Astronomers Discover Third Galaxy Without Dark Matter
keckobservatory.org
keckobservatory.org
One counter theory (oops, “hypothesis”) is that the “missing matter” is actually the stored gravitational energy of systems “weaving” among themselves (my wording.) kind of like how intense magnetic fields “braid”, in a galaxy scale all mass bodies are not sitting evenly dispersed on the orbital plane (by accretion,) rather they are perturbing each other in complex orbits as the disc churns, storing more gravitational potential than may be visibly accounted. Like a spring (compressing a spring actually increases mass.)
Galaxies without these complex orbital currents would correlate more consistent visible mass estimations.
Time dilation! As time itself emerges from space/gravity, mass and distance could introduce a “time dilation” fudge that cosmologists attribute to “dark energy/matter”!
It may be our lack of understanding of time itself that changes factors of how we calculate the cosmological expansion/contraction and other mass stability estimates.
I too find it funny that we can wrap up our ignorance into a concept and call it dark*(whatever)!