MISTAKE!
Below I meant of course: (01)
"As long as it was physically meaningful to think of arbitrarily low
temperatures, only INTERVAL scales (such as those of Celsius and
Fahrenheit) made physical sense." (02)
Sorry, Ingvar (03)
> Dear All,
>
> This my answer to John Sowa goes, I think, beyond what is of direct
> relevance for computer ontologies. It diplays the difference between my
> brand of scientific-fallibilistic realism and John's brand of pragmatism.
> But I decided to send it to the whole forum anyway.
>
> Dear John,
>
>> Ingvar,
>>
>> The important point for the UoM is that we agree that the details
>> of the physical theories are not relevant to the ontology:
>>
>> IJ> Nonetheless, I am of course of the opinion that this is not
>> > something that computer ontologists should worry about.
>>
>> In any case, I certainly admit that the definitions of the physical
>> units normally uses theoretical terminology of the time when the
>> definition was stated. But I would claim that those definitions
>> can be mapped to experimental methods that do not depend on the
>> theory.
>
> I think you are wrong. All experimental methods that measure forces rely
> on Newton's second law, F = m x a. The Kelvin (ratio) scale for
> temperature is dependent on the theory of statistical thermodynamics. It
> has an absolute zero point that presupposes the view that temperature at
> bottom is caused by, or even identical to, kinetic energy. As long as it
> was physically meaningful to think of arbitrary low temperatures, only
> ratio scales (such as those of Celsius and Fahrenheit) made physical
> sense.
>
>> > The meter is defined as "the length of the PATH TRAVELLED BY LIGHT
>> > IN VACUUM during a time interval of 1/299 792 458 of a second"....
>> > If, somewhere in the future, physicists will come to the conclusion
>> > that this is not completely true, then the definition will in all
>> > probability be modified.
>>
>> I certainly agree. But note that the first sentence can be restated
>> in terms of the technology in use at the time the definition was made.
>
> I think it cannot. Supply the definition, and I will tell you what I think
> is flawed with your pragmatist restatement.
>
>> Whatever future discoveries change the assumption about the speed of
>> light, they would undoubtedly use technology and conditions far
>> beyond anything possible at the time the above definition was stated.
>
> No, a new theory that denies that the speed of light in vacuum is
> constant, but contains the relativity theories as some kind of
> approximations, and is empirically supported with the old technology,
> would do the job you regard as impossible.
>
>> Therefore, they would not have any effect on the length of the meter
>> that was measurable at the time of that definition.
>>
>> > The ampere is defined as "that constant current which, if maintained
>> > in two straight parallel conductors of INFINITE LENGTH, of negligible
>> > circular cross-section, and placed 1 metre apart in vacuum, would
>> > produce between these conductors a force equal to 2 x 10-7 newton
>> > per metre of length". No one has ever made an experiment with
>> > "conductors of INFINITE LENGTH".
>>
>> I agree. But I would claim that the above definition is flawed
>> because it depends on the terms 'infinite' and 'negligible'.
>>
>> To be precise, the standards documents that include such definitions
>> should clarify limit terms such as 'infinite', 'negligible', 'vacuum',
>> and 'absolute zero'. They can be replaced by limiting statements:
>>
>> 1. 'infinite length' means a length that is sufficiently long that
>> no further increase has a measurable effect.
>
> To me, 'infinite length' MEANS infinite length. When mathematical formulas
> that allow talk of infinite extensions are applied in physics, I don't
> think the meaning of 'infinite length' changes as drastically as you and
> classical pragmatists are prone to suppose. Every experimenter knows how
> to handle things like these when doing experiments. No redefinitions are
> needed.
>
>>
>> 2. 'negligible' means sufficiently small that no further decrease
>> has a measurable effect.
>>
>> 3. 'vacuum' means sufficiently rarified that no further decrease
>> has a measurable effect.
>>
>> In short, all such definitions should be modified to indicate
>> a procedure for showing how the unreachable limit term can be
>> approximated while still allowing for improvements in the ways
>> of determining what is measurable.
>
> One of the classical criticisms of operationalism and pragmatism is that
> such attempted definitions are trying to do the impossible. They are
> trying both to restrict the definition to existing measurement procedures,
> and at the same time allow (JS: "while still allowing") new not hitherto
> seen ones.
>
> Ingvar J
>
>>
>> John
>>
>>
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>
>
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