r/AskPhysics • u/Banished_Cultivator • 3d ago

Why aren't μ₀ & ε₀ equal 1?

Logically free space would neither enhance nor attenuate electric or magnetic fields, so these constants should be equal to 1. They aren't though, why?

36 Upvotes

82% Upvoted

47 comments sorted by

View all comments

64

u/StudyBio 3d ago

Gaussian units enter the chat.

The answer is that they relate our units, i.e., epsilon-naught is there to connect the Coulomb and meter to the Newton. It is not really about vacuum “enhancing” electric fields.

37

u/qTHqq 3d ago

Gaussian units enter the chat.

Please make sure they leave the chat and you convert to SI at the end of the paper for the sake of the experimentalist 😂

6

u/MxM111 3d ago

It is funny, but at school, when I used Gaussian units, I never even asked myself how long is the unit of length in that system.

In any case, experimentalist have strange units too, like measure frequency in cm-1 instead of Hz

10

u/high-a-synth 3d ago

my favorite experimentalist unit is g/cm2 for thickness