Queries on Maxwell's Equations

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    Maxwell's equations
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Discussion Overview

The discussion revolves around the interpretation and implications of Maxwell's equations, particularly their role in explaining electromagnetic phenomena and the unification of electricity and magnetism. Participants explore theoretical aspects, applications, and the conceptual understanding of these equations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants question what it means for Maxwell's equations to explain all electromagnetic phenomena and seek clarity on the concept of unification between electricity and magnetism.
  • One participant suggests that Maxwell envisioned a self-sustaining electromagnetic field, which travels at the speed of light, linking this idea to later developments in relativity by Einstein.
  • Another participant asserts that Maxwell's equations apply to all classical magnetic and electric fields, not just electromagnetic waves, and emphasizes the role of charge and current densities as source terms.
  • There is a request for clarification on how the constancy of the speed of light can be derived from Maxwell's equations, indicating uncertainty about this connection.
  • Participants express interest in real-life applications of Maxwell's equations, particularly in electronics, and inquire about what can be derived from these equations.
  • A participant references external content regarding the derivation of the speed of light from Maxwell's equations, prompting further questions about the nature of this derivation.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the implications of Maxwell's equations, particularly regarding the unification of electricity and magnetism and the derivation of the speed of light. Multiple viewpoints and questions remain unresolved.

Contextual Notes

Some statements reflect assumptions about the applicability of Maxwell's equations and the interpretation of their implications, which may depend on specific definitions or contexts that are not fully explored in the discussion.

unseensoul
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"Maxwell's equations explain all electromagnetic phenomena." ...What does this mean exactly?

How do these equations represent the unification of electricity and magnetism? What's really an unification? And how can you see it from the equations?

Aren't his equations only applicable to EM waves?
 
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I don’t know if this will answer your question , but he thought what if an electric field could create a magnetic field and so on , This would be a self sustaining electromagnetic field , and this turned out to travel at the speed of light and he knew this was no coincidence , c=1/sqrt(EB) where c is the speed of light and E= is the electrical constant and B is the permeability constant. And another thing this said was that the speed of light was constant to all observers regardless of their motion , this was always in the back of his mind be he kind of ignored it , and later Einstein came along and used this to base relativity on.
 
unseensoul said:
"Maxwell's equations explain all electromagnetic phenomena." ...What does this mean exactly?

It means, that classically, any observation involving electromagnetic phenomenon can be explained by Maxwell's equations (actually, you also need the Lorentz force law).

How do these equations represent the unification of electricity and magnetism? What's really an unification? And how can you see it from the equations?

Simple, the source terms for the electric and magnetic fields in Maxwell's equations are electrostatic charge and current densities. Since a current is just moving charges, ll electromagnetic fields (both electric and magnetic) are caused by either stationary or moving charges.

Aren't his equations only applicable to EM waves?

No. They apply to all classical magnetic and electric fields.
 
cragar said:
And another thing this said was that the speed of light was constant to all observers regardless of their motion...

How can you figure that out from the equations? It's not obvious for me...
 
http://cr4.globalspec.com/blogentry/270/Deriving-the-Speed-of-Light
 
gabbagabbahey said:
...Since a current is just moving charges, ll electromagnetic fields (both electric and magnetic) are caused by either stationary or moving charges.

I didn't get this last part and how it explains the unification of electricity and magnetism.

gabbagabbahey said:
No. They apply to all classical magnetic and electric fields.

Can you give me real life applications (for instance, in electronics) where they apply? Also, what sort of things can be derived from the equations?
 
cragar said:
http://cr4.globalspec.com/blogentry/270/Deriving-the-Speed-of-Light

"The fact that the speed of light is constant regardless of your reference frame is a direct consequence of Maxwell's Equations".

What direct consequence?
 

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