I always revert to the number pi , 3.141592 .    I use it for different formulas as I assume most here do ...... at least I hope yall do!
any way I been going over aerial info , the free space impedance is 377 ohms , all good and well ....
the dielectric value of water is 78.54 , all good and well ....


if Pi is applied to each , the result is     120 x Pi = 377   ,  25 x Pi = 78.54


Im still going thru different sites but Im curious about the relationship to Pi for these particular numbers

any curious or HAM ers out there ready to shed light on this observation ?    sulaiman?    MattWatts?

This Wikipedia entry explains where the 120.pi comes from https://en.wikipedia.org/wiki/Impedance_of_free_space
the 120.pi approximation is explained near the bottom,
basiclly it is due to the way that SI units were chosen,
but that of course just reflects that there is a definite relationship between the dielectric, magnetic and electromagnetic properties of space.
If you do use the impedance of free space  in calculations,
remember that 120.pi only applies many wavelengths away from the source, in the 'far field'
in the 'near field' the ratio of voltage (electric field) to current (magnetic field) depends mainly on the source
e.g. I believe that Tesla did not accept Hertzian theory because at the frequencies that he used the wavelengths were long enough for him to be working in the 'near field', hence 'scalar' power.


and the dielectric constant of water depends somewhat on how it is measured and especially at what temperature
so I think that 25.pi is just a coincidence.

that's about all I (think that) I know

"I think therefore I am"   , that can never be a bad thing .   Im just glad I didnt get flamed  ; )

Quote from massive on October 15th, 2016, 12:54 PM

the free space impedance is 377 ohms

the dielectric value of water is 78.54 , all good and well ....

if Pi is applied to each , the result is     120 x Pi = 377   ,  25 x Pi = 78.54

Quite an important observation. More dots need connecting.

Meanwhile, a cherry pie awaits.