Dark matter is predicted to exist because the speeds of the stars within a galaxy and galaxies within clusters cannot be explained by Newtonian gravity alone.

Dark matter cannot be made of ordinary matter otherwise it could be observed from its radiation. Many suggestions have been put forward to explain dark matter and a lot of effort made to find it but so far nothing has been found and I can confidently predict that although some particle physicists will from time to time claim to have found a possible candidate it will always be found to be false.

FET shows that the motions of stars within a galaxy and galaxies within cluster are driven by the centripetal force to a much greater extent than gravity.

I have shown in “Wot, no bang?” that the gravitational pull of our Sun does not extend beyond 2 light years because in our region of the Milky Way the centripetal force of the galaxy prevents objects further away from this to be pulled inwards.