Does "land area" assume a country is perfectly flat?
Why Hacker News recommends it
HN recommends it in map projection and coastline threads as a fun look at how measurement choices change area figures.
What it is
Matt Parker of Stand-up Maths asks whether a country's reported land area accounts for hills and mountains, working through how surface area depends on the resolution of elevation data. It follows up on a question from a viewer and work by researchers who measured it.
Recommended by 3 HN commenters across 3 different months, 2020 to 2023.
What Hacker News said
Recommends swilliamsio · 2020-09 · on “Coastline Paradox”
>But then realized that the coastline paradox must also exist for 3D surfaces (TINs or DEMs or whatnot) so asking “what is the area of a surface on earth” can be a very complex question if dealing with elevation. StandUpMaths did a great video on this recently, asking whether national land area includes elevation and which nations would gain/lose the most land area if it were/weren't: [this video]
Recommends jobigoud · 2020-11 · on “The True Size Of Countries: Mercator projection”
Matt Parker from Standup Maths made a great video on exactly this subject a few weeks ago. "Does land area assume a country is perfectly flat?" [this video]
Recommends rdlw · 2023-04 · on “The longest straight line in Great Britain (without crossing a public road)”
Then it becomes a coastline problem, with different answers depending on the resolution of your elevation data. Great video on this from Matt Parker (focusing on area in this case): [this video]
Cites jobigoud · 2021-08 · on “Concrete: The most destructive material on Earth”
> over every hill, dale, nook and cranny in England That would take topography into account which another rabbit hole like calculating the perimeter of Great Britain. Cf. Stand-up Maths, Does "land area" assume a country is perfectly flat? [this video]