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Comment on Longest Straight Line Paths on Water or Land on the Earth (2018)

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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...

They only identify the Reddit user as "kepleronlyknows", but in the Reddit thread [1] he links to his video visualization [2], where his user name is Patrick Anderson.

Before he made the video visualization using Google Earth, he actually went to the library and used a string on a real globe. [3]

1: https://www.reddit.com/r/MapPorn/comments/15mwai/the_longest...

2: http://www.youtube.com/watch?v=VpQwuGueeoA

3: https://imgur.com/a/great-circle-2hYFM

Adding: The two paths respectively are about 80% and 28% of the earth's circumference.

The Portugal to (approximately) Macao one is quite interesting, thanks for the links!

I opened Apple Maps in globe mode and I still have trouble visualizing the water path.

Does it help to point out that the water path looks suspiciously like the day/night line on a map?

Like this: https://svs.gsfc.nasa.gov/5477/

yes!! why is that ? :)

The day/light line is a great circle. The "straight line paths" are great-circle segments.

It's going South and then trying to close the loop from behind. It gets interrupted by land before the loop closes.

Hope it makes sense.

Open the linked paper and scroll down, they have images of the path on a globe as well as the flat map view.

Kudos to whoever built tiled clouds background on the gcmap site.

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