A problem with this is that the river presumably goes all the way around the earth. Otherwise you could just travel west until you found its end. You really need a donut shaped earth, a sphere doesn’t help much
Finally a solution to the Königsberg Bridge problem.
Submitted 2 weeks ago by Gork@sopuli.xyz to science_memes@mander.xyz
https://sopuli.xyz/pictrs/image/cd949f66-feb9-4186-afe5-3bf6534d3479.webp
Comments
maxwellfire@lemmy.world 2 weeks ago
SaharaMaleikuhm@feddit.org 2 weeks ago
But the river running round the whole planet does not matter in this case.
maxwellfire@lemmy.world 2 weeks ago
You run into it on the planet backside and then need another bridge, right?
Xavienth@lemmygrad.ml 2 weeks ago
Surely it a river doesn’t go all the way around the earth. Rivers typically have one (or many) start points, where they are surrounded on three sides by land, meaning it’s possible to cross from one side to the other. Otherwise it’s just a strait or channel.
However, that assumes you are not on the land in between a fork in the river. In which case you would have to cross a bridge outside of Königsberg, and we might have to expand the problem to crossing every bridge on the continent once.
stevedice@sh.itjust.works 2 weeks ago
When you go to sleep tonight, Euler is gonna be under your bed.
match@pawb.social 2 weeks ago
but are there an even or odd number of bridges allng the circumnavigation
Zachariah@lemmy.world 2 weeks ago
yes
bear@lemmy.blahaj.zone 2 weeks ago
Crossing oceans, which are continuous with the river, seems to make this about as meaningful at tunneling under the river.
Tar_alcaran@sh.itjust.works 2 weeks ago
I feel that leaving Koningsberg is already breaking the rules.
Tlaloc_Temporal@lemmy.ca 2 weeks ago
The original idea was taking a walk before a meal, so maybe if you were a really fast walker…
seaplant@slrpnk.net 2 weeks ago
Don’t let the sailors tell you you have to cross oceans to circumnavigate the globe! Just walking around the headwaters of the Pregolya River is equivalent.
While this would have worked in Euler’s time, the puzzle in fact became unsolvable around 1873 when canals were built in the Masurian lakes effectively connecting a tributary of the Pregolya with a tributary of the Vistulato the south and cutting of this route. Maybe hopping across lock gates when they’re closed doesn’t count as a bridge tho?
mnemonicmonkeys@sh.itjust.works 2 weeks ago
TBF, does the problem specifically state it has to take place on Earth and not some theoretical planet with contiguous landmass?
Jumi@lemmy.world 2 weeks ago
Why not just take a boat over the river. Last time I checked boats were not bridges.
SharkAttak@kbin.melroy.org 2 weeks ago
General_Effort@lemmy.world 2 weeks ago
This must be the true reason the whole city got razed.
Allegedly, the Russians wanted to negotiate about Kaliningrad in 1990 but Germany was more horrified than interested. Straightforward decision at the time. No one wanted a reprieve of the whole Polish Corridor thing, especially without even Germans living there. Rather a mistake in hindsight.
CyberTailor@lemmy.world 2 weeks ago
especially without even Germans living there
Germans were brutally deported after WW2
redchert@lemmygrad.ml 2 weeks ago
I think there was a plan to settle volga germans there and re-recreate the volga german republic, of course only after the OG volga german republic thing failed.
BradleyUffner@lemmy.world 2 weeks ago
No bridge, no problem!
youtu.be/uuoaTsJ5WlY
fargeol@lemmy.world 2 weeks ago