Difference Between Special & General Relativity

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Discussion Overview

The discussion focuses on the differences between Special Relativity (SR) and General Relativity (GR), exploring their fundamental concepts, mathematical requirements, and the contexts in which each theory applies. The scope includes theoretical explanations and conceptual clarifications.

Discussion Character

  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants note that SR is concerned with scenarios where gravity is absent or negligible, leading to flat spacetime, while GR addresses situations where gravity is significant and spacetime is curved.
  • It is mentioned that SR can be viewed as a special case of GR, where the curvature of spacetime is zero.
  • Participants discuss the relative mathematical complexity of the two theories, indicating that SR can be understood with high school algebra, whereas GR requires advanced mathematics including multi-variable calculus and tensor calculus.

Areas of Agreement / Disagreement

Participants generally agree on the fundamental distinctions between SR and GR, but there is no consensus on the implications of these differences or the relative difficulty of the mathematical frameworks involved.

Contextual Notes

The discussion does not resolve the nuances of how the two theories interrelate or the implications of their mathematical requirements.

Jaami M.
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Nugatory said:
This idea is one of the essential concepts behind Special Relativity, so if you're comfortable with it you're well-positioned to start learning SR.
So what is the difference between the two? Special Realitivity and General Relativity.
 
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Here goes (had to try it) ;)

Special: speed of light, E=mc2
General: gravity
 
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m4r35n357 said:
Here goes ;)

Special: speed of light, E=mc2
General: gravity
Thank you
 
Jaami M. said:
what is the difference between the two? Special Realitivity and General Relativity.

SR only deals with situations in which gravity is not present or can be neglected; in such situations, spacetime is flat, or can be approximated as being flat.

GR deals with situations in which gravity is present and cannot be neglected, and spacetime is curved.
 
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PeterDonis said:
SR only deals with situations in which gravity is not present or can be neglected; in such situations, spacetime is flat, or can be approximated as being flat.

GR deals with situations in which gravity is present and cannot be neglected, and spacetime is curved.

And, if OP is wondering about why the names are what they are...

The case in which gravity is not present or can be neglected is a special case (curvature is zero) of the more general theory that works for all values (zero or non-zero) of the curvature.
 
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Although not directly related to the question, OP may also be interested in the relative difficulty of the math behind the two theories.

High school algebra can get you to a decent understanding of SR: derivation of Lorentz transforms from Einstein's postulates; calculation of spacetime intervals and proper time along the worldlines of objects moving at constant relative velocities; able to explain the elementary "paradoxes" such as pole-barn, bug-rivet; the various approaches to the twin paradox.

GR requires multi-variable calculus, differential geometry, tensor calculus, solving some of the most challenging non-linear partial differential equations you'll ever encounter. There's close to a decade of high school and college math between SR and GR.
 
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