the universe cannot be infinite because then nothing could have a center of mass
this conclusion doesn't really follow from the premise because mass isn't spacetime and spacetime isn't mass. there is no center of the universe because every part of spacetime is expanding away from every other part at the same time, like if you were to draw a bunch of dots on an uninflated balloon and then inflate it. all of the dots would be further away from all the others in every direction on the surface of the balloon, but there cannot be said to be a center of the surface of that balloon that all the dots expand away from equally.
but mass is completely different. mass can have a center because of its physical properties, regardless of what the structure and properties of spacetime are.
so void has been limited by this thing you call mass? and it's still infinite, somehow? ---
"Why is ontology so expensive?" - JH [Is this live?][Joyless planet...]