The "something" that "is wrong here" though is not merely a mathematical inconsistency in the amount of force or speed you expect. That may have been true when dark matter was first proposed as a solution for the weird spinning behavior of galaxies in 1933, but not so any more.
Dark matter is an actual physical reality that you can see with your normal human eyeballs in a photograph. The light emitting stuff is in one part of the picture, and the gravity causing stuff is in another part of the picture. You can see it with your own eyes. The bulk of the gravity of galaxies is separable from the bulk of its visible matter.
Dark Matter is the class of hypotheses that explains this plain observational reality by supposing some kind of invisible matter, which is the only explanation that fits what the photographs show.
Any attempt to discredit it must be accompanied with an alternative explanation of how the gravitational mass of galaxies seems to be removable from their visible material.
This article is like denying that the sun exists, without positing an alternative for where daylight comes from.
Dark matter is an actual physical reality that you can see with your normal human eyeballs in a photograph. The light emitting stuff is in one part of the picture, and the gravity causing stuff is in another part of the picture. You can see it with your own eyes. The bulk of the gravity of galaxies is separable from the bulk of its visible matter.
Dark Matter is the class of hypotheses that explains this plain observational reality by supposing some kind of invisible matter, which is the only explanation that fits what the photographs show.
Any attempt to discredit it must be accompanied with an alternative explanation of how the gravitational mass of galaxies seems to be removable from their visible material.
This article is like denying that the sun exists, without positing an alternative for where daylight comes from.