It is generally assumed that empty space can have properties, as this is our only way to accept the results of Relativity in modern science.
It is my firm conviction that you cannot have "floating" properties; for example you cannot split a red pen into a colourless pen and a red nothing. Space or "the vacuum" does not hold anything that can have properties and therefore space or "the vacuum" cannot have any properties.
However, we do assign the properties ε0 and μ0 to "empty space", which, IMHO is nonsensical.
Since Tesla describes how ether must contain a gaseous medium to give it electrical properties then ε0 and μ0 must be properties of either that medium or some other ether-like medium.
And, this being the case, the exact value of these properties could vary with the density of this medium.

I recently did an experiment to verify if this would indeed be measurable. If it is, then we have evidence that "properties of the vacuum" is indeed nonsense.
I cannot express how happy I am with the result and I hope that it will survive worldwide scrutiny, not because I yearn for a Nobel prize or anything like that, but it would validate the basis of Tesla's theories and this would open up a whole new field in science with countless new possibilities.

Please have a look: https://youtu.be/i9PLSMdIWx4

And tell me what you think.

Ernst.