Spinning Mass & Spatial distortion

  • Context: Graduate 
  • Thread starter Thread starter Diracs Dad
  • Start date Start date
  • Tags Tags
    Mass Spinning
Click For Summary

Discussion Overview

The discussion centers around the effects of spinning masses on the fabric of spacetime, particularly comparing rotating and non-rotating masses. It explores theoretical implications, experimental observations, and the scale of effects produced by different masses.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions whether a spinning mass affects spacetime differently than a non-rotating mass.
  • Another participant references the Kerr metric and discusses frame dragging as a prediction of general relativity, noting its implications for rotating black holes and the Gravity Probe B experiment.
  • A subsequent post raises the question of whether smaller rotating objects also cause frame dragging effects, suggesting that their smaller masses might render such effects negligible.
  • Another participant confirms that Gravity Probe B detected a small frame-dragging effect from the rotating Earth, indicating that all rotating masses exhibit this effect, albeit at a scale that is difficult to measure.

Areas of Agreement / Disagreement

Participants express differing views on the significance of frame dragging effects in smaller rotating objects, with some suggesting they are negligible while others affirm that they exist but are challenging to measure. No consensus is reached on the extent of these effects across different mass scales.

Contextual Notes

Participants acknowledge the limitations in measuring frame dragging effects for smaller masses and the dependence on specific conditions, such as proximity to the rotating mass.

Diracs Dad
Messages
3
Reaction score
0
Hi, Does a spinning mass affect the spatial/time fabric differently than a non rotating mass?
 
Physics news on Phys.org
"According to the Kerr metric, such rotating black-holes should exhibit frame dragging, an unusual prediction of general relativity. Measurement of this frame dragging effect was a major goal of the Gravity Probe B experiment. Roughly speaking, this effect predicts that objects coming close to a rotating mass will be entrained to participate in its rotation, not because of any applied force or torque that can be felt, but rather because of the curvature of spacetime associated with rotating bodies. At close enough distances, all objects — even light itself — must rotate with the black-hole; the region where this holds is called the ergosphere."

http://en.wikipedia.org/wiki/Kerr_metric
 
Thanks bobby, my next question is since black holes seem to exhibit this effect, do relatively smaller objects cause this type of frame dragging as well, or do we consider the effects to be negligible given their incredibly smaller masses.
 
If you look up "Gravity Probe B" you will learn that this satellite did find a miniscule (really small) frame-dragging effect of the rotating earth. So, yes, the same applies to all rotating masses, but it is extremely small and hard or impossible to measure.
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
1K
  • · Replies 28 ·
Replies
28
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 48 ·
2
Replies
48
Views
3K
  • · Replies 14 ·
Replies
14
Views
1K
  • · Replies 10 ·
Replies
10
Views
2K