No Big Bang? Quantum equation predicts universe has no beginning

Phys.org

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.

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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.

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.

Wow, sounds like this model will also account for dark matter and dark energy, eliminate the big bang, and determine the universe has a finite size (and therefore an infinite age). I'm not sure how it explains red shift, however.

"It is satisfying to note that such straightforward corrections can potentially resolve so many issues at once," Das said.

Read the paper : ScienceDirect.com

This is something I look forward to reading more about in the coming years (we'll see if it holds up under scrutiny, I suppose).

a reply to: Elton

I am in no way qualified to understand most of this, but I have always been bothered about the idea of nothing and then suddenly everything. I can live with a pendulum swinging on a constant active to inactive action, but cannot get my brain around some single orchestrating wand held by 'god knows whom'.

I look forward to quietly reading this when I have a lot of time to try to absorb as much of it as I can.

a reply to: Shiloh7

I love reading about cosmology and physics, but I admit the math is beyond me. I trust that other qualified people check the calculations and will determine if this is a viable model or not.

A steady state "something" makes more sense than something from nothing. It makes more sense that there always has been "something" rather than no thing.

If it answers what dark matter, etc is, this is a neat theory... and Bohm is an amazing mind (and not just for his "holographic universe" theories so popular lately). His implicit and explicit universe model is the only one that explains quantum entanglement in a rather simple manner... i.e. the two particles acting alike instantly at any distance are actually one particle that we perceive as individuated.

Anyway, cool find.. .thank you.

ETA I wonder how the lack of total light saturation is explained in this model if the universe has been here ... always?

a reply to: Elton

Thanks for screwing my head up more . Nothing , everything , finite , infinite . Edge of the universe , whats on the other side , big bang , what there before the bang , nothing . I have the same problem grasping infinity as i have grasping nothing . And people try to explain it with maths , impossible , thats a concept i can come to terms with .

Einstein wanted the universe to be in a steady state, that's why he originally introduced the cosmological constant into his equations. But we have long since discarded the steady state idea for a multitude of very good reasons. If they are saying we live in a finite steady state universe they are probably wrong in both regards; it seems to be infinite and certainly isn't steady state. They are saying the universe had no start so they must be saying time is infinite. Why then should space be finite? Seems to me what their equations are really saying is that space-time is infinite, which I'm more inclined to believe.

So the whole metaphysical universe having no beginning and being older then radiation that they used date the universe, could be right after all?

I mean I heard all this complication about math being the problem, or maybe those were just closed minded smart asses?

I will hold off on this sort of thought line until more solidified ideas are put forward. Big bang, no big bang? That's a very challenging idea. There is a limit to the physical reach of the universe? Multi-verses? Where does this end? More theories pile onto more theories. To try and fathom the entirety of this subject would scramble the brain.

To me, just a thicko, The big bang theory doesn't make sense. A big collision Theory 13 billion years ago does.

a reply to: Elton

Could you clarify the theory for me?

From what I've read from your OP, this particular model doesn't propose an eternal universe. It proposes a more "geodesic" singularity, which really does nothing to improve any current models. Am I not understanding the implications entirely? perhaps you could elaborate?

ETA:

Apologies. After reading the paper, an infinite universe does in fact seem to be what the authors are proposing. I'm not going to pretend I understand the math that has led them to this conclusion, but I suspect they have a long ways to go before they can prove a theorem which explains the origin of the universe when it seems to be entirely based on adjusting equations for quantum mechanics.

Sadly, my tiny little brain just compute any of this. I've never liked the big bang theory, I don't see how nothing can exist and then all of a sudden something comes from nothing and 'voila' here's the universe and everything in it.

So if my understanding is correct, this theory suggests that the universe has always been here and is infinite in size?

In my mind everything must have a beginning and an end, it's impossible for me to think that it was always there, it had to have 'begun' at some point and like wise must end at some point too. Surely nothing can go on forever.


I'm going for a lay down now......

a reply to: Elton

Thats the thing with theory...to be "proven" accurate, you have to start by dis-prooving all other theories. Personally, I think this is a load of baloney. Scientists (uni researchers etc) are expected to be published in scientific publications a number of times each year, this is probably a case of that. Edwin Hubble proved beyond a shadow of doubt that ALL but the Andromeda galaxy were moving away from us, on vectors making them move away from each other as well (doppler effect, red/blue shift). This translated into laymans terms means that at one point the galaxies were closer together, ergo at some point they have spawned from a common spot. This theory neatly sidelines this fact, and that's my main problem with it.

a reply to: Elton

Why, and since when, does the universe expend ?
What was then it's original size ?

a reply to: Elton

Here is another Image that helped me grasp this hypothesis.

This is an artist's concept of the metric expansion of space, where space (including hypothetical non-observable portions of the universe) is represented at each time by the circular sections. Note on the left the dramatic expansion (not to scale) occurring in the inflationary epoch, and at the center the expansion acceleration. The scheme is decorated with WMAP images on the left and with the representation of stars at the appropriate level of development. Credit: NASA

Read more at: phys.org...

a reply to: Elton

Well color me confused.

The universe is expanding and the rate of expansion is accelerating, so that would suggest that the universe was much smaller at one point it time. But how small was it?

The Brane theory seems more attractive as it gets older. Maybe our universe is just a bubble in a foam that has expanded over time, and like a bubble it interacts with others and that's what these guys are hoping to find out:

One of the more exciting ideas in high energy physics is the possibility that our three-dimensional universe is embedded in a much bigger multidimensional cosmos. Physicists call these embedded universes “branes” and say that it should be possible for stuff from our brane to leak into other branes nearby and vice versa.

Today, Michael Sarrazin at the University of Namur in Belgium and a few pals say they have worked out to detect this leakage by measuring whether neutrons can bypass barriers by leaping into another brane and back again.

These guys are proposing to measure this effect by placing a neutron detector close to a nuclear reactor to see whether neutrons appear unexpectedly as a result of being transported out of the reactor via another braneworld.

The Arxiv blog

The universe is mind boggling enough, let alone the notion that there are other universes.

How can singularities not appear in their theory when we have a whole long list of known black holes?

Unbounded space is infinite, it has always been there, it has had infinite time to develop. Whoops theres that time word. (placing limits, lol).

a reply to: Elton

If I'm not mistaken, red shift is explained by an object moving farther away from us... it has to do with light and is a Doppler effect. Unless you are talking about something else...

Also, good thread

There are certain things involved with this idea that leave me perplexed. We can see that the universe is expanding. We've even clocked the rate of expansion. Therefore we can retrace this expansion back to a point in time. How do these scientists account for the expansion rate?

Another issue I have is star composition. Stars millions and billions of light years away are simpler and only composed of hydrogen which is evidence of the evolution of star composition over the course of the life of the universe. If the universe existed forever, why did stars suddenly start forming 13.8 billion years ago? Why weren't they forming before then? And what changed to make them start forming?

This model may account for holes that the Big Bang leaves but appears to create massive holes in places that we've already explained.

originally posted by: Baddogma
A steady state "something" makes more sense than something from nothing. It makes more sense that there always has been "something" rather than no thing.

Ugh... The Big Bang theory doesn't say that something came from nothing...