The paper is basically like this (spoiler alert):

“Some random user on Reddit posted a picture claiming that this is the longest straight line path on water possible on the Earth. We implemented a smart algorithm to solve this problem, found the elevation data, ran our algorithm... yes, that random user was right. Also, here's the longest path on land.”

Thanks, I really enjoyed reading it, even though I hoped that they would disprove the original claim!

Edit: here are the gcmap links to the two paths: sea [1], land [2].

[1]: http://www.gcmap.com/mapui?P=25%B017%27N+66%B040%27E-58%B037...

[2]: http://www.gcmap.com/mapui?P=24%B033%27N+118%B038%27E-37%B02...

There's a longer land path that starts in or near Senegal and ends in China. But they miss it because it goes near the Dead Sea, and they treat anything below sea level as water.

I know the globe is unintuitive (it still blows my mind that Muslims in New York City face roughly northeast to point toward Mecca) but it still seems bizarre that the water route can start near the arctic circle, cross the Pacific ocean, nearly touch Antarctica, cross the Atlantic ocean, and cross the Indian ocean to end well north of the equator and still travel only 80% of the way around the globe. This view of the rest of that great circle helped me visualize it: http://www.gcmap.com/mapui?P=58%B037%27N+162%B014%27E-25%B01...

This geographic puzzle feels like the modern day version of the Seven Bridges of Königsberg:

https://en.wikipedia.org/wiki/Seven_Bridges_of_Königsberg

I made a "first person" perspective rendering of this: https://mrgris.com/img/landfall/longest.png

> Figure 9: Longest Drivable Straight Line Path on Earth.

Walkable, maybe, but definitely not drivable (it crosses directly over the Alps, for example).

It reminds me of a bit I did a few years ago trying to find the "longest straightest" line in Atlanta [PDF]: https://matthewritch.com/pages/LongestStraightestLine.pdf

Before I opened the solution, I knew it had to pass through the beagle straight. It is the only choke point separating the largest oceans, about both their empties areas, the far south.

I guess my biggest surprise is that there is a straight line through the Beagle straight.

But what would flat-earthers consider the longest possible paths to be? Not the ones shown in the article, presumably?

If it's the longest straight path on water OR land then surely it's just the circumference of the earth

Learned this the expensive way

If it is undrivable in a straight line, why does that count? I’d assume the longest you could drive in a perfectly straight line would either be the longest straight highway or some drivable desert.

Nerd sniping at its best... ;)

it would be interesting if it was a list of actual journeys with the sub lists of deviations required. a special club for the brutaly determined and persistant the "strait liners" things like having to beg, bluff, bribe, your way through someones house

I myself walked the longest path to 1200 karma. It was painful. Blisters of delta_karma=f*vote_points, where f could be 0.5 or 0.3 or unknown lower no. I'm tired, boss.