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0 pointsa3w6mo ago0 comments

For clarity, you cannot call north up:

North is not up. That would make left west. When standing in front of a building, with map in hand, and asking people to go start going to the street in the south, then left, I mean left in direction of travel, which is east.

Not left in direction of map conventions, which for people who cannot read a compass is probably west.

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bobbylarrybobby6mo ago

North being up doesn't make left west because left is relative to front, not up, and front can easily change directions whereas up cannot (at least not relative to the direction of gravity). It happens that when you're looking at a map mounted on a wall with north up, west is left, but if you were to turn 90° left yourself, then west would be straight (front). This is all consistent with north being up.

matrss6mo ago

But if you define "up" as the direction opposite to where gravity pulls things (which very much makes sense) then there is no possible situation in which north being up would be correct either. A compass needle never points up. You are mounting a map of something horizontal onto a vertical surface, it is just as correct - or depending on the alignment of the wall arguably even more correct - to put east up. You can only ever get at most two directions correct, after all.

ndriscoll6mo ago

Obviously "up" is the direction of of the normal vector for Earth's orbit around the Sun. North is then tilted but mostly up.

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miki_oomiri6mo ago

> North is not up. That would make left west.

Nope. You're confusing up and front.

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