Not “gravity a star has,” but the motion of stars around/near galaxies. It is the general motion of groups of massive objects that hints that there is a lot more mass ‘around’ most (not all) galaxies than what matter we observe could possibly account for.
The ‘not all’ part is critical, because it points to something actually being there as opposed to the theory of gravity or relativity breaking down at larger scales.
Not “gravity a star has,” but the motion of stars around/near galaxies. It is the general motion of groups of massive objects that hints that there is a lot more mass ‘around’ most (not all) galaxies than what matter we observe could possibly account for.
The ‘not all’ part is critical, because it points to something actually being there as opposed to the theory of gravity or relativity breaking down at larger scales.