Calculating Field Strengths of EM & Gravitational Fields

[Schreiberdk]

Hi there PF

How does on calculate the field strenght of the electromagnetic field (from Maxwells equations) and of the gravitational field (from general relativity).

I want to relate this to particle physics, where the relative strenghts of the fundamental interactions are calculated here (http://en.wikipedia.org/wiki/Fundamental_interaction#Overview), but how are these relative strengths calculated? Does it have something to do with coupling constants? and how does one find these in general relativity and in maxwells equations?

Also i would like to ask, whether these are energy dependent, as in grand unified theories, where on states that the fundamental forces become equal in strenght at certain levels of energy.

Thanks in advance
\Schreiber

 

[Schreiberdk]

Anyone? :)

 

[WannabeNewton]

In Classical GR there is no "field" strength per say since it is space - time geometry and its curvature one is modeling mathematically. One can calculate tensor quantities such as the Riemann Tensor or the Ricci Tensor for a given metric to see how much space - time is curved at each point in the coordinate system being used for the metric or the Ricci Scalar for a coordinate invariant expression for the curvature. Correct if I am wrong.

 

[Schreiberdk]

Can't one then say, that the Ricci Scalar is the coupling constant (i.e. the strenght of gravity) of gravity?

And does this correspond to the relative strenghts of the forces in the link http://en.wikipedia.org/wiki/Fundamental_interaction#Overview ?

And what about electromagnetism ? :)

 

[pmacias]

Hello \Schreiber,

Calculating the field strengths of electromagnetic and gravitational fields involves using the equations that govern these fields, namely Maxwell's equations for electromagnetism and the Einstein field equations for gravity.

In electromagnetism, the field strength is determined by the electric and magnetic fields, which are related through Maxwell's equations. The strength of the field can be calculated by solving these equations, which take into account the charges and currents present in the system.

Similarly, in general relativity, the strength of the gravitational field is determined by the curvature of spacetime, which is described by the Einstein field equations. These equations take into account the distribution of matter and energy in the universe, and can be used to calculate the strength of the gravitational field at any given point.

In particle physics, the relative strengths of the fundamental interactions are determined by coupling constants, which describe the strength of the interaction between particles. These coupling constants are derived from experimental data and can be used to calculate the relative strengths of the fundamental interactions.

It is important to note that these field strengths are not constant and can vary with energy. In grand unified theories, it is theorized that at high energies, the fundamental forces become unified and exhibit equal strength. However, this is still a topic of ongoing research and has not been conclusively proven.

I hope this helps to answer your questions. Keep exploring and learning about the fascinating world of physics!