# Can you use the Earth's rotation to get water to flow? **URL:** \ **Category:** Factual Questions\ **Created:** [July 10, 2015, 9:17am UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744 "2015-07-10T09:17:42Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [July 10, 2015, 9:17am UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/1 "2015-07-10T09:17:42Z")
Could you use the Earth’s rotation to get or help water to flow towards the Equator? E.g. through a pipe or canal from Scotland to southern England or Alaska to Texas? ---
**Author:** ![davida03801](https://avatars.discourse-cdn.com/v4/letter/d/b5e925/32.png) [@davida03801](https://boards.straightdope.com/u/davida03801)\ **Post date:** [July 10, 2015, 10:17am UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/2 "2015-07-10T10:17:02Z")
The Earths rotation is east to west, not north to south. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 10, 2015, 10:58am UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/3 "2015-07-10T10:58:57Z")
Yes, and the Mississippi River is proof of this. It flows from Minnesota to Louisiana because of centrifugal force. ---
**Author:** ![TonySinclair](https://avatars.discourse-cdn.com/v4/letter/t/49beb7/32.png) [@TonySinclair](https://boards.straightdope.com/u/TonySinclair)\ **Post date:** [July 10, 2015, 11:07am UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/4 "2015-07-10T11:07:38Z")
> [@Chronos](#): > > Yes, and the Mississippi River is proof of this. It flows from Minnesota to Louisiana because of centrifugal force. So I guess the Rhine didn’t get the memo? ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [July 10, 2015, 12:02pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/5 "2015-07-10T12:02:28Z")
> [@TonySinclair](#): > > So I guess the Rhine didn’t get the memo? Why does the Rhine flow north? Because Rotterdam sucks.😀 ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [July 10, 2015, 12:02pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/6 "2015-07-10T12:02:58Z")
And all along, I thought water simply ran downhill.:smack: ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [July 10, 2015, 12:24pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/7 "2015-07-10T12:24:33Z")
Yes. Use the wind and tides to power pumps. The wind is partially driven by Coriolis force, so you would be using the rotation of the Earth to pump water. In fact, it appears that the wind patterns on the Earth affect the ocean currents to some extent, so this effect is already happening. The flows of liquid and gas in the atmosphere are very, very gradually slowing down the Earth due to tidal effects, so it should be feasible to use the tides to pump water too if you absolutely wanted to. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 10, 2015, 12:37pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/8 "2015-07-10T12:37:19Z")
> [@Quartz](#): > > Could you use the Earth’s rotation to get or help water to flow towards the Equator? E.g. through a pipe or canal from Scotland to southern England or Alaska to Texas? I gather you are thinking of water being flung away from the earth’s rotational axis, the same way that a ball would tend to roll away from the center of a spinning turntable. If the earth’s surface were a perfect sphere, this would work. The problem is that the earth’s surface, even if you smooth out all the mountains and valleys, is not a perfect sphere; it is an [oblate spheroid.](https://en.wikipedia.org/wiki/Equatorial_bulge) This is actually due to the rotation of the earth. On a planetary scale, rock isn’t that strong or rigid, and so the rotation of the earth causes the earth itself to distort pretty much the same as it would if it were a giant ball of liquid. IOW, any liquid that would have been at the poles providing a perfectly spherical shape has _already_ flowed toward the equator and raised the ground there such that any water you pour on the ground in Glascow isn’t going to flow toward Southampton, assuming that you are considering start/end points with matching altitudes as measured with respect to sea level (sea level being that oblate spheroid shape). If instead you measured your altitudes with respect to a perfect sphere, then yes, you could get water to flow from north to south with your start/end points at matching altitudes - but you would then see that your end point was lower than your start point as measured with respect to actual sea level. ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [July 10, 2015, 12:45pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/9 "2015-07-10T12:45:23Z")
As water flows from north to south in the northern hemisphere, as in the Alaska to Texas example in the OP, its momentum has to increase as it moves further away from the North pole. In Anchorage its surface velocity is around 480 miles per hour, in Dallas it’s traveling at around 850 miles per hour. This requires an input of energy, which indicates it will not happen spontaneously. Pumping would be required. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [July 10, 2015, 1:06pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/10 "2015-07-10T13:06:18Z")
> [@Machine\_Elf](#): > > The problem is that the earth’s surface, even if you smooth out all the mountains and valleys, is not a perfect sphere; it is an [oblate spheroid.](https://en.wikipedia.org/wiki/Equatorial_bulge) Actually, this is the property that I was wondering if it were possible to take advantage of. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [July 10, 2015, 1:22pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/11 "2015-07-10T13:22:46Z")
I think the force of gravity exceeds (and therefore will negate) the other forces considered here. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [July 10, 2015, 1:36pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/12 "2015-07-10T13:36:36Z")
The Earth’s geoid is an equipotential surface, so you can’t get any energy out of its shape directly. On the other hand, tides and winds are a usable source of energy. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 10, 2015, 1:40pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/13 "2015-07-10T13:40:59Z")
> [@Quartz](#): > > Actually, this is the property that I was wondering if it were possible to take advantage of. Nope. See [here for explanation, including a vector diagram.](https://en.wikipedia.org/wiki/Equatorial_bulge#Differences_in_gravitational_acceleration) The oblate-spheroid shape results in the surface of the earth not being normal to the gravity vector (everywhere except the equator and poles). This results in a component of gravitational force being normal to the surface, and a (small) component being parallel to the surface. The component of gravity that is parallel to the surface provides the exact amount of centripetal force needed to keep water from flowing toward (or away from) the equator. > [@Chronos](#): > > Yes, and the Mississippi River is proof of this. It flows from Minnesota to Louisiana because of centrifugal force. 😕 The Mississippi river flows south because that’s the [downhill path](https://en.wikipedia.org/wiki/River#Direction) it found to the ocean. Plenty of rivers flow north, e.g. the [Red River of the North,](https://en.wikipedia.org/wiki/Red_River_of_the_North) and [the Nile.](https://en.wikipedia.org/wiki/Nile) ---
**Author:** ![Bones\_Daley](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@Bones\_Daley](https://boards.straightdope.com/u/Bones_Daley)\ **Post date:** [July 10, 2015, 2:08pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/14 "2015-07-10T14:08:30Z")
I am fairly sure that Chronos was being ironic. If he wasn’t , it’s the first dumb post I have ever seen him make. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 10, 2015, 2:16pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/15 "2015-07-10T14:16:03Z")
> [@Bones\_Daley](#): > > I am fairly sure that Chronos was being ironic. > > If he wasn’t , it’s the first dumb post I have ever seen him make. We need an irony/tongue-in-cheek icon. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [July 10, 2015, 2:47pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/16 "2015-07-10T14:47:16Z")
Yes it’s possible to use the earths rotation to move water, sometimes called a orbital siphon: [http://www.idlex.freeserve.co.uk/siphon/siphon.html](http://www.idlex.freeserve.co.uk/siphon/siphon.html) I also has a thread about this some years back. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [July 10, 2015, 2:58pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/17 "2015-07-10T14:58:35Z")
> [@eburacum45](#): > > The wind is partially driven by Coriolis force … This is misstated, the winds are driven by [convection](https://en.wikipedia.org/wiki/Hadley_cell#/media/File:Earth_Global_Circulation_-_en.svg). The velocity vectors are included on the image and the east-west components are caused by the pressure force. This is sometimes (and confusingly) called the **Coriolis effect**. These two driving forces (convection and pressure) are then deflected by the variety of frictional forces so that the wind can blow any direction anywhere on the planet. The Coriolis force is a pseudo force, the phenomena can be described as a force, but it’s not really a force. In fact, it only appears when a force is being applied to the observer, and if the observer disregards that, then everything he observes would appear to have this pseudo force. This is more often (and confusingly) called the Coriolis effect, thus we have a term which can mean two completely different things. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 10, 2015, 3:01pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/18 "2015-07-10T15:01:35Z")
> [@kanicbird](#): > > Yes it’s possible to use the earths rotation to move water, sometimes called a orbital siphon: > > [http://www.idlex.freeserve.co.uk/siphon/siphon.html](http://www.idlex.freeserve.co.uk/siphon/siphon.html) > > I also has a thread about this some years back. This concept is possible, but it won’t move water from Alaska to Texas; it will move water from Ecuador into outer space. On further thought, I suppose you could use the siphon to fling mass (of any sort) into outer space, and use the movement of that mass to do mechanical work to generate power to drive pumps to move water from Alaska to Texas. So, strictly speaking, yes, you could use the earth’s rotation to propel water from the poles to the equator - but not in the way that the OP had in mind. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [July 10, 2015, 3:18pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/19 "2015-07-10T15:18:01Z")
> [@Quartz](#): > > Could you use the Earth’s rotation to get or help water to flow towards the Equator? E.g. through a pipe or canal from Scotland to southern England or Alaska to Texas? If the pipe’s height over sea level steadily decreases the whole way water will flow. Part of what determines sea level is the rotation of the Earth. Does it make sense to you to call this using the Earth’s rotation? If so, yes you can use the Earth’s rotation for help. If not, no. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [July 10, 2015, 3:18pm UTC](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744/20 "2015-07-10T15:18:23Z")
> [@kanicbird](#): > > Yes it’s possible to use the earths rotation to move water, sometimes called a orbital siphon: > > [http://www.idlex.freeserve.co.uk/siphon/siphon.html](http://www.idlex.freeserve.co.uk/siphon/siphon.html) > > I also has a thread about this some years back. Smells like perpetual motion to me, and if this were possible then there would be easier ways to pump oil from Alaska to Texas. Just put turbines in the pipeline and draw back out all the electric energy. [Next page](https://boards.straightdope.com/t/can-you-use-the-earths-rotation-to-get-water-to-flow/724744.md?page=2)