Some experiments that may provide evidence for the multiverse include:
- Quantum experiment Studying the formation and behavior of bubbles in a lab could help us learn how multiple universes might have formed
- Ferromagnetic superfluids Scientists from Italy used ferromagnetic superfluids to recreate the formation of bubbles
Other concepts that may support the idea of the multiverse include:
- Eternal inflation
- Internal inflation
- The Cold Spot in space
However, some scientists say that the multiverse cannot be proven. They argue that the multiverse is a philosophical notion rather than a scientific hypothesis, as it cannot be empirically falsified.
The idea of parallel universes dates back to 1954, when Princeton University student Hugh Everett III developed the idea that parallel universes exist. Some scientific theories support the idea of parallel universes beyond our own, such as the Many-Worlds theory and string theory.
The Many-Worlds theory suggests that a separate parallel universe is created every time a quantum mechanical reaction occurs. However, once the parallel universe is created, there is no way of interacting with it.
String theory demonstrates that parallel universes exist, and that our own universe is like a bubble that exists alongside similar parallel universes. Unlike the Many-Worlds theory, string theory supposes that these universes can come into contact with one another.
The number of possible parallel universes tends to infinity, but does so at a particular (exponential) rate.
Eternal inflation is a hypothetical model of the universe’s expansion. It’s an extension of the Big Bang theory.
The theory of eternal inflation states that:
- The inflationary phase of the universe’s expansion lasts forever throughout most of the universe.
- Inflation ends in places, and universes form there.
- We call these universes “pocket universes” because they’re not everything that exists.
- We are living in one of these pocket universes.
- The model implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse.
Direct evidence for the eternal inflation theory has been found from data collected by the Background Imaging of Cosmic Extragalactic Polarization, or BICEP2, telescope at the South Pole. A special type of polarization pattern that was predicted to exist in the Cosmic Inflation Theory, called “B-modes”, has been found.
The model of eternal inflation implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse.
By studying the formation and behaviour of such bubbles in the lab, they argued, we could learn something about how multiple universes might have formed, filling the gaps Peiris encountered when pondering potential evidence for a multiverse, such as the probabilities of bubble universes colliding.
A ferrofluid is a liquid that is attracted to the poles of a magnet. It is made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid.
Here are some experiments that have been done with ferrofluids:
- Metamaterial “multiverse” A cobalt nanoparticle-based ferrofluid in the presence of an external magnetic field forms a self-assembled hyperbolic metamaterial.
- Osmosis Experiments on a ferromagnetic colloidal fluid at equilibrium showed equality between magnetic and osmotic force.
- Dynamic light scattering This was carried out to establish the size of the nanoparticle clusters in the ferrofluids synthesized.
- Quantum statistics The quantum statistics are apparent even when the droplets are subjected to external forces.
The multiverse is the hypothetical set of all universes. The different universes within the multiverse are called “parallel universes”, “flat universes”, “other universes”, “alternate universes”, “multiple universes”, “plane universes”, “parent and child universes”, “many universes”, or “many worlds”
The Many-Worlds Interpretation (MWI) of quantum mechanics is an interpretation that supports the multiverse concept. The MWI states that there are many worlds that exist in parallel at the same space and time as our own. The existence of these other worlds makes it possible to remove randomness and action at a distance from quantum theory.
The MWI interprets superposition as indicating that there is a world associated with each possible outcome. Since there could be different rules of quantum mechanics, there can therefore be multiple universes which all have their own “many worlds” of their own versions of quantum mechanics.
The quantum multiverse creates a new universe when a diversion in events occurs, as in the real-worlds variant of the many-worlds interpretation of quantum mechanics.
Universe discoveries 