Can gravity increase on its own?

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    Gravity increase
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Discussion Overview

The discussion revolves around the concept of gravity and its potential changes in relation to the rotation speeds of large celestial bodies, particularly in the context of orbital mechanics and energy interactions. Participants explore theoretical scenarios involving the effects of rotation on gravitational forces, touching on both Newtonian and relativistic perspectives.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant suggests that if two large objects orbit each other and increase their rotation speeds in opposite directions, it could theoretically lead to an increase in their gravitational effects.
  • Another participant clarifies that gravitational force between two objects increases as their distance decreases, questioning the meaning of "total amount of gravity."
  • Some participants assert that gravity is fundamentally dependent on mass and does not rely on rotational speed, referencing Newton's gravitational force equation.
  • A later reply introduces a relativistic perspective, proposing that an increase in energy could lead to an increase in effective mass and thus curvature of spacetime, though this may require extreme conditions.
  • There is a discussion about the distinction between surface gravity and gravitational force, with one participant noting that while surface gravity can be affected by rotation, the gravitational force between two bodies remains dependent on mass.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between gravity and rotation speed, with some asserting that gravity does not depend on rotation while others explore the implications of relativistic effects. The discussion remains unresolved regarding the initial question of whether gravity can increase on its own.

Contextual Notes

Participants highlight the importance of definitions, particularly regarding terms like "amount of gravity," and note that the discussion involves both Newtonian and relativistic frameworks, which may have different implications for the concepts being discussed.

schiz0ai
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Forgive me, for i do not have any degrees in physics.:shy:
If 1 large object like a planet were to orbit near another large planet/moon.
It would in theory be possible for both objects to increase their speed of rotation, as long as they end up rotating in opposite directions right? Of course it would require a lot of energy.
But would that mean that the total amount of gravity of both objects could increase
 
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Sorry, your post looks a bit unclear in which order you want to have what.

You can remove some energy from the system, which reduces the radius between the objects (and therefore reduces the potential energy) and increases their velocity (and kinetic energy). The gravitational force between both increases, as their distance decreases.

What is a "total amount of gravity"?
 
the amount of gravity a planet has depends on its mass and rotation speed right?

Of course its impossible for a single object to start rotating faster on its own.
But if it does this by makin another object rotate faster in the opposite direction, it should in theory be possible.

Would the gravity of both objects increase at the same time? because their rotation speed increases?
 
Gravity does not depend on rotational speed. Just look at Newton's gravitational force equation.
 
russ_watters said:
Gravity does not depend on rotational speed. Just look at Newton's gravitational force equation.

actually, Russ, if we get relativistic here, wouldn't the effective mass of the planet increase as the energy contained therein increases? and if its effective mass increases, wouldn't the amount of curvature of spacetime increase? perhaps you'ld have to spin the planet so fast that it would fly apart long before there would measurably be any increase of gravity that the planet would effectively "emit".
 
schiz0ai said:
the amount of gravity a planet has depends on its mass and rotation speed right?
If you use non-standard terms, please define them. What is "the amount of gravity"? The gravitational force on other objects just depends on the mass.
The rotation can become important if the involved velocities are close to the speed of light (or the measurements are extremely precise), but that happens in neutron stars only.
 
im sorry, i thought gravity depended on rotation speed.
I figured it out after googling some.
 
schiz0ai said:
im sorry, i thought gravity depended on rotation speed.
I figured it out after googling some.

In Newtonian mechanics, surface gravity does depend on rotational speed (some of the gravitational force of the Earth's mass is canceled out by the acceleration generated by the rotation of the Earth) but it does not affect the gravitational force between two particles, ie, the Earth and the Sun.
 

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