Talk:Coriolis effect

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Contents 1 Simple explanation 2 Popular culture 3 Nicer wording 4 Draining bathtubs/toilets 5 Ditto on the Draining of Bathtubs and Sinks 6 This article has too many errors 7 Frisbee deflection? 8 Diagram looks wrong 9 The "Force" 10 Ballistics 11 Wind 12 The Coriolis Force in Magnetism 13 Question about the Coriolis force 14 Coriolis Effects on Supertankers and Insects 15 How the Ferrel effect explains the formation of cyclonic flow 16 Coriolis is no more ficticious than other effects of inertia, Gravity, etc. 17 The Cause of the Spiral Effect in Cyclones

[edit] Simple explanation

I really miss a simple explanation of how the Coriolis effect ACTS. There are all these kinds of equations and diagrams describing it, but not a single iota about why it is like it is.

[edit] Popular culture

This article really needs a "Coriolis effect in pop culture".I think most of the people know something about the consequenses of the coriolis effect from The Simpsons.

Do readers need to guess who Ascher Shapiro is and what exactly was the nature of his experiments? Whoever put this in, what were you thinking? 75.3.8.133 03:59, 14 June 2006 (UTC)

I put it in. I agree it's not good. Before it said something about how it was possible to observe the Coriolis effect in a laboratory tank "in theory". I wanted to make it clear that it is possible in practice, and has been done. I'll add more information. Rracecarr 09:21, 14 June 2006 (UTC)

I think it should have the Simpsons reference. It was the plot catylist behind an entire episode. Valley2city 20:12, 22 October 2006 (UTC)

[edit] Nicer wording

"the magnitude of the Coriolis effect changes with the latitude and the speed of the air (and water)."

Couldn't that reasonably be changed to say "the speed of the fluid?"

Search4Lancer 17:29, 24 June 2006 (UTC)

[edit] Draining bathtubs/toilets

The Coriolis effect DO HAVE a clear influence on rotation of flushing bathtubs, toilets and mud volcanoes (and magmatic volcanoes as well). However, velocity of fluid, just as the article says, needs to be taken into account. This means that if mud is very fluid, the spiral line clockwise (Northern Hemisphere, of course) almost dissapears. A recent volcano in the Eastern region of Congo, in Africa (Nyamuragira Volcano, north of Lake Kivu), shows also de Coriolis effect, since the lava flow was not very fast (in this case), as it is possible to see in satellite images from Google Earth. This volcano has two diferent lava flows: the southern flow shows deviation towards left (we should remember it is in the Southern Hemisphere) being a proof of the Coriolis effect. However, the northern flow looks like not being affected by the Coriolis effect, maybe because of topography: most of this flow is by the eastern wall of the Rift Valley, which avoids deviation towards the left, at least, in part of it. --Fev 00:06, 3 August 2006 (UTC). Seen from the top, a mud volcano has a similar shape than the Iceland low pressure system showed in the article's first image. However, the movement of mud is clockwise (from top to the bottom around), since it is, actually, similar to a high pressure system. Just this fact is the proof that the Coriolis effect determines deviation of a straight line due to Earth's rotation: deviation is the same either in high pressure systems than in low pressure systems (towards the right in the Northern Hemisphere and to the left in the Southern Hemisphere. --Fev 01:08, 3 August 2006 (UTC). --Fev 03:08, 3 August 2006 (UTC)

[edit] Ditto on the Draining of Bathtubs and Sinks

One can easily see when travelling the greater the rate of spin when further north for sinks and bathtubes. There are even demonstrations with properly-modified upside down 2-liter bottles at the equator to estimate the equator's location to within 100 meters. The rate of spin is even noticeably different between Atlanta and Cincinnatti. It was quite a shock when i finally realized why the drains always caught my attention and seemed really strange when i visited Cincinnatti. At first i thought the bathtubs were just made different or something, but then a sink really jolted my attention and i figured it out. I've been in enough hotel rooms to know.

—The preceding unsigned comment was added by 216.186.158.98 (talk • contribs) 02:40, 18 November 2006.

The above is your personal interpretation of your observations - and therefore is not allowed in the article as it is original research, see WP:NOR. Removed OR from page. --Vsmith 03:33, 18 November 2006 (UTC)

Please can someone amend the INCORRECT description that Coriolis Force has no effect on the water draining from sinks or bathtubs, it most certainly does has effect! I have people saying to me "but it says so in wiki"

It doesn't say that the Coriolis Force has "no effect". It says that the effect is so small that it doesn't affect the direction of rotation. This is true.

However, it is a good policy to not always trust a wiki. If something seems wrong, then it is a good idea to check out the references. The section on draining bathtubs refers to this article from the Berkeley Science Review, which is probably a trustworthy source. --PeR 22:03, 15 February 2007 (UTC)

[edit] This article has too many errors

• First error: It looks like we should underestimate popular opinion. Popular opinion is based in the fact that, no matters the size of any rotating system on the Earth's surface, ALWAYS deflects in the same way according to the hemisphere where the movement takes place. This is valid for small whirling winds or mud volcanoes, for bigger tornadoes, for even bigger cyclones. Why we don't have exceptions to this rule?. We should remember than popular opinion is based on experience and this, in turn, derivates from physics laws. --Fev 23:47, 3 August 2006 (UTC)
• Second error: The Coriolis effect works also in high pressure areas, as it can be seen in the anticyclone article. It also works deviating normal track of hurricanes towards the north and eastward later.
• Third error: The article says the value of the Coriolis parameter, does vary with latitude, and that is due to the Earth's shape. It is not the Earth's shape but its rotation from West to East which is responsible for the Coriolis effect.
  • The magnitude of the Coriolis force is a function of the component of the speed of the object that is perpendicular to the earth axis. So, if the object is closer to the equator, the perpendicular component is smaller. This is dependent on the earth's shape; why should it be incorrect? Bob.v.R 01:08, 25 December 2006 (UTC)
• Fourth error: The Coriolis effect on Trade Winds (for example) does not stop at the Equator. When trade winds bring air masses near the low pressure belt around the equator they tend to climb up to a high altitude and deviate northwest first, then north and, finally, northeast. But people do not take into account that this movement of air masses from equator towards subtropical areas (opposite to Trade Winds) takes place at a high altitude and therefore, without clouds, a fact that makes keeping track of its movement less obvious. --Fev 00:27, 11 August 2006 (UTC)

• The winds go in the wrong direction on the picture of the Earth! They should be anticlockwise in the northern hemisphere, and clockwise in the southern! WolfKeeper 13:57, 25 August 2006 (UTC)
  • No Wolfkeeper, the picture is correct. A wind coming from the north will go to a region with higher local speed (eastward) of the surface of the earth, than the air particles themselves, therefor the path of this wind will be directed to the right (so: clockwise). Bob.v.R 00:59, 25 December 2006 (UTC)
• Remember a hurricane contains, in one, two kind of whirl-winds rotating in different directions: its base is formed by cold and dry air rotating clockwise (inner deviation towards the center of storm) and that makes, in turn, the climbing of warmer and moistener air climbing up with a deviation towards the left (also to the center of storm), counterclockwise. See the Cumulonimbus article, especially, the first and second images. --Fev 04:18, 19 December 2006 (UTC)

Wolfkeeper, the diagram that you removed represents (very schematically), the concept of inertial oscillations. The circles on that diagram are unrealistically large, but the diagram does give correctly the (theoretical) direction of inertial oscillations in the atmosphere. Read more about inertial oscillations in this article by the meteorologist Anders Persson.

Anyway, the phenomenon of inertial oscillations (especially as recognized in oceanography) could use an article of its own. The diagram is correct but with not enough explanation, it is easily misunderstood --Cleonis | Talk 15:03, 25 August 2006 (UTC)

Question??? When in a sauna and you throw some water on the rocks the heat reaches one side first and then rotates around the sauna. This is the coriolis force doing this isn't it?

[edit] Frisbee deflection?

I was just curious if the strange path a frisbee takes while landing is related to Coriolis forces?

Most likely, there is not any relationship. First, time flying a frisbee is not long enough. Second, frisbee takes different turning sides while landing according to the person throwing it: with left-handed persons, frisbee turns around the opposite way as right-hand players. And third, wind direction is a more important fact in frisbee playing. --Fev 20:24, 14 September 2006 (UTC)

The answer above relates to the Coriolis effect by the Earth's rotation. But what about the Coriolis effect caused by the rotation of the frisbee? It will drag some of the air under it into rotation, and there may be some effect. Any answers to that one? −Woodstone 19:29, 3 October 2006 (UTC)

There is no coriolis effect caused by the rotation of the frisbee. The coriolis force only occurs if you are standing in a rotating system (such as the earth) while imagining that you are in an inertial frame of reference (ignoring earth's rotation). Since you are acknowleging that the frisbee is rotating, it cannot give a Coriolis force. The effect on the frisbee is caused by asymetric aerodynamic drag, and gyroscopic precession. --PeR 07:58, 9 November 2006 (UTC)

[edit] Diagram looks wrong

The picture of a ball rolling on a flat plate looks wrong. The transverse speed in the rotating frame of reference should be increasing with distance from the centre, but it seems to be moving in a semicircle.WolfKeeper 00:19, 25 November 2006 (UTC)

You mean this picture?

I believe the diagram is correct. The velocity is constant in the inertial frame, which should make the path in the rotating frame an Archimedean spiral. The first 90 degrees of this looks similar to a semicircle.

Initially the ball is in the center where the centrifugal force (as seen from the rotating frame) is zero, and only the Coriolis force is at play. As the ball moves further away from the center, the centrifugal force acting outwards will be counteracting the Coriolis force. --PeR 10:34, 26 November 2006 (UTC)

I'm not saying it's actually wrong, but the perspective view is unnecessary and makes it look like a semicircle.WolfKeeper 11:20, 26 November 2006 (UTC)

The shading on the lower "plate" should be rotating just as the shading on the upper "plate" is. I disagree with PeR's analysis of "centrifugal force" and "Coriolis force" - neither one of these is a force. Cbdorsett 05:21, 30 January 2007 (UTC)

Neither Coriolis or centrifugal forces are "real" forces strictly speaking. However, they are a mathematical concept that arise when working in a rotating frame as opposed to an inertial frame; and PeR correctly used the terms. I think the problem with the image is not the "semicircle" in the perspective view (whatever curve it actually is, it looks close to that), but the track in the plan view is a straight line. It would be better if the track in that view was curved, following the actual route of the ball. One thing to bear in mind, the transverse speed may be increasing, but that would not necessarily affect the angular velocity.--Nilfanion (talk) 16:58, 30 January 2007 (UTC)

Is the animation Image:Rotating_fountain_coriolis_effect04.gif an option?

It is mathematically correct, and at 47 KB the size is reasonable. The current animation is mathematically wrong, and it is a whopping 213 KB

However, there is a disadvantage that both animations share. In the rotating fountain animation the motion of the squirts of water with respect to the rotating coordinate system needs both a coriolis term and a centrifugal term. Arguably, it is not an example of pure coriolis effect but an example of some sort of combined centrifugal/coriolis effect. --Cleonis | Talk 20:14, 30 January 2007 (UTC)

Huh? No, the fountain has both centrifugal and coriolis correct. The same thing happens in both pictures; just rotated. That's exactly what should be happening; nothing has been neglected (possibly apart from friction).WolfKeeper 17:40, 15 February 2007 (UTC)

I believe both pictures are correct. It would not be a good idea to make a picture of Coriolis effect without centrifugal force, because then the object wouldn't follow a straight line at constant speed in the inertial frame. File size is probably an important factor, and that might be a reason to prefer the "fountain" animation. (I'd love to see a real fountain built like that!) However, adding a "trace" to the water squirts would make it clearer that they move in straight lines in the first picture. This shouldn't add much to the file size. --PeR 22:16, 15 February 2007 (UTC)

In the rotating fountain animation, the motion with respect to a rotating coordinate system is described with a centrifugal term plus a coriolis term. I would like to argue the following: that is is a case of pure coriolis effect when in the equation of motion the terms that are not the coriolis term drop away against each other. Specifically: when there is a central force that is a harmonic force, then at all points in space the vector of the central force and the centrifugal term are equal in magnitude and opposite in direction. The distinction is illustrated with java applets by the meteorologist Brian Fiedler.

* Motion over a flat surface

* Motion over a parabolic surface

The main example of coriolis effect is meteorology: at all latitudes (except at the poles) a central force is present that is equal in magnitude and opposite in direction to the centrifugal term. Hence in meteorological calculations the centrifugal term drops away. In meteorological calculations, the centrifugal term is much bigger than the coriolis term, if it wouldn't drop out of the calculation, the centrifugal term would drown the coriolis term. --Cleonis | Talk 23:33, 15 February 2007 (UTC)

[edit] The "Force"

The title of this article declares the Coriolis force to be fictitious yet it is used in the article to explain things. --Eplack 16:09, 18 December 2006 (UTC)

Fictitious fource is standard physics jargon for a force caused not by a physical source, but by a non-interial frame of reference. WilyD 16:40, 18 December 2006 (UTC)

The problem that Eplack points out is real.

In the article it is stated:

The force balance is largely between the pressure gradient force acting towards the low-pressure area and the Coriolis force acting away from the center of the low pressure. Instead of flowing down the gradient, the air tends to flow perpendicular to the air-pressure gradient and forms a cyclonic flow.

That is, currently the article is claiming that something non-physical (a non-inertial frame of reference) is counteracting a pressure gradient. That doesn't make sense. --Cleonis | Talk 16:29, 25 January 2007 (UTC)

In a non inertial frame of reference the coriolis force is a physical force.WolfKeeper 03:07, 25 February 2007 (UTC)

[edit] Ballistics

I've added a section about Naval gunnery into the section on ballistics as it is a famous "example" of the coriolis effect in action. The section is not my own work, but instead was inserted into the Battle of the Falkland Islands, where it is of questionable relevance. However, I felt it was interesting and well enough written to merit inclusion here. I hope you all agree with me. Getztashida 12:19, 25 January 2007 (UTC)

That section consists of a quote of undisclosed origin (possibly a copyvio), followed by a lot of original research. It should be removed, unless someone can provide references. What is needed is a reference to a scholarly article refuting the anecdotes. If no such article exists, then Wikipedia is not the right place to publish one. --PeR 12:03, 30 January 2007 (UTC)

I support removing the naval gunnery stuff. Relevancy is insufficient, and it's anecdotal. --Cleonis | Talk 13:13, 30 January 2007 (UTC)

[edit] Wind

I removed the following paragraph:

"If you where standing on the equator the wind should appear to be going to the right north of the equator or left which is south of the equator. The reason is because of the Coriolis effect. The air is changed by the amount of sunlight or radiation that hits the earth's surface and creates distinct wind patterns on the earth's surface."

The text seems to be saying the same thing that was explained in the preceding paragraph. I considered rewriting it, but concluded that there was nothing to be gained.

Cbdorsett 05:16, 30 January 2007 (UTC)

[edit] The Coriolis Force in Magnetism

The article entitled 'The Coriolis Force in Maxwell's Equations' [1] explains very clearly how the Coriolis force equation and the magnetic F = qvXB force equation are equivalent.

Rracecarr continues to delete this reference claiming that the author is a crackpot. Would it not be better if Rracecarr would actually read the article and put a bit of thought into the matter? It is highly presumptious of Rracecarr to think that electromagnetism is so well established that nobody could possibly demonstrate that the Lorentz force contains the Coriolis force on a microscopic scale.

The fact that Rracecarr chooses to instantly delete this reference and label the author a crackpot, does not reflect well on Rracecarr. It makes one wonder why he is so determined to censor this aspect of knowledge. It would have been more professional on Rracecarr's part if he might have contacted the author privately and pointed out exactly where the error in the derivation exists, if he is so convinced that the derivation is wrong. David Tombe 9th February 2007 (210.213.225.33 16:03, 9 February 2007 (UTC))

Hi David. Wikipedia has a policy against posting original research (WP:NOR). Your research is not only original, it flies in the face of a century's worth of scientific support for and acceptance of special relativity. That, however, doesn't really matter. My deletion is justified on the basis of the aforementioned Wikipedia policy alone. Rracecarr 16:15, 9 February 2007 (UTC)

Your deletion wasn't motivated in slightest by whether or not it contradicted Wikipedia policy. You were obviously upset by the contents and you didn't want anybody else to be thinking about the link between the Coriolis force and the magnetic Lorentz force. You didn't claim that you had deleted it because it contravened Wikipedia policy. You claimed that you had deleted it because the author was a crackpot.

Why not study it with an open mind? I think that you will soon realize that the Coriolis force is heavily involved in magnetism. If it contradicts Einstein's theories of Relativity then should we not be questioning Einstein's theories of Relativity? There are many people who disagree with Einstein's theories. Einstein's theories are notoriously controversial. They may well be accepted by the so called mainstream today, but I have no doubt that in the fullness of time they will truly be seen as crackpot theories. David Tombe 9th February 2007 (210.213.225.33 16:47, 9 February 2007 (UTC))

Whether it's right or wrong, it doesn't seem notable; in google I found only one link to the article from [2]. The rules say that Wikipedia has to contain notable points of view only.WolfKeeper 16:17, 9 February 2007 (UTC)

Hi again David. I won't deny that my personal motivation for deleting the content and reference you added was because it was wrong. However, neither my reason for deleting it, nor yours for posting it, are relevant. People edit Wiki articles for many different reasons. The WP:NOR policy doesn't care about editor motivation. Neither does the WP:3RR policy, of which you are now in violation, having added your content back in 4 times after deletion by 3 different editors.

On a separate note, I think you should consider the possibility that the so-called mainstream physics community is made up of a large number of very bright people. Could it be that they're right? Rracecarr 19:02, 9 February 2007 (UTC)

Hi Rracecarr. That last note of yours shows your appalling naivity. Is this what it all comes down to? You have been taught by the ruling physics party and you have been taught Einstein's theories of relativity. You have chosen to believe in them without question. You are obviously unaware of the enormous amount of dissent as regards Einstein's theories of relativity. Am I supposed to dismiss my derivation linking the Coriolis force to the Lorentz force simply on the grounds that you claim that the physics community is made up of a large number of very bright people? What sort of an argument is that to come out with? I challenge you to show me an error in the derivation. If you can't find an error, could it not be that it's right? David Tombe 10th February 2007 (202.69.162.228 03:19, 10 February 2007 (UTC))

It doesn't matter if your theory is right or wrong. The policy on Wikipedia is that you must get it published in a peer reviewed journal first. Please read WP:NOR --PeR 07:24, 10 February 2007 (UTC)

OK. Let's sum the matter up. The topic is Coriolis force. We are all agreed that in meteorology, oceanography and in many other situations, that the Coriolis force is fictitious. The controversy here has arisen over the suggestion that a real Coriolis force is involved in magnetism. OK, let's drop the issue of "Coriolis Force in Magnetism" since it obviously breaches Wikipedia's rules. I would have hoped that the suggestion of the connection might have sparked some interest. Unfortunately it was zealously opposed by people who's motives, I suspect, were not anything to do with Wikipedia's rules. It was much more likely that they were motivated by the need to protect Einstein's theories of relativity.

But dropping the issue about the Coriolis force in magnetism doesn't mean that matters to do with centrifugal force also need to be censored. There are clearly two existing schools of thought on whether or not real centrifugal force exists. There are plenty of official citations and articles which show us that real centrifugal force is involved in planetary orbital theory.

I will hence restore the point about the difference between fictitious Coriolis force and fictitious centrifugal force, but without mentioning anything about real Coriolis force. David Tombe 10th February 2007 (222.126.33.122 09:35, 10 February 2007 (UTC))

The WP:NOR policy applies to this as well. If, as you say, "there are plenty of official citations and articles which show us that real centrifugal force is involved in planetary orbital theory", then cite those.

[[3]]

[4] see equation (15)

There are two for a start.

Note that it is not sufficient that something is on the internet.

I thought there was a rule that you didn't need to produce a citation to back up a claim that an apple is a fruit. You so-called physicists shouldn't need a citation to show that centrifugal force is involved in the planetary orbit equation.

The publication has to be noteworthy (and preferably peer reviewed). As it is, your addition is certain to be removed. (I've already reverted you twice today, so I'm not going to do it again myself.)

In addition, you removed a rather large amount of text. It is usually better to discuss such changes on the talk page first, and try to achieve consensus before a drastic rewrite. --PeR 11:42, 10 February 2007 (UTC)

This is now quite ridiculous. You are demanding evidence for something that was in my applied maths notes at university. It can be found in any textbook about orbital mechanics and it can be found instantly on the wikipedia article on Orbital Mechanics. Centrifugal force is one of the two components in the differential equation that is used to solve planetary motion. Why should I have to prove something so basic? It's not going to be in a peer reviewed journal. The equation was around long before peer reviewed journals came into existence.

Have a look at this Wikipedia article Planetary orbit and scroll down to the section entitled 'Analysis of orbital motion'. Look at the last term on the right hand side of the very first equation. That is the centrifugal force. Any textbook will back this up. Try and get the conic section solution to planetary orbital theory without using centrifugal force and see how well you get on.

Really I sometimes wonder. You're so zealous about jumping in and deleting things. Why not check the facts first? David Tombe 10th February 2007 (210.213.229.36 12:12, 10 February 2007 (UTC))

[edit] Question about the Coriolis force

If the Coriolis force is only supposed to be an artefact of the Earth's rotation, how come it's effects are visible when we look down on the Earth from above? (58.69.250.10 16:14, 21 February 2007 (UTC))

We interpret cyclones etc as being caused by the Coriolis force because we use the Earth as a reference frame. Looking at the Earth from space, there is no Coriolis force. In an inertial frame, cyclones are the result of real forces--as air that is already rotating (with the earth) converges, it rotates faster. Imagine a bucket of water sitting on a rotating turn table. If you pull a plug from a hole in the bottom of the bucket, the water will drain out, spiralling in the same direction as the table turns. The reason is that as the rotating water moves inward, it increases its rate of rotation to conserve angular momentum. But if you were a very small person living in the bucket, you might choose to use the bucket as a reference frame. In that case, you would not see any movement in the water before the drain was opened, and you would interpret the direction of the vortex as a result of the Coriolis force.Rracecarr 16:56, 21 February 2007 (UTC)

---

In general, the effect deflects objects moving along the surface of the Earth to the right of the direction of travel in the Northern hemisphere and to the left of the direction of travel in the Southern hemisphere.

Is this truly correct? If you start in the northern hemisphere and head south, your deflection due to the rotation of the earth will be to your right, and will not magically change when you cross the equator. If you're moving south, your deflection will still be to your right, even if you're in the southern hemisphere. However, every reference I can find on the web echo what is written here. Ziwcam 03:05, 24 February 2007 (UTC)

As you approach the equator though, the deflection goes to zero, due to the angle of the ground there being parallel to the rotation axis, so it's not like there's a sudden kink in your trajectory or anything, and yes, in the northern hemisphere you would be deflected to the right, and in the southern to the left.WolfKeeper 03:37, 24 February 2007 (UTC)

Ok, still having trouble envisioning how its always a certain (left or right) deflection in a particular hemisphere. If we launch a missle from 60°N 90°W, and it takes an hour to reach the equator, the earth will have rotated 15° beneath the missle, and so is 15° west (to its right) of its target (Putting it at 0°, 105°W). If that missile were to continue south, and spend another hour to reach 60°S, wouldn't it be another 15° westward (right) of its target, putting it at 90°S, 120°W)? (If this is better handled somewhere other than the talk page, let me know please.) Ziwcam 06:24, 25 February 2007 (UTC)

---

Was the bucket of water on the table a good example? The water in it was actually rotating. A Coriolis effect is about apparent motion in a rotating frame of reference. The rotational effects in the ocean currents are more than apparent. They are relative to the background stars. Dr. Seaweed (203.189.11.2 14:33, 24 February 2007 (UTC))

Try this thought experiment. Manufacture a parabolic dish in the following way: pour resin that takes several hours to set in a slowly rotating dish. After the resin is set, pour water in that parabolic dish (dish still rotating at the original angular velocity). The water will redistribute itself into a layer with even thickness, much as the earth's atmosphere is equally thick everywhere. Now open a small hole in the parabolic dish some distance away from the center of rotation. Some water will immedately pour away through that hole, creating a local area of low water level. Surrounding water will tend to flow towards the low level area, but due to the coriolis effect all incoming water tends to be deflected into cyclonic flow around the low level area. Eventually all the water will flow out through the hole, but it will take a surprising long time. Whenever water moves down the water level gradient, it tends to be deflected to cyclonic flow again.

IN the atmosphere, whenever a low pressure area has formed, cyclonic flow develops, and of course that formation process is not apparent; because of the development of cyclonic flow, a low pressure area may persist for weeks, rather than days. --Cleonis | Talk 16:07, 24 February 2007 (UTC)

You are confusing the Coriolis force with real scenarios in rotating liquids. I'll give you a proper example of the Coriolis force. Suspend a bucket of still water above the north pole and then make a hole in the bottom of the bucket. The water in the bucket will not be partaking in the Earth's motion and it will be stationary relative to the background stars. The water will flow out through the hole radially without any curl at all.

From the perspective of observers standing at the north pole, the water in the bucket will uniformly rotate and complete one revolution in 23 hours and 56 minutes. That apparent rotation is the Coriolis force and it cannot be viewed from space.

Likewise with a Foucault pendulum at the north pole. It will not precess relative to the background stars and so it will appear to have a precessional period of 23 hours and 56 minutes relative to the surface of the Earth. That is the Coriolis force. It is artificial.

The spiral effects in the weather patterns (and in the oceans) can be viewed from space and so they must be caused by something other than the Coriolis force. Dr. Seaweed (203.189.11.2 02:59, 25 February 2007 (UTC))

Actually I didn't confuse what you claim I confused. I used the expression 'coriolis effect', but the expression 'coriolis effect' is very ambiguous; inadvertendly I wrongfooted you. I am accustomed to using the expression 'coriolis effect' in a meaning that is distinct from 'coriolis force', hence the babylonian confusion.

Clearly one should not attribute physical meaning to the coriolis term. However, quite a few people assert that the Coriolis term does influence the physics taking place. Usually, this is formulated as a conditional statement: "In a rotating frame of reference, the coriolis force causes the deviation." What is awkward about that is that the condition, the expression "in a rotating frame of reference", has no physical meaning. Being "in an inertial frame of reference" as opposed to being "in a rotating frame of reference" is not a physical thing, it is a point of view. Whatever point of view one happens to choose isn't physics.

The tabletop demonstration that I described is designed to help in tracking the forces that are at play. In the demonstation that I described, one will actually see the formation of cyclonic flow. In my opinion, in seeking physical understanding, the direct approach is to track the motion with respect to an inertial frame of reference. Tracking the motion with respect to inertial space has the advantage that the bewildering complexity of the centrifugal and coriolis terms is avoided.

The first meteorologist who recognized the physical effect that needs to be taken into account was William Ferrel, around 1850 (At the time, the work of Gustave Coriolis was unknown among meteorologists). Around 1900 meteorologists started to use the expression 'Coriolis effect' for what is taken into account in meteorology. As you point out, the choice to use the label 'Coriolis effect' leads to awkward discrepancies. I suppose that if one insists that that the expression 'Coriolis effect' is inappropriate in meteorology, then the next best thing would be to introduce the expression 'Ferrel effect', after the man who first recognized it. Either that, or one accepts that the expression 'Coriolis effect' is used in several different meanings. -Cleonis | Talk 11:03, 25 February 2007 (UTC)

So what causes this Ferrel effect then? (203.189.11.2 11:28, 25 February 2007 (UTC))

Think of the bucket as the earth. The water in the bucket rotates with the bucket. The water on the earth rotates with the earth. Repeat: water in the ocean, and air in the atmospere is rotating. Yes, the Coriolis effect is the result of a rotating frame of reference. For the ant in the bucket who sees a Coriolis force due to the rotation of the bucket, or the human on earth, who sees a Coriolis effect due to the rotation of the earth, the Coriolis force produces the swirling motion. Looking from outside, in either case, it is just convergence of fluid that is already rotating. Rracecarr 18:10, 25 February 2007 (UTC)

Exactly! Water in the Ocean is rotating with the earth and this is exactly why you are wrong. The Foucault pendulum at the poles only experiences Coriolis force for the very reason that it is not rotating with the earth. Because the atmosphere and the oceans are rotating with the earth we should expect no Coriolis force. Hence there must be an alternative explanation for the spiral effects in the weather patterns and in the ocean currents. Dr. Seaweed. (203.189.11.2 11:06, 26 February 2007 (UTC))

Not to unduly complicate things, but perhaps the article could be made more clear if we introduced the concept of a Hamiltonian frame of reference, which I understand moves with a moving particle. Raylopez99 22:27, 25 February 2007 (UTC)

[edit] Coriolis Effects on Supertankers and Insects

I referenced the below and it was deleted by a user sans explanation. Please explain why. I have updated the supertanker reference to account for the opinion (not a fact) that Coriolis Effect is negligible. This doesn't mean it is not present nor corrected for, but in the opinion of an unnamed poster at the external link, it is not as significant as other effects (wind, current, etc). As for the insect cite, that's from a recent edition of Science. Several authors have specifically stated Coriolis effect on insects. Since Wiki posters probably cannot afford a subscription to Science like Daddy Warbucks I can, here is a Google link (one of many) that suggests the same thing: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1013339

- === Insect flight === - Crane flys and moths correct for Coriolis effects when flying, using either their halterers or antennae, respectively, or they would crash to earth ^[1] - - === Supertankers === - Supertankers have to correct for Coriolis effects when steering

Raylopez99 16:36, 24 February 2007 (UTC)

The force of e.g. the wind on a supertanker is hundreds of times bigger than the Coriolis force. For insects, the forces of random air currents are thousands of times bigger. The "Coriolis force" referred to in the articles has nothing to do with the rotation of the earth. Rather, it is in reference to fictitious forces generated by the rotation of parts of the insects' bodies. It is fine to include this, with an explanation, but just to say that the Coriolis force is important to insect flight implies to the casual reader that the rotation of the earth is important. Rracecarr 17:26, 24 February 2007 (UTC)

Thanks for the clarification, your edit is fine about Coriolis forces within the insect's rotating frame of reference. As for the supertanker, let's leave it out for now, though I do recall that Coriolis forces are present between front and back of a long tanker, but perhaps they are negligible Raylopez99 22:08, 25 February 2007 (UTC)

[edit] How the Ferrel effect explains the formation of cyclonic flow

I copy and paste from above:

So what causes this Ferrel effect then? (203.189.11.2 11:28, 25 February 2007 (UTC))

The physical mechanism that was first recognized by William Ferrel has a a number of aspects.

I will describe the Ferrel's line of reasoning for the example I mentioned earlier: a parabolic dish that is rotating slowly (about 10 revolutions per minute) in counterclockwise direction. To my knowledge, Ferrel didn't specifically discuss the parabolic dish example, but his line of reasoning applies perfectly in this example

Water is poured in the parabolic dish, with the dish rotating at the same angular velocity as when it was manufactured: the water will then redistribute itself into a layer with even thickness (this models the physics of the fact that the Earth's atmosphere has an even thickness.) Open up a small hole in the dish, some distance away from the main axis of rotation. A little bit of water will flow directly down that hole, creating a local area with a lower water level; surrounding water will tend to flow towards that low level area.

Let the center point of the parabolic dish be called the 'pole', and let the rim of the dish be called 'the equator' Let the counterclockwise direction be called 'east' and let the clockwise direction be called 'west'

• The water that is initially to the west of the low level area is pulled towards that area by the level gradient. Being pulled along, that water gains angular velocity around the main axis of rotation). Having gained angular velocity, that water climbs a bit higher up the incline of the parabolic dish. (Compare a car negotiating a curve on a banked circuit; the higher the velocity of the car, the stronger the tendency to climb up the embankment.)
  The pattern: water that is initially pulled in west-to-east direction tends to move subsequently towards the equator.
• The water that is initially to the east of the low level area is pulled towards that area by the level gradient. So the angular velocity (around the main axis of rotation) of that volume of water decreases. Having lost angular velocity, that water slumps down the incline of the parabolic dish.
  The pattern: water that is initially pulled in east to-west direction tends to move subsequently towards the pole.
• The water that is initially on the outside of the the low level area gets pulled towards that area, and in being pulled closer to the main axis of rotation its angular velocity increases. (Compare the example of an ice-skater who pulls her arms closer to her body, thus increasing her angular velocity.)
  The pattern: water that is initially pulled in equator-to-pole direction tends to move subsequently towards the east.
• The water that is initially on the inside of the the low level area gets pulled towards that area, and in moving away from the main axis of rotation its angular velocity decreases. (Compare the example of an ice-skater who after a couple of seconds of spinning extends her arms again. Extending her arms has the effect of slowing her angular velocity.)
  The pattern: water that is initially pulled in pole-to-equator direction tends to move subsequently towards the west.

The above combination of mechanisms comprises the line of argument of Ferrel. It explains the formation of cyclonic flow. Importantly, it explains why the tendency to develop into cyclonic flow is the same from all directions. One can refer to the entire set for all directions as the generalized Ferrel effect. I must emphasize that the expression 'Ferrel effect' has never been used. Ferrel made his discoveries around 1850, without any knowledge of the work of Gustave Coriolis. (In his papers, published in the 1730's, Coriolis had investigated energy conversions, Coriolis was interested in the efficiency of waterwheels, the amount of energy that any design of waterwheel can extract from water that moves relative to the waterwheel. There is no mention of the Earth's rotation in Coriolis' papers.) Around 1900, meteorologists started to use the label 'Coriolis effect' for the effect that they were taking into account in their calculations. --Cleonis | Talk 01:57, 26 February 2007 (UTC)

What you are basically acknowledging is that the spiral patterns in the ocean currents and in the atmosphere are actually caused by something other than the Coriolis force. I would agree with that.

Whether yours or Ferrel's explanations are adequate or not is another matter altogether. Dr. Seaweed (203.189.11.2 05:30, 26 February 2007 (UTC))

There are many ways to think about this. By far the easiest is to treat the Coriolis force as real for meteorological purposes. All other explanations are either equivalent to this (ie, produce in the end the same results), or wrong William M. Connolley 09:29, 26 February 2007 (UTC)

The Coriolis force is a fictitious effect as viewed from a rotating frame of reference. The spiral patterens in the weather are not fictitious. If you want to suddenly decide to treat the Coriolis force as being something real in meteorology, you are going to have to explain exactly how that can be so. Seaweed (203.189.11.2 11:12, 26 February 2007 (UTC))

This is an *old* discussion. Coriolis is a fictitious force in exactly the same way gravity is fictitious. Coriolis forces appear when you transform into rotating frames of reference. Within those frames you can treat them as real William M. Connolley 11:31, 26 February 2007 (UTC)

I would argue that Coriolis forces are "ficticious", but only if you use a Hamiltonian frame of reference (one that moves with a body). If you do so, there's Coriolis component, but it doesn't show up in the same way as an inertial frame of reference. How'se that for a synthesis, eh Dr. Bill? Seems we travel in the same circuit, quite by chance. Raylopez99 12:43, 26 February 2007 (UTC)

I would say that you have got it completely wrong. In Hamiltonian frames of reference there is no Coriolis force at all. The Foucault pendulum at the north pole tells us that the Coriolis force is a fictitious effect that only occurs on something that does not share in the motion of the rotating frame. Dr. Bill has also missed the point. The Coriolis force, when it occurs, may seem real to people in the rotating frame of reference. However, the rotational effects in the weather patterns and the oceans are viewed from more than just the rotating frame of reference. Hence they must be caused by something other than the Coriolis Force. Seaweed (203.189.11.2 13:01, 26 February 2007 (UTC))

Seaweed you seem all washed up, pardon my pun. First you claim that in a Hamiltonian frame of reference (which moves with a person, and thus is not inertial) tells us Coriolis acceleration is ficticious. Fair enough. But then you say there's no Coriolis force at all, which is contradicted by your further statement "may seem real". Which is it Weed? You can't have your Porphyra and Edith too. Why do hurricanes turn one way in one hemisphere as opposed to the other? Ιt's obviously a 'real' force, when viewed from a non-inertial frame. Thus the Foucault pendulum experiment shows that a "force" is present to twist the pendulum, at least until it gets to the equator, for the person in the non-inertial (Hamiltonian) frame of reference. Raylopez99 15:16, 3 March 2007 (UTC)

You didn't read what I said. I said that in a Hamiltonian frame of reference there is no Coriolis force at all. Show me where I said that Coriolis force is fictitious in a Hamiltonian frame. I said that Coriolis force is fictitious when it acts on the Foucault pendulum at the poles. The Foucault pendulum at the poles is not in a Hamiltonian frame because it does not partake in the Earth's diurnal motion. Dr. Seaweed (203.189.11.2 09:59, 23 March 2007 (UTC))

Sorry Weed but you left me even more confused than before. But this is a complicated field, and that's no LIE {group} (pun intended, see: http://www.amsta.leeds.ac.uk/Applied/news.dir/issue14.dir/art/review3.html Raylopez99 20:38, 25 March 2007 (UTC)

[edit] Coriolis is no more ficticious than other effects of inertia, Gravity, etc.

This article has a big problem. What's all this 'ficticious this' 'ficticious that' here as if all we have here is nothing more than an optical illusion? Is this a joke? Cause there is a real dynamic (Newtonoan?)effect that is called Coriolis force that does bend a rolling ball on a rotating "disc". The Coriolis force is nothing but inertia. And inertia is not branded ficticious in Wikipedia, so there is absolutely no reason whatsoever to brand Coriolis ficticious.

And what about that animation? It is not showing what happenes when a ball actually makes a curved path on a rotating disc and only shows what would happen if a ball rolls in a straight path. That is telling only half of the story. There are two things here:

1, A real bending of path of something (ball for instance) that is rolling on a rotating surface.

2, An apparent bending of a ball that is actually going in a straight line (= optical illusion)

The second one is the only one adressed here in this Wiki article. In order to achieve clarity we must realize that while the two have the same name, the physics is distinct. That (No. 2) one would happen only if the ball has sufficient initial acceleration that overrides the force coming from under it (from the rotating "disc"), like in a roulette, that would have led the ball to roll in whatever straight path it initially started. Only in that case is there an optical illusion in the eyes of someone attached to the rotating object that would cause a straight line appear to be bent. But otherwise there will be a real coriolis force that acts at the right angle to the initial would-be straight path and bends the rolling ball away from that expected straight path. And this is not an optical illusion but a real bending of the path of the ball (as seen from above (stationary frame) as well as seen while standing somewhere on the disc (rotating frame of reference).

Something must be done about this folks. Or perhaps it is better to create a separate wikipage titled "Coriolis force" (so that this one would remain only about one of the two things. Who decided to merge/redirect it all anyway? Benua 16:45, 26 February 2007 (UTC)

Nope. There is only one effect, not two. The Coriolis effect is the result of the Coriolis force, which is a fictitious force that arises in rotating frames of reference. Any motion can be analyzed from an intertial frame, in which case there is no Coriolis force, or from a rotating frame, in which there is a Coriolis force, which is termed "fictitious" because it's only there because of the chosen frame. The results are the same either way. All of which has nothing to do with the frictional force which causes a ball rolling on a rotating surface to follow a curved path. That is a real force is all frames, and is not a Coriolis force.

By stating that the Coriolis force is just inertia (you are essentially correct), and then that it causes a ball on a rotating surface to roll in a curve, in an inertial frame (you are wrong), you are contradicting yourself. Rracecarr 17:36, 26 February 2007 (UTC)

You are wrong. There is nothing ficticious about inertia. Otherwise it would have been noted there. See this mpeg where the ball DOES bend (seen from both frames): http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml Benua 17:53, 26 February 2007 (UTC)

See the mpeg yourself. When the camera is not rotating with the merry-go-round, the ball goes straight. Hold your finger or something on the screen as a reference to convince yourself of this. Please stop cluttering up this talk page. Rracecarr 18:10, 26 February 2007 (UTC)

What cluttering? Is the discussion page reserved for "serious" discussion of Coriolis insects only? Anyway I have seen the picture and the ball is affected by the rotation. Check this other coriolis deflection video: http://www.classzone.com/books/earth_science/terc/content/visualizations/es1904/es1904page01.cfm?chapter_no=visualization There are two issues here. Jury is still out.

You have both missed the point. Rracecarr is right in that the Coriolis force is only fictitious and it is an artefact of being in a rotating frame of reference. He doesn't seem to realize however that the rotational effects in the atmosphere and ocean currents are not fictitious and must be caused by something other than the Coriolis Force. George Smyth (203.115.188.254 09:37, 27 February 2007 (UTC))

No, it's not entirely ficticious. I actually disagree with the term 'ficticious' since it causes problems like these. It's a real effect caused by inertia. That's why the rotation effects occur in the atmosphere, due to inertia. I actually prefer the term pseudo-force. Pseudo implies it's real, but deceptive, in the case of coriolis it's inertia underlying the force, but the effects of the pseudo-force are as real as any force gets (arguably forces don't exist anyway, it's all potential energy, energy seems to be more fundamental.)WolfKeeper 09:53, 27 February 2007 (UTC)

This is not a matter of preference but a matter of how this force is commonly called in the physics literature. I have seen both terms used, but "fictitious force" is the most common. The usage seems to be interchangeable, so both terms could be mentioned in the Wikipedia article. --Itub 10:59, 27 February 2007 (UTC)

The point is that fictitious is a misnomer. If it was fictitious it wouldn't exist at all. On the other hand pseudo implies it's something pretending to be something else; in this case inertia. The centrifugal and coriolis pseudo forces are real and are due to inertia. Pseudo force is the term that Richard Feynmann used for example, he was generally reckoned to be a good physicist, to say the least.WolfKeeper 06:02, 1 March 2007 (UTC)

I admire Feynman and I agree that in retrospect fictitious forces may not be the best name for this forces. But the point is that in an encyclopedia we have to reflect common usage, rather than legislating ourselves which name is more "correct". I should also mention that it is normal for technical terms to have meanings that don't match exactly the common meaning of the word. In this case, "fictitious force" = "force that results from non-inertial frame of reference", not "force that does not exist". If you look at other technical terms you'll find that many of them are misnomers or don't seem to match common sense. Some examples: atom, reversible (thermodynamics), spontaneous (thermodynamics), aromatic (organic chemistry). --Itub 09:10, 5 March 2007 (UTC)

That is indeed what I am asserting, Wolfkeeper. You can't have a real inertia and a ficticious coriolis force. It is absurd. A ficticious force can't have a real effect. The second instance (optical illusion) may be considered ficticious, but in the first instance I mentioned, Coriolis force is not ficticious in this case because Wikipedia's own definition of ficticious is that it is an apparent force needed by an observer in non-inertial frame. So a real inertia with a real effect can't be ficticious. Benua 14:05, 27 February 2007 (UTC)

Ficticious forces are real - it's just a name. Well, in as much as any forces are real (debateable). But they're not different - the term ficticious force just refers to their origin (i.e. the non-inertial frame). WilyD 14:21, 28 February 2007 (UTC)

Why did Benua delete this quote?

'If the atmosphere moves with the Earth then there can be no Coriolis force in the atmosphere. This has been proved by the Foucault pendulum experiment. The precessional period of the Foucault pendulum changes from infinite to 24 hours as it moves from the equator to the poles. This means that the Coriolis force only operates to the degree to which the pendulum is not partaking in the Earth's motion. Dr. H R D Wheeler, Manchester (58.69.250.10 11:35, 27 February 2007 (UTC))

is there not a case to answer here?

• Apart from being original research, it's unverifiable because it's false. Those are the only problems I see. WilyD 14:53, 27 February 2007 (UTC)

Since when has the Foucault pendulum been original research? Everybody knows that the precessional period of the Foucault pendulum is infinite at the equator and 24 hours at the poles. Are we witnessing censorship here? Is WilyD frightened about something?

I'm frightened of bees - that's about it. WilyD 14:22, 28 February 2007 (UTC)

WilyD, I didn't know I was deleting anything when I replyed. In fact that quote by Dr. Wheeler raises an interesting point, because it means that line of argument alone proves the actual Coriolis force since it is the earth (and not every rotating thing like for eg. a ball or disc) that has an atmosphere around it that is rotating with it. Benua 18:51, 27 February 2007 (UTC)

Oh, well then those merely would have been good reasons for you to delete it. The statement is basically nonsense - the atmosphere no more "rotates" with the earth than does a pendulum. WilyD 18:55, 27 February 2007 (UTC)

With Rracecarr saying that the atmosphere does rotate with the earth and WilyD saying that it doesn't, I think we have a serious problem here. Rracecarr is actually correct on this point. If the atmosphere didn't rotate with the earth, there would be a powerful wind blowing. The Foucault pendulum rotates with the earth at the equator but not at the poles. This means that the Coriolis force only applies to the unentrained scenario. Hence the big question. What causes the spiral patterns in the oceans and in the atmosphere? It is cetainly not the fictitious Coriolis force. It must be something else. I think that alot of you need to go away and have a long hard think about all this. George Smyth (203.115.188.254 05:44, 28 February 2007 (UTC))

Well it's true, it isn't true in the way he means it, which is why he draws erroneous conclusions while doing his own, original research. The way in which the Foucault Pendulum and the Atmosphere rotate with the earth is the same, both rotate with the earth (after all, both are fixed to a point to first order) but neither is ridgedly fixed so. FWIW, the Coriolis force also acts inside the earth (which rotates with the earth) it's just that it's so much smaller than the intermolecular forces in the solid earth that its effect is entirely trivial. In any event, yes, I'll keep reverting nonsense and original research, especially when it contradicts every reliable source on the subject. WilyD 14:19, 28 February 2007 (UTC)

The Coriolis force is responsible for the rotation of cyclones. See Cyclone and Tropical cyclone, for example. Please don't change the article to state that there is any doubt about this fact, because there isn't. Rracecarr 08:06, 28 February 2007 (UTC)

If you are so sure about this, then how come we can view the spiral patterns from space? We can't view a precessing Foucault pendulum from space because it is fixed relative to the background stars.

'fraid not, that's only true at the pole. And you can indeed view a Foucalt pendulum from space.WolfKeeper 09:59, 28 February 2007 (UTC)

The cyclones are obviously rotating relative to the fixed background stars, and so this rotation cannot be a fictitious Coriolis effect. It must be something else. G Smyth (203.115.188.254 09:34, 28 February 2007 (UTC))

It can because the cyclones are not at the equator. The other factors involved include centrifugal force (i.e. more inertia) around the center of the cyclone, the pressure difference, and the coriolis effect.WolfKeeper 09:59, 28 February 2007 (UTC)

Wolfkeeper, So you are admitting then that it is only at the poles that the Foucault pendulum is fixed relative to the background stars. Good. That's what I have been trying to say too. As it moves towards the equator, its precessional period increases from 24 hours to infinite. This means that it only experiences Coriolis force to the degree that it is not rotating with the earth. At the equator, the Foucault pendulum is rotating with the earth and it experiences no Coriolis force. The cyclones do not rotate with the earth at any latitude and so they cannot experience a Coriolis force. You needn't try to bring centrifugal force to the rescue because it is a radial effect.G Smyth (203.115.188.254 12:02, 28 February 2007 (UTC))

No, you can either analyse this in a non rotating frame of reference, and in that case you get just the same rotating structures, because of the way the inertia of the air masses interacts with the pressure differences. If you wish to analyse this more simply, in a frame rotating with the earth, then you need to identify the effects on inertia due to the rotating reference frame and the coriolis and centrifugal pseudo forces appear. These pseudo forces have very real effects in a rotating reference frame such as the Earth. They are not fictitious in any normal sense of the word. For example Sherlock Holmes was a fictitious character, he never existed at all, but inertia is real, and pseudo forces which are a manifestation of inertia have real effects in such a frame.WolfKeeper 22:03, 1 March 2007 (UTC)

The facts are that Coriolis force as defined by this article cannot explain the rotational patterns in the weather. G Smyth (203.115.188.254 12:02, 28 February 2007 (UTC))

This article defines Coriolis force in accordance with all modern teaching. I cannot critize the Wikipedia definition of Coriolis force. It may not have been what Coriolis himself intended. He may have intended the 2mvXω to refer to motion in a vortex in hydrodynamics, but that is beside the point. The Wikipedia definition corresponds exactly to modern teaching. Ie., the Coriolis force is a fictious force that we observe on a moving object as observed from a rotating frame of reference. Eg. A bird flying overhead as we ride on a carousel.

I think that the problem that we are facing in this article is that the Coriolis force is being wrongly used to explain real effects in Hamiltonian reference frames such as in the oceans or in the earth's atmosphere. Perhaps the main article could be shortened to only defintions, and all the controversies surrounding meteorolgy and oceanography could be moved to a new controversial article on cyclones and ocean currents. Dr. Wheeler, Manchester (58.69.250.10 04:45, 1 March 2007 (UTC))

There is, in fact, no contraversy (at least, no evidence of one) - certainly not enough that we could cover it. WilyD 15:41, 3 March 2007 (UTC)

[edit] The Cause of the Spiral Effect in Cyclones

Rracecarr, It is not a verifiable fact that the rotational effect in the cyclones is caused by the Coriolis force. You admit yourself that,

(1) The Coriolis force is fictitious, (2) That the atmosphere rotates with the Earth. (3) That the spiral effects in the atmosphere are not fictitious because they can be viewed from space.

We also know from the Foucault pendulum experiment that the Coriolis force only acts on things that are not partaking in the motion of the rotating frame of reference, such as an aircraft or a missile flying above the earth's surface, or balls thrown over a children's roundabout.

You are imposing your own point of view here. You are asserting that the Coriolis force causes the spirals in the weather patterns. I changed it to the less assertive 'it is believed to cause'.

In fact, all the evidence suggests that the spiral effects are caused by another mechanism. George Smyth (203.115.188.254 08:25, 28 February 2007 (UTC))

• All the reliable sources assert that this is the case (if you're curious, many will also include derivations so you can see why). Your unique conclusion can't be used here because it can't be reproduced or confirmed by others. Instead of trying to convince poor Wikipedia editors, who shouldn't be trying to figure things out themselves anyways, why not submit your revolutionary theory to Nature? Nature publishes all kinds of wrong stuff, but is still considered a reliable source, or at least good for your CV - when this is done, you can cite the journal article and we can make an offhand mention about it somewhere in the article. Until then, our hands are tied - even if we wanted to include your novel conclusion, as Wikipedia is not a publisher of original research WilyD 15:05, 28 February 2007 (UTC)

I'm not sure if it my unique conclusion. I never studied meteorology or oceanography. I studied applied maths and I was merely reciting those orthodox teachings regarding the precessional period of the Focault pendulum. It is 24 sidereal hours at the poles. This means that a full Coriolis force on the Foucault pendulum is in operation at the poles. The precessional period is determined by the ω term in the Coriolis Force expression. Periods tending towards infinite as we approach the equator indicate partial entrainment.

We all know that both the atmosphere and the Earth's magnetic field are fully entrained with the earth's motion. I was surprised therefore to read that meteorologists and oceanographers are attributing the spiral patterns in the cyclones and ocean currents to the Coriolis force. I was merely concurring with the editor that mentioned the Hamiltonian frame.

But if this is the state of conventional wisdom and if that is wikipedia's policy to mirror that state, then I don't suggest that you change your article. A couple of days ago, I changed it to 'Believed to be', but somebody quickly changed it back to 'Is definitely'.

I thought that the purpose of the talk pages was to discuss these clashes of opinion.

Are you absoluely sure that it is the Coriolis force that causes the spiral effects in the ocean currents?

I suggest that you think about it at any rate. George Smyth (203.115.188.254 07:46, 1 March 2007 (UTC))

Thinking about it is not what's important. Find a reference disputing that the Coriolis force is not responsible for Hurricanes and the like and we can consider the point disputed. Until then, all we have is your own reasoning, which isn't any good. FWIW, it's fairly apparent to me that the Coriolis force should cause atmospheric torques - the atmosphere is not a rigid rotator - I'm not sure if this is obvious, but it's fairly easy to argue. The B field is same - both don't change much now because they're in a quasi-equilibrium state - where various effects balance, but local deviations (like hurricanes) still occur. WilyD 14:49, 1 March 2007 (UTC)

The B field is actually the answer, but then that is original research and so it can't be put on the main article. I tried to insert a reference a few weeks ago but it was instantly deleted along with all my other entries on centrifugal force. The Earth's magnetic field determines the circular nature in the weather patterns. The magnetic equation F = vXB is the Coriolis force. B = 2ω if B is vorticity and there is every reason to believe that B is vorticity. David Tombe (222.126.33.122 05:17, 2 March 2007 (UTC))

• If you still have the reference, I will read it - I mean, as soon as I've read the stack of papers my supervisor just dumped on me ;) WilyD 14:33, 2 March 2007 (UTC)

The reference essentially meant that the Coriolis force is responsible for the rotational patterns in the weather and the oceans, but not for the reasons described on the main article. The vorticity of the magnetic field gives rise to a real Coriolis force. The reference is [5]. There is a gap between the maths and the physics in conventional teaching. This gap results in the illogical attempts to explain a real effect with a fictitious force. David Tombe (203.87.176.3 16:32, 2 March 2007 (UTC))