What is the minimum mass required to distort space and time ?

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Discussion Overview

The discussion centers around the question of the minimum mass required to distort space and time, as framed by Einstein's General Theory of Relativity (GR). Participants explore the implications of mass on spacetime distortion, particularly in relation to quantum physics and the behavior of small particles.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions the existence of a minimum mass limit for spacetime distortion, suggesting that all mass distorts spacetime, but the extent varies.
  • Another participant notes that while all mass distorts spacetime, the distortion from very small masses, like electrons, is negligible.
  • A participant provides a mathematical expression for the spacetime metric around a point mass, indicating that significant curvature occurs only near large masses or close to the Schwarzschild radius.
  • There is a discussion about the interpretation of the Schwarzschild equation, clarifying that it is not valid for particles smaller than their Schwarzschild radius.
  • Some participants differentiate between passive gravitational mass and active gravitational field production, noting that while leptons have passive mass, there is no conclusive evidence they produce a gravitational field.
  • Speculation arises regarding the implications for General Relativity if leptons do not produce a gravitational field, with references to the equivalence principle.

Areas of Agreement / Disagreement

Participants generally agree that all mass distorts spacetime, but there is no consensus on the existence of a minimum mass limit or the gravitational behavior of very small particles like leptons. The discussion remains unresolved regarding the implications of these points.

Contextual Notes

Limitations include the dependence on definitions of mass and gravitational field production, as well as unresolved questions about quantum effects on gravitational interactions.

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Hi

What is the minimum mass required to distort space and time ?

According to Einstein's General theory of relativity .
Mass distorts Space and Time.
Well Quantum Physics does not satisfy with General theory of relativity.

So, it asks a Question does G exist in quantum size world ?
well ,

My question is that ...

"What is the minimum mass required to distort space and time ?"

I mean Does asteroid can distort space and Time ?

Does big comet can distort space and time ?

Does astronaut can distort Space and time ?

I mean What is the minimum MASS limit to distort Space and time ?

I call it "Einstein space time distortion limit !"
 
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According to GR, all mass distorts spacetime. It is only a question of how much it distorts. There is no "limit".
 
espen180 said:
According to GR, all mass distorts spacetime. It is only a question of how much it distorts. There is no "limit".
a particle would distort too ??
 
Yes, but something like an electron makes such little distortion that it is negligable.

In spherical coordinates, the radial component of the spacetime metric for a point mass is [tex]\frac{1}{1-\frac{2GM}{c^2r}}[/tex] where [tex]G=6.673(10)\cdot 10^{-11} m^{3} kg^{-1} s^{-2}[/tex] is the gravitational constant, [tex]c=2.99792458\cdot 10^{8}m\, s^{-1}[/tex] is the speed of light in vacuum, [tex]M[/tex] is the mass of the particle and [tex]r[/tex] is the distance from the particle. You can see that unless the mass is huge og you are close to the schwartzschild radius of the paricle, there really is no significant curvature.
 
If I recall correctly, the r in the Schwarzschild equation is the radius of the particle. Or am misremembering things? Otherwise, solid explanation.
 
The r in the Scwartzschild equation is definitely not the radius of the particle. The equation is only valid outside the mass, and if the radius is smaller then the Scwartzschild radius, the equation only holds outside the Scwartzschild radius. There are other coordinates which describe the interior of the black hole, and all of them (as far as I know) break down at the center (r=0).
 
Ack, you're most definitely correct. Sorry, carry on :)
 
Another way of thinking about it is that Einstein's bending of spacetime geometry is simply a different way of thinking about what we have classically thought of as the gravitational force. If you were to ask what is the smallest particle which interacts gravitationally, the answer would surely be "no matter how small the mass, all massive particles interact gravitationally."
 
Nabeshin said:
If you were to ask what is the smallest particle which interacts gravitationally, the answer would surely be "no matter how small the mass, all massive particles interact gravitationally."
But there is a difference between "interacting with gravity (passive)" and "producing a gravitational field (active)". Laboratory experiments have demonstrated that leptons have passive gravitational mass. But there is no conclusive experimental evidence to show that leptons produce a gravitational field (bend space time). This is an assumption based on theory.
 
  • #10
TurtleMeister said:
But there is a difference between "interacting with gravity (passive)" and "producing a gravitational field (active)". Laboratory experiments have demonstrated that leptons have passive gravitational mass. But there is no conclusive experimental evidence to show that leptons produce a gravitational field (bend space time). This is an assumption based on theory.

If we are talking about single leptons, I think a theory of quantum gravity is neccesary. Quantum effects would certainly be a factor in measurements of the gravitational attraction between single leptons.
 
  • #11
TurtleMeister said:
But there is a difference between "interacting with gravity (passive)" and "producing a gravitational field (active)". Laboratory experiments have demonstrated that leptons have passive gravitational mass. But there is no conclusive experimental evidence to show that leptons produce a gravitational field (bend space time). This is an assumption based on theory.

Interesting.

My first thought is, probably quite naturally, to write it off as the fact that a lepton produces a terribly weak gravitational field which is extremely difficult to detect.

If indeed a lepton did not produce a gravitational field, I have a feeling that would throw a wrench in something in GR but I can't quite put my finger on it. Equivalence principle, perhaps? Not sure. At any rate, thanks for the clarification!
 
  • #12
This thread has drifted into speculation. The answer was given in Post #2.
 

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