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I'm putting a hold on all of the other matters for the moment and focusing on conservation of energy because that is the crux of the problem right now. I'm not moving on until that issue is solved first.
If new energy could be created from a gravitational field, that would violate conservation of energy because the energy is no longer constant.
Tidal forces transform existing orbital or rotational energy into heat energy.
The formula is fixed under any tidal forces.
tidal energy is coming for free.
conservation of energy Physics. a fundamental law of physics and chemistry stating that the total energy of an isolated system is constant despite internal changes. It is most commonly expressed as “energy can neither be created nor destroyed”, and is the basis of the first law of thermodynamics.
The formula you provided measures force for a fixed distance. Almost all natural orbits are eccentric. They change their distances over time. This change in force is part of what causes the generation of heat. If two orbiting objects are at a constant distance from each other and tidally-locked to each other, there is no change in force over time and as such there is no generation of heat.
Where is the formula that proves your understanding that tidal decreases the gravity force???
As long as the common barycenter of an object under Tidal force is fixed, than there is no negative impact on the gravity force.
So, please, if you think that tidal can change the gravity force or the common barycenter - than please show the formula for that!!!
Tidal force creates new energy
energy can neither be created nor destroyed
If the planet is rotating, then there is a change in distance (and therefore a change in force) between different parts of the planet and the satellite
There is very much an impact on the gravity force as the radius changes periodically, and the tidal forces acting on the moon thus vary over time, and heat it, despite it being tide-locked.
A football shape is not spherically symmetric.
You haven't described its motion
If it represents a hollow moon that is more or less in a similar orbit about our Earth in an isolated 2-body system, they yes, it's center of mass is continuously changing since Earth exerts force on it, and force on a mass results in its acceleration, which moves its center of mass. The moon's center of mass orbits Earth, and does not stay put.
It isn't correct. 1, there is no barycenter of an object. But there is one for a system of two objects like say Earth/moon.
2 That barycenter is fixed (a non-accelerating center of gravity of the two body system) despite the fact that the moon's orbit is eccentric.
Dear KryptidLet's agree on the following: A rotating planet by itself, has no effect on Newton gravity formula!However, you claim that if the planet is rotating, then there is a change in distance.A change in distance means a change in the center of mass.So, would you kindly show the formula for that?Is it one more wishful thinking?If a planet is rotating, how it could affect its center of mass?Did Newton mention that a rotating object changes the location of its center of mass or distance?Actually this statement contradicts Newton Shell theorem:https://en.wikipedia.org/wiki/Shell_theorem"Isaac Newton proved the shell theorem and stated that:1. A spherically symmetric body affects external objects gravitationally as though all of its mass were concentrated at a point at its centre."Therefore, it can rotate as fast as you want.As long as all of it is a spherically symmetric body there is no change in its center of mass and therefore there is no change in gravity force.It is also stated:"2. If the body is a spherically symmetric shell (i.e., a hollow ball), no net gravitational force is exerted by the shell on any object inside, regardless of the object's location within the shell."Therefore, any object inside the shell can move at any direction - As Long as the whole body is still spherically symmetric shell (i.e., a hollow ball), no net gravitational force is exerted by the shell on any object inside,Hence, again, there is no change in the center of mass for a rotating object and no net gravitational force is exerted by the shell on any object inside!If you still believe in that unrealistic Idea of rotating body that can change the center of mass, than this time you must show the formula which links between the rotating activity to distance?
Quote from: Halc2 That barycenter is fixed (a non-accelerating center of gravity of the two body system) despite the fact that the moon's orbit is eccentric. I suppose that depends on how you define "fixed". As the Moon moves further away from the Earth in its orbit, the distance to the barycenter from both the Earth's center and the Moon's center must increase very slightly.
Yea, but that's the Earth and Moon both moving away from the barycenter, not any motion of the barycenter itself. Acceleration is absolute, and the barycenter does not accelerate due to the varying distance between a pair of objects with an eccentric orbit, or even if they're connected with springs and hinged counterweights and whatnot. It can't move while it's a contained system. That's just simple conservation of momentum.
That was a mis-reading on my part. I thought he was talking about a pair of objects the whole time.
I suppose that depends on how you define "fixed". As the Moon moves further away from the Earth in its orbit, the distance to the barycenter from both the Earth's center and the Moon's center must increase very slightly.
But this is all beside the point. The law of conservation of energy won't allow you to create energy. Period: https://www.sciencedirect.com/topics/engineering/conservation-of-energy"conservation of energy Physics. a fundamental law of physics and chemistry stating that the total energy of an isolated system is constant despite internal changes. It is most commonly expressed as “energy can neither be created nor destroyed”, and is the basis of the first law of thermodynamics."
I understand by now that you can't offer any formula that show that Tidal energy can reduce the gravity force.
That Orbital energy is fully under conservation of energy Physics.
However, this total orbital energy isn't affected by tidal energy that represents extra heat in any orbital body.The extra heat due to tidal is a side effect of the "fixed" orbital energy.Hence, Tidal energy has no impact on that total orbital energy.
Again - If you still think differently - than please would you kindly offer the matematics how the gravity force (or the total orbital energy) is reduced/increased by the Tidal extra energy/heat.
To show this, consider the equation to calculate tidal heating: https://en.wikipedia.org/wiki/Tidal_heating
Tidal forces don't reduce the force of gravity.
https://en.wikipedia.org/wiki/Globular_cluster"A globular cluster is a spherical collection of stars that orbits a galactic core. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes, and relatively high stellar densities toward their centers."
So is tidal energy. All energy is.
Heat is a form of energy. As such, it cannot be created. Heat can only come into being if other forms of energy are transformed into heat.
Without changing the gravity force, there is no change in the total orbital energy.Therefore, with or without Tidal - the gravity force or the total rotation energy stay the same.
Orbital and rotational energy are dissipated as heat in the crust of the moon.
This is because as tides distort a moon, rock is stretched and compressed. As you can imagine, there’s friction when you stretch rock, and friction releases some of the satellite’s orbital energy as heat.
Therefore - the internal movement of the rigid balls and the internal friction/collision increases the internal heat in that globular cluster.However, as there is no change in the gravity force between the globular cluster and the main body, that extra heat don't affect the total orbital energy.
Tidal energy is totally different from all the other energies.
That is correct for any kind of energy except - Tidal heat/energy
The friction between the balls that generates the heat will cause them to slow down. You should be quite aware that friction does exactly that: it slows things down. It is a conversion of the ball's energy of motion into heat energy. Since the balls are slowing down, they have less total orbital energy.
Tidal Energy = E(tidal)
Therefore, the statement that the Tidal energy decreases the total rotation energy without changing the gravity force is technically not realistic.Any comment?
Gravity force = F = G m1 m2 /r^2
If the orbit was not eccentric, perigee and apogee would be the same and there would be no change of force over time. No change of force means no tidal heating.
The critical part of this formula is the "r". In an elliptical orbit, the value of "r" changes over time. This makes the gravitational force experienced by the satellite change over time as well. If you want specific numbers, I will calculate them for our Moon. When the Moon is at apogee, it is at a maximum distance from the Earth (405,400 kilometers). When it is at perigee, it is at a minimum distance (363,600 kilometers).For apogee:F = G((m1m2)/r2)F = (6.674 x 10−11)((5.97237 x 1024)(7.342 x 1022)/((405,400,000)2)F = 2.92649 x 1037/1.64349 x 1017F = 1.78 x 1020 newtonsFor perigee:F = G((m1m2)/r2)F = (6.674 x 10−11)((5.97237 x 1024)(7.342 x 1022)/((363,600,000)2)F = 2.92649 x 1037/1.322 x 1017F = 2.21 x 1020 newtonsThe gravitational force experienced by the Moon is 24% stronger when it is at perigee than when it is at apogee. This is because the orbit is eccentric.
However, do you agree that in the next cycle - we should get exactly the same output?
I really don't understand how could it be that the total Rotation energy per cycle should be decreased due to tidal energy dissipation, while the gravity force between one full orbital cycle to the next one must stay unchanged.
So, would you kindly set the formula for the total rotation energy per one full cycle,
and show why this total rotation energy must go down due to tidal energy in the next full orbital cycle
while there is no change in gravity force between one full orbital cycle to the next full cycle.
The link I provided earlier gives the formula to calculate the energy loss per orbit and even gives an example calculation: https://www.physicsforums.com/threads/ultimate-source-of-energy-on-io.227907/#post-1689833
Quote from: Kryptid on 08/10/2019 22:04:41The link I provided earlier gives the formula to calculate the energy loss per orbit and even gives an example calculation: https://www.physicsforums.com/threads/ultimate-source-of-energy-on-io.227907/#post-1689833In this article it is stated:"When a moon stretches, because of the tidal effect, it's gravitational attraction to the planet will become bigger byM(moon) * M(planet) * G * d * r / R^4Where d is the height of the bulge, r is the radius of the moon and R the distance to the planet. (this is actually a simplification, assuming that the mass of the moon is divided in two halves, at a distance R+r+d and R-r-d from the planet. The real effect will be smaller, but proportional to this)."
This idea totally contradicts the shell theorem by Newton
"Isaac Newton proved the shell theorem[1] and stated that:A spherically symmetric body affects external objects gravitationally as though all of its mass were concentrated at a point at its centre."Let's look at the following image:https://en.wikipedia.org/wiki/Shell_theorem#/media/File:Shell-diag-1-anim.gifm represents the planet, while the shell represents the moon.
However, we can divide it to two halves and claim that the half at the front has more impact than the one at the back.Newton have proved (after long calculation) that as long as the half at the front in symmetrical to the half at the back the total mass of that cycle or moon is:"which suggests that the gravity of a solid spherical ball to an exterior object can be simplified as that of a point mass in the centre of the ball with the same mass."Now, if we add a symmetrical bulge at the front and at the back of this cycle, don't you agree that as the half at the front is fully symmetrical with the half at the back
Therefore, the assumption that a symmetrical bulge (in front and in the back) can change the center of mass of the moon is a fatal mistake.
Gravity is all about mass and center of mass.