Suppose the gravitation has very very tiny deviation from inverse square law……

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Discussion Overview

The discussion revolves around the implications of a hypothetical tiny deviation from the inverse square law of gravitation, particularly concerning the stability of the solar system and the potential for observable effects on Earth. The scope includes theoretical considerations, experimental evidence, and the implications of such deviations in both fundamental physics and astronomical contexts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question whether a tiny deviation from the inverse square law could lead to instability in the solar system and how long it might take for such changes to be noticeable on Earth.
  • One participant references discussions on dark matter and deviations from Newtonian mechanics observed in spiral galaxies, suggesting that gravity's behavior at large scales may not conform to traditional expectations.
  • Another participant outlines two experimental avenues: testing for deviations at tiny distances and at astronomical distances, noting that current high-precision measurements have not confirmed any breakdown of the inverse square law within established limits.
  • Theoretical justifications for potential deviations include the existence of "hidden, curled-up dimensions," which may not be accounted for in the inverse square law.
  • Concerns about the stability of the solar system are raised, with a suggestion that new gravitational features could maintain stability even if the inverse square law were found to be incorrect.
  • One participant emphasizes that the stability of the solar system remains unknown and provides links to external lectures for further exploration of the topic.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the stability of the solar system under a modified gravitational law, and there is no consensus on the implications or the existence of such deviations. Multiple competing views and hypotheses are presented without resolution.

Contextual Notes

Limitations include the dependence on experimental accuracy for detecting deviations, the potential influence of untested theoretical models, and the speculative nature of the discussion surrounding the stability of the solar system.

magnetar
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If the gravitation has very very tiny deviation from inverse square law！our solar system became unstable? If so ,how long people on the Earth can notice it?

Thank you in advance!
 
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Good question for the relativity section...a discussion under the thread DARK MATTER QUESTION discusses this issue.

Gravity is relatively weak so its tough to test in lab environments...

In some spiral galaxies, there appears to be a significant deviation from Newtonian mechanics beyond radius c^2/R (where R is the scale of the observable universe) ...the deviation results in constant velocities of orbiting stars and was originally discovered experimentally and verified by Vera Rubin...the variation is hypothesized to be caused by dark matter,,,but nobody really knows...

At the other end of the distance spectrum tests are being doing to see if gravity "leaks" into other dimensions at sub millimeter distances...so far the inverse square law appears to hold..
 
Hi, magnetar!

I will divide your question into three:
If the gravitation has very very tiny deviation from inverse square law
Many physicists are involved into theoretical and experimental considerations of this issue.
There are basically two lanes along which experementalists can take:
1. Fundamental breakdown of inverse-square law at tiny distances
This is by no means IM-possible that such a breakdown occurs, but with high-precision torque measurements, it has been established that the breakdown does not occur at distances in excess of 60 micro-meters, or so. (See referenced article from physicsworld)
2. Breakdown at astronomical distances.
As yet, high-precision measurements of the Moon's precession have not identified any such deviation within the exceeding the limits of experimental accuracy, so also here, the inverse-square law is not yet debunked (that would be cool, wouldn't it?)

3. Theoretical justifications for possible deviations:
The main thrust behind the idea that the inverse square law might be wrong, is that it does not take into account the quite possibly existing "hidden, curled-up dimensions" theoreticians postulate.
You might read the following article from physicsworld, which go into some detail:
http://physicsworld.com/cws/article/print/21822
！our solar system became unstable?
It is true that we may deduce from simplified equations (say, a two-body problem) that only the inverse square law provides for stability (unless my memory is false on this issue).
However, by possibly new features of gravitation, or other "complications", stability might well hold, even though the (then falsified) inverse square law could not any longer be the explanatory mechanism behind that stability.
If so ,how long people on the Earth can notice it?
That would be wholly dependent upon how strong the instability actually is (if there is one at all!), so any figure would be mere guesswork.
 
Thank you for your answer! arildno and Naty1
 
The stability of the solar system is unknown.

Scott Tremaine's Lecture 1:
http://www.astro.princeton.edu/~tremaine/alex/

http://streamer.perimeterinstitute.ca/Flash/e74a4975-9f9b-4d31-9f65-b01ef7add6f5/index.html
 
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