The observable universe has a diameter of 93 billion light years, but this does not imply that the universe itself has a center; rather, the center is relative to the observer. Cosmologists discuss two geometric possibilities for the universe: an infinite flat or negatively curved geometry, which suggests an edge but no center, and a positively curved spherical geometry, which also lacks a center. The matter density in the universe is uniform, supporting the idea of an infinite universe where matter is distributed homogeneously. The discussion also highlights the paradox of the observable universe being larger than the age of the universe, attributed to its expansion. Ultimately, observers in different galaxies would agree on the size of their own observable universe as 93 billion light years.