Gravitational Force on a Body: Is it Absolute?

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Discussion Overview

The discussion revolves around the nature of gravitational force and whether it can be considered an absolute force, particularly in the context of General Relativity (GR). Participants explore the implications of absolute accelerations and the classification of forces, including fictitious forces like gravity.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions if gravitational force can be considered absolute and requests an explanation.
  • Another participant asks for clarification on what is meant by 'absolute force.'
  • Some participants assert that in GR, accelerations are absolute, suggesting that any force, including gravity, can be measured absolutely.
  • There is a viewpoint that in GR, gravity is not a force but rather a reflection of proper acceleration due to non-gravitational sources, implying a distinction between proper and coordinate acceleration.
  • One participant acknowledges a previous error and requests to disregard their earlier statement.

Areas of Agreement / Disagreement

Participants express differing views on the classification of gravity as a force and the implications of absolute versus fictitious forces. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

There are limitations in the definitions of absolute force and the distinctions between proper and coordinate acceleration that are not fully explored. The discussion also reflects varying interpretations of the role of gravity in GR.

skanda9051
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Can we consider gravitational force acting on a body considered as absolute force:-) if so pleas explain
 
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Please define your meaning of 'absolute force'.
 
In GR, accelerations are absolute, so any force can be measured absolutely, including fictitious forces, such as gravity.
 
K^2 said:
In GR, accelerations are absolute, so any force can be measured absolutely, including fictitious forces, such as gravity.

Can you explain more? I agree with the first part. To me, that means, in GR, there is no such thing as fictitious forces, and gravity is not a force at all. Any proper acceleration is due to a real, non-gravitational source (EM, etc), reflecting deviation from inertial motion, latter determined by stress/energy=curvature.
 
K^2 said:
In GR, accelerations are absolute, so any force can be measured absolutely, including fictitious forces, such as gravity.
The kind of acceleration which is absolute is called proper acceleration. Coordinate acceleration is not absolute, and fictitious forces produce coordinate acceleration, not proper acceleration.
 
Ugh. Don't know what I was thinking. Disregard my previous post.
 

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