The Big Bang. ... or maybe there wasn't?

[PickelledEggs]

(Phys.org) â€"The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein's theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once.
The widely accepted age of the universe, as estimated by general relativity, is 13.8 billion years. In the beginning, everything in existence is thought to have occupied a single infinitely dense point, or singularity. Only after this point began to expand in a "Big Bang" did the universe officially begin.
Although the Big Bang singularity arises directly and unavoidably from the mathematics of general relativity, some scientists see it as problematic because the math can explain only what happened immediately afterâ€"not at or beforeâ€"the singularity.
"The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there," Ahmed Farag Ali at Benha University and the Zewail City of Science and Technology, both in Egypt, told Phys.org.
Ali and coauthor Saurya Das at the University of Lethbridge in Alberta, Canada, have shown in a paper published in Physics Letters B that the Big Bang singularity can be resolved by their new model in which the universe has no beginning and no end.
Old ideas revisited
The physicists emphasize that their quantum correction terms are not applied ad hoc in an attempt to specifically eliminate the Big Bang singularity. Their work is based on ideas by the theoretical physicist David Bohm, who is also known for his contributions to the philosophy of physics. Starting in the 1950s, Bohm explored replacing classical geodesics (the shortest path between two points on a curved surface) with quantum trajectories.
In their paper, Ali and Das applied these Bohmian trajectories to an equation developed in the 1950s by physicist Amal Kumar Raychaudhuri at Presidency University in Kolkata, India. Raychaudhuri was also Das's teacher when he was an undergraduate student of that institution in the '90s.
Using the quantum-corrected Raychaudhuri equation, Ali and Das derived quantum-corrected Friedmann equations, which describe the expansion and evolution of universe (including the Big Bang) within the context of general relativity. Although it's not a true theory of quantum gravity, the model does contain elements from both quantum theory and general relativity. Ali and Das also expect their results to hold even if and when a full theory of quantum gravity is formulated.
No singularities nor dark stuff
In addition to not predicting a Big Bang singularity, the new model does not predict a "big crunch" singularity, either. In general relativity, one possible fate of the universe is that it starts to shrink until it collapses in on itself in a big crunch and becomes an infinitely dense point once again.
Ali and Das explain in their paper that their model avoids singularities because of a key difference between classical geodesics and Bohmian trajectories. Classical geodesics eventually cross each other, and the points at which they converge are singularities. In contrast, Bohmian trajectories never cross each other, so singularities do not appear in the equations.
In cosmological terms, the scientists explain that the quantum corrections can be thought of as a cosmological constant term (without the need for dark energy) and a radiation term. These terms keep the universe at a finite size, and therefore give it an infinite age. The terms also make predictions that agree closely with current observations of the cosmological constant and density of the universe.
New gravity particle
In physical terms, the model describes the universe as being filled with a quantum fluid. The scientists propose that this fluid might be composed of gravitonsâ€"hypothetical massless particles that mediate the force of gravity. If they exist, gravitons are thought to play a key role in a theory of quantum gravity.
In a related paper, Das and another collaborator, Rajat Bhaduri of McMaster University, Canada, have lent further credence to this model. They show that gravitons can form a Bose-Einstein condensate (named after Einstein and another Indian physicist, Satyendranath Bose) at temperatures that were present in the universe at all epochs.
Motivated by the model's potential to resolve the Big Bang singularity and account for dark matter and dark energy, the physicists plan to analyze their model more rigorously in the future. Their future work includes redoing their study while taking into account small inhomogeneous and anisotropic perturbations, but they do not expect small perturbations to significantly affect the results.
"It is satisfying to note that such straightforward corrections can potentially resolve so many issues at once," Das said.

http://phys.org/news/2015-02-big-quantum-equation-universe.html

[kilodelta]

Daggumit! Big bang is easier to remember than quantum gobbligook. I don't believe in nothin' else!!!

On a serious note, it sounds interesting. The question I have is what happens to super black holes if there is no big crunch, but a continuity? My lack of knowledge shows...

[PickelledEggs]

Yeah. It's pretty hard to wrap your head around. Really neat though...

I'm actually remembering a video I posted a long while back (I can't remember the thread name) where the scientist explained the universe is expanding in to it's self... I can't remember the wording. I have to find the video and I'll repost it here. But either way it is in line with what this article says, from what I remember.

[Berati]

How does this theory deal with the expanding universe that we observe? If it's currently expanding it must have all been together at some point.
There is also the Cosmic microwave background. If there was no big bang where would that come from?

[GrinningYMIR]

There might not have been a beginning, there was just always something


*brain explodes*

[Gawdzilla Sama]

Universe existed/will exist for ever?

That's a huge load off my mind.

[Atheon]

Forever and ever, just like JEEEEEEEEZUS.

[Munch]

I hold myself to the scientific understanding that matter cannot be destroyed, only changed into other forms, so the universe has always been just that all the matter in it has been altered and reformed into something else.

For all we know, the sub atomic particles that make up our foreheads or butts might at one stage have been the core of a dwarf star, and that's humbling to know.

[AllPurposeAtheist]

You mean god didn't just go "poof" and create it all 7000 years ago?

BLASPHEMY!

[Solitary]

Thank you, thank you, I've been saying this since I came on the forum. The idea of something coming out of nothing is as ridiculous even if a god did it. As to the expansion of space, it is based on the assumption that light doesn't loose energy that would cause a red shift. The total energy in the universe is ZERO, because gravity is negative energy that cancels out positive energy according to Einstein.


http://www.livescience.com/33129-total-energy-universe-zero.html

Considering the amount of energy packed in the nucleus of a single uranium atom, or the energy that has been continuously radiating from the sun for billions of years, or the fact that there are 10^80 particles in the observable universe, it seems that the total energy in the universe must be an inconceivably vast quantity. But it's not; it's probably zero.

Light, matter and antimatter are what physicists call "positive energy." And yes, there's a lot of it (though no one is sure quite how much). Most physicists think, however, that there is an equal amount of "negative energy" stored in the gravitational attraction that exists between all the positive-energy particles. The positive exactly balances the negative, so, ultimately, there is no energy in the universe at all.

[Munch]

How does this theory deal with the expanding universe that we observe? If it's currently expanding it must have all been together at some point.
There is also the Cosmic microwave background. If there was no big bang where would that come from?

Maybe at one stage all the dark matter within black holes clustered into one ultra massive black hole, sucked everything in and spat it back out.
Actually a better theory is all the black holes from before just ate up the universe, spat out the matter and began the cycle again.

[stromboli]

http://www.youtube.com/watch?v=nQPlFLtWDwM

[Solitary]

Funny! Thanks for the video, I needed a good laugh; my wife's sister is here on vacation, who is as logical as this: http://youtu.be/nQPlFLtWDwM Solitary

[AllPurposeAtheist]

 You're all just teetering on going to H E double dirty Q-Tips® with this talk of an expanding universe that wasn't "just created" by the big spooky. Tread carefully..

[PickelledEggs]

How does this theory deal with the expanding universe that we observe? If it's currently expanding it must have all been together at some point.
There is also the Cosmic microwave background. If there was no big bang where would that come from?

There was a video I posted a while back that I'm still trying to find. It explained the expansion in lament's terms better than I did. But basically the universe was and is expanding in to it's self forever