I've been impressed by a number of sources lately on how little we know about gravity: 1) G is only known to one part in 10,000 and various measurements do not fall in each others error bands. 2) Measurements of G do not seem to be converging 3) A different value of G has to be used in solar models to make the models work. This sounds like a fudge factor to me. 4) A french group is suggesting that G varies with magnetic field strength. Going along with this is the fact that G measurements at different points on the earth's surface do vary. 5) We have no idea if gravity is propagated at c or is instantaneous 6) Altho current gravity wave detectors should have been able to detect gravity waves, according to current theory, no one has ever done so. 7) Some groups have claimed that Foucalt pendulum periods change during solar eclipses. It seems as if we have almost no real understanding of gravity. What do you think.