Comment by bottled_poe
14 days ago
Accuracy where it matters is why. Do you have a better suggestion for projecting a sphere onto a rectangle?
14 days ago
Accuracy where it matters is why. Do you have a better suggestion for projecting a sphere onto a rectangle?
I would not use such strong rhetoric as the GP, but I believe they probably mean we should lean towards using the Gall/Peters projection, which maintains lengths and areas, but not angles.
(There are of course other projections with other interesting features; or you could take the same projection but center the world differently etc.)
Web Mercator does not preserve angles.
We're currently forced to use a projection that is strictly worse than what it was based on, the Mercator projection, created in 1569.
Everyone on this thread needs to read this presentation entitled "Use Literally Anything But Web Mercator":
https://www.esri.com/content/dam/esrisites/en-us/events/conf...
Let's say that a bit louder shall we:
USE LITERALLY ANYTHING BUT WEB MERCATOR.
Thanks for that, I wasn't even aware that "web Mercator" was a thing.
Why? Why is lengths and areas more important than angles? You have to choose one, its essentially arbitrary. Personally I find it more useful to know what is parallel to what and what is at which angles from what, than some size. We have globes, so we know what the "real size" of Greenland looks like... this has always been a silly argument from the overzealous online looking for right wrongs that don't exist.
> Why is lengths and areas more important than angles?
Well, of course the answer is "it depends on what it is you want to learn from the map. If you're driving around and want to navigate, you'll take Mercator probably. But if you want to compare sizes of objects (like lakes or forests or islands or world states), especially when zoomed out, you'll prefer Gall-Peters.
Many argue, and I tend to agree, that when looking at a map of the whole world, you are typically better served with Gall-Peters in terms of what your interest is, and in fact, people _do_ use Mercator maps to semi-consciously compare sizes of things - and have false impressions about geo-politics because of it.
WEB MERCATOR DOES NOT PRESERVE ANGLES.
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This comment is inaccurate! Web Mercator causes such large errors in geolocation that the NGA had to issue an advisory about it [1].
There is a whole science behind map projections and Google ignored it entirely when they created Web Mercator, which was a hack to divide the world into a quad tree. It was vaguely clever and utterly stupid at the same time.
[1] https://web.archive.org/web/20140607003201/http://earth-info...
> Accuracy where it matters is why
Why the downvotes for correcting this laughable statement? Web Mercator is well documented as being extremely inaccurate.
Hi - I understand you feel strongly; your Web Mercator input is interesting. I would just focus on the intellectually interesting part - people might not get it; you can't control that or compel them to.
You've been repeating essentially the same comment, writing in all caps (in some comments), complaining about downvotes, telling everyone they are idiots one way or another. None of those things are likely to be welcome.
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