Tidal Bulge Theory

[roufeng_yang]

Moderator's Note: This thread was split off from the following thread: https://www.physicsforums.com/threads/beyond-the-tidal-bulge.1067812/

[url="https://www.physicsforums.com/insights/there-is-no-tidal-bulge-2/"]Continue reading...

It is good to see such a post of tidal bulge just before my new theory of tide was published at Physics of Fluids (https://doi.org/10.1063/5.0250036). If anybody wants the paper, please ask me for it.

Yes, the author of above post is right that tidal bulge (i.e., the double water bulge) is extensively appeared in printed and online forms, although most of tide workers (i.e., professional ) don't believe the existence of the bulges.

However, nobody uses any observational evidence to show the nonexistence, all is only oral argument. Anyway, as the poster's author introduced that the tidal force (the tractive force) is exerted along the earth's surface, and the two force vector fields are spatially symmetric, because almost 70% of the earth's surface is covered with ocean, thus, under the effect of the tidal force, the ocean water must be dragged to move along the force vector. So, it is not impossible that a pair of water bulges occur on the earth's surface.

So, please use observational evidence to convince others！

Haha，stressing the point above is not because I'm a follower of the double water bulge, it is because these days I just complete an investigation on the double water bulge using both ocean tide data and bottom pressure data. My conclusion is that the double water bulge really doesn't exist!

So, you must think that the right thing is that said by the dynamic tidal theory: tides are an manifestation of the response of complex ocean to the gravitational forcing, which is also accepted by most of tide workers.

If you think so, I will pour cold water on you. So far, the dynamic tidal theory is not yet proved, and the models representing the dynamic tidal theory, which are based on a set of hydrodynamic equations, reproduce tide height in open ocean with an accuracy of more than 20 cm. You know, the observed tide height in open ocean is in most of cases less than 1 m. If you know harmonic prediction, you must know that the data-constrained models (EOT20 and Fes2014) through harmonic prediction reproduce tidal height with an accuracy of 3~4 cm in open ocean. But harmonic prediction is noting but a math skill.

In the harmonic analysis and prediction, they apply the tidal force (potential) to a specific location and decompose this force into many cosines of amplitude and phase (called tidal constituents), they use each of these constituents to produce a water height for the location, and then, the final water height at the location is treated as a sum of the water heights produced by all these tidal constituents. Imagine it, for a beach that is flooded by tides, it becomes entirely exposed after the flood is retreated. And now, please apply the tidal force to the exposed beach, can the force produce a flood of tides? The answer is certainly not. Ocean water (as a fluid) is continuous, any location within it will not simply respond to any force that applies to it, and the water height variation at the location must be a consequence of the water height variations at all oceanic locations.

This place is called Physics Forum, and I believe most of users here know the difference between physics and math. So, you must have understood what I mean above.
Saying so much, the conclusion is that the harmonic prediction, a math skill, cannot endorse the dynamic tidal theory.

However, this is also not the focus of my posting here. You should read my theory of tide above carefully. Here, I will use a conceptual figure (see attachment of this post) to explain how tides occur on the earth: solid earth is mechanically elongated by a combination of the Moon's gravitational force and the centrifugal force due to the Earth's rotation around the barycenter of the Earth-Moon system. The elongated solid earth is spatially represented by a pair of solid bulges. As the earth spins, the double solid bugles are entrained to spin. As a result, ocean floor is regularly raised and put down, this causes water in the basin to move back and forth, forming global water height variation (i.e., tides).

This physics of tides is simple, and anyone may prove it by means of shaking a cup of water. Yes, ocean basin is a gigantic container, if the container is shaken, water movements (tides) are destined to occur in the container.

My research on tide began about 13 years ago when an astrophysicist bet with me. He said, if I can present a new theory of tide, he will accept my hierarchical two-body model of the universe! But now I have forget his name!

I hope to follow the author's post to discuss the issue of tide with all friends here.

 

[pbuk]

I will ... explain how tides occur on the earth: solid earth is mechanically elongated by a combination of the Moon's gravitational force and the centrifugal force due to the Earth's rotation around the barycenter of the Earth-Moon system.

Centrifugal force? Really?

And the surface tides are caused by heave of the ocean floor?

This is (among other things) personal speculation and contradicts mainstream science.

@mods, please feel free to delete my post along with the post I am replying to.

 

[Drakkith]

solid earth is mechanically elongated by a combination of the Moon's gravitational force and the centrifugal force due to the Earth's rotation around the barycenter of the Earth-Moon system.

What prevents the water itself from 'bulging' under tidal forces?

Ocean water (as a fluid) is continuous, any location within it will not simply respond to any force that applies to it

Why?

 

[weirdoguy]

You should read my theory of tide above carefully.

I'm sorry, but thinking that hundreds of thousands (or even milions!) of physicists throughout the centuries got such a simple (at its core) thing wrong, and you, a non-physicist got it right is delusional, to say the least.

This place is called Physics Forum, and I believe most of users here know the difference between physics and math.

Yes, and we know math is the only language physics can be done with. And we also know that physics is an observational/empirical science, yes. And we also know that doing physics requires years of hard studying, which rarely can be done without actually going to collage/university/whatever.

 

[roufeng_yang]

To pbuk,

Reference: https://www.physicsforums.com/threads/beyond-the-tidal-bulge.1067812/
"Centrifugal force? Really?
And the surface tides are caused by heave of the ocean floor?
This is (among other things) personal speculation and contradicts mainstream science.
Reference: https://www.physicsforums.com/threads/beyond-the-tidal-bulge.1067812/"

Yes, centrifugal force is not a real force. It represents an inertia.
Imagine it, what will happen if you shake a cup of water/box? Ocean basin is a container of water, so, if the container (ocean basin) is shaken? what will happen? This is what my theory of tide tells: the elongated spinning solid earth shakes ocean basin forming water movements in the basin (forming tides).
Of course, my idea is against mainstream science which has lasted for more than 300 years. But the public benefits from the diversity of ideas on something.

 

[roufeng_yang]

To weirdoguy,
"I'm sorry, but thinking that hundreds of thousands (or even milions!) of physicists throughout the centuries got such a simple (at its core) thing wrong, and you, a non-physicist got it right is delusional, to say the least."

Okey, It is unnecessary to say that my theory of tides must be right. But in the paper I indeed have proven in both qualitative and quantitative ways that the new theory is better than the current theory. So, it is only a choice of readers.
And if it is not convenient to read the paper, please read it through the preprint at arxiv( https://arxiv.org/pdf/2501.16926).

 

[roufeng_yang]

To Drakkith,
"What prevents the water itself from 'bulging' under tidal forces?"
This is a good question, but most of its answers have been addressed in the owner post of this long thread.
My answer is that the water's viscosity is too low, compared to the viscosity of solid materials, that's why the water must follow the shape of a container that holds it whereas solid materials can maintain their shape by themself.
The reason is very simple, image it, if a cup of water is tilt, the water in it will flow/reallocate, although the earth's gravitational force always attracts this water. Similarly, if ocean basin or its part is tilt, the earth's gravitational force is not enough to prevent ocean water to flow. Therefore, the Moon's gravitational force, which is far less than the Earth's gravitational force, is not enough to attract ocean water forming bulge of water.
From this point, one must understand that the water movement caused by shaking ocean basin is stronger than that caused by the Moon's gravitational force. So, my theory looks like more reliable than the current theory.

 

[Drakkith]

This is a good question, but most of its answers have been addressed in the owner post of this long thread.

Indeed. It seems that the Moon pulls the water 'sideways' more than 'vertical'. I suppose that makes sense given that the Earth is rotating.

 

[pbuk]

You should read my theory of tide above carefully.

Your theory is incorrect.

Solid earth is mechanically elongated by a combination of the Moon's gravitational force and the centrifugal force due to the Earth's rotation around the barycenter of the Earth-Moon system.

This is broadly true, although the tidal effect of the Moon's gravity is approximately 14x larger than the effect of the Earth's rotation around the barycenter of the Earth-Moon system.

However gravity does not differentiate between liquids and solids: the same force that "pulls up" (or "pulls out" if you prefer) on the solid part of the Earth, causing it to elongate, also pulls up (or out) on the ocean with an even greater magnitude (because it is closer to the Moon than the average of the mass of the solid part of the Earth).

The elongated solid earth is spatially represented by a pair of solid bulges. As the earth spins, the double solid bugles are entrained to spin. As a result, ocean floor is regularly raised and put down, this causes water in the basin to move back and forth, forming global water height variation (i.e., tides).

So you believe that the net up[out]wards force on the solid part of the Earth pulls it up, whereas the greater net up[out]wards force on the liquid part of the Earth makes it flow down[in]. Do you see the contradiction?

Furthermore, if this were the case (that the oceans flow away from the point nearest/furthest from the Moon), then we would tend to see the maximum flow of water away from this point around this time and therefore a low tide a few hours later: in fact the opposite is true e.g. in Honolulu today the Lunar meridian passes at 16:06 HST and high water is 19.35 HST.

This physics of tides is simple, and anyone may prove it by means of shaking a cup of water. Yes, ocean basin is a gigantic container, if the container is shaken, water movements (tides) are destined to occur in the container.

But the Earth is not being shaken by the Moon (or anything else).

 

[sophiecentaur]

actually going to collage/university/whatever

Would that be an art form then? (Sticking objects to a paper) lol

It seems that the Moon pulls the water 'sideways' more than 'vertical'.

The Moon can only attract things to itself. That would involve every direction depending which bit of the ocean we're discussing.

 

[Drakkith]

The Moon can only attract things to itself. That would involve every direction depending which bit of the ocean we're discussing.

Of course. I spoke incorrectly. I was thinking about the fact that the tides expend their energy mostly upon the western coasts of the continents, at least they do according to the links in the insights article on this topic.

 

[DaveC426913]

To Drakkith,
"What prevents the water itself from 'bulging' under tidal forces?"
This is a good question, but most of its answers have been addressed in the owner post of this long thread.
My answer is that the water's viscosity is too low, compared to the viscosity of solid materials, that's why the water must follow the shape of a container that holds it whereas solid materials can maintain their shape by themself.

The only reason water conforms to the shape of its container is because of gravity acting on it.
A glass of water in (deep) space will happily not conform to its container.
An ocean creates beaches at similar heights on opposite sides of the Earth's sphere because of the (downward) directions of gravity on those locations.

So it makes no sense to argue (as you seem to be doing) that water's viscosity is too low to be shaped by gravity. Quite the opposite; liquids are shaped by gravity more than solids are. This is what directly results in ocean tides.

The reason is very simple, image it, if a cup of water is tilt, the water in it will flow/reallocate, although the earth's gravitational force always attracts this water.

So does the Moon's.

Similarly, if ocean basin or its part is tilt, the earth's gravitational force is not enough to prevent ocean water to flow.

As a matter of fact, the Earth's water flows as a direct result of gravity's pull.

And the Moon's gravity is not a different animal than Earth's gravity.

The water will be pulled in a direction that is the vector sum of the two forces - as if it is one force.

Therefore, the Moon's gravitational force, which is far less than the Earth's gravitational force, is not enough to attract ocean water forming bulge of water.

It is not a threshold thing. It's not like the Moon's gravity only kicks in when above a certain threshold.
Even a small force of gravity leads a to a small rise in liquid.

You seem to be saying A instead of B:

From this point, one must understand that the water movement caused by shaking ocean basin is stronger than that caused by the Moon's gravitational force. So, my theory looks like more reliable than the current theory.

Oceans don't shake!

 

[berkeman]

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