I think you're drawing a tighter line around what counts as an
experiment than you intended.
> Ira Brodsky wrote
> >"Since the fixed stars in the parts of the sky near the sun become
> >visible during a total eclipse, it is possible to check this
> >theoretical conclusion [a ray of light coming from a fixed star and
> >just grazing the border of the sun will be deflected by 0.83
> >seconds of an arc] by experiment."
Robin responded:
> This isn't an "experiment" in the sense that you've been using -
> control over variables. They only looked. They didn't go move the
> sun around or anything. The closest you get is using signals from
> spacecraft, where you control where the spacecraft goes. That is a
> small fraction of astronomy (though a large fraction of planetary
> astronomy).
They can move telescopes around, make predictions for other celestial
objects and verify them, do the observations from spacecraft or
aircraft as well as ground-based observatories, etc. This seems to be
fully as controllable an experiment as you need to become convinced of
the predictive value of Einstein's conjecture.
Chris