Well, they’re always wrong, or subject to revision, but this is pretty interesting. Familiar with Dark Matter, the matter which we can’t detect but have to assume exists to make all our sums right? Well perhaps our sums were just plain wrong:
A modified law of gravity correctly predicted, in advance of the observations, the velocity dispersion—the average speed of stars within a galaxy relative to each other—in 10 dwarf satellite galaxies of the Milky Way’s giant neighbor Andromeda.
The relatively large velocity dispersions observed in these types of dwarf galaxies is usually attributed to dark matter. Yet predictions made using the alternative hypothesis Modified Newtonian Dynamics (MOND) succeeded in anticipating the observations.
“At stake now is whether the universe is predominantly made of an invisible substance that persistently eludes detection in the laboratory, or whether we are obliged to modify one of our most fundamental theories, the law of gravity,” McGaugh continued.
The MOND hypothesis says that Newton’s force law must be tweaked at low acceleration—11 orders of magnitude lower than what we feel on the surface of the Earth. Acceleration above that threshold is linearly proportional to the force of gravity—as Newton’s law says—but below the threshold, no. At these tiny accelerations, the modified force law resolves the mass discrepancy…
via Noahpinion. More at the above link.