We are generally told these days that the universe is infinite and therefore has no definable centre. Is that correct? I see the subject the subject of an edge of space has already been discussed but I would like to put a new angle on the subject. Let's say for the sake of argument, that the vacuum of space is infinite. Let's also say that the number of baryons in the universe is much greater than estimated 10^80 in the visible universe, but nonetheless finite. If the mass of the universe is finite, then there is a definable centre of mass for the universe, even if there is not a definable centre of vacuum space. If it is claimed that the mass of the universe is infinite, then that is an extraordinary claim if we use the true meaning of infinite, and don't just mean the largest number we can possibly imagine. If that is the claim, what is the evidence that rules out a finite mass for the universe?