1. If the current mass density in the Universe was about 10 protons/m3 what would be the current radius of its curvature? What would be the maximum distance between the two points in the Universe? I got the first part but not the 2nd. If I solve the Friedman equation I get the max scale factor to be density/(density -1) which in this case is 10/9. Again I'm posting here because last the people in the homework help section don;t know much cosmology. Do I need to solve for the hubble distance for this universe. btw this is a matter dominated universe with positive curvature.