Physics Banter - View Single Post

**Craig Markwardt**

Repeating your message five times is discourteous.

(Aleksandr Timofeev) writes:
We always should use the total of quantity of a planetary mass
and its satellites at evaluation of the ratioes of the given type.

Since your ratios are completely arbitrary, your choice of masses is
irrelevant.

Please make the answer to a problem:
" Why the different CELESTIAL MECHANICAL THEORIES have
different so-called
' SYSTEMS of Astrodynamic FUNDAMENTAL CONSTANTS and Parameters '? "
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^

Implicit in the above question is the presupposition that there are
different celestial mechanics theories with different "astrodynamic
constants." What is the basis for this claim? Which theories? Which
constants?

(Aleksandr Timofeev) writes:

Craig Markwardt wrote in message
...
GR is a theory which explains the dynamics of masses under
gravitation.

Since " GR is a theory which explains the dynamics of masses under
gravitation ", the " almighty " GR is obliged to give theoretical
explanation for 'The empirical law connecting values of planetary
masses in the Solar system'.

Illogical conclusion. Ohm's law has nothing to say about the
formative composition or masses of resistors, and yet it is a useful
description of the behavior of current flow. GR has nothing to say
about the compositions or masses of planets, but it is a useful
description of the dynamical behaviors of masses under gravitation.

Furthermore, it is quite possible for one to find suggestive
numerological relations between groups of quantities, whether or not
the relation is real. In the case above, the number of combinations
of ratios A/(B+C), (A+B)/C or (A+B)/(C+D) is 756. Therefore it is not
surprising that of there could be a tens of ratios close to a whole
number (within +/- 0.05) even for a purely random distribution of
planetary masses. That you found only eight of them suggests that you
could have found quite a few more, if you so chose.

I notice your lack of response to my comment.

The equivalence of inert mass and gravitational mass is physically
error guess on the basis of local measurings.

It is an assumption which has been tested extensively. See for
example Nordtvedt, *The Century of Space Science*, 2001, Kluwer,
Netherlands, p. 335-352. Tests of gravity do not require the
assumption of the equivalence principle. However, tests to date have
been consistent with the equivalence principle.

Extra-solar tests of GR rely on highly precise timing tests.

What other physical quantities you can precision measure in these
" Extra-solar tests of GR " except for " highly precise timing tests
"?

Irrelevant question. Highly precise timing tests are not
quantities. In pulsar timing, the orbit determination is sufficiently
accurate to provide tests of gravitational models *without* assuming
GR is correct.

You have
not presented a basis for your declaration that the tests are
"extremely speculative." You have not presented a quantitative or
technical argument refuting a set of results which is indeed highly
quantitative, careful and technical (for example, measurement of
Shapiro delay within a binary pulsar wystem to within 35 ns; or of
orbital decay predicted by gravitational radiation; see references).
Therefore I reject your claim.

I disagree with you, these so-called "measurings" have extremely
speculative character, since even in the Solar System we have
methodological problems in desired precision of gravitational
measurings.

This claim is unsubstantiated. As shown by decades of measurement
within the solar system, high precisions can be achieved. [ references
provided numerous times. ] Since your "empirical law" apparently has
nothing to say about the dynamics of planets, and the propagation of
radiation in the solar system, it is irrelevant to the discussion. [
I say apparently, because you have provided no evidence. ]

CM