The true size of a country or state | Hacker News Reader

The true size of a country or state

thetruesize.com

105 pointscallum8536 comments

Interesting things happen when you drag a country onto the poles.

More information: https://en.wikipedia.org/wiki/Map_projection

Thats why Mercator is not a good projection even for comparing countries this way. Because for reasonably-sized countries, north and south are still distorted.

For an extreme example, try to lookup Chile and put it over Portugal, a similarly shaped country. Watch how Chile is vastly different whether you put its southern or its northern tip over Portugal.

On one hand Chile looks like it might be less than 10 times the size of Portugal, on the other hand it looks like it might be more than 20 times Portugal.

Maybe this explains why New Zealand looks like it has about as much land area as California even though California is actually about 60% larger than New Zealand.

Drag Greenland onto Australia or Mexico and watch how much it shrinks. Australia just swallows greenland.

Can someone tell me why countries get larger as they are moved closer to the poles ?

https://en.wikipedia.org/wiki/Map_projection

When you represent a spherical world on a flat map perspective gets distorted. The map used is Mercator’s map:

http://www.buzzfeed.com/mariasherm/every-world-map-youve-eve...

I chose buzz feed because they use illustrations. Some believe it is a conspiracy though.

we essentially peel the globe like an orange and stretch to fill the empty space. The poles have the most empty space: http://i.imgur.com/JnRijN9.png

There's no way to take the surface of a sphere and flatten it out into a rectangle without distorting it in some way. It's called 'projecting' from 3D to 2D.

The projection used for the underlying map here is the Mercator, which stretches everything near the poles. It makes Greenland look almost as big as Africa, which it is not. It's the most common projection, but it's awful for accurately visualising the whole world at once.

But the Mercator is actually a really good projection for stuff like Google Maps, because it keeps shape and direction (not scale) accurate all over the world. Say you zoom into Iceland and then Ecuador... OK you'll need a different zoom level to get to the same real-world scale (e.g. to get to 10 miles per inch you need to zoom in closer to Ecuador than Iceland) but who cares. What matters is that, in either location, north is pretty much straight up, east is right, south is down and west is left. And also, a 10 mile road going east–west will look about the same length as a 10 mile road going north–south.

Other projections don't have these qualities, but are better for keeping overall scale the same all over the map, making relative sizes of countries look more like what you get on a 3-D globe. But most people just use Mercator for everything.

Hmm, I tried to drag the US back to where it is on the map, and it doesn't fit...

I think it has been rotated to fit inside Africa better. If you spawn it by typing in USA it fits back after you drag it.

This is 100% correct.

We will add the ability for users to rotate countries soon.

Just use an equal-area map projection.

Obligatory XKCD.[1]

[1] https://xkcd.com/977/

Why does the US say "contiguous 50 states"? Shouldn't this be 48? (or 49 if you consider DC a state)

I'm guessing it should be 48. When the US is placed over the US, its appears to be about the same size (therefore, not including Alaska).

EDIT: and there's a 'non-contiguous' option for the US that includes Alaska and Hawaii.

My bad.

It's fixed now.

Wow, Russia changes a lot.

Georgia, the republic of, not US, GA, cannot be viewed. Sad.

Added to our bug database. We will get it fixed eventually. Keep checking back!

This is great. I've been looking for a tool like this!

Why does South Korea have North Korea flag?...

The Republic of Korea and the People's Democratic Dictatorship of Korea have their flags reversed.

Fixed!

How do you rotate a country?

You can't ... (yet)!

The rotation code is actually done, you'll notice China is rotated when you first log on (as is the US just a little).

Creating sane UI for you to rotate countries yourselves (that works on top of google maps) is going to take us a while. But it's on the todo list after better State/Province data

No need for UI, just use the scroll wheel while dragging, or shift + scroll while the mouse is hovering a country.

The author of this tool should use history.replaceState instead of history.pushState. Otherwise the way the page saves state using the HTML5 History API makes it impossible to use the back button.

Yeah, noticed this. Kind of annoying. Overall, a very cool idea, and well executed, though!

Same thing in puzzle form:

https://gmaps-samples.googlecode.com/svn/trunk/poly/puzzledr...

http://bramus.github.io/mercator-puzzle-redux/

Except, this is the Mercator projection, which distorts the size of objects as latitude increases from the Equator[1], rendering the whole website pretty much useless.

Consider using something like the Gall–Peters projection[2]. It is interesting to compare continents at their true size.

[1] https://en.wikipedia.org/wiki/Mercator_projection

[2] https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection

That's what I thought at first but if you search for a country then drag it around, it will change its size as you get closer to or further away from the equator so it takes the distortion into account. So maybe pointing out the distortion in the Mercator projection is part of the point?

Yeah, I took that as the whole point. You can overlay one country on another to see how they relate despite being at wildly varying latitudes on this projection. E.g pull Greenland down to India.

Sorry to see you downvoted from people who think you are wrong. You are right. The projection still matters here. https://www.reddit.com/r/MapPorn/comments/3jcumk/the_democra... explained it well recently.

The country overlays change size as you move them north/south. Showing how the Mercator projection affects your perspective on country size is the whole point here.

The downvotes are likely because parent is giving the impression that they couldn't be bothered to spend 3 seconds finding out what's going on before commenting about it.

The point is that comparing shapes of different sizes still overly exaggerates the scale of the bigger one here. It does not allow for any kind of "true size" comparison.

https://xkcd.com/977/

"Gall-Peters: I hate you."

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