Gravitational Attraction of Motionless Masses

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Discussion Overview

The discussion revolves around the gravitational attraction between two motionless masses in a hypothetical universe with only space and these masses. Participants explore the implications of gravitational fields, the role of time, and the nature of motion in this context, raising questions about measurement and perception of distance and acceleration.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that the two masses would start to move toward each other due to the gravitational fields they create.
  • Others argue that without time, no motion can occur, suggesting that the scenario lacks the necessary conditions for motion.
  • A participant introduces the idea that if the only measuring device is the distance between the two masses, then describing their motion becomes meaningless, as there would be no way to identify changes in distance.
  • Another participant counters that observers on either mass could measure changing forces and accelerations as the masses attract each other, implying that motion can be detected.
  • There is a discussion about free fall and the equivalence principle, with some participants noting that a body in free fall cannot detect its state, while others emphasize that changing acceleration can be detected under certain conditions.
  • One participant presents an analogy involving a spaceship and a person inside it, arguing that the person cannot detect changing acceleration due to the equivalence of their motion with the spaceship.

Areas of Agreement / Disagreement

Participants express differing views on whether motion can occur in the absence of time and how gravitational attraction can be perceived. There is no consensus on the implications of the scenario, and multiple competing views remain throughout the discussion.

Contextual Notes

Participants rely on various assumptions about the nature of space, time, and measurement, which remain unresolved. The discussion also highlights the complexity of defining motion and acceleration in a hypothetical context.

  • #31
Dadface said:
The OP described a universe with only space and two masses but it seems that people have been adding to this universe.Where, for example, did the observers come from?
He did not mention any commentators either.
Maybe I should shut up.:smile:
 
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  • #32
Dadface said:
The OP described a universe with only space and two masses but it seems that people have been adding to this universe.Where, for example, did the observers come from?

Maybe the two masses are those of the observer...

Buckleymanor said:
He did not mention any commentators either.
Maybe I should shut up.:smile:

And the commentator... ;)
 
  • #33
hello everyone i am new to this website and forum.But i have been really good at physics this topic gravity has become quite appaling sometime now.However i believe Einstein theory to be wrong and i will keep reading the posts here and joined in where i see it fit.
 
  • #34
killshot said:
Assuming a universe with only space and two motionless masses, would the two masses start to move toward each other?
Good question man
 

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