Posted on 02/09/2015 10:55:17 AM PST by Red Badger
(Phys.org) —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 after—not at or before—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 gravitons—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.
Explore further: Did the universe originate from a hyper-dimensional black hole?
More information: Ahmed Farag Ali and Saurya Das. "Cosmology from quantum potential." Physics Letters B. Volume 741, 4 February 2015, Pages 276–279. DOI: 10.1016/j.physletb.2014.12.057. Also at: arXiv:1404.3093[gr-qc].
Saurya Das and Rajat K. Bhaduri, "Dark matter and dark energy from Bose-Einstein condensate", preprint: arXiv:1411.0753[gr-qc].
Journal reference: Physics Letters B
Well ... contrary to what some scientists says ... the universe had a definite beginning. God had told us he created it!
There are more things in heaven and earth, Horatio,. Than are dreamt of in your philosophy...................
Laugh all you want, but quantum lube beats dry every time.
Seriously.
It’s not as bad as it used to be. He’s 13 now, and he can act like normal humans for a couple of hours at a time. If I could just get him to stop talking to his Voices when he’s an altar server ...
“What’s wrong with it?”
“Well, it’s not morally wrong, like murder ... but it’s weird.”
“Oh, is it?”
“Yes. And people are watching you, wondering why you’re talking to the ceiling. It keeps them from paying attention to the service.”
“That’s not my problem.”
Psalm 147:4
He determines the number of the stars and calls them each by name.
Is he an only child?.................
No, #6 of 10.
Middle children are a lot like only children. They crave attention because they are ‘in the middle’.................
Yes, and when you have 8 middle children, it’s an absolute zoo ;-).
Pat was at the tail end of a batch of 4 in five years. It’s a wonder he even got fed (just kidding). Most of my six sons tend to the weirdly brilliant, but he’s the weirdest and probably the most brilliant. Now that he’s learning computer programming, it looks like he’s fixed for life.
When these dedicated scientists figure God out for real, THEN, and only then, will they doubt their math.
At least in this article they say “may”.
Regarding quantum fluid and the aether and God moving on the face of the waters:
Genesis:
In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
The First Day: Light
And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness. And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
The Second Day: Firmament
And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. And God called the firmament Heaven. And the evening and the morning were the second day.
What is the nature of the space outside of the space defined by the Big Bang Expansion? Into what space is the Big Bang expanding?
Photons, for example, certainly exist. Look at the glowing CFL above your head.
"Space outside" has no operable definition.
Yeah, really. This implies that any definition we can comprehend is inadequate.
The “Big Bang” is not an adequate explanation of the origin of the universe. That does not mean that this theory is correct.
“They [photons] carry momentum but have no mass IF AT REST - IN FACT, THEY CANNOT EXIST AT REST(though their phase velociy can be slowed to be near at rest).”
This statement is from a scientific forum somewhere on the web (emphasis mine). So, I admit my non-physicist brain struggles with the concept of a “massless particle” as anything but a theoretical construct, just as I struggle with the idea of the universe expanding into something - some hypothetical space - that has (as you put it) “no operable definition.”
Each one of us wants to be an individual, in complete control of our ‘personal universe’.
A computer programming interest is logical, since it gives that ‘feel’ of being ‘Master of the Universe’...................
It’ll do until something else is ‘unexplained’ by it......................
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