Electric currents and length contraction

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SUMMARY

The discussion centers on the relationship between electric currents and length contraction as explained by relativity theory. It highlights that in the stationary frame (S), a neutral wire with a current generates a magnetic field that exerts a force on a charge (q). The length contraction of proton-proton distances in a moving frame (S') alters the neutrality of the wire, resulting in an electric force on q. The question raised pertains to why electron-electron distances do not experience length contraction in frame S, maintaining the wire's neutrality.

PREREQUISITES
  • Understanding of relativity theory, specifically length contraction
  • Familiarity with electromagnetic fields and forces
  • Knowledge of stationary and moving reference frames
  • Basic concepts of electric currents and their effects on magnetic fields
NEXT STEPS
  • Study the implications of length contraction in special relativity
  • Explore the relationship between electric currents and magnetic fields using Maxwell's equations
  • Investigate the concept of charge neutrality in moving frames
  • Learn about transient states in electric circuits and their relativistic effects
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Physicists, electrical engineers, and students studying electromagnetism and relativity who seek to deepen their understanding of the interplay between electric currents and relativistic effects.

Luis Babboni
Hi people, me bother yo again!

I understand that relativity theory length contraction is the explanation of magnetics fields.
See the image:
densidadcargasencorriente.jpg

https://dl.dropboxusercontent.com/s/vuy69jhig3kni3n/densidadcargasencorriente.jpg?dl=0

1) In the S system, if q is moving at the same velocity than the electrons that made the current, the -I current into a neutral wire produces a magnetic field B that make a force Fm on q.
2) It can be explained what happens in 1) from what happens in a system S´ that is moving at the same velocity than electrons and q. The length contraction of proton-proton distances made the wire not even more neutral so q, at rest in S´, feels an electric force Fe.

My question is why in S, as I show in 3) the moving of electrons do not result in length contraction of theire electron-electron distances making the wire not neutral and then an electric force Fe appears on q?

In this case I think I have the answer but not sure if it is correct and then I ask you about it:

Is cause "a neutral wire in S" is neutral because the main distances electron-electron in a frame where electrons are a rest is the one needed to make those distances are the same as proton-proton distances in a frame where protons are at rest?

Thanks!

PS: In the case my answer is correct, the trasient from neutral wire without currents to steady current in it, would be interesting in terms of relativity effects! I´m right?
 

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Nice! Thanks.
 

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