[Raymond8922]

In 'proper-distance', the universe is 14 billion light-years in radius, because that is the furthest we can see. At that distance, we'd be looking at the start of the universe, therefore it is impossible to see further.If it were possible to see the universe as it is "now" (the co-moving distance), the part of the universe we can see (the 'visible universe') would be bigger than 14 billion light years.This is simply due to the slow speed of light. The further out we look, the further in the past we see. In the past, the universe was smaller than it is now.There is no easy formula to go from proper distance (based on the time it took light to travel from the source to here) to co-moving distance (it is an integral that needs the Hubble constant as a function of time -- the speed of expansion changed throughout the life of the universe).WMAP, a probe sent to observe the Cosmological Microwave Background radiation, tried to see signs that the universe was smaller than 14 billion light-years (possible if the universe is wrapped on itself). It did not find these signs, so all we know is that the universe is at least 28 billion light-years across (diameter) in proper distance (we can guess-timate around 60 billion l-y in co-moving distance).The universe could be infinite in spatial extent. And it could be flat. (space-time could still be curved as it includes this idea of looking back in time as we look out in distance). This would solve a lot of problems. But we have absolutely no proof that it is infinite... or that it is not.