NavList:

   

Reply

Dear Peter,
What you say actually confirms one of my points.
Science discovers truth.
This truth is an APPROXIMATION to reality.
And new scientific theories do not REPLACE the old ones
but COMPLEMENT them.

Ptolemy system WAS actually a reasonably good approximation.
Proof: it was used for almost a millenium, even after Copernicus.
The crucial step forward was made by Kepler, (not Copernicus).
And if you take a close look on how the modern Almanac is computed,
(and what sort of data it gives you), you may conclude that it is
a development of the Ptolemy system:-)

And what rotates about what is very irrelevant for navigation
purpopses.

(Actually it is irrelevant from the point of physics too:-)
As Galileo discovered in his Relativity Principle he stated in
his youth.

(The disput Galileo later had with Catholic Church
was not a scientific dispute, but more a political one,
but I do not wanat to go into this story which is quite complicated).

Alex.


On Tue, 30 Aug 2005, Peter Fogg wrote:

> An example for Alexandre:
>
> In the past there have been all sorts of models of the cosmos proposed. One 
of them was that of the familiar (to us) celestial sphere. Later on it was 
replaced by better knowledge leading to our present ideas. However regardless 
of "Truth" the celestial sphere model remains a useful one for our purposes.
>
> An irony came home to me when I read that some scientists think that if we 
could travel away from Earth in a straight line far enough we might arrive 
back here again - so if there is some "Truth" there, a version of the 
celestial spere may indeed have validity. As another model.
>
> "Truth", bless its little soul (!), remains elusive ...
>
>
>
> > Mike Hannibal  wrote:
> >
> > Hi Alexandre,
> >
> > I'll try to avoid the labels 
> >
> > I think that you mistake my point: I agree violently
> > with you about the value that science has delivered.
> > Yes life expectancy increased by about 35 years during
> > the course of last century. Yes we understand the
> > mechanisms of disease in a way we would not otherwise,
> > as we recognise all sorts of other material - DNA and
> > molecular genetics, quantum physics...
> >
> > None of that is at question. I however, to use a label
> > for myself, am not an absolutist. I believe that
> > science is a framework that provides tremendous value
> > for us. It is a useful and effective framework of
> > rules and beliefs.
> >
> > I do not therefore wish to argue aginst the theory of
> > gravitation....a theory is after all an explanation
> > for a phenomenon that an observer describes. In this
> > case the theory, the explanation, fits very well to
> > the observed phenomenon, it has utility.
> >
> > In other cicumstances that may not be so. In other
> > circumstances an alternative framework of explanation
> > may operate with greater utility.
> >
> > We should always have our eyes open to this
> > possibility.
> >
> > Kind regards
> >
> > Mike
>

   

Reply