Re: Expt & theory (was Separation of science and religion)

Moorad Alexanian (alexanian@UNCWIL.EDU)
Mon, 24 Nov 1997 13:05:21 -0500 (EST)

At 12:34 PM 11/24/97 -0500, George Murphy wrote:
>Richard Dimery wrote:
>> > Theory may suggest what experiments to do but experimental science is
>> > theory free. Experimental science is constituted by historical propositions
>> > of the type: "on such and such a day I released the stone and it fall as
>> > follows." The generalization of such events constitutes the laws of
>> > (experimental) science. The interpretation or understanding of the laws
>> > constitutes theory.
>> Even data, I'm afraid, is often seen as theory-laden. There is some
>> interpretation going on even when we report things. If you talk about a
>> stone going through a glass window, you're making assumptions about the
>> state and nature of the glass before and after the event, talking about
>> properties of glass containing counterfactuals (unbroken glass is fragile,
>> meaning that _if_ it were to have a stone thrown at it, it _would_ break.)
>> You're classifying "glass windows" as transparent sheets made of a
>> category of compounds based on aggregate. You're assuming your eyes aren't
>> deceiving you, and the stone isn't just passing through the glass.
>> Even needles flickering on electronic equipment are theory-laden
>> observations. We don't just say "oh, the ammeter needle is moving 30
>> degrees. That's interesting". We say "oh look, there are 4.5 amps moving
>> thorugh that wire" (excuse my physics). Our observations generally have an
>> extra layer of interpretation even before we start to Interpret them.
> I agree. Even very simple observations require some theory.
>E.g., an astronomer reporting positions of stars has to assume
>rectilinear propagation of light in a vacuum (in addition to the usual
>corrections for atmospheric refraction &c). & the farther our
>experiments & observations get from everyday experience - with
>elementary particle physics e.g. - the data become even more
>theory-laden. This doesn't mean that the discovery of things like
>quarks is pure "construction" as some post-modernists would say, but it
>does mean that there must be feedback between theory & experiment, &
>that the two can only advance together.
> George Murphy

Of course, there is an interplay between theory and experiment. The real
question is whether the experimental results can stand on their own without
the aid of a theory. That ought to be so since then, how can a theory be
invalidated by experimental results? Surely there is some underlying
assumptions we must make so that our sense perceptions indicate some sort of
external reality. If such assumptions are not made, there is no knowledge to
be obtained.