Interesting article on the longest straight line land route (from Portugal to China) and sailable sea route.

https://bigthink.com/strange-maps/these-are-the-worlds-longest-straight-lines

Thank you Strange, but the article lost me completely in journalistic hype.

What do they mean by a straight line?

If they mean the royal road definition, then the line from A to B is different from the line from B to A, as every geodetic surveyor should know.

Is this article sponsored by the flat Earth society?

8 minutes ago, studiot said:

What do they mean by a straight line?

A great circle. (Obviously?)

The paper is here, if you want more details: https://arxiv.org/abs/1804.07389

11 minutes ago, studiot said:

If they mean the royal road definition

What is that? It is not a term I have heard before (apart from once living on El Camino Real).

59 minutes ago, Strange said:

A great circle. (Obviously?)

The paper is here, if you want more details: https://arxiv.org/abs/1804.07389

What is that? It is not a term I have heard before (apart from once living on El Camino Real).

Why a great circle?

There are no great circles on this Earth.

 

It has to do with skew normals on the real Earth, which anyone going to all that compute trouble to calculate should be using.

Here is the short version, in particular fi94 and the paragraph immediately above it which describes what happens if one starts at A and tries to peg out the line to B, using a theodolite and then travels to B and views that line of pegs using the theodolite.

 

 

Here is the long version

http://www2.unb.ca/gge/Pubs/LN39.pdf

 

See also p88 of the long version for the steve upson's missing link in his one sided thread.

 

Edited January 5, 20196 yr by studiot

11 minutes ago, studiot said:

has to do with skew normals on the real Earth, which anyone going to all that compute trouble to calculate should be using.

You’ll have to read the paper to see if they meet your exacting standards or just used a realistic approximation. 

If it's only an approximationhow can the show that they have found the longest line?

See also my edit above.

Get a life, man. Sheesh. It’s a bit of fun.