6 ms·

I wonder what great circle or small circle passes through the most countries. Looks like a fun optimization problem.

mci 9y ago
I'm not sure if you have seen this: https://marcinciura.wordpress.com/2015/11/17/slicing-earth-carefully/ https://marcinciura.wordpress.com/2015/11/17/slicing-earth-c... — loading country polygons instead of land polygons and changing the LengthOfIntersectionInKm() function should be enough to answer your question. Be wary, however, that parts of France lie in Africa and the Americas (https://en.wikipedia.org/wiki/Overseas_department https://en.wikipedia.org/wiki/Overseas_department).
- rhizome 9y ago
  Fun fact: St. Pierre and Miquelon was the site of the only use of the guillotine in North America.
- gsich 9y ago
  just count the mainland.
  - mci 9y ago
    Doesn't work for island countries. Think Japan, Philippines, or Indonesia.
    - gsich 9y ago
      then just use the biggest islands.
      - mrb 9y ago
        Then you would ignore 98% of the territory of the Republic of Maldives.
jacobolus 9y ago
Defining “great circle” gets a bit tricky for an ellipsoid. Geodesics don’t meet back up. https://upload.wikimedia.org/wikipedia/commons/7/77/Long_geodesic_on_an_oblate_ellipsoid.svg https://upload.wikimedia.org/wikipedia/commons/7/77/Long_geo... I guess you can find the “great ellipse” on a slice passing through the center.
- askvictor 9y ago
  I'm pretty sure that for this purpose, either mapping the earth to a perfect sphere, or using the slice approach (it won't be an ellipse since we're being pedantic) will answer the question.
  - jacobolus 9y ago
    The latitude/longitude lines in this post were very carefully chosen to just barely knick several countries’ borders and pass over small islands. Differences in the definition of the line certainly will matter for figuring out all of the edge cases here.
gciruelos 9y ago
not really related, but i wrote this a while back: https://gciruelos.com/what-is-the-roundest-country.html https://gciruelos.com/what-is-the-roundest-country.html
cm2187 9y ago
Kim Jong-un optimising the impact of atomic blasts?

mci 9y ago

I'm not sure if you have seen this: https://marcinciura.wordpress.com/2015/11/17/slicing-earth-carefully/ https://marcinciura.wordpress.com/2015/11/17/slicing-earth-c... — loading country polygons instead of land polygons and changing the LengthOfIntersectionInKm() function should be enough to answer your question. Be wary, however, that parts of France lie in Africa and the Americas (https://en.wikipedia.org/wiki/Overseas_department https://en.wikipedia.org/wiki/Overseas_department).

rhizome 9y ago
Fun fact: St. Pierre and Miquelon was the site of the only use of the guillotine in North America.
gsich 9y ago
just count the mainland.
- mci 9y ago
  Doesn't work for island countries. Think Japan, Philippines, or Indonesia.
  - gsich 9y ago
    then just use the biggest islands.
    - mrb 9y ago
      Then you would ignore 98% of the territory of the Republic of Maldives.

jacobolus 9y ago

Defining “great circle” gets a bit tricky for an ellipsoid. Geodesics don’t meet back up. https://upload.wikimedia.org/wikipedia/commons/7/77/Long_geodesic_on_an_oblate_ellipsoid.svg https://upload.wikimedia.org/wikipedia/commons/7/77/Long_geo... I guess you can find the “great ellipse” on a slice passing through the center.

askvictor 9y ago
I'm pretty sure that for this purpose, either mapping the earth to a perfect sphere, or using the slice approach (it won't be an ellipse since we're being pedantic) will answer the question.
- jacobolus 9y ago
  The latitude/longitude lines in this post were very carefully chosen to just barely knick several countries’ borders and pass over small islands. Differences in the definition of the line certainly will matter for figuring out all of the edge cases here.

gciruelos 9y ago

not really related, but i wrote this a while back: https://gciruelos.com/what-is-the-roundest-country.html https://gciruelos.com/what-is-the-roundest-country.html

cm2187 9y ago

Kim Jong-un optimising the impact of atomic blasts?