How do tides work on a flat earth

Nor does any nonsensical 30 hour wave propagation time, which completely separates it from the moon.

This will come as welcome news to the poor (globular) scientists doing all the hard math on shallow wave equations to get the propagation times for tidal modeling. They can start using the far simpler Airy equations they use for storm surge propagation instead.

By the way I asked you to give me your sources, which you didn't provide. You don't even have a simplified model.

You made no effort to answer the questions I provided, the search for which would likely lead you to the answers you seek.

This will come as welcome news to the poor (globular) scientists doing all the hard math on shallow wave equations to get the propagation times for tidal modeling. They can start using the far simpler Airy equations they use for storm surge propagation instead.

Why?
Do you have any evidence they are using a 30 hour wave travel time?

Quote from: SRP

By the way I asked you to give me your sources, which you didn't provide. You don't even have a simplified model.

You made no effort to answer the questions I provided, the search for which would likely lead you to the answers you seek.

If you read my post you should have noticed that I did some research trying to answer your questions in a round Earth, while you just ignore my questions completely. That's evidence that you have been idoctrinated. One key point of idoctrination is that you do not question your doctrine. The fact that I looked up your point point saying that the explanation with the moon pulling on Earth doesn't work, shows that I question the explanations given for the round Earth and make an effort finding the most fitting explanation.

You on the other hand are only trying to find contradictions in the round Earth. You don't even bother trying to explain any contradictions I gave you, or answering your own questions. If you are not able to find a contradiction in my answers, or show me that my explanations are wrong, you simply ignore them. That's again evidence that you have been idoctrinated or are ignorant.

To answer one of the questions I asked you about the difference between celestial gravition, I going to use your wiki, unless you provide me with a better explanation (I know you won't, because you probably don't have anything better anyway).

Celestial Gravitation is a part of some Flat Earth models which involve an attraction by all objects of mass on earth to the heavenly bodies. This is not the same as Gravity, since Celestial Gravitation does not imply an attraction between objects of mass on Earth. Celestial Gravitation accounts for tides and other gravimetric anomalies across the Earth's plane.

Celestial gravition says that the celestial bodies attract objects of mass. It doesn't explain where it comes from, so I going to assume that it appears out of nowhere and applies to bodies with large masses. If that's the case it's identical to gravity at least for bodies with a very large mass, like the moon and the sun. Then it would also apply to Earth which is also a body with a large mass, otherwise you don't have an explanation, why objects fall to the ground. The universal acceleration is already contradicted in your FAQ and it contradicts the claim of the Earth not moving.

Also the explanation of the tides using celestial gravition is identical to the simplified explanation of the moon pulling on Earth and the oceans. You already explained yourself that that doesn't work and I admitted that you are right and gave you a more accurate model.

In conclusion, we are back at the beginning and the tides are still not answered for a flat Earth at all. I highly doubt it's ever going to be answered for a flat Earth. For the round Earth on the other hand it's not yet fully understood, but at least there is a somewhat working explanation, which is a lot more than your answer which only says "look it up", which by the way I did for the round Earth.

Would you mind to give all your questions again, so I have them all in one place and I try to answer them for both the round and the flat Earth. You don't seem to bother to answer your own questions anyway, so I'm just going to assume that you don't know the answers. You didn't even bother showing me where you got your information from.

Would you mind to give all your questions again, so I have them all in one place and I try to answer them for both the round and the flat Earth.

Let us do one at a time, for answering several begins to be a chore (as I well know!), and the conversation diverges in a million different directions at once.

Where does the tidal bulge come from? Or more simply, if you'd like: where does the hightide come from?

Quote from: Ski on June 09, 2018, 06:24:03 AM

This will come as welcome news to the poor (globular) scientists doing all the hard math on shallow wave equations to get the propagation times for tidal modeling. They can start using the far simpler Airy equations they use for storm surge propagation instead.

Why?
Do you have any evidence they are using a 30 hour wave travel time?

Let us do some relatively simple math first, and then you can awe me with your own calculations demonstrating the necessary depth of the oceans in the "JackBlack Model of Tides and 'Tidal Bulges'".

We have already demonstrated the tide is mathematically a shallow water wave (having a wavelength in great excess of the depth it is transversing).

As it happens there is an upper limit to wave celerity in a shallow water wave. That limit is the square root of the product of depth and the acceleration of gravity or C=√(gd)

I will now derive a simpler equation just for your ease of use when you begin to tell me how deep the oceans are. Assuming 9.8m/s/s as your value of g (feel free to use your own value, if you'd like), we see the upper limit for wave celerity is 3.13√d m/s

Using a rough mean of 4000m depth we get 3.13*63.25 we get 198 m/s (I've rounded up for our convenience) or (198*60*60)/1000 or 713 km/h (again rounded up to a whole number for your convenience).

The wave needs to cover half the circumference of the globular earth to bring the antipodal hightide to our position. I am electing to use 20000 kms as that value (the commonly accepted value is slightly higher).

20,000km/713km/hr gives us just over 28 hrs for the (rounded up) maximum wave celerity to next bring it's tide to the original position on the (rounded down) globe.

This is a maximum value for celerity, and therefore a minimum value for time, be mindful. The more shallow the water the lower the maximum celerity the wave attain for a given depth. And indeed as it happens, there is sometimes/places where there is no depth at all! We call this land.


Please demonstrate using these widely -accepted principles your model for tidal bulges wherein the tidal bulge (ie long-period wave) traverses to the antipode in 12 (or slightly over 12) hours.

Once you can reconcile that with reality, we can begin to berate me with your ridiculous elementary school presentation of tidal bulges (which were invented expressly for the purpose of telling you and your classmates).

Where does the tidal bulge come from? Or more simply, if you'd like: where does the hightide come from?

Yes, that is the important question.
RE has an answer, primarily the tidal forces of the moon and to a lesser extent that of the sun.
Due to the nature of tidal forces, this results in 2 (technically 4, 2 for the moon, and 2 smaller ones for the sun).

For FE, if you were going to use the same idea, you would either just get one, underneath the moon, or 2, one for the moon and one for the sun, which would have different periods.

So what causes the second bulge for FE?

As it happens there is an upper limit to wave celerity in a shallow water wave. That limit is the square root of the product of depth and the acceleration of gravity or C=√(gd)

Only when they have 0 flow velocity, and nothing trying to force it along like the tidal forces of the moon.
Also, that would be the velocity, nor merely the limit.

20,000km/713km/hr gives us just over 28 hrs for the (rounded up) maximum wave celerity to next bring it's tide to the original position on the (rounded down) globe.

You mean to the antipodal position.
It would be 56 hours to get it back to the original position, which is still nothing like the 30 hours you claimed.

Quote from: Ski on June 10, 2018, 01:52:03 PM

Where does the tidal bulge come from? Or more simply, if you'd like: where does the hightide come from?

Yes, that is the important question.
RE has an answer, primarily the tidal forces of the moon and to a lesser extent that of the sun.
Due to the nature of tidal forces, this results in 2 (technically 4, 2 for the moon, and 2 smaller ones for the sun).

For FE, if you were going to use the same idea, you would either just get one, underneath the moon, or 2, one for the moon and one for the sun, which would have different periods.

So what causes the second bulge for FE?

The same thing that results in your misundst second "bulge".

Quote from: Ski on June 10, 2018, 02:20:46 PM

As it happens there is an upper limit to wave celerity in a shallow water wave. That limit is the square root of the product of depth and the acceleration of gravity or C=√(gd)

Only when they have 0 flow velocity, and nothing trying to force it along like the tidal forces of the moon.
Also, that would be the velocity, nor merely the limit.

Wrong. Though, it does represent the celerity because it is the limit. It is depth dependent regardless of the acceleration or period.  If it qualified as a deep water wave, it would be period-dependant and susceptible to acceleration.

Quote from: Ski on June 10, 2018, 02:20:46 PM

20,000km/713km/hr gives us just over 28 hrs for the (rounded up) maximum wave celerity to next bring it's tide to the original position on the (rounded down) globe.

You mean to the antipodal position.
It would be 56 hours to get it back to the original position, which is still nothing like the 30 hours you claimed.

The individual wave crest has traveled to the antipode. The wave form has completed one cycle and returned to crest at our original position. Perhaps I should have worded it "28 hours for the maximum wave celerity to complete the cycle and bring the tidal crest back to our original location". If you wish the individual wave front to return to the original position, it would be 56 hours which is still divorced from your theorized 25 hr propagation time or 12.5 hr tide cycle. Resolve.

The same thing that results in your misundst second "bulge".

So your flat Earth has 2 sides and the second "bulge" is on the other side?
If not, it is not the same thing.

Wrong. Though, it does represent the celerity because it is the limit.

You seem to have no idea what celerity actually means. It is the phase velocity of the wave.
The value calculated is not the limit, it is the value.
The shallow water wave should travel with that phase velocity, assuming it has a 0 flow velocity and no forces trying to drive it.

This only works when you have something creating the wave and then having the wave propagate without further influence.

If you wanted to go down the path of ignoring perturbing factors such as the tidal forces from the moon, then you get exactly that time and thus it doesn't match your 30 hours either and still fails to match the tides, regardless of what model you want to try to use.

Perhaps I should have worded it "28 hours for the maximum wave celerity to complete the cycle and bring the tidal crest back to our original location".

Yes, that would be better wording, but that is now dealing with a fundamentally different concept.
You are no longer trying to have the wave propagate from one location to another, and are now focusing on the period. You can get almost any period for any velocity.
To link them you need to know the wavelength, and as the wave isn't a simple perfect wave around Earth (especially due to the land getting in the way), how do you plan on doing that?

You seem to have no idea what celerity actually means. It is the phase velocity of the wave.
The value calculated is not the limit, it is the value.

Yes. If you'd like to run the regular water wave celerity equation, you'd see it is dependent on wavelength.

C= √(gL/2π)

If you want to work it out, you'll see your wave with a wavelength of 20,000km would be travelling extremely fast. And a tsunami with 100km wavelength would be rather slower.

This does not happen with shallow water waves (of which both are an example). They are both limited by the depth. Hence, the shallow water celerity equation represents both the maximum value for a wave (regardless of wavelength) at a given depth. Neither the wavelength or other factors or forces will produce a greater value for celerity. The tsunami and tide wave (a true tidal wave) have the same celerity, assuming the same depth, despite far different wavelengths. C in the case of shallow-water is the limit or maximum value for a given depth.

So while flow velocity will affect celerity of a deep water wave, the wave and particle movement in shallow water are already at a maximum because of the interaction between particle motion and the seabed.

then you get exactly that time and thus it doesn't match your 30 hours either and still fails to match the tides, regardless of what model you want to try to use.

I'm sorry that my very rough math ignoring a wide variety of things that slow waves csme up with 28 hrs instead of the commonly accepted 30 hrs. Perhaps if I used a better inputs, this amateur would get a professional result. As we can see the number is well in advance of the 12.5 hour cycle you are advocating. Why is that? Where is your math?

You are no longer trying to have the wave propagate from one location to another, and are now focusing on the period. You can get almost any period for any velocity.
To link them you need to know the wavelength, and as the wave isn't a simple perfect wave around Earth (especially due to the land getting in the way), how do you plan on doing that?

I have already shown above that while that wavelength dependence would be true if it were not a shallow-water wave. It is one, however, and the wavelength in the ridiculous model you continue to berate me with for not understanding is exactly half the circumference. Adding obstructions and shelves only slows the wave farther away from the values you need for your math to work.
At least you've read enough Wikipedia this week to move on from "Why should wave celerity have anything to do with Earth's tides?"  Baby steps.

Quote from: SRP

Would you mind to give all your questions again, so I have them all in one place and I try to answer them for both the round and the flat Earth.

Let us do one at a time, for answering several begins to be a chore (as I well know!), and the conversation diverges in a million different directions at once.

Where does the tidal bulge come from? Or more simply, if you'd like: where does the hightide come from?

I found a paper explaining tides in detail for a spherical Earth. It should explain all the questions you have in greater detail than I am able to.
http://nora.nerc.ac.uk/id/eprint/119157/1/sea-level.pdf

Since I promised to give you an answer for the flat Earth as well. Here is the explanation given by Rowbotham. If you have a more detailled explanation, please add it.
http://www.sacred-texts.com/earth/za/za30.htm#page_158

Yes. If you'd like to run the regular water wave celerity equation, you'd see it is dependent on wavelength.

Or if you run the full equation without the assumptions that the only forces acting are friction at the bottom and gravity pulling it straight down, you would get a different equation.

The equation you are using relies upon the flow velocity being 0 and no additional forces.
For shallow water waves it is independent on the wavelength, but that doesn't mean independent of everything else.

C in the case of shallow-water is the limit or maximum value for a given depth.

The celerity is the phase velocity.
I am yet to find a single source which indicates it is merely the limit.

As we can see the number is well in advance of the 12.5 hour cycle you are advocating.

I have already said why.
One important point is that you are using the time taken for a wave to travel from point A to point B and pretending it should be how long between 2 crests at point A.

the wavelength in the ridiculous model you continue to berate me with for not understanding is exactly half the circumference.

Why?

Why do you repeatedly ignore what has been said which already answers your questions?

Why ignore the massive questions for FE?
Instead of focusing on how it would even be possible for FE to explain the 2 tides you waste time trying to go into more details about how tides work on the real Earth.

What causes the second bulge for FE?

The celerity is the phase velocity.
I am yet to find a single source which indicates it is merely the limit.

I can never tell if you're being deliberately obtuse.

Celerity is phase velocity, Jack.  In the case of most water waves, it is a function of wavelength. The longer the faster.

Except in the case of shallow water waves, something special happens. There is no drift. The normal celerity of the waveform is inhibited. Restricted. Limited. By depth. The new value for celerity (phase velocity) is lower than otherwise. No matter how big the wavelength, celerity is now decoupled from wavelength.  Tides have the same celerity as tsunamis despite having much longer wavelengths. Why? Because both have reached the limit of celerity determined by depth.

One important point is that you are using the time taken for a wave to travel from point A to point B and pretending it should be how long between 2 crests at point A.

Because point A to B is 20,000km, Jack. A full wavelength is also 20,000km. The circumference of the circle traversed is 40,000km.

Could you be more obtuse?

Quote from: Ski on June 06, 2018, 05:28:18 AM

Oh, you still haven't thought about it even after I spelt it out?  Now it is sad.

No, I have thought about it, and realise it is a load of crap, as I explained.
In order for your wave propagation time (which is a complete load of crap) to have any significance you would need the moon to be causing high and low tides, through a completely different mechanism to RE.
It would need to pulse up and down and allow that wave to propagate.
But that isn't what happens in reality.

So even after I have explained why it doesn't work, you still insult me by pretending I'm a moron rather than providing an actual explanation or admitting your claims were bullshit.

Grow up.

You have not explained anything.

You claim a RE-tard explanation is required for something Ski added in terms of wave propagation to work...

This simply further demonstrates your complete ignorance.

You are a moran.

And Ski has not insulted you even though you thoroughly deserve it.

You have not explained anything.

You claim a RE-tard explanation is required for something Ski added in terms of wave propagation to work...

This simply further demonstrates your complete ignorance.

You are a moran.

And Ski has not insulted you even though you thoroughly deserve it.

Thank you for your detailed input.

Celerity is phase velocity, Jack.

Yes, that is the point I was making. That is not a limit.

In the case of most water waves, it is a function of wavelength.

Again, the wavelength is not the only factor.
The equation you provided relies upon several assumptions including no forces other than gravity from Earth and friction on the bottom and no flow velocity.

Quote

One important point is that you are using the time taken for a wave to travel from point A to point B and pretending it should be how long between 2 crests at point A.

Because point A to B is 20,000km, Jack. A full wavelength is also 20,000km. The circumference of the circle traversed is 40,000km.
Could you be more obtuse?

You should try asking yourself that question.
We both know it doesn't simply travel in a circle as the land gets in the way.
We also know that the tides don't perfectly follow the moon.
We know it isn't a simple case of a wave appears and flows around Earth.
So why pretend the wavelength must be 20 000 km?

And again, you are still ignoring the main point.
How does a FE account for the second bulge?

Quote from: Ski on June 12, 2018, 06:47:30 AM

Celerity is phase velocity, Jack.

Yes, that is the point I was making. That is not a limit.

As demonstrated, it is in the case of shallow water waves, which by happy coincidence we happen to be discussing.

The equation you provided relies upon several assumptions including no forces other than gravity from Earth and friction on the bottom and no flow velocity.

Great. I look forward to seeing your math that brings down the period from 30 hrs to 12.5

We both know it doesn't simply travel in a circle as the land gets in the way.

You mean there are things slowing the velocity even slower than the 713km/h? How inconvenient for you who need the period to be 12.5 hours.

We also know that the tides don't perfectly follow the moon.

Quote

In general, you have a high tide almost under the moon and one on the opposite side of Earth.

We know it isn't a simple case of a wave appears and flows around Earth.

Indeed, it looks nothing like that at all.

So why pretend the wavelength must be 20 000 km?

And

In general, you have a high tide almost under the moon and one on the opposite side of Earth.

As demonstrated, it is in the case of shallow water waves, which by happy coincidence we happen to be discussing.

Make up your mind.
Is the celerity the phase velocity or the limit of the phase velocity. It can't be both.
All sources I have found indicate it IS the phase velocity.

And I fail to see you address any other the other points.
Quoting myself as if it is a contradiction doesn't magically make it a contradiction.
No where have I indicated the high tide is perfectly underneath the moon.
As such, pretending my comments mean that is extremely dishonest.

And yet again you fail to address the main issue:
WHAT CAUSES THE SECOND BULGE FOR FE?

Make up your mind.
Is the celerity the phase velocity or the limit of the phase velocity. It can't be both.
All sources I have found indicate it IS the phase velocity.

It's really not deliberately obtuse, is it? 

Ski: "The velocity of a falling object is a function of time. V_t=g(t) The longer an object falls in a given environment, the faster it falls.
Except when the force of resistance equals g. Then the velocity is divorced from time. It has reached the limit of velocity no matter how much time elapses. It is no longer a function of time. We are discussing such a scenario, so in our case the limit is V=√(2mg/pAC_d)"

Jack: "You seem to have no idea what velocity really means. Velocity is how fast the object is falling. The value calculated is the velocity. The value calculated is not the limit, it is the value.
 I've looked everywhere and can't find anywhere that defines velocity as a limit. Also, you'd have to know how long it's been falling to get the velocity."

Ski: "It is both the velocity and the limit in our circumstance, Jack."

 Jack: "Make up your mind! Is the velocity how fast the object is falling or the limit of how fast it will go? It can't be both. Everything I read says it IS how fast it is falling."

Ski: "The velocity of a falling object is a function of time. V_t=g(t) The longer an object falls in a given environment, the faster it falls.
Except when the force of resistance equals g. Then the velocity is divorced from time. It has reached the limit of velocity no matter how much time elapses. It is no longer a function of time. We are discussing such a scenario, so in our case the limit is V=√(2mg/pAC_d)"

No we are not.
We are not discussing an object falling through  the air reaching terminal velocity.
We are discussing wave propagation.
The celerity is the phase velocity, not a limit.

What you need to make up your mind on is if you want to pretend it is the limit of the phase velocity or if it is the actual phase velocity.
The 2 are fundamentally different things.

The terminal velocity is the speed at which the an object falls when air resistance cancels gravitational acceleration (sometimes with buoyancy taken into account).
The actual velocity of a falling object can be less than or greater than or equal to terminal velocity.

Likewise the celerity of a shallow water wave is the phase velocity of the wave when acted upon by the gravity of Earth and friction at the bottom of the water.
It is not a limit, it is merely the velocity that it would be without other influences.

Now how about you try quoting me honestly and responding to what I am actually saying?

And again, what causes the second bulge for FE?

The celerity is the phase velocity, not a limit.

What you need to make up your mind on is if you want to pretend it is the limit of the phase velocity or if it is the actual phase velocity.
The 2 are fundamentally different things.

Hahahahaha. You are funnier than the real Jack Black.  Wait?! Are you the real Jack Black?! 

In general, you have a high tide almost under the moon and one on the opposite side of Earth.

.

Please model these two bulges with a 12.5 hr phase for me because I just showed why it is mathematically impossible (hint: my approximations were helpful to your goal, but still way, too slow). Feel free to Make sure to use viscosity and inertial flow since you are so concerned they were omitted by me and indicate in your responses that they are the answer to why my demonstration does not work. If you believe continental diffusion will help you get there (since you bring that up) by all means use it. Show me the maths. (Bonus hint: it doesn't work)

Please model these two bulges

Why should I when people have already done so with papers that have been linked?

You haven't shown anything relevant to be mathematically impossible. If you want to suggest it is impossible, you do the math to show it is, making sure you account for the tidal force from the moon.

Or better yet, explain how a FE gets the second bulge?

Why should I when people have already done so with papers that have been linked?

All you do is mindlessly copy and paste anyway; why would I care where you get it from? Show us the 12.5 hr propagation of these bulges you keep saying exist. Since you said it's been linked, I assume you know where to find it. I'll wait.

Show us the 12.5 hr propagation of these bulges you keep saying exist.

Where have I ever said that exists?

Now how about you try explaining what causes the second bulge on a FE?

Physics does jack. But you don't tend to listen.

Physics does jack. But you don't tend to listen.

Care to explain how physics magically does that?

Quote

Why should I when people have already done so with papers that have been linked?

Show us the 12.5 hr propagation of these bulges you keep saying exist. Since you said it's been linked, I assume you know where to find it. I'll wait.

Why is a 12.5 hr propagation time of these bulges needed?
The main driving force has its period of close to 12 hr 24 mins, though there is a 24 hour component.
The observed tides can be anywhere from one high tide/day (Pensacola), two high tides per day (most locations) and even mixed tides with two very unequal high tides per day.

Quote from: Ski on June 12, 2018, 05:29:14 PM

Show us the 12.5 hr propagation of these bulges you keep saying exist.

Where have I ever said that exists?

Now how about you try explaining what causes the second bulge on a FE?

Oh, i thought that was the commonly accepted cycle time. Actually, RAB is right. It's 12.25 not 12.5. I just looked it up. (that means it needs more celerity! Bad news!) Do you have your own tidal cycle value?

You said my equation was wrong because I didn't add viscosity and inertial flow or add the continents. Then you said you posted it elsewhere. Do you mind showing the math again? Because I'm a big believer in math, and I don't see it anywhere. Just need the celerity equation with viscosity and inertial flow (sheer would be a nice bonus. Feel free to add some diffusion or diffraction on account of continental shelves and what not since you imply you think that that will help) that shows a tidal bulge with a 20000km wavelength travelling 20000km across Earth's ocean in 12.25 hours. Really just feel free to copy and paste it from what you said was already posted. I'm eagerly awaiting this tidal science breakthrough. New physics!

that means it needs more celerity! Bad news!

And why should it mean that?
You are still focusing on velocity rather than period.

You said my equation was wrong because I didn't add viscosity and inertial flow or add the continents.

Or other perturbing forces.
I don't think I ever mentioned viscosity.

Then you said you posted it elsewhere.

No I didn't. I said others had provided it.

that shows a tidal bulge with a 20000km wavelength travelling 20000km across Earth's ocean in 12.25 hours.

Again, where was this claimed?

And again, why not answer the main question?
How does FE account for the second bulge?