Map Projections
by Jeff
Image text: What's that? You think I don't like the Peters map because I'm uncomfortable with having my cultural assumptions challenged? Are you sure you're not ... ::puts on sunglasses:: ... projecting?
This comic is takes all the different map projections, which is the way that the sphere that is the Earth is placed into a flat map, and makes assumptions on what type of person prefers that type of map projections. Not much to explain here as the different types of map projections are laid out and all the text below the map projections are jokes.
In the image text, the joke here goes to the familiar meme from CSI:Miami, in which the star, David Caruso starts on sentence, then puts on his sunglasses and then ends it with a corny pun. Naturally, there is a youtube video that has collected all of these one liners. This internet meme has been mentioned previously by xkcd in comic 626 and possibly others.
November 14th, 2011
Does anyone else feel strangely drawn to the Goode Homolosine?
November 14th, 2011
There’s another angle on this one. ‘Cultural assumptions’ in the image text and the image itself possibly refers to the episode of The West Wing Season 2 Episode 16, where on the “Big block of cheese day”, CJ has a meeting with the cartographers for social equality.
http://www.youtube.com/watch?v=vVX-PrBRtTY
November 14th, 2011
nice find! Love the West Wing.
November 14th, 2011
See the West Wing video linked above for the reference to the Gall-Peters projection.
November 14th, 2011
My relatives in the southern hemisphere prefer a world map centred on Australia and New Zealand. To my northern hemisphere eyes that just looks odd but just goes to show that the centre is arbitrary.
And that West Wing episode is brilliant.
November 14th, 2011
Yes, and with the southern hemisphere on top and the northern hemisphere on the bottom. I’ve seen those…
November 14th, 2011
I prefer Azimuthal equidistant centered on my house. Seems best some how.
November 14th, 2011
I don’t get the Waterman Butterfly one. I mean I get that it looks like a butterfly but what about the text and the 1909 thing? I don’t get the joke
November 14th, 2011
I, too, am wondering why this explainxkcd.com text does not explain xkcd.
November 14th, 2011
I would expect that since the sub-text is there to describe the personalities, that two people who both have heard and like this projections would be instant soul mates — and they should definitively setup a date asap, as they will be unlikely to ever meet somebody just like that ever again.
November 14th, 2011
Bernard Cahill published a butterfly map in 1909, http://www.genekeyes.com/B.J.S._CAHILL_RESOURCE.html. Steve Waterman probably has the only extant “ready to go” map following the same general principles, though Gene Keys may not be far behind (first link). Waterman has a poem with graphics in a similar vein to the this xkcd comic that is worth reading: http://watermanpolyhedron.com/worldmap.html.
The Cahill/Keyes/Waterman projections are arguably the only map projections, thus far, that more or less equally balance the inevitiable “all maps lie” distortions in size, shape and area. The joke is that this dude really deeply gets map projections.
November 15th, 2011
http://www.genekeyes.com/Cahill,1909_Butterfly_Map.html
November 14th, 2011
Why does he hate Gall-Peters?
November 14th, 2011
Yea I don’t get that one either…
November 14th, 2011
No, Randall doesn’t hate Gall-Peters. If you prefer the Gall-Peters map that implies that you hate everyone you meet.
November 14th, 2011
Respectfully disagree. The comic is what ‘your’ favourite map says about ‘you’. Each map describes ‘you’re…’ eg. ‘you’re not a complicated person…’ – if your favourite projection is a globe, Randall notes ‘yes, you’re very clever’. Thus, ‘I hate you’ is Randall’s comment on the person who prefers the Gall-Peters projection.
Can’t add any insight as to why, though
November 14th, 2011
From Wikipedia: “On Peters’s projection, by contrast, areas of equal size on the globe are also equally sized on the map. By using his “new” projection, poorer, less powerful nations could be restored to their rightful proportions. This reasoning has been picked up by many educational and religious bodies, leading to adoption of the Gall–Peters projection among some socially concerned groups.” Some groups opt for this particular projection for emotionally-charged sociopolitical reasons, thus injecting strong emotions into what we’d expect as dispassionate cartography.
November 15th, 2011
After reading everyone about the Gall-Peters Projection, I actually kind of like it.
I was surprised when I read that on a standard Mercator projection map, Greenland is represented to be larger than Africa, whereas in reality Africa is 14 times as large. While it’s not what I would normally choose, the Gull-Peters definitely offers a nice alternate perspective on the correct proportions of countries.
http://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection
November 14th, 2011
Possible explanation – I hate people that look thin, and this map makes everything look thinner than it seems
November 15th, 2011
I think that, although apparently there’s a lot of people who don’t appreciate your joke, what you’re saying is very close to accurate. Fact is, the map is completely unrealistic in its depictions, regardless of geographic location. In the other maps, some things are a little messed up and some things are more, but with the Gall-Peters, everything is completely messed up.
November 18th, 2011
Personally, just looking at the Gall-Peters map fills me with loathing. I’m not sure why Randall hates it, but the first thing I notice about maps is whether or not Antarctica is fairly represented (not overly huge like Mercator and not barely visible like Hobo-Dyer), and when Antarctica isn’t even important enough to make it on, I *know* the map must be grossly inaccurate. It’s a freaking continent, cartographers, the seventh of seven, and even if you never plan on visiting, people do live and work there. It had better at least be included.
November 14th, 2011
I feel that there are several inside jokes here that I’m still missing. What’s the 1909 Waterman Butterfly map he’s refering to? What about Gall-Peters, and why does he hate those who prefer that map? Are all of the map names real, or are they jokes in themselves, and what do they refer to (ex: Hobo-Dryer)? I’d love to have this comic further disected and explained.
November 14th, 2011
Methinks part of what makes xkcd great is binding mundane social emotions to extreme geekiness. Given any niche specialization you’ll find people who get passionate about obscurities which most people aren’t even aware of. There are sociopolitical and semantic motivations behind each of those map projections, and topical infighting may have occurred to get them generally recognized/accepted as possible standards – hence some people can be pigeonholed by which styles they prefer, to the point of “if you like X then, well, you just suck”. Put another way, “religious wars” happen with devotees of any subject.
BTW: Wikipedia is your friend.
November 14th, 2011
The gender-neutral text, i believe, is in reference to Dinosaur Comics 2079-2081, where Ryan North makes jokes about ‘thon,’ a made-up gender-neutral pronoun.
November 14th, 2011
Not necessarily. Gender-neutral pronouns predate Dinosaur Comics, specifically, the Spivak pronouns such as “e”, “eim”, “eir”, or other systems, like using “zhe” or “zhim”.
Most of us consider these people to be prats.
November 15th, 2011
B.J.S. Cahill invented an octahedral world map nicknamed the Butterfly Map, in 1909. Steve Waterman designed a variant in 1996. Though I like Bucky Fuller’s 1954 Dymaxion Map, I judge it to be far inferior to Cahill, in my very detailed comparison-critique. Meanwhile, I’ve been working on my own variant of Cahill since 1975: the Cahill-Keyes Multi-scale Megamap, now in a recenty uploaded computer-drawn version. These are all linked from my website, genekeyes.com.
November 15th, 2011
Yours looks surprisingly good actually
November 14th, 2011
There’s a good Wikipedia article on different map projections and what they mean and why they came about. I think waterman-butterfly reference is a joke about geeky people, perhaps who like maps that fold into globes resembling D&D dice or Bucky Balls, I dunno… Good Wikipedia article on that too. Just google “Map Projections” and “Waterman Butterfly”. You’ll find it – top hit.
Argh, filter won’t let me post links…
http://www.colorado.edu/geography/gcraft/notes/mapproj/mapproj_f.html
http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html
November 15th, 2011
Those look an awful lot like links.
November 15th, 2011
Yes; it wouldn’t let me post all the links I wanted (e.g. to the relevant Wikipedia articles). Thanks for pointing that out… ;-D
November 14th, 2011
I don’t – what?
November 14th, 2011
i’ve often wondered what the purpose of this site was. to “explain xkcd”, sure. but does explaining mean “stating the obvious”?
why does “randall” hate anyone who likes the gall-peters projection? why is he so excited about the “waterman butterfly”? what’s with the cultural imperialism reference?
in my opinion there are many things that ought to be explained here. in your opinion there aren’t. but why should i come here if i still have to google the different types of map projection myself?
in my opinion, berg does a much better job in analyzing these comics.
November 14th, 2011
who/where is berg?
November 14th, 2011
I have to admit it would be hard. Randall covers so freakin much ground. It’s an impressive feat for one individual. Still, the site might be better in a sort of pseudo-blog-wiki format. I don’t know that great software for that already exists, though I suppose it could be done with mediawiki.
November 15th, 2011
I like this website, and HunterAdams, I agree, but this is what the comments section is for. Jeff has a certain take on the comic and it’s our job (as literate commentators) to either agree and add to that, or disagree and “correct” Jeff’s explanation… although for an site about xkcd there seems to be quite a lot of explication going on and to me contextual/explicative interpretations reek of something you do in an English Lit course in college… but I love interpreting and looking at contextual evidence so… I still say a Science Major pay off in the end!
November 14th, 2011
I’m glad commenters eventually post really good explanations because “the different types of map projections are laid out and all the text below the map projections are jokes” is not an explanation. Thanks, the text of a comic is a joke.
According to Wikipedia, the Gall-Peters is a bit of a joke – it’s not novel, in the sense that cartographers had used the ideas for a long time; it’s not distance factual; it has extreme distortions of form; it doesn’t have absolute angle conformality (whatever that is).
November 14th, 2011
“Rosencrantz: I don’t believe in it anyway.
Guildenstern: What?
Rosencrantz: England.
Guildenstern: Just a conspiracy of cartographers, then? ”
― _Rosencrantz_and_Guildenstern_are_Dead_
November 18th, 2011
What a wonderful play!
November 14th, 2011
Some map projections are faithful in regard to distances, or angles, or areas… the geek proves his worth by knowing what a certain kind of map can do, and what it cannot do.
In the Mercator projection, you can fly the same azimuth (regarding true North) during the whole journey and you will end up where you intend to arrive, but your journey will not be the shortest one.
The Mercator portrays Greenland as big as Africa, but in reality Greenland is three times the area of Texas. (Africa support groups will never use a Mercator chart, this said.)
As a protest against atomic tests, some Pacific islands have issued world maps centered on French Polynesia.
November 14th, 2011
I think there’s one angle (no pun intended?) missing here: this is a geeky/nerdy play on the “What your * says about you” meme that you often see in, e.g., various women’s/teen magazines (YM, Seventeen, etc.).
November 14th, 2011
Of course the image text also has a double-pun, which I don’t think anyone so far has explicitly mentioned – *projecting* your feelings onto someone else, and a map *projection*.
November 14th, 2011
The explanations alludes to this, though you’re right it doesn’t explicitly explain it, simply mentioning it ends with “a corny pun”. Non-native-english speakers might not get the pun.
November 14th, 2011
The hell? That didn’t explain ANYTHING!
November 15th, 2011
It should be noted that the dymaxion joke may refer to the fact that it can be mounted as an Icosahedron, wich is the 3d form of a D20 rpg dice
November 15th, 2011
Which dymaxion joke?
November 15th, 2011
D’oh! THAT one. Sorry!
November 15th, 2011
“Not much to explain here”??? This is one of the most esoteric comics I’ve ever seen in my life. I guess the author of explainxkcd is an expert cartographer, but many of us are not and could’ve used some explanation.
November 15th, 2011
I agree. I checked in here just to see how Jeff handled it, and was a bit disappointed. Perhaps my expectations are to blame.
November 15th, 2011
I’m a little torn because while the final punchline doesn’t read if you don’t know much about maps, the rest pretty much do. (I’m particularly blown away by people not getting the Waterman Butterfly one, given that it requires *no* understanding of the actual map.) So while a little more info might have been useful…I’m going to agree that there’s not a WHOLE lot to explain.
November 15th, 2011
It would have been nice to have explanations of what the joke is for each one of these maps, but I can understand how that would have made for a very long post. Each of these are real maps, and if you look them up on Wikipedia you can see how you might stereotype a fan of each one based on the history and/or design goals of that particular map.
For instance, the Mercator map has a lot of distortion, but became very widely published for a long time just because it’s rectangular. If it was your favorite map projection, that would indicate that you probably haven’t looked into map projections at all.
The Dymaxion Map was developed by Buckminster Fuller, the free-thinker hippy engineer who promoted a lot of similarly clever (but largely also impractical) alternatives to everyday things, most famously the geodesic dome house. It manages to almost entirely eliminate distortion in the shape and size of the land masses, but does so by rejecting several normal map design goals. The other things it says Dymaxion Map fans would enjoy similarly indicate a personality that prefers functionality and novel solutions, at the expense of aesthetics and cultural norms.
Other commentors have explained the joke about the Gall-Peters map pretty well. Essentially, if that’s your favorite map, it means you are more concerned with political matters than mathematically accurate map projection, and you think that cartographers who reject the Gall-Peters map are First-World-centric cultural imperialists. Hence the map-obsessed narrator’s “I hate you.”
For the record, I had a poster of the Dymaxion Map in my bedroom in college. And I use the Dvorak keyboard layout. So, I think Randall’s got me pretty well figured out.
November 15th, 2011
He figured us all out. I prefer a globe, and yes I am very clever
November 15th, 2011
So now we are getting to the core of the comic. Maybe we’re still able to get a full explanation of all the texts below the map projections. You covered 3 of them, let’s see how much I’ll get:
The Van der Grinten map has no nice properties, not even equal-area (in contrast to mercator). The only “advantage” (or disadvantage, depending on your likes and dislikes) is that it’s a circle. So if you like this map, you probably aren’t really into maps either, but like circles more than rectangles.
Robinson is a rather mainstream map, too. It’s a compromise b/w equal-area and conformal maps and was once used by NatGeo. Africa looks as huge as it should, while on the other hand the northern hemisphere remains familiarly large. The text description sums up other main stream or compromise solutions for your life. As I know xkcd, it’s not by coincident that it’s depicted next to Dymaxion.
Winkel Tripel has been kind of competitive to Robinson, with similar features and drawbacks (and too similar for non-profs to tell the difference). If you like this one, you probably are an outsider indeed, but not for the cost of aesthetics. Therefore the disgust in view of toe-shoes (they *are* ugly, aren’t they?) and the favour for these “slightly-rebellious” post-genres. To stay this way, you cannot use this map anymore since it’s been adopted by NatGeo, so you’ll switch to the (again similar-looking) former SU standard Kavrayskiy vii.
Good homolosine is an “easy” solution in the way that it’s what the layman would probably come up with when looking for a way to flatten orange rind (which is, pictorial speaking, the cartographers’ task). It has even the nice equal-area property. There are of course some hidden problems “normal people” with their “easy answers” do not see. I’m not a cartographer, so the only one I can think of is that it’s not easy to find routes on this map since it’s interrupted. There are probably bigger problems. The airline thing is also a simple-looking solution, the drawbacks of which have to be pointed out by someone interested in economics. The oil-change thing I don’t really get.
Hobo-Dyer, originally upside down, has similar goals as Gall-Peters, so Randall describes the standard politically correct gender-aware environmental-campaining world saver. Not sure, though, what “bad things” can be heard about Gall Peters and why he hates only Gall-Peters disciples while taking the time to describe in detail those who favour Hobo-Dyer.
Plate carée is the easiest mathematical solution. The sphere (i.e. earth) is a 2D surface and can be described in local coordinates. Take latitude and longitude, and you can take all but one meridian (including the poles) as coordinate environment. Who cares about a zero set, anyway? All the crucial points of the other maps (aesthetics, cultural imperialism, equal-area, conformality etc.) are unimportant to you. So let’s just take an easy map and go ahead with important things like, food intake.
A globe is, of course, no projection. Hence the ironical statement, “you’re very clever.” Problem solved by neglection.
The text to Peirce quincuncial is not entirely understandable for me. It’s about existencialism, but what has this map to do with existencialism anyway? Maybe it’s because you can tesselate the plane with this map, like here: http://www.progonos.com/furuti/MapProj/Normal/ProjConf/Img/pqTiled.jpg – I sometimes find myself looking at square tiles on a wall or floor and thinking about some “deeper meaning” of anything – does this make me a typical Peirce supporter? Well, thinking about it, a bathroom wall tesselated with Peirce world map tiles would be teriffic.
November 15th, 2011
He does project the globe, which why it can show the entire planet. I still prefer this projection though. It just requires you to have multiple projections. For real maps (like map books) though, it is not really a problem though, they can center a projection on the area they are zoomed in on.
November 16th, 2011
The double projection of the sphere, showing east/west hemispheres, really is my favourite. Too bad it is so neglected that he didn’t even go the one step further after the globe to show the “backside” too. No time today to try to find out if the double circle globe projection has a name among cartographers. Can anyone help out here?
November 15th, 2011
When Peters published his projection, he talked about ut as though cartographers still preferred the Mercator projection. This offended real cartographers who had been trying to explain the problems with Mercator for uses outside navigation for decades. For instance I have my mother’s 1943 Goode’s School Atlas (at that time the most common in US schools) with an extensive preface on map projections, the importance of equal areas, and the “Evil Mercator.” I have looked at more recent student atlases, and they have been dumbed-down in this regard: they say Mercator is politically incorrect without going as deeply into the mathematics. Mercator never intended his map as a general-purpose map, he designed it as a practical tool for solving a specific problem of navigation for which it remains uniquely suited. Professionals in any field get understandably annoyed at outsiders who ignore what they have long known.
November 15th, 2011
Not sure if this is posted, but they also did this joke with http://xkcd.com/524/.
November 16th, 2011
HELP! I prefer the Winkel-Tripel and I dislike the Dymaxion… but I wear toe shoes! I’ve been wearing nothing but toe shoes since April in fact – even have a pair of black leather ones for going to church.
Should I seek psychiatric help to correct my choice of map projection or to correct my choice of footwear?
November 18th, 2011
Mercator Projection – you actually use maps for their original purpose – navigation. You think people are annoying that pick map projections for some kind of political or aesthetic reason and only use them to draw fruity colors representing population density or biomes.