In this comic, Cueball (or perhaps Ranall) says he can't distinguish between two sets if they both have exactly seven objects. This leads him to exchange the items in the sets without noticing, to the point where every item belongs to a different set.
The number seven being the number for when sets become indistinguishable is a reference to Miller's Law
Guacamole = 7-layer dip ingredient
18.104.22.168 05:08, 5 September 2014 (UTC)Anonymous XKCD reader
Seventh Seal more likely to be a reference to Book of Revelation (I think he's brought it up before?) or the film? 22.214.171.124 05:17, 5 September 2014 (UTC)
Arctic Ocean is one of the modern Seven "Seas" of the world.
Green is the 4th color of seven in the Arthur Hamilton song "I Can Sing a Rainbow". 126.96.36.199 (talk) (please sign your comments with ~~~~)
I guess the title text is a play on the fact that the dwarves in the new Snow White (2001 film) are called Monday, Tuesday, ... That is the connection between Snow White dwarves and days of the week. The filmmakers decided to intermix sets of seven in the first place. Sebastian --188.8.131.52 06:27, 5 September 2014 (UTC)
There could be a pattern with order.
- Sneezy: 1st dwarf of the seven dwarves in Snow White.
- Phylum: 2nd rank in the Seven Taxonomic Ranks
- Europe: 3rd continent of the world
- Sloth: 4th sin of the Seven Deadly Sin
- Guacamole: 5th Layer in a 7 Layer Bean Dip
- Data Link: 6th Layer in the OSI Model
- Collosus of Rhodes: 7th Wonder of the Ancient World
- Monday: 1st Day of the Week (American).
- Arctic: 2nd ocean in the modern Seven "Seas" of the world.
- Wellesley: 3rd college of the Seven Sister colleges
- Green: 4th color in the Arthur Hamilton song "I Can Sing a Rainbow".
- Electra: 5th sister of the Pleiades, the Seven Sisters.
- Synergize: 6th Habit in the Stephen R. Covey self-help book "Seven Habits of Highly Effective People".
- Seventh Seal: 7th Seal of the Seven Seals in the Book of Revelations
184.108.40.206 (talk) (please sign your comments with ~~~~)
- The list on the page needs to be fixed to show Europe third. --220.127.116.11 11:15, 5 September 2014 (UTC)
The Pleiades is Randall's favorite constellation. 18.104.22.168 08:40, 5 September 2014 (UTC)
- It says so here. 22.214.171.124 20:16, 6 September 2014 (UTC)
- This could mean that Electra is the fifth star in the Pleiades cluster. If counting from the 12 o'clock position clockwise on a diagram of the Pleiades cluster the order would be Sterope, Maia, Taygeta, Caleano, Electra, Merope, and Alcyone (for the sisters), with Atlas and Pleione rounding out the named stars in the cluster.126.96.36.199 20:40, 8 December 2015 (UTC)
It sure is nice seeing the explanation getting more refined and complete every time I visit... 188.8.131.52 10:37, 5 September 2014 (UTC)
- There is not pattern like the one mentioned above. The first dwarf in Disney is always the leader Doc! even alphabetically. There is no reason to put Europe third, Arctic 2nd, Electra 5th or the Colossus 7th. Data Link is the 2nd although you usually put them in reverse making it the 6th (and in America first day is Sunday!). This I have corrected and made a table more for the Title text Kynde (talk) 12:35, 8 September 2014 (UTC)
- Doc may be the leader, and (hierarchically) first of the seven, but in my experience it's Doc who is often the forgotten one (unless remembered specifically for being forgotten) when someone is challenged to name the seven dwarves... E.g. "Happy, Sleepy, Dopey, Sneezy, Grumpy... erm... Bashful... oh... don't tell me..." (Bashful being the one those who specifically remember Doc tend to forget, unless they've got over this alternative memetic stumbling block.) 184.108.40.206 23:58, 8 September 2014 (UTC)
- In the Disney (1937) version, Snow White guesses the names of the dwarves in the following order: Doc, Bashful, Sleepy, Sneezy, Happy, Dopey, and Grumpy. --220.127.116.11 17:00, 18 September 2014 (UTC)
I've always been told there are only six continents. North America and South America are one continent. The seventh continent sometimes refers to this gigantic area filled with plastic rubbish in the Pacific Ocean. 18.104.22.168 11:47, 5 September 2014 (UTC)
- See here: https://www.youtube.com/watch?v=3uBcq1x7P34 But no one talks about the Great Pacific garbage patch as a continent. 7 continents is the most common model, with some (mainly Latin Americans) considering the Americas a single continent. Some others consider Eurasia a single continent (personally that's what I prefer, it makes the most sense). --Zagorath (talk) 12:12, 5 September 2014 (UTC)
- I've only ever heard folks say there are seven continents. By strict definition of the word, North and South America do form a single continent (at least did prior to the Panama Canal cutting them apart) the vast majority of people see then as two separate continents. Dividing the Eurasian landmass in two, however, that one never made much sense. 22.214.171.124 16:53, 5 September 2014 (UTC)
- I think the garbage patch confusion stems from the mislabeled picture of a bunch of floating garbage. In fact it's very spread out and in no way possible to confuse with a landmass. See http://io9.com/5911969/lies-youve-been-told-about-the-pacific-garbage-patch --JSekula71 (talk) 08:46, 6 September 2014 (UTC)
Guacamole may also be a reference to a famous joke which made the rounds about 15 years ago, where somebody had compared the 7 layers of the OSI network model to Taco Bell's 7-layer burrito. Guacamole was the 5th layer, which lends credence to this idea. It's still available on the WayBack Machine: http://web.archive.org/web/19990826193318/http://www.europa.com/~dogman/osi/ 126.96.36.199 11:59, 5 September 2014 (UTC)
I suspect Electra is from the list of extant complete plays of Sophocles: Ajax, Antigone, The Women of Trachis, Oedipus the King, Electra, Philoctetes and Oedipus at Colonus. Besimmons (talk) 13:42, 5 September 2014 (UTC)
I find it interesting that although Randall is American he lists Monday as the first day of the week. That's where it's positioned in most cultures outside the USA, but Americans normally consider Sunday to be the first day. --RenniePet (talk) 13:51, 5 September 2014 (UTC)
- I can't speak for anyone outside the US, but as someone who has spent 99.9% of my life within US borders (few weeks in Canada, if you think that should essentially count...), I only acknowledge that the first day listed on any monthly calendar I see around here is most often Sunday. If you were to ask me what the first day of the week is, I would very quickly and easily say "Monday". That is what I'm teaching my 4- and 2-year olds... There are a few reasons I would give to explain that other than "I think of it as the first day of the week". It's the first work day of the "work week", and since life is for most people centered around one form of work or another, that gives the "work week" high importance. By extension, Sunday is the last day in the "weekend". By Judeo-Christian beliefs, God rested on the "seventh" Day - most Christians believe that to be Sunday; others (I believe mostly Jewish) believe it to be Saturday - I think, though that even those who consider Saturday to be a holy day, if you were to ask them in casual conversation what the first day of the week is (I may be wrong, but), I think they would say "Monday"... (?) Any other "Americans" or "Non-Americans" (I'd ask for you to clearly identify with one or the other) want to weight in on this? - Brettpeirce (talk) 15:51, 5 September 2014 (UTC)
- I wouldn't make any guesses about what "most Christians" believe, but scholars clearly agree that Saturday (beginning sundown on Friday evening) is the seventh day, and Sunday is the first day (the "Lord's Day"). The reason for the shift isn't so clear, but they generally agree with the Jews about the numbering of the days, and even that the boundary between days happens at sunset: http://en.wikipedia.org/wiki/Sabbath_in_Christianity 188.8.131.52 14:39, 9 September 2014 (UTC)
- The reason claimed for the shift is because Jesus rose on the first day of the week, though the only thing that's made explicit is that the tomb was discovered empty on that day. But even at that, He made no command to change Sabbaths or replace it with a Sabbath equivalent. There are scriptures which many Christians often claim indicate that the disciples changed it -- one about a collection being taken up then and one about them meeting then -- but nothing clarifying that that was the intent. By the by, "The Lord's Day" is used once in the Bible, in Revelation, but left undefined. It is most commonly interpreted as Sunday for the earlier reason, but it could as easily be interpreted as the already-existing Sabbath, as He'd said He's "Lord of the Sabbath", or even equivalent to "The Day of the Lord", an eschatological term, which would be appropriate considering the book in which it appears. Also, having read up on the ISO standard week, the new numbering -- as in, only a few decades old -- is to make the week "labor-oriented", i.e., put the working days first. And since the majority of people treat Sunday as the weekly day of rest, people moved it to last. But before people started treating it as such, the numbering was already labor-oriented, with Saturday, the Sabbath, as the seventh day. Nyperold (talk) 18:14, 24 July 2015 (UTC)
- I can't really comment on anything talked about by Brettpeirce, but I can say a few words about the "first day of the week" problem as seen by a computer programmer. It causes huge problems when your program displays a calendar because you have to take into account that Americans want it one way and most other people want it a different way. And supposedly simple things like scheduling an appointment "first work day next week" has a completely different result if it is done on a Sunday in the USA or on a Sunday in Europe. And then there's the problem of week numbers (used a lot in Europe but not so much in the USA). Week numbers depend on which week is designated as the first week of the year, which in most countries is defined as the first week with at least 4 days in the year. Now if January 3rd is Sunday, then in the USA it is the start of week 1, while in Europe it is the last day of the last week of the previous year (week 52 or 53). It's enough to drive you to drink (which is OK on Sunday some places but not others). --RenniePet (talk) 20:36, 5 September 2014 (UTC)
- Oh, and then there are the incompatibilities in programming languages. American-developed computer languages like C and Basic and C++ and C# number the week days 0 - 6 meaning Sunday - Saturday. Meanwhile Java numbers week days 1 - 7 meaning Sunday - Saturday, except that the newest version, Java 8, has improved date/time facilities, and if you use them then week days are numbered 1 - 7 meaning Monday - Sunday. --RenniePet (talk) 20:52, 5 September 2014 (UTC)
- Contrary to ISO 8601, I think the week should start on Sunday for the sake of symmetry. 184.108.40.206 01:18, 25 November 2015 (UTC)
I find instead interesting that he makes no mention of the seven notes, while mentioning other sets less ubiquitous --220.127.116.11 14:13, 5 September 2014 (UTC)
OMFG, the second picture of a dwarf in the list is Dopey, why the hell did somebody say it's Fievel!? http://www.bing.com/images/search?q=seven+dwarfs+dopey&qpvt=Seven+Dwarves+Dopey&FORM=IGRE
18.104.22.168 19:44, 5 September 2014 (UTC)
- The Dwarfs here are drawn somewhat off-model, with bigger noses than in Disney artwork. Perhaps someone is confusing the second figure's nose, which is drawn much larger than Dopey's, with Fievel's other ear. It's similar to the Gardevoir nose illusion. --Tepples (talk) 20:16, 5 September 2014 (UTC)
- To be fair, the dwarves are more on-model than the people. -22.214.171.124 03:09, 6 September 2014 (UTC)
Arctic is the second ocean alphabetically. Someone should change the list to reflect that, I think. Zweisteine (talk) 19:53, 5 September 2014 (UTC)
Re the "trivia" note suggesting Arctic is a deliberate mistake for Antartica in the list of continents: Even if I thought Randall might be including deliberate mistakes, it is unlikely he'd use the continents as a list in the title. He already used them in the main comic, and he didn't repeat any other sevens. MGK (talk) 14:12, 6 September 2014 (UTC)
Did anyone else come here because the one thing they didn't get was guacamole? And now feel like, "duhhh?" 126.96.36.199 16:36, 6 September 2014 (UTC)
So how many continents are there really https://www.youtube.com/watch?v=3uBcq1x7P34 Spongebog (talk) 23:54, 6 September 2014 (UTC)
The stated order of 7-layer dip in the table is all wrong. Cheese goes on top, then sour cream, and the rest doesn't matter. 188.8.131.52 03:50, 9 September 2014 (UTC)
The Fields medallist Vladimir Voevodsky used this in a recent talk on the foundations of mathematics https://github.com/vladimirias/2014_Paul_Bernays_Lectures/blob/master/2014_09_Bernays_3%20presentation.pdf, to illustrate the abstract concept of set. 184.108.40.206 (talk) (please sign your comments with ~~~~)
"This leads him to exchange the items in the sets without noticing, to the point where, when attempting to list a single set, each item mentioned actually belongs to a different set."
Technically, they also belong to the same set- in fact, there are infinitely many sets that contain any subset of those listed. So saying "they all come from different sets" isn't quite correct. Hppavilion1 (talk) 04:43, 26 October 2016 (UTC)