It's been said that the universe has no edge, it's expanding, it has no center and the big bang was the birth of energy, matters and space-time. I also often hear that it's been estimated the universe has approximately 200 billion galaxies or more or much more. Also the number of particles and matters is finite, otherwise we would have infinite amount of event, earth, you, me, star (the sky wouldn't be dark at night???) and scotch whisky (hell yeah!). My question is where is the center of that collection of that 200 billion galaxies or any finite amount of particles? I mean if we had only 4 galaxies (or 4 stars) in the whole universe, we could calculate its center or its center of mass with any form of matter distribution and allocation in 3d space, right? Many thanks!