Re: Scalar waves

Thomas Heger <ttt_heg@web.de> wrote:

Am Montag000006, 06.05.2024 um 13:52 schrieb J. J. Lodder:

Mikko <mikko.levanto@iki.fi> wrote:
 

On 2024-05-06 09:36:27 +0000, J. J. Lodder said:
>

A measurement is not a measurement unless it can be traced
to a primary standard.
So your multimeter measures 204.5 mA when it says so
because the manufacturer of it says so.
Your manufacturer can guarantee that,
because he has calibrated the thing
against his standard ampere meter.
He knows that his standard meter measures amps
because he takes it to his national standards lab,
where they calibrate it for him.
And ultimately (if you live in a small country)
your national lab takes their standards to NIST, or BIPM,
where they do have a primary standard.

>
Possibly. Or the manufacturer or certifier or the national
laboratory may have a reference that they compare directly
to the definition.

 
Certainly. Whatever,
the point is and remains that a measurement isn't a measurement
unless it can be traced to an SI standard.
In many cases this is even required by law.
Whatever is doing the calibrating must be a state-approved agency.

 
Well, no!
 
You can use any other consistent system of units, if you don't like
SI-units.

Certainly, and you can use any other system of dimensions
than the one that is conventionally associated with the SI.

But actually I was talking about dimensions and how those are defined.
 
That term refers to WHAT is measured, while units define the quantities
of the measurement results.

Sure, you can invent your own definitions,
but that is not how the term 'dimension' is used in physics.

Simple example:
 
you have a distance of roughly 1 meter and want to measure that.
 
you could use inch, yards, forlongs, lightseconds, Angstroem, mm and the
size of the emperors feet.
 
The choice of a unit would only influence the numerical value, but not
the measured distance.

You forget the only length unit that is still in everyday use,
the second, up to an unconvenient conversion factor.
Do I really need to remind you again that the meter has been abolished
as a primary standard, and that all length measurements
must (by the definition of the meter) be calibrated in seconds?

And yes, that includes your tape rule,

Jan