# Re: [ Re: Variable Capacitance and Inductance]]

```Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

Hi Dave:

Tesla list wrote:

> Original poster: "David Thomson by way of Terry Fritz

<twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>
> Hi Dave,

>   > If they are variable, then how do these accurate measuring
>   > devices get the same exact result each time?

> 	By making sure the surrounding results are the same.

> You're saying the same thing Tesla is saying

Tesla said many things, some i agree with, some not.

> but disagreeing just for the sake of disagreeing.

False.

> If everything around the coil were the same, such as
> sun position,

What has that to do with anything?

> earth position,

What has that to do with anything?

> elevation, etc, then naturally there would be no change in

> induction or capacitance.  The point Tesla was making was

> that the environmental conditions are not the same for all

> locations and times and therefore the inductions and

> capacitances will be variable.

For some influences, this is well known.

He ALSO made the SPECIFIC assertion that capacitance
of an isolated capacitance INCREASED as it was
elevated.  No One else, including some here, has
observed this.

> 	Also (and more to the point) variation in the _measured_
> 	value is different than variation in the device.

> The inductance is what the inductance is under given circumstances.  There
> is no separation of the measurement and the device.  The device cannot have
> a separate value than the measurement and the measurement cannot exist
> without the device.

>> 	Tesla asserted that he observed changes
>> 		LARGER IN SIZE
>> 	and
>> 		OPPOSITE IN DIRECTION
>> 	from everybody since (and some/all) before.

> And Tesla was correct.

> The previous notion that capacitance of a sphere was
> the same under all conditions is false,

It was (is) an initial simplification, and is,
within its stated purpose, true: as a mathematical
model.  It is of little use to object that a model
is not reality.  Its not supposed to be.  Its a model.

> just as Tesla clained, and even Terry admits that this
Which 'this'?
Variation between model and reality?
DIRECTION of variation?
MAGNITUDE of variation?
CAUSE of variation?

>   > Perhaps the more relevant observation is that "free space" has
>   > inherent permeability and permittivity;

> 	Which are well known, well measured, well understood and
> 	have DIFFERENT effects, in magnitude and direction from
> 	(some of) those Tesla reported.

> You make general comments with no substance

We differ then, in the defintions of 'substance',
among other things.

> but with highly charged words.

I think not.  I specifcally stick to facts, repeatable
demopnstrable, testable facts.

> The tendency would simply be to accept your allegations at face

> value since they are said with such force.

I never use 'force'.

> But a simple re-examination of your claim shows them to be

> meaningless without some kind of reference to what
> DIFFERENT effects you are talking about.

I have refined and refined.  Also, some basics are
best acquired from references, courses, etc.

>   > the stuff that "makes" inductance and capacitance.  This is why
>   > inductance and capacitance can be variable for a material object
>   > such as a coil or capacitor.

> 	Put either in a shielded box.
> 	Do the measurement.

> You must be missing something.  We're talking about variable capacitance
> within our present environment.  Not on some strange, lonely asteroid on the
> outskirts of the universe.  I'll just assume you are being contrary for the
> some personal reason but that you really agree with Tesla's assertion.

The question has wandered, as discussion has taken place.
That is the nature of discussion.
Engineers routinely put components in shielded boxes to
get repeatable results.
Again:
No doubt exists that external effects will cause
measured (however measured) values to vary.  However
the direction, magnitude and causes are well known, and
in disagreement with (some of) Tesla's reported
observations, sometimes substantially different.

>>> 	2) The environmental effects are well known, exhaustively
>>> 	studied and different from those Teal's observations require.

>> 1) CF above.

>>> That sounds just like how the "best instruments" you reference,
>>> work.  As far as I know, there is not a machine on the face of
>>> this planet that measures inductance or capacitance directly.

>> 	There are a few, used to calibrate the standards used	by the rest.
>> 	They get closer than those available to Tesla.

> Once again, Dave.  You are being very general.

> Do you expect me to take your word for this?

The web, libraries, and courses of all sorts are available.

> Give me the name of one machine that measures capacitance or

> inductance directly.  This would be of great interest to

cf above.  Web searches and training courses (tho
specialized ones) will do nicely, arguably better than I.
Think about the fundamental defintions of capacitance
(or whatever) and think up an instrument for the
fundamentals.

best
dwp

```