The ekpyrotic theory says the universe started with a Big Bounce

Whenever you hear about the dawn of the universe, you’ll probably also hear something about the Big Bang. But wait. What if everything hadn’t gone as planned?

What is called the Big Bang was less a bang than an ultra-rapid expansion of an infinitely small cosmic singular, whose heat and density were also infinite. Enter the ekpyrotic model of the universe. Like the Big Bang theory, it still assumes that the universe has expanded and cooled, and is still expanding – but go back far enough and there was no singularity. It may sound like a Doctor Strange twist, but it’s possible.

The ekpyrotic model proposes that the universe has no beginning or end. Instead of a bang, what happened is seen as a “Big Bounce”, the moment when the universe, which was slowly contracting to an incredibly, but not infinitely small point, “bounced” back into expansion. It is based on string theory, which views particles as one-dimensional strings. Physicists Robert Brandenberger and Ziwei Wang co-authored a study venturing deeper into the ekpyrotic emergence of the universe in Physical Review D.

“The challenge for ekpyrotic cosmology is to achieve a transition from the contraction phase to our current standard Big Bang expansion phase,” Brandenberger told SYFY WIRE. “Getting it in a controlled way has been difficult, and that’s where our job comes in.”

General relativity and quantum mechanics often clash. Because string theory tries to bring together the four fundamental strengths, it could possibly unify general relativity, which sees the universe on a large scale, and quantum mechanics, which sees it on an extremely small scale. While general relativity suggests a smooth and predictable universe, quantum mechanics sees it as a realm of chaos where you can only use probabilities to predict things. If both are applied to the Big Bang theory, they decompose.

The ekpyrotic theory is not exactly a contradiction of the Big Bang (this would mean that the universe is not expanding at all). Think of it as an extreme overhaul of an incomplete theory that would end in an epic failure of a universe. This universe would have no mechanism to create galaxies and other huge structures, so the Big Bang theory needs additional theories to explain what happened in the nano-nano-nanoseconds where the universe as we know it began to exist. These theories lead to results that correspond to current observations.

“We show that fluctuations generated during the contraction phase (starting with quantum vacuum perturbations) transform into cosmological perturbation spectra that are consistent with current observations,” he said.

What Brandenberger and Wang found was that the ekpyrotic contraction would have brought everything into alignment in a way that also matched current observations. However, to do this you hypothetically need to produce a rebound in a controlled manner, which they were able to do. The absence of singularity prevents this theory from collapsing. Although the Big Bounce is not necessarily the pinnacle of the birth of the universe, Brandenberger thinks it has an advantage over the inflationary theory, which involves a singularity.

After the Big Bounce, matter would have been evenly distributed throughout the universe to begin with, which solves another Big Bang problem. Inflation theory says the universe began infinitely hot and dense in this singularity before expanding wildly. The fact is, if the Big Bang Theory didn’t have the help of the Inflationary Theory or some other adjacent theory, you would end up with a universe that started with uneven globes of matter everywhere. Not that the universe would remain eternally homogeneous. With gravity acting unstable and moving things on eons and eons, our universe it’s much more complicated now that about 15 billion years ago.

“The standard Big Bang theory with an initial singularity is incomplete,” Brandenberger said. “We’re not saying the ekpyrotic scenario is the best, but it has an advantage over the current paradigm of early universe cosmology.”

Even weirder is that we could live in a universe with extra dimensions. This is also based on string theory. It can also allow for more than the four dimensions – the three dimensions of space (which we can see) and time (which we cannot) – that we already have. We could be living in ten dimensions without knowing it, because the extra dimensions would not be visible to the human eye. Who knows what crawled out of the primeval universe.

“String theory predicts that space has nine dimensions,” Brandenberger said. “There are the three that we see, and there are six
others that are wrapped so small that we do not see them.”

It would blow Doctor Strange’s mind with or without supernatural powers.

Sharon D. Cole