For those of you betting against dark matter, look out. It’s just conquered perhaps its biggest obstacle to success, providing a physical mechanism for how stellar light and galactic rotation go together at last.
I wouldn’t have bet against Newtonian mechanics back in 1687, but I’d have been wrong. I still like a variant on dark fluid as a means of unifying dark matter and dark energy into a single cohesive theory that makes sense. But, whatever the case, there’s no doubt this element of cosmological knowledge is going to have to be assembled piecemeal. Data such as the above are a step in that direction.