Re: Galileo

[Jack Uretsky <jlu@HEP.ANL.GOV>]

                You and I are ggiving a perfect example of communication
breakdown.  What is the statement that needs interpretation, and in what
context was the statement made?
        See, e.g.,
http://www.hopkintonschools.org/middle/03-04/project7/hannah-g/views/views.htm
        as one of about 800 Google hits on: sphere "perfect shape".


On Sat, 17 Jul 2004, Jim Green wrote:

> At 14:04 17 07 2004 , the following was  received:
> > As in all such questions, it is important to start with the supposed
> > "fact" to be explained and the context from which the "fact" is taken.
> > "Perfect spheres" as I seem to recall, had to do with orbits.  So what
> > needs to be explained?
>
> First, spheres were thought to be the "perfect" shape  ie spheres are
> referred to as "perfect spheres" not because they are spherical rather than
> nearly spherical, but because they were thought to be "perfect."
>
> Second, during Galileo's time it was thought that the Earth was surrounded
> by several hollow rotating transparent crystalline spheres of various
> diameters -- remember they already knew that the Earth was spheroid -- They
> assumes spherical.
>
> The various spheres held various celestial objects.  This assignment was
> not universally agreed to, but generally the stars on one, the planets on
> another(s), etc.
>
> So the original question seems reasonable.
>
> Jim
>
>
> Jim Green
> mailto:JMGreen@sisna.com
> http://users.sisna.com/jmgreen

--
"Trust me.  I have a lot of experience at this."
                General Custer's unremembered message to his men,
                just before leading them into the Little Big Horn Valley