Watch the path of a raindrop from anywhere in the world
river-runner-global.samlearner.com
river-runner-global.samlearner.com
The US drops seemed a lot cleaner
Still a really cool idea, and when it works well it's good fun. I can see there being great practical applications if it was more accurate too (though I'm sure the people who could put it to use already have good data)
I guess the names are taken from an underlying hydrologic dataset, and Google (or whoever) maps used purely for visualization.
The treaty was made before the Andes were fully explored, and so it doesn't handle some interesting edges cases like the Southern Patagonian Ice Field. The field has the property that when rain falls there, it freezes and goes nowhere!
[0] https://en.wikipedia.org/wiki/Boundary_Treaty_of_1881_betwee... [1] https://en.wikipedia.org/wiki/Southern_Patagonian_Ice_Field
China built over 1,000 km of canals 1,000 to 2,000 years ago. Inland travel within England and Great Britain was revolutionised by the development of canals. The US opened up its interior with the Erie Canal, on which a single mule could haul an 80-foot barge laden with 40 tonnes of goods or people. Not only was the travel efficient (in terms of motive power and drovers) but it was comfortable. A four-foot-deep ditch (the Erie Canal) was immune to the rutting and mud of a road, and though the speed of travel was low, in a matter of a few days people could travel in great comfort across New York from the Hudson to Lake Erie and from there to points inland via the Great Lakes, Chicago, and Mississippi / Missouri / Ohio / Red, and other, rivers.
I'd realised the political boundaries aspect looking at a map of European watersheds created by Robert Szucs:
<https://www.seattlepi.com/local/science/article/Viral-maps-s...>
(Europe is in the carousel at the top, third image, isolated here: <https://s.hdnux.com/photos/54/21/22/11605137/3/960x0.webp>)
It's not that national borders are specifically identified as watersheds, but in large part you can patch together current state boundaries out of watersheds and rivers, or find internal divisions (e.g., UK counties, German states, French provinces) out of watersheds.
In regions in which borders were more arbitrarily assigned, as with the inland US, Middle East (o hai Sykes-Picot), and Africa, the artificiality of imposed borders is highly evident, though regional affiliations become clearer.
South American countries are, as you note, more closely aligned with watersheds. It's also more evident why the north-eastern region of South America is so politically divided: it's largely composed of non-contiguous watersheds which have become their own polities.
Wide rivers are slow. Narrow rivers are fast. That is the nature of fluid dynamics.
Wide rivers are obstacles to movement on the land and facilitators of movement on the water; narrow rivers are worse at both of those things.
Fast rivers or wide rivers are challenging, the former as they're inherently treacherous, the latter as they're difficult to bridge.
Narrow rivers can be bridged. Slow rivers can be traversed by boats, ships, barges, etc.
Yes, wide rivers tend to be slow, and narrow rivers tend to be fast, all else constant, but all else is rarely constant such that there are narrow slow rivers and wide fast / treacherous ones.
But up near the source where it splits into thousands of small tributaries which move and change a lot? That's a recipe for boundary disputes.
Whereas a watershed rarely changes far, even on geological timescales.
1 year on glacier, once snow is compressed into ice which takes few years, is represented by maybe 1-2m layer in European Alps.
Thats why glaciers have crevasses - they bend as valleys flow (or over some hard bottom bumps that weren't grinded flat yet), and it cracks at those bends. Just like say chocolate on surface of cold Snickers bar if you try same bending
Nice.
2022 (790 points, 115 comments) https://news.ycombinator.com/item?id=29841737 2021 (887 points, 128 comments) https://news.ycombinator.com/item?id=27297689
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I've also noticed it'll often not start the raindrop anywhere near where you click, so it's not quite anywhere in the world. Definitely most places though.