The 'Big Bang' is the beginning of each generation of the universe, but never the end. The end of each generation of the universe is the 'Big Crunch', when the entire universe is crushed back into the singularity from which it originated.

Russian physicist and mathematician Alexander Friedmann, in the early 1920s, became the first person to embrace the idea that the equations of Einstein’s general theory of relativity called for a universe in motion.

The Friedmann universe begins with a Big Bang, which is the beginning of an expanding universe and continues expanding for untold billions of years—that’s the stage we’re in now. But after a long enough period of time, the mutual gravitational attraction of all the matter slows the expansion to a stop. The universe then starts to fall in on itself, replaying the expansion in reverse. Eventually all the matter collapses back into a singularity, in what physicist John Wheeler likes to call the “Big Crunch,” which is the end of that generation of the universe.

A singularity is a region of space-time in which matter is crushed so closely together that the gravitational laws explained by general relativity break down. In a singularity, the volume of space is zero and its density is infinite. Scientists believe such a singularity exists at the core of a black hole, which occurs when a super-massive sun reaches the end of its life and implodes.

General relativity also demands such a singularity must exist at the beginning of an expanding universe, from which singularity our eternal oscillating and ever evolving universe is resurrected to continue on in that everlasting process.

The Theory of the BIG BANG as the origin of this universe, begins with an infinitely dense, infinitely hot, infinitesimally small ‘SINGULARITY’ which was spatially separated and spewed out, as an extremely hot liquid like plasma of electromagnetic energy in the trillions upon trillions of degrees, in fact our scientists claim that the universal temperature at the instant of the Big Bang, was 100 million trillion trillion kelvins, or 180 million trillion trillion degrees Fahrenheit, a temperature in which no physical element can exist.

As light came out of the darkness according to scripture, we see a day as a period of Darkness which is followed by an equal period of light. Although we call the period of darkness, evening or night, and the period of light, we call day: as Jesus once said; "A day has 12 hours does it not, so work while the light is with you."

Genesis 2: 4; in reference to the 6 days of creation, it is written, "These are the generations of the universe."

This day in which we live or rather this generation of light, which came out of the darkness, has existed for some 13.8; billion years, and although we can see the evidence that the gathering of this universe back to the singularity of origin has already begun, science believes it will be many more billions of years before the process is completed, and there will be the next period of Darkness.

But as a singularity is a region of space-time in which matter is crushed so closely together that the volume of space is zero and its density is infinite, there can be no momentum and therefore no time, and to an observer there would appear to be no time between the completion of the Big Crunch, to the next Big Bang the observer would see the universe being crushed to the size of a ball then immediately bouncing back to begin expanding again.

And we see this in a study Courtesy Penn State University and World Science staff. Where three physicists say they have done calculations suggesting that before the birth of our universe, which is expanding, there was an earlier universe that was shrinking. To arrive at their pre-existing universe finding, Ashtekar’s group used loop quantum gravity, a theory that seeks to reconcile General relativity with quantum physics.

These two seemingly fundamental theories are otherwise contradictory in some ways. Loop quantum gravity, which was pioneered at Ashtekar’s institute, proposes that spacetime has a discrete “atomic” structure, as opposed to being a continuous sheet, as Einstein, along with most us, assumed. In loop quantum gravity, space is thought of as woven from one-dimensional “threads.” The continuum picture remains mostly valid as an approximation. But near the Big Bang, this fabric is violently torn so that it’s discrete, or quantum, nature becomes important. One outcome of this is that gravity becomes repulsive instead of attractive, Ashetkar argued; the result is the Big Bounce.

Paul Steinhardt of Princeton University, a cosmologist who has explored some related concepts, wrote in an email that the new research “Supports, in a general way, the idea that the Big Bang need not be the beginning of space and time.” The universe “may have undergone one or more bangs in its past history,” he added. Steinhardt and colleagues have also proposed a bounce of sorts, but it’s different. It could turn out that the two scenarios are equivalent at some deep level, but that’s not known, he added. Steinhardt‘s scenario makes use of string theory, another attempt to reconcile General Relativity with quantum physics. Some versions of string theory portray our visible universe as a three -dimensional space embedded in an invisible space having more dimensions.

Our zone, called a braneworld [the word comes from its similarity to a sort of membrane] could periodically bounce into another parallel braneworld. Such an event might look to us, stuck in a few dimensions as we are, as a Big Bang. “I don’t know if Ashetkar’s case translates into a bounce between braneworlds like we are describing,” Steinhardt wrote. But by his estimate, this cataclysm won’t take place for another roughly 300 billion years—so there is hopefully plenty of time to answer the question. (This is questionable)

Just as the Big Bang theory has been evolving over the years and is continuing to evolve as new data becomes available, these big Crunch theories that are just beginning to emerge are still in their infancy.
Because three-dimensional time as we know it, does not exist prior to the Big Bang: from the return of the universe to the supposedly infinitely hot, infinitely dense and infinitesimally small singularity of origin to the next Big Bang when three dimensional space and time would begin again, it would appear to an outside observer, that no time had elapsed, thus [As I believe] the erroneous Big Bounce theory.

Peace Morph.