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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.

No difference

"In the inertial frame of reference (upper part of the picture), the black object moves in a straight line. However, the observer (red dot) who is standing in the rotating frame of reference (lower part of the picture) sees the object as following a curved path."

Where´s the difference? Either is the object following a curved path or the object which you call frame of reference is following one, because the object itself can also be seen as a frame of reference. By the way: in the first picture there are two observers which differ from each other (the person who sits in front of the display and the moving red dot) while in the second picture the observer behind the display (that´s you) is the same as the red dot - because they both don´t move.

In the first picture the black dot only makes a move down the y-axis, while the red dot moves in the x-axis to the right and on the y-axis upwards. In the second one the red dot doesn´t move at all while the black dot moves down the y-axis and first moves the x-axis to the right, comes to a halt and then moves the x-axis to the left. Therefore it´s not a fictitious force but the movement of the red dot on the x-axis in the first picture is fragmented into two parts of movement of the black dot on the x-axis in the second picture.

91.19.40.170 (talk) 11:54, 1 March 2009 (UTC)

Coriolis effect on Sinks and Toilets

My question has to do with the section Corrections to common misconceptions about the Coriolis effect. Anyway the part about Shapiro's experiments states something about a 'perfect sink'. What is that? It's not defined in this article, nor the article on Ascher Shaprio

--SunshineOdyssey (talk) 22:41, 26 March 2009 (UTC)

Confusing the Coriolis force with the cyclonic effect

The conservation of angular momentum means that there is no net transverse force, hence,

${\displaystyle 2{\dot {r}}{\dot {\theta }}+r{\ddot {\theta }}=0}$

The first term on the left hand side is the Coriolis force which is the transverse deflection of a radial motion in planetary orbits and in all vortices, and it is real. Coriolis force even exists in the water that swirls out of a kitchen sink. The Coriolis force is mathematically balanced by an equal and opposite angular force, ${\displaystyle r{\ddot {\theta }}}$.

The Earth's rotation sets the direction of angular momentum in the large scale cyclones in the atmosphere and in the ocean currents. The cyclonic direction is set by inertia. The cyclonic effect is too weak to be involved in small scale vortices such as the water swirling out of a sink and so the initial angular momentum is arbitrary. Tornadoes are cyclonic because of the existing angular momentum in the larger cyclones within which they form.

This article has got the Coriolis force mixed up with the cyclonic effect which is why they can't explain how a so-called fictitious force can cause a real effect that is observable from outer space. David Tombe (talk) 00:53, 14 April 2009 (UTC)

This article has got the heads mixed up with the tails on a coin, which is why it can't explain how a so-called head can mean that there is always a tail that is observable from the other side. I claim that there is no such thing as a head, there is only a tail, and there must be only one article that covers that. YHBT- (User) Wolfkeeper (Talk) 01:55, 14 April 2009 (UTC)

Wolfkeeper, I'm not sure that I get your point. All I was saying was that the Coriolis force lies inside the conservation of angular momentum, and not inside the cyclonic mechanism. By 'cyclonic mechanism', I am referring to the mechanism which causes the initial direction of angular momentum to be determined by the direction of the Earth's rotation. The Coriolis force will be present in all vortex phenomena and in non-circular planetary orbits. Even you are one of the few to have acknowledged the Coriolis force that defelects the radial motion in an elliptical orbit. That is a real effect.

The cyclonic mechanism is the inertial effect that is associated with the Earth's rotation and it determines the direction of large scale cylones and ocean currents, and even tornadoes. But it doesn't affect the water swirling out of a kitchen sink because it is not strong enough to overcome stray currents on that scale. The cyclonic effect does not involve Coriolis force. The apparent deflections that are associated with the cyclonic effect are only superimpositions. The real deflections that are associated with the Coriolis force can be viewed from outer space.

This article has got two effects confused. Nevertheless, a well written article would carefully explain both of these effects. There is no need for two articles, and I think that you agree with me on that point. David Tombe (talk) 11:03, 14 April 2009 (UTC)

The so-called important lost sentence

Woodstone, would you kindly explain what exactly was so important about that sentence. I was trying to shorten the introduction by removing unnecessary sentences. We all know that force equals mass times acceleration.David Tombe (talk) 15:43, 25 April 2009 (UTC)

Ah, yes indeed, so normally, the heavier the object is, the less acceleration a force causes. However all the pseudoforces always cause the same acceleration, regardless of the body acted on. So the force itself is proportional to the mass. It is one of the clues giving away a pseudoforce. −Woodstone (talk) 19:49, 25 April 2009 (UTC)

Woodstone, The situation is no different than in the case of gravity. The acceleration of an object due to gravity, relative to the common centre of mass, is independent of that object's own inertial mass. And the very involvement of a centre of mass, as per Newton's third law, means that in actual fact, the acceleration is ultimately dependent on its own mass. This is an interesting topic which can only become fully understood once we introduce the concept of charge to mass ratio. The charge to mass ratio is constant when we are studying gravity, large scale centrifugal force and large scale Coriolis force and so the 'same acceleration' effect which you have mentioned above is somewhat of an illusion. The proportionality of these forces with mass is not a feature that is in anyway connected with the fact that the latter two, centrifugal force and Coriolis force, are connected with rotation. That's why I don't think that it needs to be mentioned in the introduction to this article. David Tombe (talk) 00:40, 26 April 2009 (UTC)

According to the equivalence principle gravity is an acceleration of the reference frame. As such, gravity may be considered to be due to a non inertial frame of reference, and that is why the 'charge to mass' ratio as you put it is constant.- (User) Wolfkeeper (Talk) 03:42, 26 April 2009 (UTC)

Wolfkeeper, When all the facts are in, you will see that the sentence which Woodstone insists on having in the introduction is nothing more than a statement of Newton's second law of motion. Consider the radial equation as applied to a planetary orbit. The two planets will orbit about a common centre of mass. That is where both their masses becomes of importance. And that is equally so for both the inverse square law gravity term and the inverse cube law centrifugal term. See problem 8-23 at the end of chapter 8 of Taylor. Here is the relevant equation,

${\displaystyle {\ddot {r}}=-k/r^{2}+l^{2}/r^{3}}$

The apparent inertial mass independence is as relevant to the centrifugal term as it is to the gravity term, and it should be noted that it is only apparent. It is only apparent because their inertial mass determines their actual acceleration relative to the common centre of mass. David Tombe (talk) 12:36, 26 April 2009 (UTC)

Bad Coriolis

There's an interesting web link here called 'Bad Coriolis'. It's a few questions and answers, and one of them highlights the ultimate controversy in this topic. See .

See the question a few sections down entitled 'the teacher was right'. The debate is over whether or not the Coriolis force acts on any velocity, or only just radial velocities. When textbooks are dealing with the topic 'rotating frames of reference' the Coriolis force is free to rotate in any direction according to the inducing velocity, like a weather cock on a pole. This view comes from looking at the final mathematical result while ignoring the restrictions that were implicit in the derivation. But in planetary orbital theory, the Coriolis force is strictly and unequivocally confined to the transverse direction, and specifically induced by radial motion.

So we have one lot of textbooks attributing the Coriolis force to the inertial effect, and we have other textbooks putting it down as a real transverse force that is connected with the law of conservation of angular momentum.

Both cannot be right. Should this controversy be highlighted in the main article? David Tombe (talk) 19:33, 21 May 2009 (UTC)

The Coriolis force as arising from a rotating reference frame cannot rotate in "any direction". It is always perpendicular to the rotation axis. In the derivation there is no assumption preventing a radial component. −Woodstone (talk) 21:39, 21 May 2009 (UTC)

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