Peters Map Projection

[Sycophant]

So if anyone is a West Wing fan like myself, you will remember in the Big Block of Cheese day episode the crazy cartographers with their crazy map...

It is the Peters Projection Map (http://www.petersmap.com/) and it is accurate, unlike the tradtional Mercator Projection we are familiar with.

It will blow your mind. The atlas is fucking lying!!!

[Adora]

I know! I fucking love these maps. I've had one of them stuck on my wall for years (all N.I.'s fault, they had a free one in one of their issues and I was like "OMG *squee*"). Viva la fucking revolution!

[Dingfod]

Maybe this is why it looks so easy for us to possibly conquer wee little countries like Iran, which is in reality the size of Alaska, but only looks to be the size of Texas on the Mercator map, which is about half Iran's real size. Holyfuk, I just found out that Sudan is actually almost the size of the U.S. east of the Mississippi River.

[ceptimus]

Even the Peters map is politically biased, though less so than the Mercator. It still has Europe (Greenwich, London specifically) at the left-right centreline of the map, and Europe at the top.

Why is this? Simply that such maps were first made for and by European seafarers of the fourteenth and fifteenth centuries - tradition has kept them the same from then.

If world travel had first been devised by the natives of Australia, we would no doubt be used to maps with south at the top, and Australia near the centre.

[Dingfod]

One reason I can think of for having the Greenwich meridian in the middle of the map besides historical context is because the Atlantic Ocean is much smaller than the Pacific. If they centered the map on the International Date Line instead, almost half the map in the middle would be ocean with the land masses at the far edges of it.

Aboriginal Aussies, world travel, they didn't, moot.

Think how much having a flat earth would solve all these problems.

Personally, I think the center of the universe is where ever I am at the moment and that all maps and charts should reflect that. And North is whichever way I say it is, at my whim.

[wade-w]

One reason I can think of for having the Greenwich meridian in the middle of the map besides historical context is because the Atlantic Ocean is much smaller than the Pacific. If they centered the map on the International Date Line instead, almost half the map in the middle would be ocean with the land masses at the far edges of it.


Well, there's nothing special about the International Date Line, other than the fact that it's 180 degrees from the Prime Meridian. Any line of Longitude would work as well for a Prime Meridian, and whatever happened to be on the opposite side would then be the international Date Line. The current choice is purely arbitrary other than from a historical perspective.

Changing it to something else would cost a shitload of money, though, and cause all current geographical data relating to longitudes to instantly go out of date. I don't see any good reason for changing it now.

[Godless Wonder]

I don't know... it doesn't seem to be blowing my mind. Maybe because I've always had a globe around the house? The Mercator projection has always looked pretty messed up to me, esp. up north.

BTW,. there's a bigger one here:
http://www.mastersandscribes.com/item498.htm

[ceptimus]

The Interrupted Goode Homolosine Projection attempts to keep the shapes roughly right, as well as the land areas.

http://www.progonos.com/furuti/MapProj/Normal/ProjInt/ProjIntC/projIntC.html

As Godless Wonder said, globes are best.

[Skep]

Interrupted maps certainly reduce distortion in shape and area but do so at the expense of visual appeal. I'm rather partial to The Robinson Projection (http://www.geography.wisc.edu/maplib/rob_proj.html) used by The National Geographic Society and Rand McNally for their world maps.


The Robinson projection is unique. Its primary purpose is to create visually appealing maps of the entire world. It is a compromise projection; it does not eliminate any type of distortion, but it keeps the levels of all types of distortion relatively low over most of the map.

[Farren]

I can spend hours poring over maps. I've got a map fetish. That's a very cool map.

[JoeP]

...
It is the Peters Projection Map (http://www.petersmap.com/) and it is accurate, unlike the tradtional Mercator Projection we are familiar with.

It will blow your mind. The atlas is fucking lying!!!

I like the Peters Projection. But it lies. Mercator is the only true map. In this (specialised) sense: it preserves direction. If you're at latitude X longitude Y and the place you want to get to appears due north-west on the mercator map, you sail north-west. Pretty damn useful if you're navigating a ship. Can't do that with no peters projection.

[ceptimus]

True to a degree, but remember, if you wish to sail, or fly the shortest course between two points, a straight line on a Mercator map is not what you want.

All things being equal, you'd want to use a great circle route, and these will almost always be curves on the Mercator map. So to sail to a point due west, you might need to start sailing northwest, then gradually change to west, and arrive at your destination going southwest. Ever thought why airline routes never seem to go by the shortest route on such maps? It's because the maps are misleading.

[Clutch Munny]

True to a degree, but remember, if you wish to sail, or fly the shortest course between two points, a straight line on a Mercator map is not what you want.

All things being equal, you'd want to use a great circle route, and these will almost always be curves on the Mercator map. So to sail to a point due west, you might need to start sailing northwest, then gradually change to west, and arrive at your destination going southwest. Ever thought why airline routes never seem to go by the shortest route on such maps? It's because the maps are misleading.

One of my favourite moments in teaching is when I'm introducing Poincare and Reichenbach's remarks on the conventionality of geometry in physics. I bring in a globe and ask, Which lines are the straight ones? It's astonishing how often the students who got straight As in high school physics join everyone else in pointing to the lines of latitude.

[Shaguar]

Great links.
Any of you that like this sort of thing may want to read "Longitude" by Dava Sobel. The true story of the man (Harrison) who struggled to make a time piece accurate enoughto enable seafarers to calculate their position. It may be hard to believe but the book is highly readable

[livius drusus]

I don't find that hard to believe at all. I saw a mini-series based on the book and although it was tolerable, the best thing about it was that it made me want to read the book. Many thanks for the reminder.

[ceptimus]

Longitude (the book) is one of my favourites. I've read it about five times. It's short enough to read at one sitting. Starts out a bit slowly, so skip the first few chapters if you find it dragging.

One of the chapters starts with this one-word-sentence: Sauerkraut.

[Darren]

It is the Peters Projection Map (http://www.petersmap.com/) and it is accurate, unlike the tradtional Mercator Projection we are familiar with.

It will blow your mind. The atlas is fucking lying!!!

The Peters projection is accurate with regard to scale, i.e. it gives an accurate picture of the relative sizes of the Earth's landmasses. On the other hand it is innaccurate with regard to shape. The Mercator projection, on the other hand, is accurate regarding shape and position but innaccurate regarding the relative sizes of landmasses and oceans.
So, the first is good for political maps because, for example the Peters doesn't downsize Africa and expand North America and Europe the way the Mercator does. It gives a truer idea of the relative sizes of individual countries and continents which is more relevant to Human Geography than accuracy with regard to shape would be.
The second is good for navigation because a straight line on a Mercator indicates a direct bearing in reality.

It's all a question of using the right tool for the right job, and there's no denying that the Mercator projection has been misused for political maps in various ways, but you wouldn't use a Peters for navigation!

All atlasses lie, without exception, because if you want to represent a sphere on a flat surface you have to squash, stretch or snip (or any combination of these 3 processes) to achieve any result whatsoever.
If you want a "true" representation of the Earth, get a globe! (and even then there remains the question of orientation - what makes North up and South down, objectively speaking?)

(I haven't read through this entire thread yet, so I hope my post is not redundant by repetition of someone else's!)

[xouper]

True to a degree, but remember, if you wish to sail, or fly the shortest course between two points, a straight line on a Mercator map is not what you want. All things being equal, you'd want to use a great circle route, and these will almost always be curves on the Mercator map.
As in the following example. The red curved lines show the shortest flying distance (great circle routes) from London to Los Angeles or Atlanta.

http://www.xoup.net/img/klax-katl-egll.jpg

Image courtesy of www.landings.com

[livius drusus]

When I was a girl there was route from New York to Rome my dad called "The Green Way" which passed over the southern tip of Greenland just like the London-LA in that map. It looks like it would be a far sharper curve though, like a parabola almost, and that strikes me as a little wierd. I did a quick Google and couldn't find anything pertinent. Now I'm wondering if he made it all up. :hrm:

Oh well, either way, I did get to the Northern Lights from a plane once. That was indescribably awesome.

[xouper]

When I was a girl there was route from New York to Rome my dad called "The Green Way" which passed over the southern tip of Greenland just like the London-LA in that map. It looks like it would be a far sharper curve though, like a parabola almost, and that strikes me as a little wierd. I did a quick Google and couldn't find anything pertinent. Now I'm wondering if he made it all up. :hrm:
If you go here (http://www.landings.com/evird.acgi$pass*69462846!_h-www.landings.com/_landings/pages/search/search_dist_apt.html) and type in the ICAO identifiers for the departure and destination airports, leave the other boxes empty, check "Show area map of flight route", and click the send button, it will give you a map showing the great circle route between the two airports.

Here are some ICAO airport identifiers:

Rome: LIRF
New York: KJFK
London: EGLL
Dubai: OMDB

You can also find more ICAO airport identifiers here (http://www.landings.com/evird.acgi$pass*69462846!_h-www.landings.com/_landings/pages/search/search_ap-ident.html).

The great circle route between Rome and New York doesn't quite go near enough to Greenland, I'm sorry to say. (Dubai to NY is also an interesting flight path, if you notice the initial heading out of Dubai.)

However, many flights between Europe and eastern North America do stop in Greenland and/or Iceland if they are unable to make it non-stop. So I don't think your father made it up. It is a common route for those who want to fly near land every once in a while along the way, even though it is slightly north of the great circle route. You can even fly a four seat Cessna on that route through Greenland.

[xouper]

Another interesting great circle route is Chicago (KORD) to Tokyo (RJAA).

[livius drusus]

Thanks for the links, xouper. It's fascinating to see the routes I've flown a hundred times on a map, and even more fascinating to see the cool routes I've never flown, like Dubai-NY and Chicago-Tokyo.


The great circle route between Rome and New York doesn't quite go near enough to Greenland, I'm sorry to say. (Dubai to NY is also an interesting flight path, if you notice the initial heading out of Dubai.)

However, many flights between Europe and eastern North America do stop in Greenland and/or Iceland if they are unable to make it non-stop. So I don't think your father made it up. It is a common route for those who want to fly near land every once in a while along the way, even though it is slightly north of the great circle route. You can even fly a four seat Cessna on that route through Greenland.

I think you may be right that my dad was talking about a stopover flight. In my admittedly very dim recollection, there were at least a couple of times when we had to stop before reaching New York, so either Greenland or Canada had to be involved.

I can't imagine making such a trek in a little bitty Cessna. :eek: Have you done it? I know this is a totally idiotic question, but wouldn't it be really cold?

[xouper]

I can't imagine making such a trek in a little bitty Cessna. :eek: Have you done it? I know this is a totally idiotic question, but wouldn't it be really cold?
I haven't done it. Yet. But lots of other people have:

http://www.gruner.com/flight/chapter2/

[livius drusus]

Holy crap! Those icing stories are fucked up. That answers my question, at any rate: those gigantic testicled pilots bundle themselves up like mountain climbers for the Nothern Route.