Astronomers, cosmologists and some physicists have been exploring for decades the possibility that higher dimensions and multiverses exist. Many have contended over the years that our universe—thought to be almost 14 billion years old—is just one of an infinite number of "bubble" universes that are in the process of infinitely creating new universes.
The math supports this concept and current theoretical physics—especially particle and quantum physics—relies on multiverses to make the string theory work. For more on string theory go here: "The Official String Theory Website"
If our universe is indeed part of a multiverse, then the Big Bang that created this universe was actually another universe "giving birth" to our own.
Now, however, the Big Bang model has been called into question again.
The alternative theory that eventually fell out of favor with scientists back in the 1960s, the Steady State Theory, held that there was no sudden creation of this universe. Instead, this universe is eternal; it always was and always will be. The spacetime continuum expands outwards and as it does the bubble grows infinitely outwards.
Famous British astronomer, Sir Fred Hoyle of the Institute of Astronomy at Cambridge was the major defender of Steady State. A Fellow of the Royal Society, Sir Hoyle advocated the view of an eternal universe up until his death in 2001.
On the other hand, the majority that support the Big Bang theory of creation believe that everything that now is was once smaller than an electron. Before that nothing existed. It's argued the word "before" cannot even be applied to anything preceding the Big Bang as nothing preceded it.
The accepted model of creation is the universe popped into existence from nothing, expanded (called cosmic inflation) rapidly outwards for a mere fraction of a second, and then fell into the slower expansion that we are witnessing today. Proponents of the Big Bang theory argue that the universe will continue to expand forever until it becomes an empty, featureless void.
Now, one of the most respected scientists in the field of physics, Sir Roger Penrose, disagrees with the Big Bang theorists. Pointing to the fact that the universe was created in a low state of entropy, he argues that a very high degree of order must have existed. Therefore, the universe was not—could not—have been born from chaos. In essence, Penrose argues that the popular Big Bang model has never been able to account for the low entropy known to exist at the moment of creation.
He has proposed an eloquent solution: the universe is just the latest in a chain of universes that each ignite with a Big Bang starting a new universe that replaces the one that preceded it. Therefore, the creation of universes is cyclical. Almost like a new software program writing over the older version, the universe evolves by recreating itself over and over again ad infinitum.
Penrose's modified universe creation model posits that as each universe winds down after tens of billions of years, the universe falls back into a state of low entropy. Black holes are the reason for this return to a lower level of entropy.
When reduced to its basics all energy—of which matter is just one form—is nothing more than quantified information. Black holes suck all the information from the universe and given enough time the entropy will fall to an exceedingly low level.
The continued expansion of an empty universal bubble causes the black holes to gradually evaporate. At that point, the universe becomes exactly as it was before the Big Bang—as Penrose points out, there was a "before."
All the naked singularities of the black holes converge—collapsing into themselves—until they reach the critical size of roughly an electron. When that size and critical mass are met, the energy can no longer be contained and a new Big Bang occurs.
The theory has some new twists and turns, but is not really new as it is similar in some respects to the old theory of an oscillating universe.
What is new, however, is Penrose's announcement that he has found measurable evidence to support the model.
The cosmic microwave background (CMB) is extremely short wave radiation that permeates the universe. Theorists think it was formed around 300,000 years after the ignition of the Big Bang.
Yet Penrose, working with Vahe Gurzadyan, has found concentric circles in the data—analogous to ripples in a pond being formed after a stone is tossed into it—that suggests pockets of radiation in some areas had much narrower temperature ranges that other regions of the expanding universe. Penrose and his colleague Gurzadyan believe those concentric circles are evidence of "windows" into the previous universe. He sees them as spherical ripples—an aftereffect of the gravitational effects of converging, evaporating black holes and the singularities that were exposed in the previous universe.
Has Penrose managed to puncture the inflationary model of the universe? He asserts that the circles don't fit the accepted inflation model. Current theory holds that all the variation in temperature in the CMB should be absolutely random.
So perhaps the oscillating model is correct, or perhaps Sir Penrose is really staring at Alice's Looking Glass and seeing the evidence of a bubble universe that gave ours life.
"Penrose claims to have glimpsed universe before Big Bang"