The concept of space between universes is a speculative idea that arises in certain theories that propose the existence of a multiverse. It suggests that there could be separate and distinct universes that exist alongside or "next to" our own universe.
In these theoretical frameworks, the term "space" is used metaphorically to describe the separation or distinction between different universes or realms. It does not refer to physical space as we commonly understand it within our universe, with three dimensions of space and one dimension of time.
It's important to note that the notion of a multiverse and the space between universes are still highly speculative and not yet confirmed by empirical evidence. Theoretical physicists and cosmologists propose these ideas as a means to explain certain observations and address fundamental questions about the nature of our universe, such as the fine-tuning of physical constants or the nature of cosmic inflation.
However, the specific nature of the multiverse, the mechanisms by which universes might interact or be separated, and the properties of the space between universes, if it exists, are still open questions. These ideas are actively studied and explored through theoretical models and mathematical frameworks, but they currently remain speculative and subject to ongoing scientific investigation and debate.