Equation for how much an object curves space-time

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    Curves Space-time
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Discussion Overview

The discussion centers around the question of whether there is a specific equation to determine how much an object curves space-time, particularly in the context of general relativity versus Newtonian gravity. Participants explore the differences between these frameworks and suggest resources for further understanding.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant mentions that the equation provided by their physics teacher, f=Gm1m2/r^2, is for Newtonian gravity and may not apply in all situations, particularly when dealing with dense or rapidly moving bodies.
  • Another participant explains that the Einstein Field Equations are the relevant equations for understanding how energy and mass curve space-time, relating the stress-energy tensor to the Einstein Tensor and the metric of space-time.
  • There is a suggestion to consult Wikipedia for a basic understanding of the Einstein Field Equations, although some participants caution against relying on it for scientific learning.
  • Recommendations for popular and introductory textbooks on general relativity are provided, including titles by Geroch, Wald, and Thorne, as well as more advanced textbooks suitable for undergraduate physics majors.

Areas of Agreement / Disagreement

Participants generally agree that the Newtonian equation is not sufficient for all scenarios involving space-time curvature, but there is no consensus on a singular equation or model that fully describes the curvature of space-time.

Contextual Notes

The discussion highlights the complexity of relating mass and energy to space-time curvature, with references to different levels of understanding and types of resources available for learning.

Who May Find This Useful

This discussion may be useful for students beginning their studies in physics, particularly those interested in general relativity and the mathematical frameworks that describe gravitational phenomena.

rubecuber
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hey guys, I asked my( well she's not mine since i don't take physics yet)physics tacher if there is an equation to find out how much a body can curve space-time, but she gave me f=Gm1m2/r^2. But I'm pretty sure that's not it. I know that the equation is not linear. Could one of you guys who knows about this help clarify this?
 
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That is the equation for Newtonian gravity, which is correct for many situations. Only when things are very dense of moving very quickly does that not work.

The full set of equations (at least as far as we know) are called the Einstein Field Equations.

Without going into the full mathematical detail, this set of equations equates the 'stress-energy tensor' which describes the energy present in the situation you're dealing with, and the Einstein Tensor. The Einstein Tensor is actually a function of something called the metric, and it is the metric that tells you how much space-time is curved. So for a given distribution of energy, the field equations are solved to find the metric for which the Einstein Tensor equals the Stress Energy Tensor (I hope that made sense!).

Some folk around here caution against using Wikipedia to learn science, for good reason, however the Wiki entry for the Einstein Field Equation isn't terrible, so you could have a read of that.

A better option would be to try a textbook. I recommend 'Gravity' by James Hartle but there are plenty of other introductory Relativity textbooks that may also be useful.
 
thank you very much
 
Recommend some good popular books

I agree with Wallace, except that if you, rubecuber, haven't taken a lot of college physics, I'd recommend instead a popular book by an expert, such as Geroch, General Relativity from A to B, Wald, Space, Time, and Gravity, or Thorne, Black Holes and Time Warps, all of which are excellent. For advanced undergraduate physics majors, the textbooks by Hartle, Carroll, Schutz, D'Inverno, Stephani, OHanian and Ruffini, would all be excellent choices (there are still more which would not be bad, but these would all be particularly good first textbooks, I think).
 
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