A Is there a basic example that works based on gravitoelectromagnetism?

[sergioperezf]

The definition says Gravitoelectromagnetism (GEM), refers to a set of formal analogies between the equations for electromagnetism and relativistic gravitation; specifically: between Maxwell's field equations and an approximation, valid under certain conditions, to the Einstein field equations for general relativity.
But I don't find an useful real example.

 

[Ibix]

Under certain simplifications the Einstein field equations simplify to the same form as Maxwell's equations. When you do the simplification mass density and mass density flow occupy the same place in the maths as charge density and current density in Maxwell's equations, the Newtonian gravitational field acts like the electrostatic field, and a "gravitomagnetic field" acts like the magnetic field.

The correspondence is not precise because you can only have positive mass density where you can have positive or negative charge density. And the equations are only approximations to the full form of the Einstein field equations.

Does that help?

 

[Vanadium 50]

What @Ibix describes is "gravitomagnetism", which is fairly useless. In some situations it is a good approximation, but this doesn't spare you from the full GR, because you need to know if you are in a situation where this approximation works or does not.

But the OP didn't write "gravitomagnetism". He wrote "gravitoeletromagntism" which I have never heard of,

 

[berkeman]

(Note: OP is on a 10-day vacation from PF for some other issues.)

 

[martinbn]

..
But the OP didn't write "gravitomagnetism". He wrote "gravitoeletromagntism" which I have never heard of,

My guess is that his source is this wikipedia page https://en.wikipedia.org/wiki/Gravitoelectromagnetism

 

[Vanadium 50]

Could be. I guess we will find out in ten days.

 

[robphy]

My guess is that his source is this wikipedia page https://en.wikipedia.org/wiki/Gravitoelectromagnetism.

The OP's attachment looks like a screenshot from that page.

 

[PeterDonis]

the OP didn't write "gravitomagnetism". He wrote "gravitoeletromagntism" which I have never heard of

They're the same thing. What @Ibix posted pretty much matches the description given on the Wikipedia page for "gravitoelectromagnetism". "Gravitomagnetism" is just focusing on the "magnetic" part of "gravitoelectromagnetism" (the "electric" part is just ordinary Newtonian gravity).

 

[pervect]

Gravity probe B seems like an application for gravitoelectromagnetism. It's mentioned in wiki, https://en.wikipedia.org/wiki/Gravity_Probe_B. The analogy to magnetism is also mentioned in https://einstein.stanford.edu/MISSION/mission1.html. However, I haven't seen a thorough numerical analysis of the GP-B experiment using GEM.

 

[romsofia]

To add onto pervect's post...
'The 1995-99 measurements of the Lense-Thirring effect using laser-ranged satellites' https://iopscience.iop.org/article/10.1088/0264-9381/17/12/309

'Gravitoelectromagnetism: A Brief Review'
https://arxiv.org/abs/gr-qc/0311030

'Gravity Probe B: Final Results of a Space Experiment to Test General Relativity'
https://arxiv.org/abs/1105.3456

Of course, LARES 2 launched two years ago, which you can find some info here: https://www.lares-mission.com/LARES_2.asp
But, LARES one has a lot of papers out, which you can find here: https://www.lares-mission.com/pubblicazioni.asp

And, some of the ideas behind LARES 1 before it was launched can be found here:
'Towards a One Percent Measurement of Frame Dragging by Spin with Satellite Laser Ranging to LAGEOS, LAGEOS 2 and LARES and GRACE Gravity Models'
https://link.springer.com/article/10.1007/s11214-009-9585-7

And some drama between some physicists in this field : https://retractionwatch.com/2014/06...sing-fake-names-to-criticize-papers-on-arxiv/