The observable universe is the portion of the universe that we can currently see or detect using our instruments and telescopes. It is limited by the distance that light has had time to travel since the Big Bang, which is estimated to be about 13.8 billion years. Beyond this boundary, there may be much more universe that is currently beyond our observational reach.
However, it's important to note that our understanding of what lies beyond the observable universe is limited, and there are several possibilities that scientists consider:
More of the same: One possibility is that the universe extends indefinitely, with regions beyond the observable universe similar in nature to what we can observe. In this case, there would be more galaxies, stars, and other cosmic structures, but they would be too far away for us to ever observe due to the limitations imposed by the finite speed of light.
Multiverse: Another possibility is that our universe is part of a larger "multiverse" that contains many other universes, each with its own unique properties. These universes may have different physical laws, constants, and even dimensions. However, direct observational evidence for the multiverse is currently lacking, and it remains a topic of theoretical speculation.
Curvature of space: The geometry of the universe is an open question. If the universe is flat or positively curved, it could extend indefinitely beyond the observable universe. However, if the universe is negatively curved, it could be finite and wrap around on itself, meaning that if you traveled far enough in one direction, you would eventually return to your starting point.
Unknown phenomena: There is also the possibility of encountering entirely new phenomena or structures beyond the observable universe that we have not yet conceived of or discovered. Future scientific advances and observations may provide new insights into the nature of the universe and what lies beyond its boundaries.
It's important to remember that our knowledge and understanding of the universe are continually evolving as scientists conduct more research and make new discoveries. Therefore, what lies beyond the observable universe remains a fascinating subject of study and exploration in cosmology.