Sigh. Sure, it's possible, but very unlikely.<p>These "MOND" gravity theories purport to explain observations better than the theory of dark matter, but they don't. They explain some things and leave gaping holes elsewhere. On the whole they are hugely inferior theories in terms of matching observational evidence. Their only advantage is that they lack the existence of massive, weakly interacting particles, which a lot of people seem to have strong objections to despite the fact that several types of such particles are already known to exist.<p>Throughout the entire history of the development of the theory of dark matter the bias has always been against the idea of true dark matter, unseen particles that make up most of the mass of the Universe. But at every single step all of the other possibilities have been eliminated as realistic explanations of the evidence. The cold WIMP dark matter theory is the only one that explains the structure of the cosmic microwave background radiation, the large scale structure of the Universe, and the structure and behavior of galaxies and galaxy clusters. At this point the theory of dark matter is remarkably well hemmed in, it would be absolutely shocking to an extreme degree if it did not truly exist in the form we think it does.<p>There's additionally a very elegant mechanism behind the formation of dark matter. It seems most likely to be composed of super-symmetric particles. Such particles would only be able to form in extreme, high-energy conditions. Precisely the sort of conditions that existed in the early era of the Universe immediately after the Big Bang. So the early Universe would have been creating huge quantities of such particles, which would then not interact much due to their weak interactivity. It wouldn't be until the Universe had expanded enough and cooled down enough to halt their production. This would neatly explain why so much of the mass of the Universe is in the form of dark matter rather than conventional matter.