[Ga_x2]

Please create a thread on round earth tides and discuss about it how much you want

This isn't round Earth. This is the relationship between the moon's influence and the sun's influence. Nothing to do with the Earth except for distance between it and the moon and sun. What am I saying that's controversial in the slightest?

nothing you said is controversial, but unless you can use it to answer the question in the OP is an off topic musing

[3DGeek]

One week later, and this is the situation:
- 3dgeek couldn't resist explaining how tides work in a RE  (I knew you couldn't! );

The tides happen (roughly) twice per day - one high tide when the moon is overhead and (*low tide*) when it's overhead on the opposite side of the world.

Because the moon's motion around the Earth is combined with the Earth's rotation, the tides are actually about 12.5 hours apart, not exactly 12.   This fact of tide times really brings home the fact that tides are definitely related most strongly to the cycles of the moon.   However, the sun actually adds (or subtracts) it's own tides on a precise 12 hour cycle.   But because the sun is SO far away (at least in RET) it's tidal effects are rather small.

So if you look at water level charts, you see two sine-waves added together - one with that 12 hour cycle and another with a roughly 12.5 hour cycle

Explaining all of this subtlety is FAR beyond what FET can manage.

In RET, the explanation is really very simple.

3DGeek makes a valid point, in spite of admonition from Ga_x2. The equation for gravitational force is (and has been proven to be, with or without a flat Earth) (G(m1m2))/(r^2).

But there's one thing. The proportion of gravitational force between Sun&Earth and Moon&Earth are (in SI units) ((Msun)/((distance[Earth--Sun])^2))/(Mmoon/((distance[Earth--moon])^2)), which would be ((1.989 × (10^30)[kg])/((1.496 x (10^8)[km])^2))/((7.34767309 × (10^22)[kg])/((3.844 x (10^5)[km])^2)) = 178.726326. The sun has 178 times the gravitational pull that the moon has upon the Earth. The sun has a higher pull upon the Earth than the moon does. So the tides should, according to this logic, rise and fall with the sun. But it doesn't. What do you people make of that?

Two things you're misunderstanding about tides:

FIRSTLY:

The tides caused by the sun DO exist - if you look at the graphs, they are the sum of TWO sinewaves, a large amplitude swing with a period of about 12.5 hours due to the moon and a smaller wave with a 12 hour period due to the sun.

We see the total of those two superimposed waves.

Sailors and other people who care about tides talk about "neap tides" and "spring tides" (badly named!) - where the tide is less than or greater than "normal".   Why?  You'd think the moon was always at the same distance and always has the same gravity - so why are there these special tides?

The neap tide happens when the sun and moon are about 90 degrees apart in the sky and the sun is trying to raise the tidal level while the moon is depressing it (or vice-versa at low tide).

The spring tide happens when the sun and moon are either close together in the sky or on opposite sides of the earth and the two tidal effects reinforce each other - so you get a higher "high tide" and a lower "low tide".

Hence we most certainly do see an effect from solar tides - it's just a lot smaller than lunar tides.

SECONDLY:

Tides don't depend only on the AMOUNT of gravity from a remote body - they depend only on the fact that the gravitational pull from sun/moon on one side of the earth is more than on the other.

So the key factor is the DIFFERENCE between the sun/moon's gravity on one side of the planet versus the other.  Since the sun is about 400 times further away than the moon, the difference in distance between the two sides of the planet from the sun is a smaller percentage than that for the moon.

So even though the moon's gravity is FAR less than the sun's in absolute terms, it's proximity to us makes the tides much higher.

Sadly, although all of these effects are easily demonstrated in RET.   NONE of these effects would be present in a flat earth...so...the two-tides-per-day thing is hand-waved away - along with issues of spring and neap tides.

[Revel]

Two things you're misunderstanding about tides:

FIRSTLY:

The tides caused by the sun DO exist - if you look at the graphs, they are the sum of TWO sinewaves, a large amplitude swing with a period of about 12.5 hours due to the moon and a smaller wave with a 12 hour period due to the sun.

We see the total of those two superimposed waves.

I'm unfamiliar with the graphic relationship, which might constitute most heavily on my misunderstanding.

SECONDLY:

Tides don't depend only on the AMOUNT of gravity from a remote body - they depend only on the fact that the gravitational pull from sun/moon on one side of the earth is more than on the other.

So the key factor is the DIFFERENCE between the sun/moon's gravity on one side of the planet versus the other.  Since the sun is about 400 times further away than the moon, the difference in distance between the two sides of the planet from the sun is a smaller percentage than that for the moon.

So even though the moon's gravity is FAR less than the sun's in absolute terms, it's proximity to us makes the tides much higher.

I understand that the moon is closer, but even then, the sun's size more than makes up for its poor vicinity, as shown in the equation I used. It should still have a more overwhelming effect on tides, seeing that its gravitational effect is so much higher. Gravitational pull already accounts for the relationship between distance and size. The moon's effect should be 1/179th of the total effect assuming there exist no outside forces apart from the sun and moon, since the sun has 178 times the effect that the moon has.

[Revel]

Please create a thread on round earth tides and discuss about it how much you want

This isn't round Earth. This is the relationship between the moon's influence and the sun's influence. Nothing to do with the Earth except for distance between it and the moon and sun. What am I saying that's controversial in the slightest?

nothing you said is controversial, but unless you can use it to answer the question in the OP is an off topic musing

It's totally relevant! I'm using facts, not cases specific to the round Earth. If I'm not controversial, then you can use my facts about high tides to apply to the theoretically flat Earth.

[3DGeek]

I understand that the moon is closer, but even then, the sun's size more than makes up for its poor vicinity, as shown in the equation I used.

No - your not looking at the right equation.

The tidal force is the force of gravity pulling on one side versus the other.

I'm a software engineer - so I tend to think more in program code than equations.  Here is a program I recently wrote to figure out how much gravity the planet "Trappist-1e" has - but I also calculated the sun and moon's gravity for the Earth to be sure I didn't make an error in my code:

Code: [Select]

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

// All data sourced from Wikipedia.

const double G                    = 6.67408e-11      ; // m3 kg−1 s−2
const double AU                   = 149597870700.0   ; // m

// Solar system:

const double MassSun              = 1.98855e30          ; // kg

const double MassEarth            = 5.97237e24          ; // kg
const double RadiusEarth          = 6371000.0           ; // m
const double OrbitalDistanceEarth = 1.0 * AU            ; // m

const double MassMoon            = 7.342e22             ; // kg
const double RadiusMoon          = 1737000.0            ; // m
const double OrbitalDistanceMoon = 384399000.0          ; // m

const double MassMercury            = 0.055  * MassEarth   ; // kg
const double RadiusMercury          = 0.3829 * RadiusEarth ; // m
const double OrbitalDistanceMercury = 0.387098 * AU        ; // m

// Trappist-1 system:

const double MassTrap_1             = 0.0802  * MassSun     ; // kg
const double MassTrap_1e            = 0.62    * MassEarth   ; // kg
const double RadiusTrap_1e          = 0.918   * RadiusEarth ; // kg
const double OrbitalDistanceTrap_1e = 0.02817 * AU          ; // m

// Math:

double gravity ( double m1, double m2, double r ) // N
{
  return m1 * m2 * G / ( r * r ) ;
}

double tidalForce ( double m1, double m2, double orbit, double radius ) // N
{
  return gravity ( m1, m2, orbit - radius ) -
         gravity ( m1, m2, orbit + radius ) ;
}

int main ( int argc, char **argv )
{
  double SolarTideEarth   = tidalForce ( MassEarth  , MassSun   , OrbitalDistanceEarth  , RadiusEarth   ) ;
  double LunarTideEarth   = tidalForce ( MassEarth  , MassMoon  , OrbitalDistanceMoon   , RadiusEarth   ) ;
  double SolarTideMercury = tidalForce ( MassMercury, MassSun   , OrbitalDistanceMercury, RadiusMercury ) ;
  double SolarTideTrap_1e = tidalForce ( MassTrap_1e, MassTrap_1, OrbitalDistanceTrap_1e, RadiusTrap_1e ) ;

  printf ( "Earth       Lunar Tidal Force = %0.3e Newtons\n", LunarTideEarth   ) ;
  printf ( "Earth       Solar Tidal Force = %0.3e Newtons\n", SolarTideEarth   ) ;
  printf ( "Mercury     Solar Tidal Force = %0.3e Newtons\n", SolarTideMercury ) ;
  printf ( "Trappist 1e Solar Tidal Force = %0.3e Newtons\n", SolarTideTrap_1e ) ;

  return 0 ;
}


Basically, I use the standard calculation for the force of gravity at some distance - then calculate the tidal force by doing the calculation twice - once for the near-side of the planet - and again for the far side - then subtracting one from the other to get the total TIDAL force.

The result of this is:

Earth       Lunar Tidal Force = 1.314e+19 Newtons
Earth       Solar Tidal Force = 6.033e+18 Newtons
Mercury     Solar Tidal Force = 2.191e+18 Newtons
Trappist 1e Solar Tidal Force = 1.232e+22 Newtons

So you can see that the moon's tidal force is a little more than twice that of the sun.

It should still have a more overwhelming effect on tides, seeing that its gravitational effect is so much higher. Gravitational pull already accounts for the relationship between distance and size. The moon's effect should be 1/179th of the total effect assuming there exist no outside forces apart from the sun and moon, since the sun has 178 times the effect that the moon has.

Sorry - I don't have the time to explain the physics to you - and this is the wrong place for it anyway.

(Trappist-1e has IMPRESSIVE tides!)

[douglips]

Tidal force depends on the inverse CUBE of the distance. The overall gravity force depends on the SQUARE OF THE DISTANCE. So no, the distance is not "more than made up for" by the large mass of the sun.

[Revel]

Tidal force depends on the inverse CUBE of the distance. The overall gravity force depends on the SQUARE OF THE DISTANCE. So no, the distance is not "more than made up for" by the large mass of the sun.

Even if it is cubed, that doesn't qualify it as larger than any base number. Sure, the rate of change of a cubed number is much greater than one that is fixed, but mind you, 9 is greater than 2^3. Mass could still potentially make up for the larger distance when it comes to gravitational force, as I demonstrated in the equation I used. But I am incorrect on a different note, one that 3DGeek addressed to me recently.
And by the way, totally irrelevant but still a mistake, in terms of two-body gravity, distance is squared. So, inverse square of the distance. Tidal force should be very close to gravitational force.

[3DGeek]

Tidal force depends on the inverse CUBE of the distance. The overall gravity force depends on the SQUARE OF THE DISTANCE. So no, the distance is not "more than made up for" by the large mass of the sun.

Indeed.  https://en.wikipedia.org/wiki/Tidal_force#Mathematical_treatment

[douglips]

Tidal force depends on the inverse CUBE of the distance. The overall gravity force depends on the SQUARE OF THE DISTANCE. So no, the distance is not "more than made up for" by the large mass of the sun.

Even if it is cubed, that doesn't qualify it as larger than any base number. Sure, the rate of change of a cubed number is much greater than one that is fixed, but mind you, 9 is greater than 2^3. Mass could still potentially make up for the larger distance when it comes to gravitational force, as I demonstrated in the equation I used. But I am incorrect on a different note, one that 3DGeek addressed to me recently.
And by the way, totally irrelevant but still a mistake, in terms of two-body gravity, distance is squared. So, inverse square of the distance. Tidal force should be very close to gravitational force.

No, gravitational force goes as the inverse square. The add-on on top of it from tidal force goes as inverse cube. See the wikipedia article 3DGeek linked, tidal acceleration is approximately 2 (delta R) (GM/R^3) where R is the earth-sun distance and  (delta R) is the difference in distance between the earth-sun distance and where the observer is at the surface of the earth. (i.e. at low and high tide, delta R is the radius of globe earth).

The gravitational acceleration is just GM/R^2, which is what you used in your calculation that said that the sun exerts 178 times the gravitational force on the earth than the moon does. If you just take that equation and turn the ^2 to ^3 in both places, you get that the sun exerts 0.45 as much tidal force as the moon does on the earth.

[Revel]

Tidal force depends on the inverse CUBE of the distance. The overall gravity force depends on the SQUARE OF THE DISTANCE. So no, the distance is not "more than made up for" by the large mass of the sun.

Even if it is cubed, that doesn't qualify it as larger than any base number. Sure, the rate of change of a cubed number is much greater than one that is fixed, but mind you, 9 is greater than 2^3. Mass could still potentially make up for the larger distance when it comes to gravitational force, as I demonstrated in the equation I used. But I am incorrect on a different note, one that 3DGeek addressed to me recently.
And by the way, totally irrelevant but still a mistake, in terms of two-body gravity, distance is squared. So, inverse square of the distance. Tidal force should be very close to gravitational force.

No, gravitational force goes as the inverse square. The add-on on top of it from tidal force goes as inverse cube. See the wikipedia article 3DGeek linked, tidal acceleration is approximately 2 (delta R) (GM/R^3) where R is the earth-sun distance and  (delta R) is the difference in distance between the earth-sun distance and where the observer is at the surface of the earth. (i.e. at low and high tide, delta R is the radius of globe earth).

The gravitational acceleration is just GM/R^2, which is what you used in your calculation that said that the sun exerts 178 times the gravitational force on the earth than the moon does. If you just take that equation and turn the ^2 to ^3 in both places, you get that the sun exerts 0.45 as much tidal force as the moon does on the earth.

Ah. I apologize for being stubborn. I haven't learned that yet, I thought there wasn't a difference between force on tidal waves and bodies of planets. It's proportional, but of course, not equivalent.

[3DGeek]

Tidal force depends on the inverse CUBE of the distance. The overall gravity force depends on the SQUARE OF THE DISTANCE. So no, the distance is not "more than made up for" by the large mass of the sun.

Even if it is cubed, that doesn't qualify it as larger than any base number. Sure, the rate of change of a cubed number is much greater than one that is fixed, but mind you, 9 is greater than 2^3. Mass could still potentially make up for the larger distance when it comes to gravitational force, as I demonstrated in the equation I used. But I am incorrect on a different note, one that 3DGeek addressed to me recently.
And by the way, totally irrelevant but still a mistake, in terms of two-body gravity, distance is squared. So, inverse square of the distance. Tidal force should be very close to gravitational force.

No, gravitational force goes as the inverse square. The add-on on top of it from tidal force goes as inverse cube. See the wikipedia article 3DGeek linked, tidal acceleration is approximately 2 (delta R) (GM/R^3) where R is the earth-sun distance and  (delta R) is the difference in distance between the earth-sun distance and where the observer is at the surface of the earth. (i.e. at low and high tide, delta R is the radius of globe earth).

The gravitational acceleration is just GM/R^2, which is what you used in your calculation that said that the sun exerts 178 times the gravitational force on the earth than the moon does. If you just take that equation and turn the ^2 to ^3 in both places, you get that the sun exerts 0.45 as much tidal force as the moon does on the earth.

Ah. I apologize for being stubborn. I haven't learned that yet, I thought there wasn't a difference between force on tidal waves and bodies of planets. It's proportional, but of course, not equivalent.

This has probably reached the point of off-topicness.   Revel - you are CLEARLY wrong - and everyone is telling you so.  It's time you went and asked the question you have on some RET forum where you'll get a good answer.   May I recommend either the Wikipedia science desk (https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science) or the Quora section on Tides (https://www.quora.com/search?q=Tides).

The thing you're STILL failing to understand is that tidal forces depend on the ratio of the size of the 'target' (Earth in this case) to the distance from the source (the Sun or Moon) - that ratio is a TINY number for the Sun and BIG number for the Moon - and that difference by FAR outweighs the Sun's larger mass.

But either way - this is not the place for this debate.   We're really discussing how FlatEarth physics explains tides ("badly" being the only answer I've seen so far!) and not your personal failure to understand RET physics.

[Revel]

What haven't I understood? You just taught me that gravitational force is not equally distributed across the Earth, since it is not a point, but a 3-dimensional object. Therefore, tidal force takes into account the strongest portion of the Earth that receives gravitational force: the nearest part of the Earth. That's why the two entities could be considered, to a good degree, proportional. But you're right, I digress.

[J-Man]

Just as the J-Man of God has explained, NASA has now had to get on board the truth and reveal as J-Man did here first, for the readers, that in fact, the Earth Breathes.....

https://www.space.com/38806-nasa-satellites-watch-earth-breathe-video.html

The video shows Earth "breathing"

===========

Probably not a good Idea to mess with the WORD....

[mtnman]

Just as the J-Man of God has explained, NASA has now had to get on board the truth and reveal as J-Man did here first, for the readers, that in fact, the Earth Breathes.....

https://www.space.com/38806-nasa-satellites-watch-earth-breathe-video.html

The video shows Earth "breathing"

===========

Probably not a good Idea to mess with the WORD....

LOL

First of all they are not talking about tides, at all, anywhere on the page. As usual, you see a web page with one word you think agrees with you and you post it. Did you read it?

Second of all, you are posting a compilation of satellite data because you think it agrees with you (they used the word breathe!). But you don't believe in NASA or satellites. Why do you do this? Oh, I remember. FE faithful accept anything they think agrees with them without thought, and claims everything that disagrees with them is fake.

My theory must be true if I ignore everything that says otherwise. It's like arguing with a child. Or maybe that's just what it is.

[J-Man]

Lets see you replicate a globe with 1/4 inch of water on it that sticks while you spin it. We'll wait....begin


Thank you all, especially qeek for confirming you can't replicate it, not here, not in outer space. It's all BS water sticking to a ball.

Breathe deep God, the tides work great like old faithful.

I'll get right on that after you prove anything you said about the Earth breathing tides.

Seriously, no one could actually be this ignorant. I guess you just like trolling for sake of trolling.

Add one to the FE response standard plan.
Option 1:Derail by changing subject.
Option 2:Ignore.
Option 3:Derail by suggesting something so stupid everyone forgets the original subject.

Mtnman just can't handle the truth. He is shocked that his beloved satanist NASA has said the earth breathes. And yes it will come out soon that this is in fact the delivery of tidal changes....

Carry on. Slash bonk kick

This is J-Man !

[douglips]

The video shows Earth "breathing"

....

Do they not have metaphors on your home planet? The video is clearly described as showing the yearly cycle of plant life increasing and decreasing with the seasons. This is about as far away from your notion of the Earth breathing twice a day to explain tides as a Volkswagen beetle is from a Saturn V.

Oh sorry, that was also a metaphor. What I mean is: you are completely misrepresenting the video. Is this intentional on your part?

[mtnman]

The video shows Earth "breathing"

....

Do they not have metaphors on your home planet? The video is clearly described as showing the yearly cycle of plant life increasing and decreasing with the seasons. This is about as far away from your notion of the Earth breathing twice a day to explain tides as a Volkswagen beetle is from a Saturn V.

Oh sorry, that was also a metaphor. What I mean is: you are completely misrepresenting the video. Is this intentional on your part?

He saw a word he liked on a page with sciencey stuff, nothing deeper than that.

[mtnman]

Mtnman just can't handle the truth. He is shocked that his beloved satanist NASA has said the earth breathes. And yes it will come out soon that this is in fact the delivery of tidal changes....

Carry on. Slash bonk kick

This is J-Man !

The truth? You just posted a link with video from NASA, which you don't believe in. Showing images from a satellite, which you don't believe in. Showing images of a round Earth, which you don't believe in. All because they used the word "breathe".

So if this proves the Earth breathes, then it also proves NASA filmed the round Earth with a satellite. So do you believe all these things now?

[J-Man]

Mtnman just can't handle the truth. He is shocked that his beloved satanist NASA has said the earth breathes. And yes it will come out soon that this is in fact the delivery of tidal changes....

Carry on. Slash bonk kick

This is J-Man !

The truth? You just posted a link with video from NASA, which you don't believe in. Showing images from a satellite, which you don't believe in. Showing images of a round Earth, which you don't believe in. All because they used the word "breathe".

So if this proves the Earth breathes, then it also proves NASA filmed the round Earth with a satellite. So do you believe all these things now?

Really? It's obvious NASA monitors my posts here and loved my breathing exercise debate and decided to use it. You can't have like 3 people on this site offering FE examples and 10 arguing against for RE and not have a NASA JPL or dirty 3 digit .org posting along here. They took my stuff back and used it in shop. CGI shop.....

Besides J-man's explanation of the "Breathing Earth" I doubt you can google it anywhere and find it in cyber space. God invented it and I relayed it. Can't happen.

[mtnman]

Mtnman just can't handle the truth. He is shocked that his beloved satanist NASA has said the earth breathes. And yes it will come out soon that this is in fact the delivery of tidal changes....

Carry on. Slash bonk kick

This is J-Man !

The truth? You just posted a link with video from NASA, which you don't believe in. Showing images from a satellite, which you don't believe in. Showing images of a round Earth, which you don't believe in. All because they used the word "breathe".

So if this proves the Earth breathes, then it also proves NASA filmed the round Earth with a satellite. So do you believe all these things now?

Really? It's obvious NASA monitors my posts here and loved my breathing exercise debate and decided to use it. You can't have like 3 people on this site offering FE examples and 10 arguing against for RE and not have a NASA JPL or dirty 3 digit .org posting along here. They took my stuff back and used it in shop. CGI shop.....

Besides J-man's explanation of the "Breathing Earth" I doubt you can google it anywhere and find it in cyber space. God invented it and I relayed it. Can't happen.

That's some serious delusion there. Like anyone at NASA would care about these ridiculous discussions. But sure, NASA read read your post a few weeks ago, and decided to launch that satellite in 1997, which I strongly suspect was before you were born.