But if air is not necessary for the coupling to work, if no physical
medium is required to transmit the electromagnetic energy - as the
absence of air between the coils, from what I gather, would not
interfere with the production of resonant rise, then should we
really keep classifying it as an 'air core' transformer then?
Granted, it is very rare that one hears of a tesla coil being built
in anything other than 1 atm, but I cant help but think that this is
circumstantial.
I know it may have been called an 'air core resonant transformer' for
a very long time, and old habits die hard, but if having air present
between the primary and secondary is not a _requirement_ for it to
work - then perhaps the 'air core' part of what we call it should be
omitted - or otherwise reflect the nature of what is always true
about the coupling and transfer of energy from one coil to the other
- whether in oil, air, or vaccum, just so long as the fluid between
the pri. and sec. it is a non-conductive material?