The question of whether the entire universe is similar to our observable universe or if there are significant differences beyond our observational reach is an intriguing one, and it remains a subject of scientific investigation and speculation.
Our observable universe is the portion of the universe that we can see and study based on the light and information that has had sufficient time to reach us since the Big Bang. It extends for about 93 billion light-years in any direction, which is the distance light has traveled since the beginning of the universe. However, the entire universe is believed to be much larger than our observable universe.
Based on our current understanding of cosmology, the observable universe is thought to be a representative sample of the larger universe. The fundamental physical laws, constants, and basic principles that govern our observable universe are presumed to hold throughout the entire universe. This assumption is called the cosmological principle, which suggests that the universe is homogeneous (uniform) and isotropic (the same in all directions) on a large scale.
However, beyond our observable universe, there is still much that remains uncertain. Some cosmological models, such as inflationary cosmology, propose that the universe underwent a period of rapid expansion in its early stages, leading to the formation of multiple regions or "bubbles" with different physical properties. If this is the case, then regions beyond our observable universe might exhibit different characteristics, such as variations in physical laws, constants, or even the number of dimensions.
Additionally, some theories, like string theory, suggest the possibility of a "landscape" of different universes or vacua with distinct properties. These theories propose that the fundamental constants and physical laws can vary across different universes, giving rise to a multiverse with diverse regions.
While these ideas offer potential scenarios for variations in the universe beyond our observation, it's important to note that direct empirical evidence for them is currently lacking. Studying and understanding the properties of the broader universe, particularly beyond our observable universe, present significant challenges due to the limitations imposed by the finite speed of light and the vast distances involved.
In summary, while our observable universe is thought to be a representative sample of the larger universe, the existence of variations, different regions, or even diverse universes with distinct properties beyond our observational reach remains a topic of speculation and ongoing scientific investigation.