This question was asked in an article of scitechdaily:
There are theories being alternative to the popular “dark matter” suspection, which is used to explain why stars in galaxies show motions different from Newtonian dynamics. A “pull” of stars has been detected which is attributed to an “external force”. In all these attributions, it is assumed that non-Newtonian effects are evoked by mass-based forces. Scientists have not enough phantasy to imagine that a different type of dynamics could explain the observed effects also. Dynamics has to do with linear momentum and angular momentum. So the scientists should think about such sources of impact. Then they would perhaps encounter ECE theory which explains their “unexplainable” effects very simply and consistently by angular momentum.