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Comment by xg15 | Hacker News Reader

Mercator projection striking again.

The largest surprise for me (besides the massive size of Africa and South America of course) was that Australia has roughly the same area as the entire US. Somehow I had always imagined it smaller.

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Brazil is the largest surprise for me. It's an absolute massive country.

Not only in area, but also in population: about 200 million, 2/3 of the USA population. The population of our 5 largest cities (São Paulo, Rio de Janeiro, Brasília, Fortaleza, Salvador, Belo Horizonte) is bigger than the 5 largest cities of the USA (New York, Los Angeles, Chicago, Houston, Phoenix):

https://pt.wikipedia.org/wiki/Lista_de_munic%C3%ADpios_do_Br...

Wikipedia says contiguous USA is smaller, 95% of Brazil size.

Wow - in my head, Australia was somehow ~20-25% the size of US (I'm from Europe) - really surprising, and shows how misleading the projection can be in this regard.

I wish schools would stop using it so much. Mercator is useful, yes. But having good size comparisons is much more important for most everyday tasks.

It's useful for navigation in the open ocean without satnav or even a chronometer, which is what it was designed for in the 1500s. Not for much else.

Is the use of Mercator in schools common, globally? Based on what I've read on the internet it's common in the US, but I have no idea about other countries. In Finland I think I only ever saw Robinson or Winkel-tripel type compromise projections. Mercator was maybe used as an example of how projections distort things.

I thought Mercator became popular due to online maps like Google using it. It's convenient for tiles because it's square.

I don't think I've ever seen a Mercator map of the world printed out, though. Is that seriously a thing? It looks completely ridiculous. Every poster I've seen has been a more rectangular projection like Robinson.

Google Maps doesn't use Mercator — it uses a 3D globe. If you zoom out you can see the whole globe and there doesn't seem to be any jump where the projection changes, or any distortion of country sizes.

Edit: I just noticed that Google Maps on Firefox and Chrome is indeed 3D, but on Safari it is 2D Mercator.

Italian here. We learned about the existence of different projections in school, but only used Mercator when actually discussing geography.

It preserves angles, which is what makes it useful in navigation. Mercator is bad at relative sizes for places far apart, but when you look at a small patch shapes are less distorted. For that reason, online maps use a version of Mercator.

Huh. Swede here. Went to school in the 80:ies and 90:ies. Only ever saw Mercator. Perhaps things have changed since.

German is Mercator only. Learned about different projection on the internet years after school

Is (was?) in Geographie Gymnasium Klasse 6 or 7.

I only visited Realschüler and switched to gymnasium in 11. Tbh I don't remember much of my geography lessons, was not my primary interest in school

I wonder if Mercator maps that aren't aligned with the equator would already do the trick. (pinging Randall Munroe)

A flat map on a wall does not take any three-dimensional space. You can't say the same for a globe, though!

Which everyday tasks?

I was really surprised that China isn't much bigger than the US. I always assumed it was about twice as large.

The real surprise is ~95% lives on 1/3 of that land. Other 1/3 is plateau, 1/3 is desert. An extra dumb derrived stat I like is about ~25% of the worlds smokers are concentrated on ~0.6% of earth's land mass (that 1/3 of PRC).

Australia and Canada are both slightly bigger but if you consider population density they are immense territories. Then there is Russia, which is in a league of its own. You don't see many "Check fuel. Next gas, xxx miles" signs in the US.

> "Check fuel. Next gas, xxx miles"

You don't see that in Australia either: we don't use miles, and we don't call it 'gas'. Typically it would be "No fuel next X km"

One of the rules I came up with while driving the coast of Aus a good while ago was just "always fill up". Oh and also "carry a jerry can of spare fuel"

The first bit came after one day when I skipped a servo and then it was over half my remaining fuel further along the road, I hadn't seen another and I realised "well I can't go back. Shit."

The second bit got expanded to two jerry cans after I had to use one because even though I made it to the servo in rural FNQ, it was 5.15pm and they were already closed. Thankfully that day the extra 20l got me to Port Douglas.

We do still have a few remnants of the imperial system - "90 mile straight" on the Nullabor comes to mind. The longest straight road in Aus, or maybe the world I don't know. When you're already suffering brainrot on your multi-day Nullabor drive, the announcement that you're not even going to have to turn the steering wheel for over an hour is... well it didn't fill me with joy!

There's an awful lot of "X Mile Beach"-es in Aus.

See: https://thepeoplesrepublicofcouch.org/beaches/

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