The question of whether the entire universe is more or less the same beyond our observable universe is an area of active scientific investigation and speculation. Our observable universe is the portion of the universe that we can see and study, limited by the distance that light has had time to travel since the Big Bang, approximately 13.8 billion years ago. However, the universe is thought to be much larger and may extend far beyond what we can currently observe.
Based on our observations of the universe's large-scale structure, such as the distribution of galaxies, clusters, and cosmic microwave background radiation, it appears that the universe is relatively homogeneous and isotropic on the largest scales. This means that on average, the properties and structures we observe in our observable universe are likely representative of the broader universe.
However, it is important to note that our knowledge of the universe beyond the observable region is limited. We cannot directly observe or study those regions, so our understanding relies on theoretical models and extrapolations from the observations we have made within the observable universe. Speculating about the nature of the universe beyond our observational limits involves making assumptions and extrapolations, which are subject to revision as new data and observations become available.
The concept of cosmic inflation, an early rapid expansion of the universe, is one of the theories that attempt to explain the large-scale homogeneity and isotropy observed in our observable universe. If inflationary cosmology is accurate, it suggests that the universe underwent a period of exponential expansion, smoothing out irregularities and making different regions of space appear similar.
However, it is also possible that there are regions of the universe beyond our observable limits that differ significantly from what we observe. Cosmic inflation could have caused regions with different physical laws or properties, resulting in a multiverse scenario where each region has its own set of conditions.
Ultimately, the question of the uniformity of the entire universe and the nature of regions beyond our observable universe remain intriguing and open topics of scientific investigation.