🚀 go-pugleaf

In article <STEINLY.92Sep29105205@topaz.ucsc.edu> steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes:

> Figured I might as well interject at this point.
> Tom? You lurking there waiting to pounce??? ;-)
> The "gravity" from each component in a binary star does
> not arrive delayed, see for example LPPT 12.4 and MTW 18.4 and 39.9,
> especially eqn 39.64

I know I've said this before, but I may as well say it again: I think
we're begin confused over semantics; we have to be careful over what
it means to talk about the speed of propagation of gravity.

I contend that in a static situation (i.e., one where there is no
gravitational radiation), it is meaningless to talk about the speed of
propagation of gravity, since nothing is propagating.  I contend,
then, that detecting a finite speed of gravitation is equivalent to
detecting the effects of gravitational radiation.

And, as is well known, this has been done in the case of binary
neutron star systems.  The effects of radiation show up in (if I'm
remembering right) the post-post-post-Newtonian approximation, and
they have been observed.
--
Matthew Austern                   Just keep yelling until you attract a
(510) 644-2618                    crowd, then a constituency, a movement, a
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