# Are these maps of Africa optical illusions?

My first reaction when seeing this was to be dumbfounded and outraged. But then, peering at it more closely, I started wondering if there is really a conflict between the two maps or if it just looks that way. I’m not sure how to evaluate this accurately and quantitatively, so I turn to you fine folks for help.

Why would you be outraged?

Either way, if you wanted to verify it on your own, you could just try printing a map, cutting out the various countries and seeing if they fit on top of Africa. You could even try using several maps since it’s my understanding that different map makers have different biases as to the sizes of various countries.

Actually, that probably won’t work since the projections are going to be screwy and cause issues.

It’s true. The Mercator projection (the most common one) exaggerates size as you near the poles. Since Africa is nearer the equator than most other areas, the countries look smaller compared to those at higher lattitudes.

An Equal-Area projection shows things more accurately as far as area is concerned.

:rolleyes:Of course, the explanation must be an -ism

I took the top map and cut out some countries in Photoshop and pasted them over Africa.

The map does not seem to be refuting the idea that Africa is larger than several large countries combines.

But that is clearly not the Mercator projection. Look how small Russia and Scandinavia look.

ETA: Nice job, **ZipperJJ **and I thank you profusely–what you did truly illustrates why this place is so great. I suspected on second look that this might be the case. So then the question is: what made the blogger, the blogger’s source, my wife (who sent this to me), and–initially–me, all think there was some huge disparity?

Looking at the numbers, the US is 9 million sq. km. Algeria, Libya, Mauritania, Chad, Niger, Sudan, Egypt, and Mali are more than that.

And the numbers on the side of the chart show the math. Cutting countries and pasting them doesn’t matter. The numbers trump any visuals.

The ‘true area’ one? Seems about right. China and USA are each about one third of the land area of Africa.

It’s a damn clever visualisation too.

I’m confused what the page’s point is. I think the top map is equal-area projection. And it looks visually consistent with the bottom map, at least to me.

It’s not an optical illusion, it is an artifact of the projection used to create the map. The issue arises from the simple fact that the surface of a globe cannot be directly projected to a flat surface without distortions. There’s a number of other projections that do a better job of avoiding distortions, but there’s other limitations with those, particularly with discontinuities, and they still have distortions of their own.

This particular project is fairly common because it projects to a simple shape of a rectangle and has the nice propery of having all longitudinal lines parallel and equidistant, which they are not in reality. It also has the desirable properties of having the Equator and Prime Meridian bisect it and not having weird divisions in bad places. As a result, relative to the equator, land masses nearer the poles will appear larger. This obviously affects Antarctica the most, since it’s right on the pole, so it appears significantly biger than it is, but no one really cares. Africa appears smaller because it not only lines up on the Equator, but a lot of it’s land mass is near the equator, so it appears relatively smaller than it is.

Obviously, one could use the same projection but pick another point besides the Equator and Prime Meridian point to center on, which essentially is what the second map did, presummably centered the projection in the middle of each country and Africa to minimize the distortion. But, really, if you want an undistorted map, use a globe, otherwise use whatever is most convenient for your purpose.

And the implied charge in the link in the OP that it’s motivated by racism, considering all of the reasons for the projection being the way it is arise from clearly useful properties and simple artifacts of how the Earth actually is, that charge just doesn’t hold water.

Mercator was a navigation map. The value of Mercator was that a straight line on the map was the same compass heading all the way along the line. the downside of Mercator is that the area toward the poles is more exagerrated. Canada and Greenland look to be the same size as Africa, Russia much larger. Alaska looks like half the size of the continental USA. They are nowhere near that big.

This is always the problem in tryng to display a globe’s surface on a flat sheet.

Unfortunately, most North American (and European?) classrooms have mercator projections.

This, Molleweide - http://www.progonos.com/furuti/MapProj/Normal/ProjInt/ProjIntC/Img/bog-I.png - is probably a closer approximation to valid areas. The equal-area map linked compensates for paralell longitude by shrinking the distance between latitudes, a different distortion.

I’m getting confused by all the answers here. I also wonder “what is the point of the blog post?” The blog post is saying “MAPS PRINT AFRICA REALLY SMALL! You totally can’t tell that the US, China, India and Europe fit inside of Africa but they totally do!”

But…the map they used as an example…clearly you can put the map’s US, China, India and western Europe in Africa.

So I am too confused as to the point of the blog post.

For a second I thought you were saying that each of those countries was larger than the United States. Just to clarify, all of those countries combined exceed the size of the United States.

The United States is considerably smaller than the continent of Africa, but as individual countries go it is huge - 3rd largest in the world by land area ( 4th behind Russia, Canada and China if you go by total area ). The largest African country is Algeria at number 10.

Zipper, to a number of people (not you or scr4, but I’ll cop to initially being one), it really *does *look like “MAPS PRINT AFRICA REALLY SMALL! You totally can’t tell that the US, China, India and Europe fit inside of Africa but they totally do!”

Unless you are guilty of some kind of Photoshop skulduggery (which I seriously doubt), you have proven this assertion to be empirically incorrect. But there nevertheless remains some kind of psychological/visual effect here that affects a not-inconsiderable number of people, and that still seems to me an interesting enigma to ponder.

First of all I think that some projections are indeed chosen due to the geographers sense of importance of the North, at least to the extent that that certainly would not choose one in which Africa is larger.

That said the example they chose is a poor one. Africa is the correct size in it. However, it always looks like you can fit fewer oddly-shaped small objects into one larger object than you really can, because you tend to round off the smaller objects and think of them as bigger than they are. Which is why it’s mildly surprising that you can fit all of those countries into Africa, but if you would have asked me I would have only been off by like %15 or so, due to the previously mentioned tendency to think of irregular objects taking up all of the space in their immediate vicinity.

I’m not clear on the point being made either. Africa and S. America are the continents least affected by distortion in most projections, at least relative to the fixed size of the earth. The projection they used squeezes the continent horizonatally a little, but most projections don’t. You’re supposed to look at Greenland and Australia when you want to make points about continent size and map projections.

Diffeomorphism?

Seriously though, have you ever heard any racists ever bring up the argument, “Race X is inferior because they come from a place that looks small on the map”. If anything, modern racism has taken the idea that the master race is the one that comes from a small, exclusive, homeland.

I don’t just want to echo everything that’s already been said here, but I thought the view of Africa from space was pretty interesting.

The answer to the OP’s question seems to be “yes”.

As far as I can, the same type of issue is being discussed over in “So do babies/toddlers REALLY think you stop existing during peekaboo?”:

Look at the “rain gauge” and “cookie” discussions.
As noted by previous posters, conflicting appearances with regard to size and shape are inherent in projecting a three-dimensional object (planet) onto a two-dimensional space (map).

The way you determine relative sizes is by measuring them, not by eyeballing the results of different map projections. Especially if what you are looking for is evidence of some discriminatory agenda.

The contiguous United States, Canada, Europe west of the Urals, China, Brazil and Australia each clock in about one-third the size of Africa. So you can cut and past all sorts of combinations.

If I were an editor, I would summarize the blog post linked to in the OP as “I don’t understand maps so the world must be racist.”