The multiverse (or meta-universe) is the hypothetical set of infinite or finite possible universes (including the historical universe we consistently experience) that together comprise everything that exists and can exist: the entirety of space, time, matter, and energy as well as the physical laws and constants that describe them. The various universes within the multiverse are sometimes called parallel universes.
The structure of the multiverse, the nature of each universe within it and the relationships among the various constituent universes, depend on the specific multiverse hypothesis considered. Multiple universes have been hypothesized in cosmology, physics, astronomy, religion, philosophy, transpersonal psychology and fiction, particularly in science fiction and fantasy. In these contexts, parallel universes are also called "alternative universes", "quantum universes", "interpenetrating dimensions", "parallel dimensions", "parallel worlds", "alternative realities", "alternative timelines", and "dimensional planes," among others.
The first direct evidence of cosmic inflation — a period of rapid expansion that occurred a fraction of a second after the Big Bang — also supports the idea that our universe is just one of many out there, some researchers say.
Scientists announced new findings that mark the first-ever direct evidence of primordial gravitational waves — ripples in space-time created just after the universe began. If the results are confirmed, they would provide smoking-gun evidence that space-time expanded at many times the speed of light just after the Big Bang 13.8 billion years ago.
new research also lends credence to the idea of a multiverse. This theory posits that, when the universe grew exponentially in the first tiny fraction of a second after the Big Bang, some parts of space-time expanded more quickly than others. This could have created "bubbles" of space-time that then developed into other universes. The known universe has its own laws of physics, while other universes could have different laws, according to the multiverse concept.
Other researchers agreed on the link between inflation and the multiverse.
"In most of the models of inflation, if inflation is there, then the multiverse is there," Stanford University theoretical physicist Andrei Linde, who wasn't involved in the new study, said at the same news conference. "It's possible to invent models of inflation that do not allow [a] multiverse, but it's difficult. Every experiment that brings better credence to inflationary theory brings us much closer to hints that the multiverse is real."
When Guth and his colleagues thought up cosmic inflation more than 30 years ago, scientists thought it was untestable. Today, however, researchers are able to study light left over from the Big Bang called cosmic microwave background radiation (CMB).
In the new study, a team led by John Kovac of the Harvard-Smithsonian Center for Astrophysics found telltale signs of inflation in the microwave background. The researchers discovered a distinct curl in the polarization pattern of the CMB, a sign of gravitational waves created by the rapid expansion of space-time just after the Big Bang.
"You have something growing exponentially," he added. "If you just let it go … it will continue exponentially growing, so this [the known universe] is one possibility of something going wrong with this instability, which is very, very right for us because it has created all of our space. Now, we know that if anything can go wrong, it will go wrong once and a second time and a third time and into infinity as long as it can go."
Source: Space.com and others.
New Universes for explore? good idea for GalCiv 3? Stardock Developers?