So now we have three observations: the Pioneer anomaly, the flyby anomaly, and the interesting degree of the Pioneer effect. To these I added another anomaly, the galaxy rotation problem, which notes that the arms of spiral galaxies, from just outside the central bulge to the edge of the galaxy, spin at an almost constant speed...and according to Newtonian physics, such masses traveling at such speeds would tend to fly away and escape from the galaxy.

Interesting, even if somewhat crunchy ...