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What is the source of energy for the orbital motion?


Dandav
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Do you agree that Based on Newton's second law any change in the linear momentum of an object must consume energy?

https://en.wikipedia.org/wiki/Momentum

"Newton's second law of motion states that the rate of change of a body's momentum is equal to the net force acting on it. Momentum depends on the frame of reference, but in any inertial frame it is a conserved quantity, meaning that if a closed system is not affected by external forces, its total linear momentum does not change."

Therefore, in any inertial frame, the total linear momentum of an object does not change.

Hence, based on Newton's second law of motion, any object must get external force/energy inorder to bend its linear momentum.

However, as gravity bends the linear momentum of an object into circular motion, then can we agree that energy must be consumed in this process?

Edited by Dandav
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44 minutes ago, JeffreysTubes8 said:

I believe the em is factored in on orbit due to rotation 

remember the four forces? It’s like a chime. String nuclear, weak, en, grav 

Do you mean that as energy must be consumed due to the orbital motion, then this energy lost should be taken from the EM energy?

However, why do you think about EM energy?

Don't you agree that there is a possibility for orbital motion without EM energy, however, there is no orbital motion without gravity force/energy?

Therefore, Why can't we agree that as the orbital motion consumes energy, that energy must be taken from the gravity force/energy (or from the orbital kinetic energy) and therefore over time it must be reduced?

Edited by Dandav
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We all know that the orbital kinetic energy is as follow:

Ek = 1/2 m^2 G / R

Let's assume that dEk represents the orbital comsumption 

Therefore,

Ek (t) = Ek (t=0) - dEk

However, as the mass and the G are constant, then the only way to reduce the orbital kinetic energy is by increasing the orbital radius.

We all know that increasing the orbital radius means decreasing the orbital velocity.

Hence,

The correct formula for orbital kinetic energy is as follow:

Ek(t) = 1/2 m^2 G /R(t)

While R(t=0) = R

Hence, any orbital motion represents outwards spiral motion!

Therefore, our moon spirals outwards from Earth, while Earth spirals outwards from the Sun.

In the same token all the planets (and almost all the moons) in the solar system spiral outwards.

Edited by Dandav
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3 hours ago, Dandav said:

We all know that the orbital kinetic energy is as follow:

Ek = 1/2 m^2 G / R

Let's assume that dEk represents the orbital comsumption 

Therefore,

Ek (t) = Ek (t=0) - dEk

However, as the mass and the G are constant, then the only way to reduce the orbital kinetic energy is by increasing the orbital radius.

We all know that increasing the orbital radius means decreasing the orbital velocity.

Hence,

The correct formula for orbital kinetic energy is as follow:

Ek(t) = 1/2 m^2 G /R(t)

While R(t=0) = R

Hence, any orbital motion represents outwards spiral motion!

Therefore, our moon spirals outwards from Earth, while Earth spirals outwards from the Sun.

In the same token all the planets (and almost all the moons) in the solar system spiral outwards.

Gravity is the source of energy of orbital motion. The influence of gravity causes the curved paths of the objects due to the curvature of the space and time in the local area caused by the mass and energy of the object being orbited.

"Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915), which describes gravity not as a force, but as the curvature of spacetime, caused by the uneven distribution of mass, and causing masses to move along geodesic lines."

Due to the geodesic lines being bent in a curved path then the orbit follows the bent geodesic line. The geodesic equation is below and from that you can obtain the motion of an object through a gravitational field with bent geodesics.

geodesiceq.jpg

balls-showing-gravity-effects.jpg

 

This is a paper about orbits in general relativity, link = PHY390, Orbits in General Relativity (sunysb.edu)

So overall, it is much more complicated than what newton's equations basically newton's equations are incomplete and somewhat wrong.

Edited by Vmedvil5
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16 hours ago, Vmedvil5 said:

Gravity is the source of energy of orbital motion. The influence of gravity causes the curved paths of the objects due to the curvature of the space and time in the local area caused by the mass and energy of the object being orbited.

"Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915), which describes gravity not as a force, but as the curvature of spacetime, caused by the uneven distribution of mass, and causing masses to move along geodesic lines."

Due to the geodesic lines being bent in a curved path then the orbit follows the bent geodesic line. The geodesic equation is below and from that you can obtain the motion of an object through a gravitational field with bent geodesics.

This is a paper about orbits in general relativity, link = PHY390, Orbits in General Relativity (sunysb.edu)

So overall, it is much more complicated than what newton's equations basically newton's equations are incomplete and somewhat wrong.

 

All the above is correct, however, what about the energy lost due to the orbital motion?

I fully agree that "Gravity is the source of energy of orbital motion." and "Due to the geodesic lines being bent in a curved path then the orbit follows the bent geodesic line".

However, do you accept Newton's second law as a valid law?

https://en.wikipedia.org/wiki/Momentum

"Newton's second law of motion states that the rate of change of a body's momentum is equal to the net force acting on it. Momentum depends on the frame of reference, but in any inertial frame it is a conserved quantity, meaning that if a closed system is not affected by external forces, its total linear momentum does not change."

If so, do you agree that any change in the linear momentum of an object must consume energy?

Let's focus on general theory of relativity (proposed by Albert Einstein in 1915):

Based on this theory "Gravity does not described as a force, but as the curvature of spacetime, caused by the uneven distribution of mass, and causing masses to move along geodesic lines."

The title of articale that you have offered is: "Black Holes, Neutron Stars and Gravitational Radiation"

So, it is all about "Gravitational Radiation" that is causing masses to move along geodesic lines. 

However, again - what about energy lost in this "Gravitational Radiation" due to the orbital motion?

I would compare this "Gravitational Radiation" to EM radiation.

Don't you agree that when EM radiation bends the motion of electrom then some EM energy must be lost?

In the same token, as this "Gravitational Radiation" is causing masses to move along geodesic lines then some energy must be lost in this process.

So, how could it be that Newton, Albert Einstein and all the other scientists ignore the impact of this Gravitational energy lost due to orbital motion (based on Newton's second law)?

If you claim that there is no gravitational energy lost due to orbital motion, then by definition we discuss about motion without energy lost. Do you think that this kind of motion is realistic?

Edited by Dandav
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14 hours ago, JeffreysTubes8 said:

The goal of a unified field theory is to reduce the four forces into gravity really.

Please answer my question:

Do you agree that when "Gravitational Radiation" bends the linear motion of an object into orbital motion, then some EM energy/radiation must be lost?

Yes or no please?

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On 10/15/2022 at 9:27 AM, Dandav said:

Do you agree that Based on Newton's second law any change in the linear momentum of an object must consume energy?

Hi Dave. Thank you so much for taking your nonsense to a new forum. You will continue to ignore replies here just as you ignored them elsewhere I see.

Newton's 2nd law does not mention energy. No, this suggestion is wrong. An orbiting object (your example) shows the linear momentum of say the ISS changing (per Newton's law) and yet its energy in the frame of the Earth/ISS system (both potential and kinetic energy) remaining unchanged.

On 10/15/2022 at 9:27 AM, Dandav said:

Therefore, in any inertial frame, the total linear momentum of an object does not change.

Only in a closed system, which you neglected to  mention. Your assertion is akin to saying that all acceleration is impossible.

On 10/15/2022 at 9:27 AM, Dandav said:

Hence, based on Newton's second law of motion, any object must get external force/energy inorder to bend its linear momentum.

Here you sneak in energy again, when only force is mentioned in your quote. They're not the same thing. Yes, force is required to alter its liner motion in Newtonian mechanics. Energy is not.  Gravity is a force under Newtonian mechainics.

On 10/15/2022 at 9:27 AM, Dandav said:

However, as gravity bends the linear momentum of an object into circular motion, then can we agree that energy must be consumed in this process?

Gravity bends the path of the object into a curved one. It doesn't make sense to talk of curved momentum. No energy need be consumed by this, as demonstrated by the ISS.

Edited by Noax
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Hi Halc

You are totally incorect!

On 10/18/2022 at 5:15 PM, Halc said:

Yes, force is required to alter its liner motion in Newtonian mechanics. Energy is not.  Gravity is a force under Newtonian mechainics.

Gravity bends the path of the object into a curved one. It doesn't make sense to talk of curved momentum. No energy need be consumed by this, as demonstrated by the ISS.

Work is defined as the action of displacing an object by exerting a particular amount of force on it. 

When a force causes motion, work is said to done. Any force's work is influenced by a number of factors. The distance the body moves in the direction of the force is one of the elements. The force is the second factor. Work is defined as the product of a body's displacement and force in the direction of the force. Work equals F*S, where F stands for force and S stands for distance. Work is equal to FS Cosθ when a body is displaced by a distance with a force operating on it.

Work = force × displacement towards the force

Therefore, Gravity force means work and works means energy:

Energy must be transferred to an object to help it move, and the energy can be transferred in the form of force. The energy transferred by force to move any object is known as work or work done. Therefore, work and energy have a direct relationship. The difference in the kinetic energy of an object is called work done by the object. Work and energy are common terms in Physics and can be considered two sides of a coin.

 

On 10/18/2022 at 5:15 PM, Halc said:

Gravity bends the path of the object into a curved one. It doesn't make sense to talk of curved momentum. No energy need be consumed by this, as demonstrated by the ISS.

Hence, when gravity force bends the expected linear motion of the object, then energy must be consumed in this process.

On 10/18/2022 at 5:15 PM, Halc said:

Newton's 2nd law does not mention energy. No, this suggestion is wrong. An orbiting object (your example) shows the linear momentum of say the ISS changing (per Newton's law) and yet its energy in the frame of the Earth/ISS system (both potential and kinetic energy) remaining unchanged.

Newton's 2nd law is absolute and it is valid for orbital motion. 

once you agree that there is a need for force to bend the linear motion of the object into an orbital motion, then this force means energy.

We all know the the Earth is drifting away from the Sun and the moon is drifting away from the earth.

This outwards drifting means increasing in the orbital radius and decreasing in velocity and orbital kinetic energy.

It shows that the orbital kinetic energy of orbital object is decreasing over time.

That decreasing is due to the energy that had been lost due to the orbital motion.

If we would be able to set the calculation for the energy that is needed to bend the moon in one orbital motion around the earth and deduct that energy from its orbital kinetic energy, we can calculate by 100% the drifting outwards distance that the moon must shift in that single orbital motion.

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On 10/15/2022 at 6:27 AM, Dandav said:

Therefore, in any inertial frame, the total linear momentum of an object does not change.

That is a category error. It is the energy of objects in a closed system, not the system itself that experience entropy 

Edited by write4u
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2 hours ago, write4u said:

It is the energy of objects in a closed system, not the system itself that experience entropy 

Yes, but there is a possibility for energy transformation

If there is one object in a closed system then its linear momentum does not change.

In other words, there is no external force on that object and no change in its velocity vector and therefore there is no change in its kinetic energy.

If there are two objects in a closed system then the gravity force bends the linear momentum of the orbital object.

In other words, there is a constant change in its linear momentum / velocity vector.

Based on Newton's 2nd law there is no possibility to get free change in the linear momentum / velocity vector of an object.

Therefore, that change must consume energy from the gravity radiation.

In order to compensate the lost of energy from the gravity radiation and due to energy transforamtion, the orbital object must drift outwards, reduce its orbital velocity and its kinetic energy.

 Hence, in orbital system the distance/radius between the objects must increase over time.

 Therefore:

The correct formula for orbital kinetic energy is as follow:

Ek(t) = 1/2 m^2 G /R(t)

While R(t=0) = R

R(t) = R + dR

dR = the increase in the radius over time.

Hence, orbital motion represents outwards spiral motion!

Therefore, our moon spirals outwards from Earth, while Earth spirals outwards from the Sun.

In the same token all the planets (and almost all the moons) in the solar system spiral outwards.

Edited by Dandav
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6 hours ago, Dandav said:

Hence, orbital motion represents outwards spiral motion!

Therefore, our moon spirals outwards from Earth, while Earth spirals outwards from the Sun.

In the same token all the planets (and almost all the moons) in the solar system spiral outwards.

You are forgetting gravity that counteracts the centrifugal force.  The objects you cite travel in a straight line. It is the fabric of space that is curved. 

What Would Happen If Gravity Was More?What-Would-Happen-If-Gravity-Was-More-788x400.jpg

https://newstextarea.com/what-would-happen-if-gravity-was-more/

Edited by write4u
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3 hours ago, write4u said:

A car accelerating to 60 mph does not have a change in momentum?  I think Newton saw this differently.

Car motion is all about energy transformation.

3 hours ago, write4u said:

You are forgetting gravity that counteracts the centrifugal force.  The objects you cite travel in a straight line. It is the fabric of space that is curved. 

We have already discussed this issue:

On 10/16/2022 at 5:38 PM, Dandav said:

Let's focus on general theory of relativity (proposed by Albert Einstein in 1915):

Based on this theory "Gravity does not described as a force, but as the curvature of spacetime, caused by the uneven distribution of mass, and causing masses to move along geodesic lines."

The title of articale that you have offered is: "Black Holes, Neutron Stars and Gravitational Radiation"

So, it is all about "Gravitational Radiation" that is causing masses to move along geodesic lines. 

However, again - what about energy lost in this "Gravitational Radiation" due to the orbital motion?

I would compare this "Gravitational Radiation" to EM radiation.

Don't you agree that when EM radiation bends the motion of electrom then some EM energy must be lost?

In the same token, as this "Gravitational Radiation" is causing masses to move along geodesic lines then some energy must be lost in this process.

So, what do you want to say?

Do you claim that Based on Newton's 2nd law there is a possibility to get free change in the linear momentum / velocity vector of an object?

Do you agree that In order to compensate the lost of energy from the gravity radiation and due to energy transforamtion, the orbital object must drift outwards, reduce its orbital velocity and its kinetic energy?

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1 hour ago, Dandav said:

Do you agree that In order to compensate the lost of energy from the gravity radiation and due to energy transforamtion, the orbital object must drift outwards, reduce its orbital velocity and its kinetic energy?

I believe the reverse is true, when there is a balance between the forces of "outward momentum" and "inward gravitation" eventually , the loss of energy and momentum of the orbiting object will cause it to be drawn (falling into) the gravity well toward the host star, however the resulting increase in momentum will again restore a balanced orbit with the orbiting object traveling at a greater speed, and so on until the orbiting object succumbs to the gravitational well and falls into the host star.

AFAIK, unless there is a third external gravitational influence such as a passing massive object, the orbiting object eventually succumbs to the gravitational pull of the host star.  

 

Quote

Car motion is all about energy transformation

And increase in momentum., no?

 

Edited by write4u
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