Who Derived the Value of Magnetic Permeability in a Classical Vacuum?

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Discussion Overview

The discussion revolves around the derivation and value of magnetic permeability in a classical vacuum, specifically focusing on the constant μ0. Participants explore its historical context, practical applications, and citation practices in academic work.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Meta-discussion

Main Points Raised

  • Some participants state that μ0 = π * 4E-7 is a commonly accepted value, described as "comfortable."
  • One participant explains how to calculate the magnetic field strength H and the magnetic flux density B using μ0, noting that B approaches 1T in practical applications.
  • There is a suggestion that the value of μ0 was agreed upon by members at a congress, with the factor π being accepted as appropriate.
  • Another participant mentions that when using the value of μ0 in research, one should reference electromagnetic theory and electromagnetism.
  • Participants discuss the importance of citing the BIPM brochure for the definition of SI units, including μ0.
  • One participant suggests that reading journals could provide citation examples for the value of μ0.

Areas of Agreement / Disagreement

Participants express varying views on the historical derivation of μ0 and its citation practices. There is no consensus on who should be credited for the value, and the discussion includes both agreement on the value itself and differing opinions on its historical context.

Contextual Notes

Some statements reflect assumptions about the acceptance of certain values and the historical process behind them, but these assumptions are not universally agreed upon. The discussion also highlights the practical implications of using μ0 in research without resolving the complexities of its derivation.

Who May Find This Useful

This discussion may be useful for students and researchers in physics and engineering who are interested in the historical and practical aspects of magnetic permeability and its applications in academic writing.

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Who is credited for deriving the value of magnetic permeabilty in a classical vacuum?
How would one go about sourcing information in relation to such a value?
 
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μ0 = π * 4E-7. It's just a passed value, that is comfortable.

Say you have a long straight conductor carrying a current = 1 Adc.

In a distance, R = 1 m, you will find H = 1A / 2πR [ A/m ] = 1 / 2π [ A/m ].

To find the B-value, you multiply by μ0, so

B = 2E-7

which some people regarded as a comfortable value ?

Anyway the value π is not included in the value of B, and B "becomes close to" about 1T in practical applications ( a magnet you know where to buy ).

It's just like 1 meter = a long step.
 
Hesch said:
μ0 = π * 4E-7. It's just a passed value, that is comfortable.

Say you have a long straight conductor carrying a current = 1 Adc.

In a distance, R = 1 m, you will find H = 1A / 2πR [ A/m ] = 1 / 2π [ A/m ].

To find the B-value, you multiply by μ0, so

B = 2E-7

which some people regarded as a comfortable value ?

Anyway the value π is not included in the value of B, and B "becomes close to" about 1T in practical applications ( a magnet you know where to buy ).

It's just like 1 meter = a long step.

when using this value in a research paper who would I give credit to?
 
Well, mayby the members at some congress have voted as for the factor 4*10-7.

I think the factor π has just been accepted as ok. :smile:

The idea has just been to achieve a practical unit ( Tesla ) with a value about 1. ( for a "normal" magnet ).
 
Last edited:
µ0 = 4π×10−7 N / A2 ≈ 1.2566370614...×10−6 H / m or T·m / A or Wb / (A·m) or V·s / (A·m)

So when using any of the above values in a peer review research paper, I would give reference to electromagnetic theory and electromagnatism?
 
If you had taken the advice PF had given you, you would be reading journals, and you would have all the citation examples you could use.
 
Thread closed.
 
Last edited by a moderator:

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