Newton's Constant Help: Kainaan's Question

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Discussion Overview

The discussion revolves around Newton's constant (G) and its implications in the context of gravity, particularly in relation to the Schwarzschild radius. Participants explore the nature of G, its constancy, and hypothetical scenarios involving different values of G in alternate universes.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Kainaan expresses curiosity about the meaning of Newton's constant (G) and its role in the equation for the Schwarzschild radius.
  • Some participants propose that G is a measure of the strength of gravity, suggesting that if G were larger or smaller, gravity would be correspondingly stronger or weaker.
  • Others argue that G is a constant and therefore does not change, but they entertain the idea of imagining different universes where G could take on different values.
  • A later reply discusses the challenges of conceptualizing changes to non-dimensionless constants like G and references the idea of dimensionless constants.
  • Further clarification is provided that in hypothetical scenarios with different values of G, gravity would behave differently than in our universe.

Areas of Agreement / Disagreement

Participants generally agree that G is a constant in our universe, but there is a debate about the implications of imagining different values of G in alternate universes. The discussion remains unresolved regarding the conceptualization of G's variability in hypothetical contexts.

Contextual Notes

Limitations include the dependence on definitions of constants and the challenges in discussing changes to non-dimensionless constants like G.

Kainaan
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Hello my name is Kainaan i just joined this forum, I am 14 and i love every related to physics, i study quantum hysics and general relativity. I have a question about Newtons constant, i have been reading on the Schwarzschild radius and came across the equation for it, in the eqaution it has the variable G which stands for Newtons constant, i understand all of the other stuff in the equation and i know what Newtons constant is (6.7 x 10 to the -11), but i don't understand what it means like what it is.

if you could please explain it to me that would be awesome, i hope to talk to you all about other physics topics in the near future.
 
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In some sense, G is a measure of the strength of gravity. If G were larger, gravity would be stronger; if G were smaller, gravity would be weaker.
 
but isn't G a constant and therefor always the same, so i can not be larger or smaller its just always the same thing.
 
Last edited:
Kainaan said:
but isn't G a constant and therefor always the same, so i can not be larger or smaller its just always the same thing.
Yeah, but you can imagine a different universe where the constant takes a different value, and figure out how the behavior of matter and energy would be different in that universe. Although, there are problems with talking about changes to values of non-dimensionless constants like G or the speed of light...see the discussion here, and see here for a list of dimensionless constants (all particle masses can be made dimensionless by dividing by the Planck mass).
 
Kainaan said:
but isn't G a constant and therefor always the same, so i can not be larger or smaller its just always the same thing.

Right. The idea is to imagine universes that have different values of G than the value of G that we measure in reality.

If in an imaginary universe G is larger than what we really measure, gravity in the imagined universe would be stronger that it is in our universe; if in an imaginary universe G is smaller than what we really measure, gravity in the imagined universe would be weaker that it is in our universe.

Edit: JesseM was faster.
 
ok now i understand thanks for the help
 

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