Re: NIF: Kepler part II

["A. R. Marlow" <marlow@beta.loyno.edu>]

On Thu, 2 May 1996, Rauber, Joel Phys wrote:

> Before I continue to spend time on this, let me make sure that the following 
> is OK. As Mallinckrodt I can obviously only do the task for a case that 
> would correspond to circular orbits in inertial frame. That's why I asked 
> the question originally.  There never "in general" exists a frame in which 
> two independent bodies in arbitrary motion remain at rest.  Only for 
> specific particular cases can that be; and I'm assuming that it is OK if I 
> choose a situation that corresponds to such a particular case; namely the 
> frame specified, which correspondes to circular orbits.
>
> I hope this is satisfactory to everyone, if not let me know.
> ...

That's acceptable, just get rid of any reference to orbits  --  the orbits
consist of two fixed locations.  The conditions are as stated "Assuming
there is a reference frame in which Earth and Sun are at rest, apply 
Newton's laws in that frame, Etc."

But John Mallinckrodt's construction does bring up an added stipulation
that should be made explicit, but that has so far been only implicit:
"Without introducing adjustable constants, i. e., using only constants
of the nonadjustable kind such as Pi, G, g, Etc."

If we can introduce adjustable parameters, I can do it in any frame with
just one:  M+m itself.
   
Note to J. M.  --  However, if you do find a way to evaluate your 
constants in a practical way, I think the binary star people will be
very much interested in your methods.  To my knowledge, they have not
yet been able to get separate values for masses of binary components. 
But I'm not up on their techniques beyond Newton's version of Kepler's
law III.


A. R. Marlow                          E-MAIL:  marlow@beta.loyno.edu
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