Okay... so this draws on a couple of things which can be confusing. 1) perspective projections 2) mapping spheres onto 2D planes.
Usually when we think of a field of vision we imagine some projection that maps the 3D world in front of us to some 2D rectangle image. And that's all fine and well. We don't expect the lines in the image to conserve the angles they had in 3D.
I think what the author of the post is saying is that if you use a cylindrical projection that wraps around 360 degrees horizontally, then the lines will appear parallel when you unwrap it. ... (read more)
There is no real paradox here, of course. At least not in reality. Only in a bird's head perhaps, when he says:
Those two birds in front of me are flying parallely; one is going North, one is going West.
Well if the bird knows they fly apparently parallel, then he's good.
Okay... so this draws on a couple of things which can be confusing. 1) perspective projections 2) mapping spheres onto 2D planes.
Usually when we think of a field of vision we imagine some projection that maps the 3D world in front of us to some 2D rectangle image. And that's all fine and well. We don't expect the lines in the image to conserve the angles they had in 3D.
I think what the author of the post is saying is that if you use a cylindrical projection that wraps around 360 degrees horizontally, then the lines will appear parallel when you unwrap it. ... (read more)