Is Gravity Enlarged at Small Distances?

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Discussion Overview

The discussion revolves around the concept of whether the gravitational constant (G) may increase or decrease at very small distances, exploring various theoretical perspectives and experimental constraints. The scope includes theoretical implications, potential models, and experimental observations related to gravity at microscopic scales.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants inquire about theories suggesting that G may be enlarged at small distances and seek references to such theories.
  • One participant notes that while G may vary, it could potentially decrease rather than increase, depending on differing viewpoints.
  • Another participant mentions that significant scale-dependent variations in G have been experimentally ruled out down to approximately 0.05 mm.
  • A participant discusses multidimensional theories proposing that G might "leak" into other dimensions, which could contribute to gravity being the weakest known force.
  • Reference is made to Lee Smolin's work, which suggests that probing gravity at sub-microscopic lengths requires a background independent framework, indicating that space and time should be viewed as dynamic rather than rigid.
  • It is suggested that as one approaches Planck size, conventional understandings of length, time, and forces may become indistinguishable, potentially leading to a weakening of gravity at extremely small scales.
  • Another participant highlights that quantum mechanics and general relativity face challenges near singularities, where space and time exhibit extreme curvature and may lose their typical characteristics, raising questions about the validity of these theories in such contexts.

Areas of Agreement / Disagreement

Participants express differing views on whether G increases or decreases at small distances, and there is no consensus on the existence or implications of theories regarding variations in G at these scales. The discussion remains unresolved with multiple competing perspectives presented.

Contextual Notes

Limitations include the lack of consensus on the behavior of G at small distances, dependence on theoretical frameworks that may not be universally accepted, and unresolved mathematical implications related to quantum gravity and singularities.

exponent137
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Are exist some theories that G is enlarged at very small distances?
Can you give some links?

Regards
 
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exponent137 said:
Are exist some theories that G is enlarged at very small distances?
Can you give some links?

Regards

Well G runs but it may well get smaller not larger depending on who you ask...
 
All sorts of theories exist. Experimentally, significant scale-dependent variations in G (dG/G~1) are ruled out down to approx. 0.05 mm.
 
I have NOT read of an increasing G at small distances.

In some multidimensional theories there is theory that G may leak to other dimensions, even parallel universes, and that that happens even at larger everyday scales...and might be a reason gravity is the weakest of known forces...

THREE ROADS TO QUANTUM GRAVITY by Lee Smolin is a modern popular non mathematical treatment...meaning three theories...

to probe gravity at sub microscopic lengths, Smolin feels a background independent framework is required, meaning the space and time must be formulated as dynamical relationships, not like a rigid lattice for example.

In addition as you approach Planck size, it would appear that everything we know may disappear in quantum foam; length, time, forces become indistinguishable, and hence appear might weaken at near the ultimate microscopic dimensions in the vicinity of
10-33 cm.
 
I should have also mentioned: we know that quantum mechanics and general relativity encounter irregularities (infinities) in the vicincity of singularities like the big bang and black hole centers..where space and time become incredibly curved/distorted/ and lose some of their everyday characteristics...so either something is wrong with those formulations or something is wrong with each of QM and GR...
 

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