Speed of light depending on gravitational constant?

Click For Summary

Discussion Overview

The discussion centers around the potential relationship between the speed of light in a vacuum and the gravitational constant G. Participants explore whether there are any peer-reviewed theories linking these two constants, akin to how Maxwell calculated the speed of light using permittivity and permeability.

Discussion Character

  • Exploratory
  • Debate/contested

Main Points Raised

  • One participant wonders if any serious theories exist that link the speed of light and gravitational constant G, suggesting a calculation of the speed of light based on G.
  • Another participant argues that the concept does not make sense, stating that the speed of light is used to measure distances and questioning how it could change in an objective way.
  • Some participants assert that only dimensionless constants are fundamental, implying that other constants can be redefined without altering physical laws.
  • One participant mentions that while the idea lacks physical content, it is possible to define units that could create arbitrary relationships between constants.
  • Another participant introduces the notion that under certain circumstances, a link might make sense but refrains from elaborating due to speculation concerns.
  • A later reply references a Wikipedia article on variable speed of light and discusses the speed of gravitational interaction, noting theoretical support for it being equal to the speed of light, while acknowledging the rarity of experimental confirmation.

Areas of Agreement / Disagreement

Participants generally agree that there is no established peer-reviewed theory linking the speed of light and gravitational constant G. However, there are competing views regarding the implications of redefining constants and the potential for speculative scenarios.

Contextual Notes

Some participants express limitations in discussing speculative ideas due to forum guidelines, and there is mention of the lack of experimental evidence supporting certain theoretical claims.

SpiderET
Messages
82
Reaction score
4
I just wonder if there were any serious (and peer reviewed published, to be in line with guidelines) theory, which had proposed some link between speed of light in vacuum constant and between gravitational constant G. For example a calculation of speed of light based on G.
Tried google search but with no result, so I guess the answer is no, but maybe somebody here will know better.

Something similar to Maxwell approach calculating speed of light based on permittivity and permeability.
 
Science news on Phys.org
I don't think that concept would make sense at all. We use the speed of light to measure distances. How can the speed of light change in an objective way?
Only dimensionless constants are fundamental, all other constants can get arbitrary values without changing physics by redefinition of our units.
 
mfb said:
I don't think that concept would make sense at all. We use the speed of light to measure distances. How can the speed of light change in an objective way?
Only dimensionless constants are fundamental, all other constants can get arbitrary values without changing physics by redefinition of our units.

Under some circustances it would maybe make sense, but I can't write here about it, because it would be pure speculation, which would be agaist guidelines.
But thanks for reply anyway, it seems that the answer is no, there is no such peer reviewed theory.
 
There is no such theory, for the reason given. You can define your units of time and length to make c be anything you like, and your units of mass to do the same for G. You can even define funky units that change over time or across space to establish any relationship you like. There is simply no physical content to the idea.

You may find this article helpful: http://math.ucr.edu/home/baez/constants.html
 
SpiderET said:
Under some circustances it would maybe make sense, but I can't write here about it, because it would be pure speculation, which would be agaist guidelines.
But thanks for reply anyway, it seems that the answer is no, there is no such peer reviewed theory.

Even if wikipedia is not a recommended source here, you may be interested by the recently reviewed article: "http://en.wikipedia.org/wiki/Variable_speed_of_light" which I think is addressing for a part your questioning.
A by side interrogation seems to be: "With which speed does the gravitational interaction really move?" I know the theory and you can find professionally verified demonstrations proving that that speed theoretically is c, the same than the one of electromagnetic interactions (e.g.: Lichnerowicz, 1955). But on the other side of the reality you shall obviously discover that experiments confirming these theoretical demonstrations are, perhaps not missing, but rare and yet discussed. I hope it brings a positive and constructive contribution to your questioning.
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
13K
  • · Replies 29 ·
Replies
29
Views
4K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 7 ·
Replies
7
Views
913
Replies
60
Views
5K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 15 ·
Replies
15
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
9K
  • · Replies 13 ·
Replies
13
Views
3K