The concept of a multiverse, where multiple universes with different properties and laws of physics exist, is a speculative idea that is not yet confirmed by empirical evidence. However, within certain theoretical frameworks, such as string theory or inflationary cosmology, the existence of a multiverse is proposed.
In these theories, different universes within the multiverse may have distinct sets of physical laws and constants. If these universes were somehow connected or had a border, it is difficult to precisely envision what it would look like since it goes beyond our current understanding of physics. Nevertheless, we can speculate on a few possibilities:
Smooth Transition: It is conceivable that the transition between universes could be smooth and gradual, similar to a continuous change in physical laws and constants. In this case, there might not be a distinct "border" in the conventional sense. Instead, the properties of the universe could gradually transition from one set of laws to another.
Discontinuity: Alternatively, the border between universes might involve a sharp transition or discontinuity where the laws of physics abruptly change. The nature of this border is highly speculative and could be influenced by the underlying mechanisms that give rise to the multiverse. It is challenging to predict how particles existing in one universe but not the other would behave if they attempted to cross such a border.
It's important to note that the idea of particles crossing between universes with different physical laws is purely hypothetical and speculative. We currently have no experimental evidence or theoretical framework to support such inter-universal interactions. The concept of different physical laws in different universes is primarily explored within the realm of theoretical physics and remains an area of active research and debate.
As our understanding of the universe and the potential existence of a multiverse evolves, scientists will continue to investigate and develop theories that explore these intriguing possibilities.