gravity effects

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21 years 9 months ago #2858 by Jim
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The answer you gave is not relative of the question I asked. If the energy required to stop a body being accelerated in a gravity field can was calculated would that be the equal to the energy aquired by the body from the gravity field? The total orbital energy of the body is not equal to the maintainance energy which is equal acceleration times mass as I understand the dynamics. As usual-I may be wrong for sure. I'm just wondering and I know you told me not to go there. I am sure there is a great deal to learn from the force as well as acceleration of gravity and I'm puzzled by your posture on this matter.

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21 years 9 months ago #2789 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[Jim]: If the energy required to stop a body being accelerated in a gravity field can was calculated would that be the equal to the energy acquired by the body from the gravity field?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

We are not "acquiring energy" from the gravity field we reside in. In general, no, the energy to stop an orbiting body is not equal to the total energy of the body. That is just the kinetic energy, and ignores the potential energy.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>The total orbital energy of the body is not equal to the maintainance energy which is equal acceleration times mass as I understand the dynamics.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Acceleration times mass is force, not energy. Force times distance it is applied would equal work done, which is a form of energy.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>I am sure there is a great deal to learn from the force as well as acceleration of gravity and I'm puzzled by your posture on this matter.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

There are two ways to understand why all bodies fall at the same rate in a gravitational field:

(1) the force applied to any body automatically adjusts up or down in proportion to the mass of the body so that it produces the exact same acceleration as for every other body. Moreover, each body, no matter how tiny, produces the same huge force back onto the Earth.

(2) momentum from gravitons simply accelerates every atom in a field by the same amount, independently of all other atoms.

If you go down path 1 and do not return, I doubt you will ever truly understand all the unique properties that gravity has that other forces do not have. -|Tom|-


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21 years 9 months ago #4626 by Jim
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I absolutly understand that all bodies fall at the same rate. This is a given-my question is not about acceleration. And I'm quite aware gravity has special effects nothing else can come close to. You don't need to worry that I'll forget that fact.

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21 years 9 months ago #3743 by Jim
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Doing a rough estimate of force in the dynamics of the orbit of Earth it is easy to find a total force of ~10E22 newtons is required to maintain the dymamics of Earth. This is exactly equal on Earth and on the sun. The effect is not equal because the mass ratio is large. The effect of the force on the Earth is well known. The effect of the force on the sun is not even documented. You say the effect is the same as on Earth only smaller in that the sun moves in a little copy of the orbit of Earth. I did the math for this effect and found the force of 10E22 newtons on the sun is much too tiny to move a mass as large as the sun more than mm/s or so. Since the sun is a fluid body I see no logical method for the sun to move at as a result of force from any of the planets. The fluid surface of the sun can rise as the Earth passes over the surface which would absorb the force of gravity the Earth and other planets exert upon the sun. In this way the gravity center of the remains fixed relative to the planets and the binary system can be modeled with a barycenter that moves as a balance scale would indicate. The sun's center never moves. I don't know if this is right but knowing force and the rule of force seems to clear up some of the confusion that is built into the current model.

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21 years 9 months ago #3791 by tvanflandern
<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>The effect of the force on the sun is not even documented.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Your personal library needs a few additions. How is it that every astronomer who has studied orbits knows about the Sun's motion if it is an undocumented secret? And why do observations of the Sun relative to the star background show it shifting back and forth in rhythm with the planets?

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>You say the effect is the same as on Earth only smaller in that the sun moves in a little copy of the orbit of Earth. I did the math for this effect and found the force of 10E22 newtons on the sun is much too tiny to move a mass as large as the sun more than mm/s or so.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

True, but why mention it at all? The total effect is that Earth moves the Sun in a circle with a 500 km radius. Jupiter moves it by 800,000 km. Given your slightly low estimate for the strength of the force, you might only get 100 km for Earth and 200,000 km for Jupiter. But clearly, the Sun moves, even by your figures.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Since the sun is a fluid body I see no logical method for the sun to move at as a result of force from any of the planets.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

You said that you understood, and would keep in mind, that every body, large and small, falls at the same rate in a gravitational field. The same applies to solid, liquid, or gaseous. Gravity is not affected in the least by the fluidity of a body. Tidal forces are, but those have nothing to do with the large-scale motions we are discussing here. At best, tidal forces can add tiny changes to orbits. But the orbits themselves just come from the acceleration law. -|Tom|-


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21 years 9 months ago #4769 by Jim
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I would love to acquire the data you say my library needs. Can you tell me where this data is posted? I hope its not NSSDC. The access to that site is beyond my abilities and there is no one alive there.

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