> Howeveer the problem is that "dark matter" is also needed on local scales, The link you provided doesn't seem to say that: "Well, since that time, there hav

> Howeveer the problem is that "dark matter" is also needed on local scales, The link you provided doesn't seem to say that: "Well, since that time, there have been additional challenges to how gravitation works in our Universe, albeit on much larger scales than our Solar System. From the 1930s to the 1970s, galaxy clusters and individual galaxies had their speeds measured very precisely for the first time. This meant that the speeds of individual galaxies in clusters could be measured relative to the center-of-mass of the cluster itself, and the rotational speeds of spiral galaxies could be measured relative to the center of the galaxy itself. In both cases, it was found that the motions did not line up with the predictions of general relativity in a Universe where matter was made up primarily of protons, neutrons, and electrons."