"ralph sansbury" writes:
[ Oliver writes: ]
in U. If light-time is taken into effect, the eclipses of V471 are
easily predicted to an accuracy of a second in time, without it one
has to assume that the time of eclipses is exactly modulated by a
function that mimics the earth's orbital motion. The same is true
of all eclipsing systems but few have such a sharply defined eclipse
as V471.

Could you expand on this and the possibility that this is not
due to the speed of light delay.

There are lots of binary systems where precision timing can be
performed. These include eclipsing systems and binary pulsars. In
the case of binary pulsars, the timing residuals can be as small as
~35 NANOseconds ( = 10 meters of light travel ).

Without correction for light travel time effects, all binaries show a
365.25 day periodic variations in their times of detection of
pulsations or eclipses.

So the question is: could it really be that all the binaries in the
solar system have a planet with 365.25 day period? And furthermore,
that the inclinations of those planets are somehow exactly aligned
with the plane of the ecliptic? (because light travel time effects
scale as cos(ecliptic_latitude))

And further yet, could it really be that radar ranging time to
spacecraft, Venus and other asteroids, always scale as the distance
between the earth and the target, is just a coincidence?

And still further, do we really believe that pulsars' pulsations, and
the unique stochastic variations of distant AGN used for VLBI studies,
both have time delays which vary *exactly* according to the motion of
the observatory(ies) around the earth's center?

The answer is of course, NO, to all of these questions. It is not a
coincidence that all of these phenomena are observed. One cannot
simply explain away each and every binary star system, every
spacecraft, every planet, every VLBI observation as coincidental
source variations, because then that makes a bigger problem of
thousands of unexplained coincidences.

There is one simple explanation for all of these phenomena: finite
light travel time.

CM