Multiverses

What is the multiverse?

A complex subject but lets give it a go.

Multiverse theory proposes that our universe, with its hundreds of billions of galaxies and stars, spanning tens of billions of light-years, may not be alone in space. There may be additional universes, separated from our own. Indeed, there could be an infinity of universes, all with their own physical laws, their own stars and galaxies, and likely even their own intelligent civilizations.

That is, it could be that our universe is just one member of a much grander, much larger multitude of universes: a multiverse.

Proposed types

Physicists Max Tegmark and Brian Greene have proposed two different classification schemes for multiverses and universes.

Tegmark’s four-level classification consists of Level 1: an extension of our universe, Level 2: universes with different physical constants, Level 3: many-worlds interpretation of quantum mechanics, and Level 4: ultimate ensemble.

Brian Greene’s nine types of multiverses include quilted, inflationary, brane, cyclic, landscape, quantum, holographic, simulated, and ultimate. These ideas explore several dimensions of space, physical laws, and mathematical structures to explain the existence and interactions of multiple universes. Some other multiverse concepts include twin-world models, cyclic theories, M-theory, and black-hole cosmology.

From the above alone, we can consider the concept of multiverses one of profound complexity [to a layman like me] but nonetheless critical for understanding what is really ‘out there‘.

From my perspective, we are starting to envisage other worlds and dimensions beyond our own on a somewhat different scale that may also include links to the afterlife.

Evidence

Many scientists have sought more critical evidence for the multiverse’s existence. If a neighboring universe, for example, happened to be close to ours long ago, it may have collided with our universe, creating a detectable signature.

That signature could be in the form of distortions in the cosmic microwave background (the light left over from when the universe was a million times smaller than it is today) or in strange galaxy properties in the direction of the collision, according to the Early Universe blog published by University College London.

But all of these types of searches have thus far come up empty, so the multiverse remains hypothetical.

Heling Deng, a cosmologist at Arizona State University and an expert in multiverse theory, is searching for evidence of the multiverse by looking for special kinds of black holes. These black holes could be artifacts from our universe that separated into their own universe via a process called quantum tunneling. If some regions of our universe separated this way, they would have left behind “bubbles” in our universe that would turn into these unique black holes, which may still exist today, according to Deng. 

“The potential detection of these black holes can then point to the existence of a multiverse,” Deng says.

Conclusion

Let’s leave the last word to astrophysicist Ethan Siegel. 

 This Is Why The Multiverse Must Exist (forbes.com)

“If you have an inflationary Universe that’s governed by quantum physics, a Multiverse is unavoidable. As always, we are collecting as much new, compelling evidence as we can on a continuous basis to better understand the entire cosmos. It may turn out that inflation is wrong, that quantum physics is wrong, or that applying these rules the way we do has some fundamental flaw. But so far, everything adds up. Unless we’ve got something wrong, the Multiverse is inevitable, and the Universe we inhabit is just a minuscule part of it.”

References and Further Reading and Viewing

https://en.wikipedia.org/wiki/Multiverse

https://alldimensions.fandom.com/wiki/Multiverse

https://www.livescience.com/multiverse

https://www.forbes.com/sites/startswithabang/2019/03/15/this-is-why-the-multiverse-must-exist