Dark matter/ dark energy
this whole cosmic construct is looking more and more "epicyclic" if you know what I mean.
Anticlinic and synclinic, too.
In other words, the "dark" stuff explanation is probably not correct, but it provides something to hang on to while the problem is worked on in a variety of ways.
Of course it took about 1500 years to work out the problem of -- or rather the error of -- the geocentric solar system.
Some things take time!