Dear All,
>From an engineering point of view, a scientific theory does not have to be
>true. It just has to be useful.
When a scientist builds a bridge it will collapse, but the scientist can
perfectly explain why it collapsed. When an engineer builds a bridge it will
not collapse, but the engineer will not have a clue why it does not collapse.
I'm afraid some of these homely sayings seem to me to miss some of the points.
If you have a 'theory' (e.g. a set of equations) which works, but you don't
understand why (or it's not true), then it's potentially dangerous. 'It works'
means that it works under the set of circumstances where it has been tested.
You could use it outside those circumstances and not realise you had done so.
A scientist explaining bridge collapse isn't trying to build a good bridge:
(s)he is playing a different game (albeit one that may later benefit bridge
building).
An engineer who doesn't understand why their bridge stays up (i.e. hasn't
bothered to undserstand the theory properly) may have built a bridge that will
later collapse under unpredicted circumstances.
Traditional electr(on)ic engineering had many areas where you can work well
from simple theories and experience. You can choose an audio inter-stage
coupling capacitor like that. But modern engineering also has many areas which
are far more complicated - you can't design stripline by rule of thumb and feel
(unless you've designed something very similar before), nor 3-phase AC-to-AC
converters handling hundreds of megawatts.
"For now I see the true old days are gone." Cue chorus of old-timers blaming it
on beat music and the lack of capital punishment. Actually, I think they are
still here; it's just that the forefront of electronics nowadays is the far
more complicated stuff. Fortunately, as radio amateurs, we set our own agendas
and can choose to work in whatever part of that spectrum we wish.
73,
Chris G4OKW
-----------------------
Dr Chris Trayner
School of Electronic & Electrical Engineering,
The University of Leeds,
Leeds LS2 9JT, United Kingdom
Tel: +44 113 34 32053
Fax: +44 113 34 32032
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