Gravitic Field of Rotating Disk-Shaped Mass Along Ecliptic

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    Ecliptic Gravity
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Discussion Overview

The discussion centers on the gravitational field of a rotating, disk-shaped mass, particularly in relation to its density along the ecliptic. Participants explore whether a second mass passing through the ecliptic would experience differences in gravitational effects, such as tidal forces or perturbations, and how the gravitational pull varies axially versus radially.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if the gravitational field of a rotating disk-shaped mass is denser along its ecliptic and whether this affects a second mass passing through it.
  • Another participant notes that the gravitational field of a disk differs from that of a sphere and references plots of gravitational potential, suggesting that the force is stronger where equipotential lines are denser.
  • A third participant interprets that the gravitational field is densest at the center of the disk and weakest horizontally, indicating a denser region outside the disk radially.
  • Another participant mentions that if the disk has cylindrical symmetry, its rotation may not affect the gravitational potential, unless relativistic effects are considered.

Areas of Agreement / Disagreement

Participants express differing views on the effects of rotation and symmetry on the gravitational field, with no consensus reached on the implications for tidal forces or perturbations experienced by a second mass.

Contextual Notes

There are unresolved aspects regarding the dependence on definitions of gravitational potential and the treatment of relativistic effects, which may influence the discussion.

havonasun
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I am curious to know if the gravitic field of a rotating, disk-shaped mass is denser along its ecliptic. I'm referring to rotating bodies such as stellar systems, galaxies, etc. I would like to know if a second mass, passing through the ecliptic, would experience a difference such as tidal forces or perturbations. Basically, does a massive disk have any difference in its gravitic pull axially vs radially? From a great distance, it would just be a point-source, but up close I'm thinking that the magnitude of the vectors of individual bodies comprising the whole would be less axially than radially.
 
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The gravitational field of a disk is different from the field of a sphere. For a disk of uniform mass, this website has some plots of the gravitational potential. The force is orthogonal to the equipotential lines and stronger where the lines are denser.
 
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From what I can interpret, the graph I would be using would be 'rotating w/star.' The field is densest at the center because of law of squares, and weakest horizontally from the center. It shows another dense region outside the disk radially. So, yes?
 
The page doesn't load right now, but as far as I remember the "rotating" probably included effective potentials for orbiting bodies. I'm not sure if you want that.

If the disk has a cylindrical symmetry, its rotation does not matter for the gravitational potential (ignoring relativistic effects).

Edit: Looks like relativistic effects are considered. Do you really want that?
 

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