Re: [Phys-l] Simulating a disturbance of a stable planetary system.

[Ludwik Kowalski <kowalskil@mail.montclair.edu>]

On Jan 1, 2008, at 6:14 PM, John Denker wrote:

> . . . Secondly, much of the discussion has suffered from
> assuming that the system was "stable" according to one
> misdefinition, and then assuming that it would behave
> as "stable" according to some other misdefinition.  This
> is not what I would call pedagogically correct.  It's not
> good pedagogy.  It's not good science.  It's not even
> good scholasticism.

1) What I would like to learn, from messages on this thread, is how to 
distinguish a stable system from an unstable system. Don't we need a 
definition of stability (for the kind of systems being discussed)? If 
so then what is the acceptable definition?

2) This question is practical, not scholastic. The simulation software 
I am using , I.P.,  seems to be highly reliable (consistent with 
underlying physics). How to use such software to account for 
unavoidable perturbations? The I.P. does not account for them. Please 
help me with this issue.



_______________________________________________________
Ludwik Kowalski, a retired physicist
5 Horizon Road, apt. 2702, Fort Lee, NJ, 07024, USA
Also an amateur journalist at http://csam.montclair.edu/~kowalski/cf/