River Police

[Juggernaut1981]

Some of this is pure myth. Two of Europe's biggest rivers - the Rhine and Elbe as examples - flow northward, i.e. away from the equator. If rivers avoided higher levels above sea level they wouldn't be able to flow down to the sea (not that all rivers do that). They'd have to flow up to it.

Um, that is kind of my point... Rivers LEAVE the areas that are ABOVE sea level and travel TOWARDS Sea Level. And if you look at the geography of Europe, it's a bit hard to flow south with the Alps where they are, consequently those rivers tend to head north.

So Height Above Sea-Level beats centripetal force tendencies for the water to head towards the equator.


*Physics Side-note and the reason for the equator comment...
Any object covered in liquid that is then rotated will have the water move towards the point of greatest radius from the axis of rotation. Catch is that Landform will trump centripetal motion.

[bartmoss]

*Physics Side-note and the reason for the equator comment...
Any object covered in liquid that is then rotated will have the water move towards the point of greatest radius from the axis of rotation. Catch is that Landform will trump centripetal motion.

That's very theoretical though, in the real world you'll hardly find a planet smooth enough. Indeed, I'd argue that the mere presence of rivers axiomatically means that the sphere can not be smooth enough for such a situation.

And how much does deformity of a planet caused by centrifugal force influence water behavior? I certainly am not good enough at math to figure this one out, but geek enough to want to know the answer!

[Steel General]

The Niagara river also runs north (and it is north of the equator).

[bartmoss]

I think we can call "rivers run towards the equator" settled, it is a silly notion. :-)

[Gamerprinter]

The Vermillion River in Illinois (mouth into the Illinois River is about 15 miles from me) is the only river in North America east of the continental divide that flows north west for its entire length - it too of course is north of the Equator. Topography is rather flat here, however.

[NeonKnight]

Well, I can certainly see Juggernaught's point. There was an interesting fact from the program. The Earth 'bulges' at the equator from the water. If the earth was to stop spinning, then the oceans would flow to the north and south.

http://channel.nationalgeographic.co...ideos/07932_00

[bartmoss]

Well, I can certainly see Juggernaught's point. There was an interesting fact from the program. The Earth 'bulges' at the equator from the water. If the earth was to stop spinning, then the oceans would flow to the north and south.

Ocean != Rivers, the two are quite different...

[RobA]

Well, I can certainly see Juggernaught's point. There was an interesting fact from the program. The Earth 'bulges' at the equator from the water. If the earth was to stop spinning, then the oceans would flow to the north and south.

http://channel.nationalgeographic.co...ideos/07932_00

I've not seen the show, but if such "speculative fiction" is the current product of the Nat. Geo. Channel then they just lost most of my respect. Producing such sensationalism nonsense isn't really necessary, imoo, when there are so many awesome things in the here and now that could be documented.

-Rob A>

[bartmoss]

Actually the Earth DOES bulge at the equator, it's not a sphere. (This is not "from the water" but because of the centrifugal force of the planet's rotation.) It's just that the effect is totally negligible for most purposes, and certainly for the flow of rivers.

About that show, well... yeah, sounds like a time waster. Otoh without having actually watched it, who knows, might be a fun thought experiment.

[Jaxilon]

Hehe, total hi-jack but there's an interesting conversation: is centrifugal force a fictitious force? Arguments abound and I was taught in my physics class that it was Centripetal force that folks should be referring to. In this case I guess it would be the centripetal force of the earth's gravity keeping the water on the planet while it spins instead of allowing it to just fly straight out into space? (actually there is probably the additional force of the earth going around the sun as well but now we are getting even more complex.) I wouldn't be surprised if I'm saying it all wrong either. After all, I'm older, not a physicist, and it's been years since I've tried to explain anything along these lines. I do know that if you go into an older Physics book you won't find centrifugal force in there. I think the newer ones have it so maybe the definition has changed? I dunno.

Anyway, this should probably be in another thread but I know we have at least one real physicist around here. Personally, I gave up arguing over this a long time ago but it always does make me smile when I see the word.

On a side note: I'm not busting bartmoss' chops for using it because it's often used to explain what seems to happen. I just get a kick out of it I guess. English is jacked up in a lot of ways due to it's being a living language and it does change over time. Eventually words become real if enough people use them, even if they started out being used incorrectly. (Ie, "Irregardless" which should just be "regardless" but whatever )