7 ms·

This guy "loves world maps" but chose Mercator for the wall of his room? I guess there's no accounting for taste. There are hundreds of projections to choose

This guy "loves world maps" but chose Mercator for the wall of his room? I guess there's no accounting for taste. There are hundreds of projections to choose from, why choose the one optimized for navigation by compass?

seqizz 12y ago
This was also my first reaction. "Nice Africa-sized Greenland you have there.."
- daigoba66 12y ago
  That is rather striking: http://www.pratham.name/images/mercator.png http://www.pratham.name/images/mercator.png
fougerejo 12y ago
Maybe because he used Google Maps, and they use Mercator?
- jpatokal 12y ago
  By default, but this can be changed in the API: https://developers.google.com/maps/documentation/javascript/maptypes#Projections https://developers.google.com/maps/documentation/javascript/...
  - ars 12y ago
    But then you can't stitch images together.
anc84 12y ago
I was hoping to see what he learned was projections. Still better than no map on the wall. The style looks lovely at this scale! I would have made my own map from NE and OSM data but not everyone knows how much great data is available for free and how easy making maps with it is. We who know should do a better job of sharing.
- cmrx64 12y ago
  Me too. Sorely disappointed, but he does mention the issue in the footnotes. Glad he's happy with it though! It's a neat project.
- deleted 12y ago
  [deleted]
skrause 12y ago
Relevant xkcd: https://xkcd.com/977/ https://xkcd.com/977/
- teh_klev 12y ago
  And obligatory West Wing "Gall Peters Projection" clip: "What the hell is that?" "It's where you've been living this whole time" https://www.youtube.com/watch?v=vVX-PrBRtTY https://www.youtube.com/watch?v=vVX-PrBRtTY
  - kremlin 12y ago
    That was extremely funny. Especially the bit about putting the north on the bottom. "But you can't do that."
UnoriginalGuy 12y ago
He only had a Mercator map source data. Unless you know how to switch Google Maps into Peters Projection mode? I am surprised people who read the article are even asking this considering how much he struggled even to get the source image (and how he ultimately wound up manually stitching together print screens).
- maxerickson 12y ago
  He chose Mercator source data. I can understand why someone wouldn't want to set up their own tile rendering system (and hence not use something like OSM with whatever projection they want), but it likely would have been less work than screenshots.
- pricechild 12y ago
  Incase anyone really does want to do this: http://www.gdal.org/gdalwarp.html http://www.gdal.org/gdalwarp.html is awesome.
  - erroneousfunk 12y ago
    But he had the map data and the text data all compressed into a single image -- the text would have been warped as well.
    - pricechild 12y ago
      Hopefully someone will find it useful for the reverse, warping an overlay image to place on top.
- tomgp 12y ago
  Jason Davies has done excellent work on addressing this problem in the browser https://www.jasondavies.com/maps/raster/ https://www.jasondavies.com/maps/raster/
  - gambiter 12y ago
    Except, that's also going to screw with the nice 4pt fonts he talked about...
mewo2 12y ago
I can't believe I'm doing this, but I think I'm going to defend Mercator here. The Mercator projection was indeed originally designed for compass navigation, but the reason it's still used for web mapping is slightly different. The Mercator projection is conformal. What this means is that angles (and hence in some sense shapes) are preserved locally. When we zoom in on a small section of the Mercator projection, we get a reasonably accurate representation of the actual shape of features. This is generally not true for most more fashionable projections, which will stretch and skew things, so they don't always look great when zoomed. In general with map projections, you have to make a compromise between global properties and local properties. Choosing Mercator means going full-on for local quality, at the expense of the global map being quite distorted. This makes it great for zoomable web maps, because most of the time the global map is just used to find the area you're actually looking for. Now, you could argue that for a living-room wall, you want something that looks good globally. If it was my wall, I'd agree with you. However, this guy seems to be really interested in local detail. He worries about his four-point fonts becoming blurry, and about having as many small villages marked on the map as possible. If he's interested in that kind of detail, then I think he probably cares far more about local properties than the kind of global properties that would bother me or you.
- allemagne 12y ago
  >The Mercator projection was indeed originally designed for compass navigation, but the reason it's still used for web mapping is slightly different. The Mercator projection is conformal. Just speculating here, but it's also a big rectangle that is easy on the eyes. Non-rectangular online maps would fit awkwardly in websites. As for Gall-Peters, that map is just irredeemably ugly to me, and I'm ignorant of other rectangular projections that could compete with Mercator.
  - mewo2 12y ago
    Yes, absolutely! The Mercator projection isn't the only conformal projection, but it is the only one for which north-south maps to the vertical axis, and east-west to the horizontal axis. That means that it maps the whole world onto a rectangle, which works well both for computers and interior decorating. As for other rectangular projections, the most common is the equirectangular (or plate carrée), which simply maps (longitude, latitude) to (x, y). This is a pretty common representation for gridded global data.
deleted 12y ago
[deleted]
mg1982 12y ago
Guarantee everyone in this comment thread saw that episode of the West Wing where CJ meets the cartographers for social cartography. Me too. Big block of cheese, indeed...
- visakanv 12y ago
  That was a very amusing episode! I enjoyed it.
- Kluny 12y ago
  Ha, it permanently ruined (Mercator) maps for all of us!
Goladus 12y ago
> I guess there's no accounting for taste. Unless you're a hipster nerd trying hard to seem sophisticated. In that case, fashion is everything.
- freyfogle 12y ago
  relevant: http://geohipster.com/ http://geohipster.com/
jpwagner 12y ago
yeah he should've used the dymaxion with the continuous ocean https://en.wikipedia.org/wiki/Dymaxion_map#/media/File:Dymaxion_map_ocean2.png https://en.wikipedia.org/wiki/Dymaxion_map#/media/File:Dymax...
deleted 12y ago
[deleted]
skywhopper 12y ago
I have to agree. I love the idea here, it's something I've dreamt of myself, but even after trimming Antarctica and the Arctic, I feel like the map is dominated by the least interesting possible features on the globe: Greenland and Siberia. Worse, those features fall closest to eye level. On some level this is an unsolvable problem, but I was disappointed to see him spend more time on the pins he used than on the tradeoffs involved in the projection.
malkia 12y ago
For the same reason we have long accepted sci-fi movies with sounds in space. Imagine Star Wars without that. Now I wish we did not accepted that fast the lens-flares, but hey - my kid loves them.
parennoob 12y ago
Yeah, a world map that shows Greenland and South America at the same size is probably not a map I want in my living room. Even sticking pins in it would feel weird, knowing that Brazil is the size of Montana or whatever.
sliverstorm 12y ago
Stylistically speaking, Mercator is classic. If the map is just there as art, maybe your goal is to invoke the map on the wall of some ancient study in England.
rasz_pl 12y ago
he didnt, he just printed what google showed him

seqizz 12y ago

This was also my first reaction. "Nice Africa-sized Greenland you have there.."

daigoba66 12y ago
That is rather striking: http://www.pratham.name/images/mercator.png http://www.pratham.name/images/mercator.png

fougerejo 12y ago

Maybe because he used Google Maps, and they use Mercator?

jpatokal 12y ago
By default, but this can be changed in the API: https://developers.google.com/maps/documentation/javascript/maptypes#Projections https://developers.google.com/maps/documentation/javascript/...
- ars 12y ago
  But then you can't stitch images together.

anc84 12y ago

I was hoping to see what he learned was projections. Still better than no map on the wall. The style looks lovely at this scale! I would have made my own map from NE and OSM data but not everyone knows how much great data is available for free and how easy making maps with it is. We who know should do a better job of sharing.

cmrx64 12y ago
Me too. Sorely disappointed, but he does mention the issue in the footnotes. Glad he's happy with it though! It's a neat project.
deleted 12y ago
[deleted]

skrause 12y ago

Relevant xkcd: https://xkcd.com/977/ https://xkcd.com/977/

teh_klev 12y ago
And obligatory West Wing "Gall Peters Projection" clip: "What the hell is that?" "It's where you've been living this whole time" https://www.youtube.com/watch?v=vVX-PrBRtTY https://www.youtube.com/watch?v=vVX-PrBRtTY
- kremlin 12y ago
  That was extremely funny. Especially the bit about putting the north on the bottom. "But you can't do that."

UnoriginalGuy 12y ago

He only had a Mercator map source data. Unless you know how to switch Google Maps into Peters Projection mode? I am surprised people who read the article are even asking this considering how much he struggled even to get the source image (and how he ultimately wound up manually stitching together print screens).

maxerickson 12y ago
He chose Mercator source data. I can understand why someone wouldn't want to set up their own tile rendering system (and hence not use something like OSM with whatever projection they want), but it likely would have been less work than screenshots.
pricechild 12y ago
Incase anyone really does want to do this: http://www.gdal.org/gdalwarp.html http://www.gdal.org/gdalwarp.html is awesome.
- erroneousfunk 12y ago
  But he had the map data and the text data all compressed into a single image -- the text would have been warped as well.
  - pricechild 12y ago
    Hopefully someone will find it useful for the reverse, warping an overlay image to place on top.
tomgp 12y ago
Jason Davies has done excellent work on addressing this problem in the browser https://www.jasondavies.com/maps/raster/ https://www.jasondavies.com/maps/raster/
- gambiter 12y ago
  Except, that's also going to screw with the nice 4pt fonts he talked about...

mewo2 12y ago

I can't believe I'm doing this, but I think I'm going to defend Mercator here. The Mercator projection was indeed originally designed for compass navigation, but the reason it's still used for web mapping is slightly different. The Mercator projection is conformal. What this means is that angles (and hence in some sense shapes) are preserved locally. When we zoom in on a small section of the Mercator projection, we get a reasonably accurate representation of the actual shape of features. This is generally not true for most more fashionable projections, which will stretch and skew things, so they don't always look great when zoomed. In general with map projections, you have to make a compromise between global properties and local properties. Choosing Mercator means going full-on for local quality, at the expense of the global map being quite distorted. This makes it great for zoomable web maps, because most of the time the global map is just used to find the area you're actually looking for. Now, you could argue that for a living-room wall, you want something that looks good globally. If it was my wall, I'd agree with you. However, this guy seems to be really interested in local detail. He worries about his four-point fonts becoming blurry, and about having as many small villages marked on the map as possible. If he's interested in that kind of detail, then I think he probably cares far more about local properties than the kind of global properties that would bother me or you.

allemagne 12y ago
>The Mercator projection was indeed originally designed for compass navigation, but the reason it's still used for web mapping is slightly different. The Mercator projection is conformal. Just speculating here, but it's also a big rectangle that is easy on the eyes. Non-rectangular online maps would fit awkwardly in websites. As for Gall-Peters, that map is just irredeemably ugly to me, and I'm ignorant of other rectangular projections that could compete with Mercator.
- mewo2 12y ago
  Yes, absolutely! The Mercator projection isn't the only conformal projection, but it is the only one for which north-south maps to the vertical axis, and east-west to the horizontal axis. That means that it maps the whole world onto a rectangle, which works well both for computers and interior decorating. As for other rectangular projections, the most common is the equirectangular (or plate carrée), which simply maps (longitude, latitude) to (x, y). This is a pretty common representation for gridded global data.

deleted 12y ago

[deleted]

mg1982 12y ago

Guarantee everyone in this comment thread saw that episode of the West Wing where CJ meets the cartographers for social cartography. Me too. Big block of cheese, indeed...

visakanv 12y ago
That was a very amusing episode! I enjoyed it.
Kluny 12y ago
Ha, it permanently ruined (Mercator) maps for all of us!

Goladus 12y ago

> I guess there's no accounting for taste. Unless you're a hipster nerd trying hard to seem sophisticated. In that case, fashion is everything.

freyfogle 12y ago
relevant: http://geohipster.com/ http://geohipster.com/

jpwagner 12y ago

yeah he should've used the dymaxion with the continuous ocean https://en.wikipedia.org/wiki/Dymaxion_map#/media/File:Dymaxion_map_ocean2.png https://en.wikipedia.org/wiki/Dymaxion_map#/media/File:Dymax...

deleted 12y ago

[deleted]

skywhopper 12y ago

I have to agree. I love the idea here, it's something I've dreamt of myself, but even after trimming Antarctica and the Arctic, I feel like the map is dominated by the least interesting possible features on the globe: Greenland and Siberia. Worse, those features fall closest to eye level. On some level this is an unsolvable problem, but I was disappointed to see him spend more time on the pins he used than on the tradeoffs involved in the projection.

malkia 12y ago

For the same reason we have long accepted sci-fi movies with sounds in space. Imagine Star Wars without that. Now I wish we did not accepted that fast the lens-flares, but hey - my kid loves them.

parennoob 12y ago

Yeah, a world map that shows Greenland and South America at the same size is probably not a map I want in my living room. Even sticking pins in it would feel weird, knowing that Brazil is the size of Montana or whatever.

sliverstorm 12y ago

Stylistically speaking, Mercator is classic. If the map is just there as art, maybe your goal is to invoke the map on the wall of some ancient study in England.

rasz_pl 12y ago

he didnt, he just printed what google showed him