[SFDXA] Fun with universal constants

[Kai Siwiak]

Today's "Ham Facts" on our SFDXA web page tackles that value of the speed of 
light - and they got it wrong.  The speed of light is one of the constants of 
nature, and has been DEFINED internationally as EXACTLY 299,792,458 m/s. (Refer 
to CODATA).  Since 1987 the meter has been defined as "the length of the path 
traveled by light in vacuum during a time interval of 1?299,792,458 of a second"

Since the magnetic constant is also precisely defined, that makes some of our 
radio-related constants "exactly known" values, like the permittivity  and the 
intrinsic impedance of free space (vacuum).  All of this means that the "second" 
is left as the floating, or imprecisely known unit.  This gives rise to 
imprecision in concepts like "Honey, I'll be there in a second", "Wait a 
second", all of which taken the precision shared with "mañana".

Have fun with numbers,
73
Kai, KE4PT