The nature of what exists beyond the edges of our observable universe is a subject of speculation and ongoing scientific investigation. It's important to note that our current understanding of the universe is limited, and there are several theories about what might lie beyond.
The Observable Universe Limitation: The observable universe is the part of the universe that we can currently see or detect with our instruments. It is limited by the distance light has had time to travel since the Big Bang, estimated to be about 93 billion light-years in diameter. Beyond this observable boundary, there could be more universe that we simply cannot observe or access due to the finite speed of light.
Inflationary Cosmology: According to the theory of cosmic inflation, the universe underwent a rapid expansion in its early stages, leading to a vast expanse beyond our observable universe. This theory suggests that our observable universe is just a tiny fraction of a much larger "multiverse" that contains other regions or "pocket universes" with different properties.
A Multiverse: The concept of a multiverse suggests the existence of multiple universes, possibly with different physical laws and properties. These universes may exist alongside ours, separated by vast distances or in different dimensions. Some theories propose that these universes could be in the form of bubble universes or brane universes in higher-dimensional space.
A Cosmic Void or Nothingness: Another possibility is that there may be a vast region beyond our observable universe that is relatively empty or devoid of matter and energy. This idea suggests that our universe might be embedded within a larger cosmic structure, such as a void or supervoid, where matter and galaxies are sparser.
It's important to note that these ideas are speculative and theoretical. While scientists propose these concepts to explore the possibilities, empirical evidence is limited due to our current technological constraints. Further observational data and advances in theoretical physics will likely be needed to gain a deeper understanding of what lies beyond our universe's edges, if anything at all.