Mapthematics Forums

Today is Gerhard Mercator’s 500th birthday. Mark Monmonier kindly notified me of this German commemorative: He sent it with question, “What’s wrong with this stamp?”

So. Have at it. What’s wrong with the stamp?

— daan

Well, perhaps it's because the stamp suggests that the Mercator projection can be constructed perspectively. It can't ... but that's inside cartography. OK for a stamp, I think. -Noel

Bingo! The portrayed projection isn’t a Mercator. It’s a cylindrical perspective. Indeed, if the image I have has correct aspect ratio, then the projection is a “central cylindric” with a vertical stretch of 1.09, though there is some asymmetry north versus south. The southern stretch is more like 1.11.

— daan

… and seven years later:
Tonight at 20:15 CEST, there will be an episode of the German science TV show "Terra X" on the public service broadcasting – which claims that the Mercator projection was constructed perspectively.

It is followed by the assertions that all the world maps we know "basically look exactly like the one Mercator developed" (and if you think that basically exactly is an oxymoron, I translated it just right) and that to see the real areal relationships, we need "to look at the Earth from the outside, seeing the whole sphere" which serves as transition to talk about the Copernicus Programme and thus is prone to misinterpretation at least (namely that the real areal relationships can only by seen with the help of satellites).
*sigh*


And no, regrettably I’m no precog, but the episode is already available via the network’s website. I guess there’s no need to post the link because it’s a) in German and b) protected by geoblocking.

“Basically exactly like” = “flat”?


— daan

daan wrote:“Basically exactly like” = “flat”?

Possibly.
I’m not sure, it also could mean that all world maps show the same continents and oceans that can be found on a Mercator map.

Atarimaster wrote:I’m not sure, it also could mean that all world maps show the same continents and oceans that can be found on a Mercator map.

My suspicion is that it means exactly what it said. That is, the person on the TV show was claiming (in effect) that the only projections used for world maps are the Mercator, the Miller Cylindrical Projection, and the Gall Stereographic. Nobody ever uses an equal-area projection to draw a world map. Or, possibly, he was also admitting the possibility that world maps drawn on the Van der Grinten I projection exist as well.

quadibloc wrote:That is, the person on the TV show was claiming (in effect) that the only projections used for world maps are the Mercator, the Miller Cylindrical Projection, and the Gall Stereographic.

Well, even that claim would be wrong. As I’ve said, it was a German TV show, and in Germany, Winkel Tripel (which surely doesn’t look like Mercator, although of course it isn’t equal-area) is used quite a lot in atlases and for wall maps.
Admittedly, I don’t know about the usage of map projections other countries.

quadibloc wrote:Nobody ever uses an equal-area projection to draw a world map.

Let’s say "equal-area maps are rarely used for world maps" – then, I have to agree.
But I do have atlases (and a wall map) which use Wagner VII, and of course there’s the Peters projection…



P.S.: Nice to have you here! I really like you website on map projections!

Atarimaster wrote:Well, even that claim would be wrong.

Oh, yes, that claim would be outrageously wrong. I knew that, but from how this TV program was being described, I would not have put it past those responsible for making it anyways. I am sorry that my posting was unclear.