priority, that pilots should follow to prevent them from being distracted. Failing to follow it might make the aircraft crash or suffer other problems. As a {{w|mnemonic}} device, all the activities end in ''-ate''.

# '''Aviate''' means keeping the aircraft in control. If the pilot fails to do this the aircraft might crash, so this should be the highest priority for the pilot.
# '''Navigate''' means knowing where you are and where you're going. Failing to follow this might make the aircraft go into restricted airspace, for example, make the journey take too long, or cause the flight to crash into terrain obscured by clouds.
# '''Communicate''' means talking with air traffic control (ATC) and your company's people through the radio. In the standard list, this is the lowest priority because talking through the radio might distract the pilot from other more important tasks.

By deferring less important activities until the prior need is deemed satisfied, the immediate dangers of flight into terrain ({{w|United Airlines Flight 173|uncontrolled}} and {{w|controlled flight into terrain}}) are reduced — as the pilot's {{w|Loss of control (aeronautics)|current circumstances}} allow — and yet can provide for addressing {{w|Separation (aeronautics)|other hazards}}.

[[Randall]] humorously "extends" this standard list with other ''-ate'' checklist items that pilots could do if they're not too busy aviating, navigating and communicating. These extra tasks range from somewhat hilarious to physically impossible or dangerous; see the [[#Table of extended priority items|table]] below for explanations. These actions {{w|Sterile flight deck rule|should generally not be taken}}, as they could distract the pilot and prevent them from reaching the cabin in case of an emergency, or vaporize everyone inside along with portions of the airframe.

[[File:Airspace classes (United States).png|thumb|Airspace classes in the United States]]

The title text adds another ''-ate'' item to the checklist: Celebrate, whereupon congratulatory cakes are served to the passengers. The "inverted tiers" refers to the {{w|Airspace_class_(United_States)|airspace class}} diagram used in the United States, used by planes circling over airports. The class diagram starts with a small circle over the airport and then becomes wider in one or two steps at higher altitudes. When depicted graphically, this looks like an {{w|File:Airspace classes (United States).png|inverted tiered cake}}, as opposed to a [https://3brothersbakery.com/product/wedding-white-chandelier-tier/ regular tiered cake]. Randall suggests that after having congratulated yourself for flying an aircraft, you could then celebrate by serving the passengers cakes in this inverted shape. It would, however, be unsuitable for an aircraft to serve cakes that are smaller at the bottom than at the top because of turbulence.

{{clear}}

===Table of extended priority items===
{| class="wikitable"
! Checklist item
! Description
! Explanation
|-
| Decorate || Make the cockpit fancy || {{w|Interior design}} of aircraft cockpits is usually starkly utilitarian and could conceivably benefit from enhancements if they aren't distracting. See for example [https://futurism.com/boeings-spaceship-cockpit-looks-strikingly-different-spacexs this comparison of SpaceX and Boeing space capsule cockpits.]
|-
| Accelerate || See how fast you can go || While pilots are often keenly interested in the extents of their aircraft flight capabilities, maximum speed is inefficient in jet aircraft, and probably best explored during testing rather than passenger flights. Exceeding VNE might even destroy an airplane, see [https://www.australianflying.com.au/news/vne-and-flutter-explained]
|-
| Roller skate || Zoom down the aisle || Passengers would probably not appreciate this,{{cn}} although fellow crew members might be amused. Or possibly vice versa.
|-
| Exfoliate || Scrub away dead skin || {{w|Emery board}}s and {{w|pumice}} are used to prevent flaking and the development of {{w|callus}}es but dermatologists caution exfoliation is very often unnecessary and can have unwanted consequences. {{w|Volcanic_ash_and_aviation_safety|Volcanic ash has an exfoliating but unwelcome effect on aeroplanes}}.
|-
| Sublimate || Turn directly into a vapor || To the contrary, one of the most important duties of aircraft pilots is to prevent passengers and crew from vaporizing because the ANC checklist is impossible to perform in gaseous form. But it's fine for anyone to {{w|Perspiration|perspirate}} for {{w|Evaporative_cooler#Physical_principles|evaporative cooling}}.
|-
| Pollinate || Fly low to stir up pollen || Low-flying helicopters can assist in plant {{w|pollination}},[https://www.sciencedirect.com/science/article/abs/pii/S037842901931175X] and are offered as a [http://www.flyingmair.com/ag-services/corn-pollination/ commercial service by helicopter pilots.] It is unlikely that airliners flying at much higher altitudes would be able to do the same, however.
|-
| Congratulate || You're doing a good job flying a plane! || This item suggests that the pilot should praise themself for "doing a good job flying a plane", when ironically, if they did all of the above items, they would not be doing a good job of this.
|-
| Celebrate (title text) || Serve passengers tiered cakes shaped like the airspace class diagram || See discussion of the title text above.
|}

==Transcript==
:[A list with ten numbered points are shown. Above the list is a large header. Below this is a divided line with a section header written in a smaller than standard font. The three first numbered points are below this. Then follows another divided line with section header written in smaller font and below this the next seven numbered points. All ten points have two lines of text. A line with a normal sized font and below each of these a description in a smaller light gray font.]
::<big>Pilot Priority List</big>
:-----------Standard section-----------
:1. Aviate
::Maintain control of the aircraft
:2. Navigate
::Figure out where you're going
:3. Communicate
::Stay in touch with ATC and others
:-----------Extended section-----------
:4. Decorate
::Make the cockpit fancy
:5. Accelerate
::See how fast you can go
:6. Roller skate
::Zoom down the aisle
:7. Exfoliate
::Scrub away dead skin
:8. Sublimate
::Turn directly to a vapor
:9. Pollinate
::Fly low to stir up pollen
:10. Congratulate
::You're doing a good job flying a plane!

{{comic discussion}}

[[Category:Aviation]]
[[Category:Food]]

Talk:2687: Division Notation

2022-10-24T08:27:09Z

172.70.86.48:

Fun fact: In Poland, we don't write the long division like that; we just write A:B with the bar above. I was VERY confused the first time I saw that notation. [[Special:Contributions/172.70.246.235|172.70.246.235]] 21:03, 19 October 2022 (UTC)
:Unrelated to {{w|Polish notation}}, i presume? [[Special:Contributions/172.70.134.13|172.70.134.13]] 22:43, 19 October 2022 (UTC)Bumpf
::Unrelated. Never used Polish notation in school. [[Special:Contributions/172.71.160.23|172.71.160.23]] 10:25, 20 October 2022 (UTC)
:In German elementary school we learned the a:b notation. When we learned more complex divisions in secondary school it was with the "scientist" notation. And as I am a software engineer AND (presumably) a normal person I use in general the respective notations. [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 07:24, 20 October 2022 (UTC)

For me, the version on the xkcd website has an additional line ("A/B: Software Engineer") that's not on this site. I think the comic might have been updated. Is anyone else seeing that? [[User:JBYoshi|JBYoshi]] ([[User talk:JBYoshi|talk]]) 23:20, 19 October 2022 (UTC)
:Updated. [[User:Natg19|Natg19]] ([[User talk:Natg19|talk]]) 00:31, 20 October 2022 (UTC)

For the Unicode one, I think it’s a reference to ⁄ (U+2044, fraction slash) or characters like ½, ¼, etc. - [[User:Cherryblossom|Cherryblossom]] ([[User talk:Cherryblossom|talk]]) 00:24, 20 October 2022 (UTC)

Is it important to note that 1/2 auctocorrects to ½ in many text-based programs like Microsoft Word?--[[User:Theunlucky|Theunlucky]] ([[User talk:Theunlucky|talk]]) 02:32, 20 October 2022 (UTC)

It's possible to use fraction-style notation in LaTeX by using \frac, or am I missing something?--[[Special:Contributions/162.158.2.125|162.158.2.125]] 05:49, 20 October 2022 (UTC)

"the long division symbol is only used in some countries". Only English-speaking ones, to be more precise. Most of the countries of the world use a different notation. [[Special:Contributions/172.68.51.80|172.68.51.80]] 06:19, 20 October 2022 (UTC)

In the UK, the 'long division symbol' is nowadays often referred to (particularly with Primary classes, children aged 4 - 11) as the "Bus Stop Method". Because it looks like a UK bus shelter. [[User:MarquisOfCarrabass|MarquisOfCarrabass]] ([[User talk:MarquisOfCarrabass|talk]]) 07:07, 20 October 2022 (UTC)
: I always used (still use, on the rare occasions that I do it) the notation inverted - B)_A - so that the answer is output beneath the problem, which makes more sense to me, given that we generally read down the page. I guess that would be a vandalised bus stop?[[Special:Contributions/172.70.162.147|172.70.162.147]] 09:16, 20 October 2022 (UTC)
:: When doing long-division, the intermediary sums (the calculated 'integer remainders' subtractions of progressively high-to-low powers of ten) would be done below in the 'standard' long-multiplication/addig/subtraction direction. The answer-figure is progressively created by the 'carry'-inverse to these more normal-looking arithmatic. Or so I surmise. Haven't used long-division, much, in 40 years or so (except in a polynomial-factoring thing, occasionally, using an extended version of the principle upon powers-of-whatever) so I might have the wrong-idea as to why the answer goes high (in that the non-answer that nevertheless leads to the answer goes low). ;) [[Special:Contributions/162.158.159.29|162.158.159.29]] 16:17, 20 October 2022 (UTC)
:::For me, the remainders go in small figures above the next integer, so that they basically form a new number to divide.[[Special:Contributions/172.70.86.48|172.70.86.48]] 08:27, 24 October 2022 (UTC)

As a Dutch primary schoolchild, I have used a÷b for calculations and "a over b" for fractions (e.g. ⅘).
For more difficult divisions, like what is 785/35, we used [https://nl.m.wikipedia.org/wiki/Staartdeling Staartdelingen] (nl), long division, of which the primary notation is 35/735\.
I think in early highschool we started using a over b for more complex calculations, "like (x+3) over 5 = 2, what is x". I had up to this XKCD never seen B⟌A, and would confuse it for what we use as square root symbol (√). [[User:IIVQ|IIVQ]] ([[User talk:IIVQ|talk]]) 07:16, 20 October 2022 (UTC)
:Come to think of it, it's kind of odd that we used ":" for division. Why are there this many different division notations anyway? Same for multiplication. There's x, *, ⋅, x but centered vertically, and concatenation (for letter variables)!
:: The : operator is for ratios, where a:b could be a/b or b/a, but also metaphors, where a:b::c:d means a is to b as c is to d. [[Special:Contributions/162.158.166.73|162.158.166.73]] 09:05, 20 October 2022 (UTC)

In Austria, school children are using the "scientist" notation from this comic. [[Special:Contributions/172.68.50.51|172.68.50.51]] 08:17, 20 October 2022 (UTC)
: Same thing in Russia [[Special:Contributions/172.71.98.97|172.71.98.97]] 08:46, 20 October 2022 (UTC)

I live in Denmark, and “÷” seems to be often used here for subtraction, instead of a minus sign! Got confused a few times. [[User:Nclm|nicolas]] ([[User talk:Nclm|talk]]) 08:52, 20 October 2022 (UTC)
:Also from DK and have often seen ÷ used as % and on my keyboard as I type this there is a ÷ on the number part of the keyboard to the right. But when I push it I get this: "/" In school we used this A:B to mean A/B, just as in Poland as mentioned above. Today I would write 10/2 not 10:2 or 10÷2. But I never used the last version. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:08, 23 October 2022 (UTC)

; tableau
: tab·leau /ˌtaˈblō/ noun
::a group of models or motionless figures representing a scene from a story or from history; a tableau vivant. "in the first act the action is presented in a series of tableaux"
I don't think it means what the editor including it thinks it means. [[Special:Contributions/172.69.22.185|172.69.22.185]] 09:02, 20 October 2022 (UTC)

: "A graphic description or representation" - https://www.merriam-webster.com/dictionary/tableau
: It derives from the idea of 'things set out on a table'. The arrangement of cards in a solitaire game is also called a tableau. [[Special:Contributions/172.70.162.147|172.70.162.147]] 09:24, 20 October 2022 (UTC)
:: changed to radices. [[Special:Contributions/172.70.206.93|172.70.206.93]] 10:18, 20 October 2022 (UTC)
:::Well that's not right, is it? - [https://www.merriam-webster.com/dictionary/radish "the pungent usually crisp root of a widely cultivated Eurasian plant (Raphanus sativus) of the mustard family usually eaten raw"]... [[Special:Contributions/172.71.178.13|172.71.178.13]] 13:22, 20 October 2022 (UTC)
::::Naw... A radish is "like, almost 'rad', man, but not quite!", while "radices" are totally cool freezer-food!

The discussion of matrices and commutative rings is off topic. The comic is clearly about scalars alone. Please! [[Special:Contributions/172.69.134.17|172.69.134.17]] 20:46, 20 October 2022 (UTC)
: I thought it seemed on topic given the joke and demographic, but I think it could be presented better. [[Special:Contributions/172.70.110.231|172.70.110.231]] 02:07, 21 October 2022 (UTC)

2687: Division Notation

2022-10-20T17:00:42Z

172.70.86.48: /* Explanation */ Need to check.. there's a "comics that have been updated" category... Needs adding 8f not already done.

{{comic
| number = 2687
| date = October 19, 2022
| title = Division Notation
| image = division_notation_new_2x.png
| imagesize = 235x310px
| noexpand = true
| 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!
}}

==Explanation==
{{incomplete|Created by a GROUP OF SCHOOLCHILDREN DIVIDED AMONGST THEMSELVES. Do NOT delete this tag too soon.}}

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]

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.

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 one was [[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 ideosyncratic character set modeled after traditional arithmetic.

The expression on the fourth line, a/b, 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.

The fifth notation is the way division is written in science: the dividend on the top of the expression over the divisor on the bottom under a horizontal line. 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.

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-1 is equal to A/B only if A and B are in a commutative ring (and B has an inverse). If A and B are, for example, matrices, AB-1 is not the same in general as B-1A (and the notation A/B is never used in this case as it would be ambiguous).

The AB-1 format is also often used to express physical units.

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.

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.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:Division notation
:A÷B
:B)Ā Schoolchild.
:A/B Software engineer.
:A⁄B Normal person or Unicode enthusiast.
:A over B Scientist.
:AB-1 Fancy scientist.
:F(A, B) such that F(G)= (text getting smaller) Oh no, run

{{comic discussion}}

[[Category:Math]]
[[Category:Science]]
[[Category:Programming]]
[[Category:Science tip]]

Talk:2684: Road Space Comparison

2022-10-17T10:07:59Z

172.70.86.48:

Hold on, I'm trying to concoct an interesting 30 goats/20 cabbages/10 wolves problem... [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 20:53, 12 October 2022 (UTC)
S3C0ND P0ST [[Special:Contributions/172.71.150.131|172.71.150.131]] 21:12, 12 October 2022 (UTC)

You have no idea how many car-centric infrastructure arguments happen in my discord servers, this is a fantastic comic to post for that[[Special:Contributions/188.114.102.55|188.114.102.55]] 21:23, 12 October 2022 (UTC)

What if the last panel also references other river crossing puzzles like the "Missionaries and cannibals problem" or the Flash "Japanese River Crossing" puzzle so you have extra rules for each member of each species? [[Special:Contributions/172.71.98.97|172.71.98.97]] 22:11, 12 October 2022 (UTC) Alex

My name is GreyFox, and I added the transcript for this page. [[Special:Contributions/172.71.150.171|172.71.150.171]] 22:13, 12 October 2022 (UTC)

So [[1035|the takeway is]]... we can put humans in hamster balls by the handful all season and feel no worse about it than about cars driving down the road? This is awesome! [[Special:Contributions/162.158.2.215|162.158.2.215]] 22:20, 12 October 2022 (UTC)
:No, unfortunately the comic is missleading! Even though it is labelled as 50 hamsterballs the image only shows 39! [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]])
::The comic never said it was one person per hamsterball. There's plenty of space in those for the hamster equivalent of a sidecar. [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 05:30, 13 October 2022 (UTC)
:::But the image shows only one shioulette per hamsterball. I assume this picture is intentionally misleading and Randall was payd by the hamsterball-industry in order to manipulate society towards being pro hamster-ball [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]])
:::::Eleven of the silhouettes could be of people wearing an occupied baby-carrier. The varieties of the silhouettes could allow it without requiring finer detail. [[User:These Are Not The Comments You Are Looking For|These Are Not The Comments You Are Looking For]] ([[User talk:These Are Not The Comments You Are Looking For|talk]]) 02:06, 17 October 2022 (UTC)
::::Regarding the hamster wheels: I think the description is missing a reference to sphere packing. It’s the first thing I thought of when I saw panel 8: how many circles/spheres can you fit/pack into a given space is a famous mathematical problem that I believe Randall has played with before. [[Special:Contributions/75.174.26.242 |75.174.26.242]]13:14UTC, 13 October 2022 (UTC)

Saw this one recently, can't be a coincidence [https://files.fietsersbond.nl/app/uploads/2011/07/18104628/enfb_ruimtegebruik.jpg NL Fietsersbond Ruimtegebruik] [[Special:Contributions/108.162.221.105|108.162.221.105]] 22:25, 12 October 2022 (UTC)

:No, it can not. --[[Special:Contributions/172.71.142.39|172.71.142.39]] 16:13, 13 October 2022 (UTC)

I'm a bit unsure about the linked "52 person tandem" (also, the way it is currently made a bottom-of-page reference link, which we avoid on this site). It took me a while (behind all the popups the referenced link gave me, typically) to realise the only picture of it was the miniscule thumbnail planted at the start. Which explained the anomolous wheel-count, if I understand the low-res image correctly. I would dispute Ripleys'/Guiness's acceptance of that thing as a 'tandem'. It is clearly a multi-stage {{w|Trailer bike|Rann Trailer}}-style construction (possibly with individual tandem-'trailers' in there to get the wheel count down to ''no more'' than the rider-count). Also, how on earth would a linked line of trailers actually start bursting tyres? The load of riders plus frames would spread out about as evenly as for any given single occupant bike (certainly less than the forces on the wheels of a proper tandem/trandem, or even a tandem-trike!), so I'm not sure how they even buckled a wheel. So I'd like to know what the longest two-/three-wheel tandem is (and certainly how anything like Randall's slightly snaking frame does not buckle), if anybody has their finger on that rather more relevent information, rather than that faux-tandem. [[Special:Contributions/172.71.178.137|172.71.178.137]] 03:03, 13 October 2022 (UTC)

Is it just me, or is the last block also a subtle dig at Putin's blown-up Kerch bridge? [[Special:Contributions/172.70.175.146|172.70.175.146]] 12:22, 13 October 2022 (UTC)
:then it would be 50 people with 30 sleeping bags, 20 guns and 10 medikits :) [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]])

Intrinsic problems to the multi-human/goat/cabbage/wolf riddle:

- How many generic objects can you take at once? (If you can take 110+, there is no riddle here)

- How many goats can one person transport at once? (Can you put 30 goats on a boat without pandemonium?)

- How many people are required to corral the goats? (Will the goats all run away when they get to the other side?)

- Are the humans able to catch the goats? And, if the humans *can* catch the goats, does that mean the wolves can, too?

- Is there a way to restrain the wolves?

- Can a wolf be lonely?--[[User:Cwallenpoole|Cwallenpoole]] ([[User talk:Cwallenpoole|talk]]) 13:23, 13 October 2022 (UTC)
:"Can you put 30 goats on a boat without pandemonium?" - nicely done. :o)[[Special:Contributions/172.70.162.147|172.70.162.147]] 13:51, 13 October 2022 (UTC)

: If one person only is needed to "corral" 30 Goats/Wolves/Cabbages, then the problem is moot - the first boat ride just leaves a human on the other side of the water to watch over whatever is brought
[[Special:Contributions/172.70.230.105|172.70.230.105]] 14:20, 13 October 2022 (UTC)

I suppose instead of being critical numbers it has to be done with critical ratios. Gives you a little more wiggle room in the ordering of the trips and optimization but would read basically as the solution to the original but 25 times in a row. [[Special:Contributions/108.162.241.51|108.162.241.51]]

*raises eyebrows at the suggestion that a 50-person tandem is only impractical in a city...*[[Special:Contributions/172.70.162.147|172.70.162.147]] 13:52, 13 October 2022 (UTC)

The multiseater 'bike' drawing is off, for me. A tandem (including trandem, quad, quint, etc) tends to root the stoker's(/subsequent stokers') handlebars directly under the seat of the rider in front of them (steersman/intermediate stokers) in any decent scratch-built frame, not well behind the seated body (and presmably a head/hat of each person, seated upright). It's closer in longitudinal scale to what you get of an overhead view of a [https://www.cyclinguk.org/article/campaigns-guide/guide-tag-longs-trailer-bikes compound bike] with handlebars on or just behind the towing-point (though now it looks a little too close, practically, as there might not be room between the bottom-bracket/down-tube/head-tube to clear the rear wheel of the bike-rear in front of them... if not {{w|Moulton Bicycle|Moulton-sized}} units, which causes other building problems). Which also perhaps accounts for the slightly snaking plan view, being articulated. If well constructed with the right attachment geometries, this could actually travel city streets quite well by ensuring the wheel track of each compound unit follows the path of the weaving wheel(s) ahead of them. Although it'd need practiced riders to prevent lateral oscilations causing rolling forces to drag the whole thing sideways down to hit the ground. But I'll forgive Randall, as he clearly doesn't have enough practical experience with bike/tandem construction. Anyway, as the original '52 seat tandem bicycle' link was not a tandem (nor a bicycle) I looked up what I ''think'' is the correct most-seated tandem (tried checking Guiness Book Of Records website, just in case, but its cookie-authorisation popovers made it impossible to read) and added that as well as caveating the existing presumption of tandemness for the drawing and the already suggested machine. [[Special:Contributions/172.71.178.5|172.71.178.5]] 18:54, 13 October 2022 (UTC)

There used to be a lot of videos on YouTube with rigid human-sized hamster balls, but the only ones I can find are the flexible inflatables now, and all the stunts seem to be with concentric inner compartment inside a shock-absorbed outer core. Wasn't there some horrible injury in the news some years back? [[Special:Contributions/172.69.34.54|172.69.34.54]] 08:30, 14 October 2022 (UTC)

The “one giant pulled by many smalls” thing has been done by Märklin (manufacturer of H0-scale locomotives). 200 H0-scale locomotives pulled one real passenger wagon. Of course, similar stuff has been done by other groups. --[[Special:Contributions/162.158.90.191|162.158.90.191]] 13:51, 14 October 2022 (UTC)

Note that, as the author of [https://www.explainxkcd.com/wiki/index.php?title=2684:_Road_Space_Comparison&diff=prev&oldid=296876 this removed statement], I can absolutely tell that other editor that it was not written as an anti-bicycle statement, but ''as'' a cyclist. Not worth reinstating, but the image given clearly goes against both my own and the [https://www.cyclinguk.org/blog/why-highway-code-should-protect-riding-two-abreast generally] [https://www.britishcycling.org.uk/campaigning/article/20220127-Highway-Code-%E2%80%93-Riding-two-abreast-0 accepted] [https://www.gov.uk/guidance/the-highway-code/rules-for-cyclists-59-to-82 official rules] in my location. It does annoy motorists (and pedestrians; and me, in whatever capacity I am currently journeying) when ill-informed/uncaring/provocative people on bikes flout those rules, and then makes it worse for those who obey the rules (ride abreast, at any given time, because it would never be safer for a motorist to pass a vastly longer single-file group; or simply to ride on the road, as is both our right and responsibility). Not knowing how the rules and regs work outside the UK (but assuming that the practical conventions are similar, where not totally over-regulated out of existence) I had wanted to just say that a 'peleton group' like that is not good practice on the open-road.
 And, obviously, there are exceptional circumstances (if not rules being bent) if we see human-hamsterballs, cars stacked atop other vehicles, stradle-driving and insisting on taking wolves(/etc) through a flooded section of road, which may or may not be 'open' in any real sense, especially to other forms of traffic... But I'm a lot more familiar with the cycling issue, so I added that ''pro-''cycling bit of advice. Not that it will improve matters, or significantly add to understanding, but it made me feel a tiny bit better at the time, and so thanks for reading. [[Special:Contributions/172.70.86.48|172.70.86.48]] 10:07, 17 October 2022 (UTC)

2685: 2045

2022-10-16T09:40:05Z

172.70.86.48: Undo revision 296826 by 172.70.247.34 (talk) rv vandalism

{{comic
| number = 2685
| date = October 14, 2022
| title = 2045
| image = 2045_2x.png
| imagesize = 350x457px
| noexpand = true
| 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."
}}

==Explanation==
{{incomplete|Created by a GIGANTIC NUCLEAR FURNACE (THE SUN) - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

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, 2023.) 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.

Black Hat claims he can't make it, as he vaguely and obscurely claims he already knows 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, 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.

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.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball, a friend also drawn as Cueball, Danish, and Black Hat are standing together. Danish is looking at her phone.]
:Cueball: ...And then after the one in 2024, there's another on August 12, 2045.
:Friend: We're in! We can invite our kids, assuming we have any.
:Danish: I'll create an event. Do you think we'll still be using Google Calendar in 2045?
:Black Hat: Sorry, I'd love to make it, but I have a thing that day.

:Caption: It's weird making plans for eclipses.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Comics featuring Danish]]
[[Category:Comics featuring Black Hat]]

194: Penises

2022-10-16T09:38:31Z

172.70.86.48: /* Transcript */ Given the last edit, this also is now more right than wrong.

{{comic
| number = 194
| date = December 8, 2006
| title = Penises
| image = penises.png
| titletext = The penis varies in size when flaccid and is pretty consistently about yea big when erect. Anyway, back to the sitcom one-liners and the constant flow of spam.
}}
==Explanation==
The comic takes aim at what is considered by some to be the apparent societal obsession with the {{w|human penis|male sexual organ}} ("phallocentrism"), especially in regards to size. In general, depictions of an erect penis (also called {{w|phallus}}) represent male potency.

While present in every human civilization, the symbol of the penis is also prominently featured in modern mass media. Many films and television series make use of penis-related jokes. A very common trope is the male obsession with the idea that a larger penis is considered more desirable, and a smaller penis less manly or satisfying to women.

Megan criticizes this obsession by pointing out that most penises are about the same size, and normal variations in size are not worth getting worked up about.

The title text refers to the excessive advertisement for {{w|Sildenafil|potency pills}} and {{w|penis enlargement}} in {{w|Email spam|spam emails}}. The symbol of the phallus can be regarded by some as omnipresent in modern Western society (but not necessarily in other cultures){{Citation needed}}, with presumably every public toilet sporting at least one badly drawn depiction of a penis.

==Transcript==
:PENISES:
:Megan: They are about this big.
:[Holds her hands close together, about half a foot apart.]
:Now can we PLEASE, as a culture, move on?

{{comic discussion}}
[[Category:Comics featuring Megan‏‎]]
[[Category:Penis]]

406: Venting

2022-04-13T15:47:32Z

172.70.86.48: /* Explanation */ I resent "grammar Nazi" as an insult, because it demonises people for being a bit pedantic -- or not even that in in some cases, if they're trying to make sense of a near-unreadable post. I also made some miscellaneous improvements.

{{comic
| number = 406
| date = April 4, 2008
| title = Venting
| image = venting.png
| titletext = P.P.S. I can kill you with my brain.
}}

==Explanation==
This is yet another xkcd comic referencing ''{{w|Firefly (TV series)|Firefly}}'', but it's not so much about ''Firefly'' itself as about {{w|Summer Glau}}. Summer Glau is an American actress best known for playing {{w|River Tam}} in ''Firefly'' and ''{{w|Serenity (film)|Serenity}}'', as well as Cameron in the ''{{w|Terminator: The Sarah Connor Chronicles}}'' series.

[[Cueball]] says that he gives a long and seemingly well-researched reply to a stupid comment on a blog when he feels angry as a way to vent. What we see of his comment begins with Cueball describing the original commenter's incoherent and inconsistent spelling and grammar. Then, he proceeds to rip apart the commenter by citing their historical and political ignorance. He signs his comment as 'Summer Glau', after which he reminds the blogger to watch the next season of ''Terminator: The Sarah Connor Chronicles series''.

One likely reason that he uses 'Summer Glau' is that she is worshiped by geeks the world over, even those incapable of writing coherent blog posts or comments. CrackMonkey74 would not risk responding negatively to the post, just in case it was actually written by Summer Glau, as they don't want everyone to hate them for attempting to argue with her. In this way, Cueball is assured of the last word in this argument, which makes for a most satisfying vent.

Another possible explanation is that River Tam has a genius-level intellect and is also mentally disturbed. Given xkcd's trend of comparing ''Firefly'' characters to their respective actors (Especially [[The Race]]), Cueball is probably using Summer Glau's name simply because an exhaustively researched blog comment seems like something River Tam -- and thus possibly Summer Glau -- would do.

The title text refers to the famous dialogue delivered by River Tam in ''Firefly'' Episode 11: "{{w|Trash (Firefly)|Trash}}".

==Transcript==
:When I need to blow off steam, I find a particularly stupid blog comment and reply with an exhaustively researched word-by-word rebuttal, which I sign 'Summer Glau'.
:Cueball (typing): In conclusion, on examining the above post by CrackMonkey74, after carefully working my way through the haze of spelling errors (documented in section 3), abuse of capitalization (section 4), and general crimes against grammar and syntax (sections 7-8), I have demonstrated that, beneath it all, the work betrays the author's staggering ignorance of the history and the workings of our electoral system. While the author's wildly swerving train of thought did at one point flirt with coherence, this brief encounter was more likely a chance event (see statistical analysis in table 5) than a result of even rudimentary lucidity.
::-Summer Glau
:P.S. Don't forget to check out the next season of the ''Sarah Connor Chronicles'' this fall on Fox!

==Trivia==
*Cueball's statement has been widely reused by many bloggers after the release of this comic.
*The name ''CrackMonkey74'' also appears in [[202: YouTube]] as one of the clueless YouTube commentators, and later appears in [[574: Swine Flu]].

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Summer Glau]]
[[Category:Language]]
[[Category:Terminator]]