Greetings ! I wonder if we really need to pursue just the dark matter direction to explain why galaxies turn the way they do and the whole cosmology part about the form of Universal space-time. Has there been an attempt to explain the motion of galaxies by adding another Universal law or purhaps altering the law of Gravity for larger scales (in a way partially similar to what Einstein attempted to justify a supposedly stable Universe) ? If so (talking about an extension of Gravity), has there been a consistent pattern observed - a similar connection between the normal mass of the galaxy and the estimated required mass of the dark matter ? In addition, could such an assumption experience difficulties or alternativly help solve some other cosmological puzzles ? Thanks ! Live long and prosper.