explain xkcd - User contributions [en]

Talk:2972: Helium Synthesis

2024-08-16T03:29:12Z

172.68.144.140:

I had imagined that, rather than destroying the entire universe, they just somehow made a big bang INSIDE THE MACHINE that they could somehow obtain helium from safely. [[Special:Contributions/141.101.109.166|141.101.109.166]] 07:34, 15 August 2024 (UTC)
:I get the impression that, like an abbreviated version of the cyclical {{w|Big Bounce}} hypothesis, they did indeed recreate the conditions for a (sufficiently similar) universe.
:The question as to whether they obliterated their current one (in a short-sighted and {{w|Instrumental convergence#Paperclip maximizer|paperclip-maximiser}}-like effort that disregards the safety of their current existence) or create a new instance of universe-within-the-universe (like [[2688: Bubble Universes]], presumably with some way of [[248: Hypotheticals|bringing the stuff out]]) is left open.
:If the latter, it could be that the ''reason'' why each universe's helium-users are chronically short of helium is that their universe ''has'' been used as a source for the next-universe-out's helium by the equivalent outwards recursion of the very same people. (The former would imply a kind of {{w|The Last Question}} situation, only not with the same timing.) [[Special:Contributions/162.158.74.118|162.158.74.118]] 08:25, 15 August 2024 (UTC)
::I'm going to go out on a limb and suggest that you probably couldn't create a big bang in the lab capable of replaying the events of the current universe exactly without obliterating at least, as the explanation says, all the closest galaxies. If new inflation pushes the existing universe apart, it's still smeared quite thinly outside the new expanding edge.
:::You think in such three-dimensional terms - and I don't mean it as a praise, just like the Borg Queen. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 03:07, 16 August 2024 (UTC)
::But I really like the idea, it's kind of like Rick's car battery in ''Rick and Morty'', one of my favorite episodes. [[Special:Contributions/172.70.210.4|172.70.210.4]] 08:34, 15 August 2024 (UTC)
:::What if inflation doesn't disturb the matter and space around it, it just shrinks the apparent size of the matter inside it to create the expanded space relative to observers inside, by curving the interior spacetime and distorting the gravitational field to block it from its surroundings? [[Special:Contributions/172.70.206.45|172.70.206.45]] 10:04, 15 August 2024 (UTC)
::::Black hole universe, anyone? https://arxiv.org/abs/2204.11608 video: https://www.youtube.com/watch?v=71eUes30gwc [[Special:Contributions/172.71.147.192|172.71.147.192]] 18:16, 15 August 2024 (UTC)
:::[https://wiki.lspace.org/Roundworld Universe within a (continuing) universe] isn't exactly hard to imagine. [[Special:Contributions/162.158.33.216|162.158.33.216]] 13:07, 15 August 2024 (UTC)

Could this comic maybe be a reference to a certain popular space video game? Sadly, in what I call a reverse spoiler, I cannot tell you which game I mean without massively spoiling that game. I hope some people know which one I mean and can reply basic on that guess. [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 09:30, 15 August 2024 (UTC)
:If it's [https://www.mobiusdigitalgames.com/outer-wilds.html Outer Wilds], there's nothing here that's a gameplay spoiler, is there? Just for a pretty small part of the story, right? [[Special:Contributions/162.158.187.55|162.158.187.55]] 10:08, 15 August 2024 (UTC)
::[not OP] It's a pretty big story spoiler and it could be considered a gameplay spoiler indirectly, or it could it there was more specifity. It's fine to discuss it here. Most xkcd fans would love that game even if they can only watch play-throughs, I reckon. So I consider the discussion here a net positive, really, and I suspect most of the authors would too. [[Special:Contributions/162.158.91.36|162.158.91.36]] 17:19, 15 August 2024 (UTC)

This is also a bit reminiscent of the classic Perry Bible Fellowship comic "[https://pbfcomics.com/comics/reset/ Reset]". [[Special:Contributions/172.68.144.140|172.68.144.140]] 03:29, 16 August 2024 (UTC)

2957: A Crossword Puzzle

2024-07-19T01:36:18Z

172.68.144.140: correctly completely wrong explanation

{{comic
| number = 2957
| date = July 10, 2024
| title = A Crossword Puzzle
| image = a_crossword_puzzle_2x.png
| imagesize = 740x937px
| noexpand = true
| titletext = Hint: If you ever encounter this puzzle in a crossword app, just [term for someone with a competitive and high-achieving personality].
}}

==Explanation==
{{incomplete|Created by a CROSSWORD MAKER FREE FALLING - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

{{notice|<big>'''SPOILER ALERT!'''</big> Stop scrolling! These crossword clues comprise a single hidden joke, which you can figure out yourself. If you read on, the joke is spoiled and your chance of finding out the joke yourself is gone instantly!|image=warning!!.png}}

This crossword may seem extremely difficult, with questions covering a wide variety of trivia, linguistics, mathematics in various forms, alongside wordplay typical of crossword puzzles. But the joke is that every single letter of every single answer is "A".

The name of this comic, “A Crossword Puzzle”, is a double entendre which could, in itself, be considered a cryptic clue; the “A” can be interpreted both as the indefinite article “a”, and as an identifier saying that this crossword puzzle is specifically an “A” puzzle, due to the answer being all “a”s.

The title text is a play on a "type A" personality. The term for someone with a competitive and high-achieving personality is "Type A". In the context of the title text, this answer is a hint that the entire puzzle can be completed in a crossword-solving app by typing the letter A repeatedly.

===Explanation of clues===
{| class="wikitable" style="margin:auto"
|-
! Location !! Clue !! Explanation !! Squares
|-
| 1-Across || Famous Pvt. Wilhelm quote || Reference to the {{w|Wilhelm scream}}, a widely used stock sound effect. || 10
|-
| 11-Across || {{w|IPv6}} address record || An IPv4 record is an "A" record; an IPv6 record is four times the length and is designated an "AAAA" record. || 4
|-
| 15-Across || “CIPHERTEXT” decrypted with Vigenère key “CIPHERTEXT” || A "{{w|Vigenère Cipher}}" translates the original text by the distance from A from the key, letter by letter. For instance, if the plaintext is "XK" and the key is "CD", the C shifts X 2 forward to become Z, and the D shifts K 3 forward to become N, yielding a ciphertext of "ZN". Since the ciphertext and the key are the same in this case, decryption just shifts all the letters back to A, akin to subtracting a number from itself and getting 0. || 10
|-
| 16-Across || 8mm diameter battery || An {{w|AAAA battery}} is a 1.5 V battery that measures 8.3 mm in diameter, 2.2 mm smaller than the more common AAA battery. || 4
|-
| 17-Across || “Warthog” attack aircraft || The {{w|A-10 Warthog}} is an attack aircraft. Here, A-10 has been turned into AAAAAAAAAA (ten As). || 10
|-
| 18-Across || '''E'''ve'''r'''y t'''h'''ir'''d''' le'''t'''te'''r''' in the word for “inability to visualize” || {{w|Aphantasia}} is the inability to experience mental images. Following the example of the pattern in the clue, taking the first letter and every third one after (rather than just every third letter) we determine that '''A'''ph'''a'''nt'''a'''si'''a''' gives us the word "aaaa". This clue is particularly mean because of how it instructs you to visualize the letters highlighted within the word in order to get the answer. || 4
|-
| 19-Across || An {{w|acrostic}} hidden on the first page of the dictionary || The first page of the dictionary (if you ignore the copyright page and the index) is the list of words starting with A. An acrostic of this page, taking the first letter of each line and arranging them in order, would just be a sequence of As. || 15
|-
| 21-Across || Default paper size in Europe || {{w|A4 paper}} (here written as AAAA) is the default size in Europe. At 210×297 mm, it is approximately 0.24″ narrower and 0.71″ longer than the 8.5″×11″ paper used in the United States, and due to having an aspect ratio of 1:sqrt(2), can be cut or folded in half to create two half-sized sheets (A5) with exactly the same aspect ratio. A4 is, itself, also a halving of A3 and of identical ratio, as is the case with all A-sizes higher and lower in the sequence.|| 4
|-
| 22-Across || First four unary strings || A unary number system represents numbers using just one symbol. For example, 7 in unary would be 1111111. The first four strings in unary, if you used A as the first (and only) symbol, would be A, AA, AAA, AAAA. || 10
|-
| 23-Across || Lysine codon || {{w|Lysine}} is an amino acid, with codons AAA and AAG. || 3
|-
| 24-Across || 40 CFR Part 63 subpart concerning asphalt pollution || [https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-63/subpart-AAAAAAA?toc=1 "40 CFR Part 63"] refers to federal air pollutant regulations in the Code of Federal Regulations. The subpart for "asphalt processing and asphalt roofing manufacturing" is AAAAAAA (also part LLLLL). || 7
|-
| 25-Across || Top bond credit rating || The highest {{w|credit rating}} for bonds is AAA. || 3
|-
| 26-Across || Audi coupe || First of three Audi references. {{w|List_of_Audi_vehicles|Audi's car models}} range from A1 (subcompact hatchback) to A8 (full-size luxury sedan); the A5, the one referenced here, is a compact executive {{w|coupe}}. || 5
|-
| 27-Across || A pair of small remote batteries, when inserted || Two {{w|AAA_battery|AAA}} batteries, which are often used to power remote controls for domestic devices. These have been combined to give AAAAAA — "Inserted" is often a cryptic hint that one word should surround another, although such a cryptic clue would normally also contain a more direct clue (albeit ambiguously) to the full answer. || 6
|-
| 29-Across || Unofficial Howard Dean slogan || A reference to Howard Dean, an American Democrat who ran for the party's nomination in 2004. He famously [https://www.youtube.com/watch?v=l6i-gYRAwM0 yelled at a rally] in a way that was thought to be bizarre and which, it is thought, doomed his campaign. || 7
|-
| 32-Across || A 4.0 report card || A 4.0 GPA, at least {{w|Academic_grading_in_the_United_States|in the USA}}, is all As. This clue assumes seven classes. || 7
|-
| 33-Across || The “Harlem Globetrotters of baseball” (vowels only) || The {{w|Savannah Bananas}}, the vowels for whom are aaaaaa. The {{w|Harlem Globetrotters}} are an exhibition basketball team, with the Savannah Bananas following a similar formula in baseball. || 6
|-
| 34-Across || 2018 Kiefer song || “[https://genius.com/Kiefer-aaaaa-lyrics AAAAA]”. This is the only five-letter song title in Kiefer's 2018 album Happysad. || 5
|-
| 35-Across || Top Minor League tier || The top {{w|Minor League Baseball}} tier is AAA. || 3
|-
| 36-Across || Reply elicited by a dentist || With your mouth open at the Dentist, the only reply a dentist can elicit from a patient is AAAAAAA || 7
|-
| 38-Across || Anaa’s airport || {{w|Anaa}} is an atoll in the {{w|Tuamotu archipelago}} of {{w|French Polynesia}}. AAA is the {{w|IATA}} code for its airport. || 3
|-
| 41-Across || Macaulay Culkin’s review of aftershave || In the movie ''{{w|Home Alone}}'', Kevin (played by {{w|Macaulay Culkin}}) puts on his father's aftershave lotion. The eight-year-old boy is not used to the lotion's antiseptic and screams as the stinging sensation kicks in. || 10
|-
| 43-Across || Marketing agency trade grp. || The {{w|American Association of Advertising Agencies}}, also called the 4As (here AAAA). An abbreviated word in a clue, here "grp.", is a common way to signal that the answer also should also be written as its abbreviation. || 4
|-
| 44-Across || Soaring climax of Linda Eder’s ''Man of La Mancha'' || Refers to [https://youtu.be/BWP7l0OTXJI?t=130 the 18-second-long wordless passage in Eder's opus], or possibly the final high note in the song “The Impossible Dream”. || 15
|-
| 46-Across || Military flight community org. || The {{w|Army Aviation Association of America}}, or AAAA. || 4
|-
| 47-Across || Iconic line from ''Tarzan'' || Tarzan has a famous {{w|Tarzan yell|war cry}} he shouts, usually when swinging from a vine. || 10
|-
| 48-Across || '''E'''v'''e'''r'''y''' o'''t'''h'''e'''r letter of Jimmy Wales’s birth state || The birth state of {{w|Jimmy Wales}}, the co-founder of Wikipedia, is Alabama. Taking every other letter of '''A'''l'''a'''b'''a'''m'''a''' gives "Aaaa". || 4
|-
| 49-Across || Warthog’s postscript after “They call me ''mister'' pig!” || Pumba in ''{{w|The Lion King}}'' yells "aaaaaaaaaa" while charging at the hyenas who insulted him. || 10
|-
| 50-Across || Message to Elsa in ''Frozen 2'' || The call which Elsa hears in ''{{w|Frozen 2}}'' is a sequence of four notes which resemble the requiem music {{w|Dies Irae#Music|Dies irae}}. The sequence is sung entirely with an open rounded vowel sound, or a soft "a" sound. || 4
|-
| 51-Across || Lola, when betting it all on Black 20 in ''Run Lola Run'' || In ''{{w|Run Lola Run}}'', Lola ({{w|Franka Potente}}) [https://youtu.be/OTSz1w-cuZM?si=2vc51WCWvn20Hjoo&t=116 screams loud enough to affect the outcome] of a roulette wheel where she has just bet all her money on Black 20. The scream could be transcribed as "AAAAAAAAAA" || 10
|-
| 1-Down || Game featuring “a reckless disregard for gravity” || ''{{w|AaAaAA!!! – A Reckless Disregard for Gravity}}'' - notably the title is commonly extended in promotional material beyond 6 As. || 6
|-
| 2-Down || 1010101010101010101010102→16 || 10101010 10101010 10101010 in binary is equivalent to "AAAAAA" in hexadecimal. || 6
|-
| 3-Down || Google phone released July ’22 || The {{w|Pixel 6a}} was released in July 22. Stylized in this puzzle as "AAAAAA" ('A'×6) || 6
|-
| 4-Down || It’s five times better than that ''other'' steak sauce || Five times better than {{w|A1 steak sauce}} would be A5, stylized in this puzzle as AAAAA. || 5
|-
| 5-Down || ToHex(43690) || The decimal number 43690 converted to hexadecimal is AAAA. || 4
|-
| 6-Down || Freddie Mercury lyric from ''Under Pressure'' || A drawn-out 'Aaaaahhhh' rising in pitch, from a song by Queen and David Bowie. || 15
|-
| 7-Down || Full-size Audi luxury sedan || Second of three Audi references. As mentioned previously, the A8 referenced here is their full-size luxury sedan. || 8
|-
| 8-Down || Fast path through a multiple choice marketing survey || The "fast path" is just to select the first option over and over again. Usually the options are labeled A, B, C, and D (or more) - choosing the first option for every question would be answering entirely with As. || 7
|-
| 9-Down || 12356631 in base 26 || Randall is expressing base 26 using the letters of the alphabet with 1=A, in which case 1235663110 = AAAAAA26. (It's unclear how one would express the digit 026 this way.) || 6
|-
| 10-Down || Viral Jimmy Barnes chorus || A reference to the music video for Kirin J Callinan's song “{{w|Big Enough}}”, which features rocker {{w|Jimmy Barnes}} in a cowboy hat screaming "Aaaaaaaaaaaaaaa!" while in the sky over mountain scenes. || 15
|-
| 11-Down || Ruby Rhod catchphrase || Ruby Rhod is a radio host in the film ''{{w|The Fifth Element}}''; he has a scene with a memorable scream. || 5
|-
| 12-Down || badbeef + 9efcebbb || In hexadecimal, badbeef and 9efcebbb add together to equal AAAAAAAA (195,935,983, 2,667,375,547, and 2,863,311,530 in decimal respectively). || 8
|-
| 13-Down || In Wet Leg’s ''Ur Mum'', what the singer has been practicing || In the song "{{w|Ur Mum}}" by {{w|Wet Leg}}, the bridge starts with "Okay, I've been practicing my longest and loudest scream", which is apparently eight As long. || 8
|-
| 14-Down || Refrain from Nora Reed bot || The "Endless Scream" bot on social media, made by Nora Reed, posts "AAAAAAAAAAA" (with or without an h) at varying lengths. || 8
|-
| 20-Down || Mario button presses to ascend Minas Tirith’s walls || In ''Mario'' games you typically use the A button to jump. In games where you don't press a button to move (e.g., games with a joystick), then the button presses required to ascend a vertical structure would probably all be A. This clue might have been inspired by the {{w|A-button challenge}} / [https://ukikipedia.net/wiki/A_Button_Challenge A Button Challenge], which tallies the number of A presses needed to beat ''Super Mario 64''. Additionally, {{w|Minas Tirith}} is a fictional city in ''{{w|The Lord of the Rings}}'' with seven concentric rings, each with a wall around it and higher than the last ring. Presumably, it takes seven jumps to get to the highest area of the city, so the answer is "AAAAAAA". || 7
|-
| 24-Down || Vermont historic route north from Bennington || {{w|Vermont Route 7A}}, or AAAAAAA. || 7
|-
| 26-Down || High-budget video game || A high-budget video game is usually referred to as a Triple-A game, or AAA. || 3
|-
| 28-Down || Unorthodox Tic-tac-toe win || {{w|Tic-tac-toe}} is usually won by getting either three Xs or three Os in a row, making XXX and OOO normal Tic-tac-toe wins. One could achieve a win of AAA by making the unorthodox choice of playing with the letter A instead of X or O. Alternatively, Randall is envisaging the grid as defined by rows 1, 2, 3, and columns A, B, C, so an AAA win would be simply playing in the first column each time - a strategy which should be obvious and easy to stop, even for young children who have not yet worked out that ''any'' route to winning can be blocked. || 3
|-
| 29-Down || String whose SHA-256 hash ends “…689510285e212385” || <code>printf AAAAAAAA <nowiki>|</nowiki> sha256sum</code> outputs <code>c34ab6abb7b2bb595bc25c3b388c872fd1d575819a8f55cc689510285e212385</code>.
Note that this 'clue' would be normally be ''particularly'' difficult, in isolation, as the nature of a {{w|hash function}} means that it is possible for multiple inputs to produce a given output, and that finding any of these (and definitely identifying ''all'' of them, to ensure you have the correct original) would require a {{w|brute-force attack}}; i.e. a test of all possible initial states to discover which of them might be viable candidates. Even more problematic is that we are only given a partial hash string, meaning we are possibly talking of a multiple of full hashes, each of them with a possible multiplicity of original plaintexts behind them. However, given the context of this puzzle, it's reasonable to guess that a sequence of 8 As might be the answer, and indeed its hash does match the clue given.
 The number of possible hashes in the clue is 1664/1616, i.e. 1648, or approximately 6x1054, although there really is no reason (aside from the fundamental impracticality) to try to solve this problem from each and every 'hash end'. Instead you would 'only' check every combination of 8 letters (presuming no digits, punctuation or whitespace would be inserted, that no “foreign”/accented characters are present and that uppercase is universally presumed, is 268; i.e. ~208 {{w|billion|short-scale billion}} possibilities) and discover which (one?) of these sufficiently matches the hash fragment given. Testing a hundred of these every second, it would take a little over 66 ''years'' to complete the task of checking every single possibility (rather than stopping at the first confirmed answer, which might well be the initial one in this particular case).
 In the context of a crossword such as this, however, you can significantly reduce this search by having established (or at least sufficiently narrowed down) the answers to the various across-clues which intersect with ever character of it (this form of crossword grid being of the {{w|Crossword#American-style crosswords|dense type}}, with no singly-clued spaces as with the more open lattice-types), reducing the necessary checks drastically. This could mean, having solved at least some of the perpendicular answers, that you have enough information to 'guess' at some likely answer, and then merely need to ''confirm'' that whatever guess(es) you make will resolve themselves into the clue-answer provided. (Much as you might with a more normally difficult clue, where you merely have to satisfy yourself that the surprise answer is at least justified as resulting from the original hint.)
| 8
|-
| 30-Down || Arnold’s remark to the Predator || A reference to [https://www.youtube.com/watch?v=OsFYPVxHKdc this scene] from ''{{w|Predator (film)|Predator}}'', starring Arnold Schwarzenegger. || 8
|-
| 31-Down || The vowels in the fire salamander’s binomial name || The vowels in {{w|Salamandra salamandra}} are aaaaaaaa. || 8
|-
| 32-Down || Janet Leigh ''Psycho'' line || The iconic scene in ''{{w|Psycho (1960 film)|Psycho}}'' is the shower scene, in which {{w|Janet Leigh}} gives a long piercing scream as she is murdered. This can be written as 8 As if one wishes. || 8
|-
| 34-Down || Seven 440Hz pulses || A sound with a frequency of 440 Hz is a middle "A" note. Seven such pulses would be AAAAAAA. || 7
|-
| 37-Down || Audi luxury sports sedan || Third of three Audi references. The A6, the one referenced here, is their executive car. Actually, the A7, their executive liftback sedan, would fit the prompt of "luxury sports sedan" better, but 37-Down only has room for six As. || 6
|-
| 38-Down || A half-dozen eggs with reasonably firm yolks || Eggs can be [https://www.saudereggs.com/blog/egg-grading-system/ "graded on a variety of aspects"], with grades B, A, or AA. Eggs with a reasonably firm yolk are graded A, so having half a dozen of them gives you AAAAAA eggs. || 6
|-
| 39-Down || 2-2-2-2-2-2 on a multitap phone keypad || A "{{w|multi-tap|multitap keyboard}}" is a text entry system for mobile phones. Most numbers are associated with three letters, and tapping the same number multiple times in rapid succession selects the 1st, 2nd, or 3rd number. 2 is "A", 22 is "B", 222 is "C", 3 is "D", etc. 2-2-2-2-2-2 translates to "AAAAAA". (If pressed quickly enough, this input may accidentally wrap around the letter list twice and simply result in a "C".) || 6
|-
| 40-Down || .- .- .- .- .- .- || .- is {{w|Morse Code}} for A. It reads out as AAAAAA. || 6
|-
| 42-Down || Rating for China’s best tourist attractions || China's Ministry of Culture and Tourism provides ratings for many tourist attractions in China on a scale from A to AAAAA, with AAAAA being the best. Examples of well-known tourist attractions with the AAAAA rating include the {{w|Forbidden City}}, sections of the {{w|Great Wall of China}}, and the {{w|Terracotta Army}}. || 5
|-
| 43-Down || Standard drumstick size || 5A is a common, middle-range size for drumsticks (the sticks used to play drums, not the drumsticks that get eaten). Here, it's written as AAAAA. || 5
|-
| 45-Down || “The rain/in Spain/falls main-/ly on the plain” rhyme scheme || An AAAA {{w|rhyme scheme}} means each of the four lines ends with the same sound. Furthermore, the sound in question is the standard vocalization of the letter A. || 4
|}

==Transcript==
:[A square 15x15 crossword puzzle is shown. Only 21 of the 225 squares are black. The black squares are in a pattern that are 180 degree rotationally symmetrical. Three black squares down from the 11th column and similarly three black squares up from the 5th column. Three black squares out from the right in row 7 and then two more black squares diagonally up from the end. Similarly three black squares out from the left in row 9 with two more black squares diagonally down from the end. A single black square is three above the first black square on the diagonal going down to the right and similarly there is a black square three under the first of the diagonal squares going down to the left. (Row 6 column 12 and Row 10 column 4). Finally there are three black squares on a diagonal crossing over the central point by going up from the left through the central point (Row 8 column 8). There are numbers at the top of every column (except the one that is a black square) and similarly at the left edge of all rows (except the one that is a black square). There are also numbers at the bottom of every black segment (except the one that reaches the bottom) and all rows after black segments except the one that reaches the right edge. In total all numbers from 1 to 51 are written. They are written in reading order from 1 to 51.]
:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

:[Below the square there are two columns of clues for each number that belongs to across (rows) and to the right there is one column of clues for each number that belongs to down (columns). Both segments have an underlined and bold title above the clues. ]
:<big>'''Across'''</big>
:1. Famous Pvt. Wilhelm quote
:11. IPv6 address record
:15. "CIPHERTEXT" decrypted with Vigenère key "CIPHERTEXT"
:16. 8mm diameter battery
:17. "Warthog" attack aircraft
:18. '''E'''ve'''r'''y t'''h'''ir'''d''' le'''t'''te'''r''' in the word for "inability to visualize"
:19. An acrostic hidden on the first page of the dictionary
:21. Default paper size in Europe
:22. First four unary strings
:23. Lysine codon
:24. 40 CFR Part 63 subpart concerning asphalt pollution
:25. Top bond credit rating
:26. Audi coupe
:27. A pair of small remote batteries, when inserted
:29. Unofficial Howard Dean slogan
:32. A 4.0 report card
:33. The "Harlem Globetrotters of baseball" (vowels only)
:34. 2018 Kiefer song
:35. Top Minor League tier
:36. Reply elicited by a dentist
:38. ANAA's airport
:41. Macaulay Culkin's review of aftershave
:43. Marketing agency trade grp.
:44. Soaring climax of Linda Eder's ''Man of La Mancha''
:46. Military flight community org.
:47. Iconic line from ''Tarzan''
:48. '''E''''''v''''''e''''''r''''''y'''''' o''''''t''''''h''''''e''''''r''' letter of Jimmy Wales's birth state
:49. Warthog's postscript after "They call me ''mister'' pig!"
:50. Message to Elsa in ''Frozen 2''
:51. Lola, when betting it all on Black 20 in ''Run Lola Run''

:<big>'''Down'''</big>
:1. Game featuring "a reckless disregard for gravity"
:2. 1010101010101010101010102→16
:3. Google phone released July '22
:4. It's five times better than that ''other'' steak sauce
:5. ToHex(43690)
:6. Freddie Mercury lyric from ''Under Pressure''
:7. Full-size Audi luxury sedan
:8. Fast path through a multiple choice marketing survey
:9. 12356631 in base 26
:10. Viral Jimmy Barnes chorus
:11. Ruby Rhod catchphrase
:12. badbeef + 9efcebbb
:13. In Wet Leg's ''Ur Mum'', what the singer has been practicing
:14. Refrain from Nora Reed bot
:20. Mario button presses to ascend Minas Tirith's walls
:24. Vermont historic route north from Bennington
:26. High-budget video game
:28. Unorthodox Tic-Tac-Toe win
:29. String whose SHA-256 hash ends "...689510285e212385"
:30. Arnold's remark to the Predator
:31. The vowels in the fire salamander's binomial name
:32. Janet Leigh ''Psycho'' line
:34. Seven 440Hz pulses
:37. Audi luxury sports sedan
:38. A half-dozen eggs with reasonably firm yolks
:39. 2-2-2-2-2-2 on a multitap phone keypad
:40. .- .- .- .- .- .-
:42. Rating for China's best tourist attractions
:43. Standard drumstick size
:45. "The rain/in Spain/falls main-/ly on the plain" rhyme scheme

==Trivia==
*This comic got a [[Header_text#A_Crossword_Puzzle|comic-specific header text]] after the first day it was up.
**This was because one of the comics Randall lists as one of those he enjoys, [https://www.buttersafe.com/ Buttersafe], had already posted a similar comic back in 2011: [https://www.buttersafe.com/2011/02/17/crosswords/ Crosswords].
**Randall had forgotten this, but now pays tribute to this, stating that he must have been accidentally inspired by that comic.
*[[User:Elfakyn|Elfakyn]] posted a link to a picture of the solved crossword puzzle in the [[Talk:2957:_A_Crossword_Puzzle#Solved_puzzle_picture|comments]] and allowed it to be included here:
[[File:2957_A-Crossword_Puzzle-Solved.png|500px|center]]
*All the black squares are in a symmetrical pattern, which is generally the case for crossword puzzles in the US and UK. See description of the pattern in the [[#Transcript|transcript]].
*Crosswords have been mentioned previously in [[2896: Crossword Constructors]].
*Out of 60 clues in the puzzle, 10 are references to screaming or yelling, making the puzzle approximately 17% screams.
{{comic discussion}}

[[Category:Language]]
[[Category:Math]]
[[Category:Songs]]
[[Category:Video games]]

Talk:2911: Greenland Size

2024-03-25T23:01:11Z

172.68.144.140:

Anyone else really wanting to know the radius for which the title text is true? I got [[356]]'d
[[User:Rxy|Rxy]] ([[User talk:Rxy|talk]]) 20:28, 25 March 2024 (UTC)

New life goal: Go to the poles, find the ring that is mapped to-scale, and color it. Require all satellite maps to be modified to add this stripe of color. [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 22:37, 25 March 2024 (UTC)

This is clearly based on Lewis Carroll's Sylvie and Bruno Concluded (1893) which discusses a map made at a scale of 1:1. [[User:Take The A Train To Watertown|Take The A Train To Watertown]] ([[User talk:Take The A Train To Watertown|talk]]) 22:49, 25 March 2024 (UTC)

Which latitude of Greenland is 1660miles across? I'm noodling around and can find a spot in the northern part which is - more or less - 1660*km* wide, but nothing close to that number in miles.

Talk:2908: Moon Armor Index

2024-03-20T08:08:50Z

172.68.144.140: indent

Can someone hurry up/w the explanation?[[Special:Contributions/162.158.159.162|162.158.159.162]] 22:43, 18 March 2024 (UTC)
:Did it :) --[[User:1234231587678|1234231587678]] ([[User talk:1234231587678|talk]]) 00:16, 19 March 2024 (UTC)

According to https://sl.bing.net/kR6wrqrekg0 it would be 43.1 meters. [[Special:Contributions/172.70.174.117|172.70.174.117]] 23:17, 18 March 2024 (UTC)

Bing was wrong, it screwed up the units [[Special:Contributions/172.70.38.181|172.70.38.181]] 23:39, 18 March 2024 (UTC)!

Anyone figure out if this takes the recently-discovered moons into account? I'd expect as much but it would make a good addition to the explanation. [[Special:Contributions/172.70.131.155|172.70.131.155]] 01:39, 19 March 2024 (UTC)
:The new moon around Uranus is 8 km in diameter, and the moons around Neptune are 23 km and 14 km in diameter. The inventory of outer moons is believed to be complete down to 2 km for Jupiter, 3 km for Saturn, 8 km for Uranus, and 14 km for Neptune. And the total combined mass of smaller moons (e.g. in Saturn's rings) is also constrained.

:All these moons are round, and thus approximately ball-shaped. The volume of a 3-ball with radius r₀ is 4⁄3 πr₀³. Uranus and Neptune are also approximately ball-shaped with radii of 25,559 km and 15,299 km, respectively. (I don't know exactly how these radii are defined, but I assume optically. Uranus and Neptune don't have solid surfaces.) The volume of a spherical shell is just the difference of the outer and inner spheres, so 4⁄3 π(R³−r³) if the outer radius is R and the inner radius is r. These volumes are equal if the whole moon is converted into a spherical shell. So for Uranus, we have 4⁄3 πr₀³ = 4⁄3 π(R³−r³), where r₀ is the radius of the moon, r is the radius of Uranus, and R−r is the thickness of the shell. Solving gives R−r = ³√(r₀³+r³)−r. Plugging in r₀ = 8 km and r = 25,559 km gives R−r = 0.26 mm. If we laid it on top of the other moons instead of the "surface" of Uranus itself, it would make practically no difference. Doing the same calculation for each newly-discovered moon of Neptune gives thicknesses of 17 mm and 3.9 mm (for a total of 21 mm).

:In other words, they are tiny rounding errors. [[User:EebstertheGreat|EebstertheGreat]] ([[User talk:EebstertheGreat|talk]]) 03:17, 19 March 2024 (UTC)
::Not for Pluto, it seems... small planet, huge moon. [[User:Transgalactic|Transgalactic]] ([[User talk:Transgalactic|talk]]) 21:30, 19 March 2024 (UTC)

I like that turning the Moon into a spherical shell coating the Earth is not definitely stated to be impossible with current technology. There's so much hedging going on I feel like I'm trapped in a maze in ''The Shining.'' [[User:EebstertheGreat|EebstertheGreat]] ([[User talk:EebstertheGreat|talk]]) 03:17, 19 March 2024 (UTC)

The formula used seems to give the instantaneous technical distance, but in reality, there would be a rate of change of the surface area of the planet as each layer of thickness x was added. Does anyone know if this is significant with the distances we are talking, or does it just turn out to be a rounding error? [[Special:Contributions/172.68.0.254|172.68.0.254]] 03:34, 19 March 2024 (UTC)
:For most, I suspect it is indeed the roundingest of rounding errors. Obviously, Earth+Moon and Pluto+(Charon+the others) would be the most ''out'', but subtending difference of area at (say) sea-level radius and sea-level plus 43km doesn't sound like much to account for.
:A=4πr², so Adif of A2-A1 would be (4πr2²)-(4πr1²) or 4π(r2²-r1²) ((which looks like you could work it out as a pythogorean calculation, i.e. model a new line-length that would go at a tangent out from r1 until it hits the endpoint of the r2 radius elsewhere ... but that's probably not useful!)).
:Given Earth at a normal 6371km (between equatorial and polar radii, to simplify as a true sphere), Earth+Moon therefore 6371+43 (using figure stated by comic), that gives ...if I've done it right... now an extra 7 million km² on top of the roughly 510 million that it normally has. An increment of 5%, by the time you start spreading your arbitrarily thin final layer (so approximate back to being 2.5% extra by volume, without actually using Eebster's alternate direct shell-volume calculation or doing an integration).
:Pluto (saying 44km of layering, as slightly more than Earth's 'pile', on its far smaller radius) isn't that much more 'off'. It would increase the surface by about 8% (so says my mental arithmatic, at least) so maybe 4% more volume than a "flat surface raised up prismatically".
:(Not quite the same as "wrap a string around a tennis ball, add an inch to its length, what is its additional radius? / wrap a string around the Earth, add an inch ..." sort of thing, due to the extra dimensionality involved, but I don't feel like doing the full algebraic differentiations necessary to establish the trend of departure.).
:It certainly initially looks like the '≈'ing of the result holds fairly well under even the two most extreme examples (cases of particularly large moons-by-volume). And, at a certain point, a planet's (single largest) moon cannot be made bigger without drifting into double-planet territory (indeed, Pluto/Charon may be considered double-dwarfs!), and then, soon after, you're switching their roles around and dismantling the 'planet' (really a moon) to armour the 'moon' (now the planet). So that probably suggests we're at our limit, with twin-binary capping our one-satellite scenarios, until you get into 'busy' N-ary systems with many not-insignificant moons but somehow an identifiable 'main body' planet in the midst of them.
:I don't think "armour the Sun with all the planets (''and'' their moons), dwarf-planets, minor-planets, random detritus, etc" will strain that relationship. Top of my head estimate is that it'd be nowhere near as high as Earth/Pluto examples, if the Oort cloud isn't oddly massive in total. But someone can correct me if I've goofed or overly hand-waved something. [[Special:Contributions/172.69.195.118|172.69.195.118]] 06:35, 19 March 2024 (UTC)

I'm glad there are at least links to them, but shouldn’t there be at least ONE sentence HERE on explainxkcd saying what the heck the last five ‘worlds’ are? I’d bet that’s what most people needing an explanation come here to find out! and all there are are links. [[Special:Contributions/162.158.186.98|162.158.186.98]] 09:59, 19 March 2024 (UTC)
:I added a sentence about the trans-Neptunian dwarf planets. But I don't know why Randall left out Makemake, Orcus and Sedna... any hypotheses? [[User:Transgalactic|Transgalactic]] ([[User talk:Transgalactic|talk]]) 12:20, 19 March 2024 (UTC)
::I don't know this for a fact, but is it possible that those objects have no known moons to contribute any armor thickness? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 13:06, 19 March 2024 (UTC)
:::Makemake has a small moon. Orcus has a fairly large moon relative to is size, similar to Pluto. I'm slightly bitter that Salacia is here guven that astronomers don't even consider it a dwarf planet. Orcus is also much more interesting. [[Special:Contributions/172.68.64.133|172.68.64.133]] 08:07, 20 March 2024 (UTC)

Imagining (especially) the gas planet examples, and some sort of mechanical means (partly overlapping plates of 'moon armour', that can slide over each other, remaining gas-tight?) allowing free vertical moment, I'm wondering how much the shell could contain and actually compress the predominantly atmospheric mass below it. Not being in orbit (perhaps give it the nominal gas-cloud spin), having chosen the amount of atmosphere it sits upon it'll not really be held up by the previously uncapped atmosphere, but as it falls inwards it must eventually pressurise the volume within until it equalises against the hermetic (and magically balanced, to not crumple and fold inwards irregularly) shielding material... [[Special:Contributions/172.69.194.21|172.69.194.21]] 16:14, 19 March 2024 (UTC)

Now, the real challenge is doing it quickly - that is, on noticing danger, armor the planet, then dearmor and rebuild the moon when danger passes. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 20:00, 19 March 2024 (UTC)

I thought I was being very clever when I added the gravitational compression effects, because some tiny moons have a low density, and some of them aren't remotely as solid as the Earth's Moon because they only formed from separate rocks quite recently. But then someone applied this thought to the planet itself, where I feel (without any motivation to do the math) that such effects should be utterly negligible 5 billion years after the solar system's formative period... (though, who knows what else Pluto/Charon hold in store??) So: I'm not sure if the bit in brackets about the minuscule gravitational compression effect on the host planet should stay in the explanation. [[User:Transgalactic|Transgalactic]] ([[User talk:Transgalactic|talk]]) 21:30, 19 March 2024 (UTC)

Since as far as we currently know, there is no life on the other planets, isn't rather biocentric to suggests that the preservation of life is relevant to protecting the planet earth? (Intended as humor, if you didn't get it.) [[User:Inquirer|Inquirer]] ([[User talk:Inquirer|talk]]) 00:22, 20 March 2024 (UTC)