Philosophical/quantum implications of Big-Bang singularity

[eloheim]

Okay one more question for you guys I'm having trouble figuring out, probably because the search function on here is difficult to use successfully if you're unfamiliar with the terminology involved.

One of the popular physics books I've read is called "The Conscious Universe" by Kafatos and Nadeau. I guarantee you it is actually more substantial than the title, or even the following passage might indicate , but the part I'm quoting stuck out because it seemed almost out of place for its generality and lack of supporting evidence:

As Bernard d'Espagnat argued, non-locality should obviously not be assumed to be a fact of nature only in the special laboratory conditions in the experiments testing Bell's theorem. What these experiments reveal is a general property of nature in which particles that interact with other particles in these terms must be viewed as a single quantum system which responds together to further interactions. Virtually everything in our immediate physical environment is made of quanta that have been interacting with other quanta in this manner from the Big-Bang to the present. The atoms in our bodies are made up of particles that interacted at that time in a single quantum state can be found in the most distant star. This means, however strange or bizarre it might seem, that the quanta that make up our bodies are as much a part of a unified system as the photons propagating in opposite directions in the Aspect experiments.

My question about this, I hope, is fairly confined. If the Big-Bang is modified to a theory in which there is not a singularity at the moment of creation (as with some I've heard of), does the idea that the entire Universe is/once was part of a single 'quantum state' have to abandoned?

 

[skippy1729]

Okay one more question for you guys I'm having trouble figuring out, probably because the search function on here is difficult to use successfully if you're unfamiliar with the terminology involved.

Use google in this form:

"search phrases or terms here" site:physicsforums.com

for example:

quantum singularity "big bang" site:physicsforums.com

Skippy

 

[baywax]

Okay one more question for you guys I'm having trouble figuring out, probably because the search function on here is difficult to use successfully if you're unfamiliar with the terminology involved.

One of the popular physics books I've read is called "The Conscious Universe" by Kafatos and Nadeau. I guarantee you it is actually more substantial than the title, or even the following passage might indicate , but the part I'm quoting stuck out because it seemed almost out of place for its generality and lack of supporting evidence:



My question about this, I hope, is fairly confined. If the Big-Bang is modified to a theory in which there is not a singularity at the moment of creation (as with some I've heard of), does the idea that the entire Universe is/once was part of a single 'quantum state' have to abandoned?

I would abandon the idea that the universe was a single quantum state during the event of the big bang. I say this only because there has to be a medium in which the event takes place. Therefore... "it takes two to tango" or as Doris Day has put it "you can't have one without the other".

 

[Chronos]

Plenty of work is in progress to remove the big bang 'singularity'. It is highly theoretical and speculative - largely because we have little or no clue haw to obtain the necessary observational evidence. We are fairly certain singularities are illogical, but, lack the math/evidence to dismiss them with any confidence. The nature of the universe remains quite mysterious.

 

[Chalnoth]

I take issue with the assumption that non-locality is a feature of quantum mechanics at all. All of the wavefunction dynamics of quantum mechanics are local. It is only the collapse of the wavefunction that leads to the appearance of non-locality, and that is easily understood as being due to local physics through decoherence.

That said, there is definitely truth to the statement that everything in our universe can be described as a single massive wavefunction. This is just how quantum mechanics works, and I don't see how there can be any reasonable doubt to this claim. However, it's also not horribly useful for understanding our universe, because decoherence ensures that classical, non-quantum physics is an extraordinarily accurate description of our universe in almost all situations, and because speed of light limitations prevent the behavior of one part of the wavefunction from affecting other parts in many situations.

 

[jackmell]

The nature of the universe remains quite mysterious.

And she is very deceptive as well. I would have thought it was flat, that the sun, moon, the entire crystal sphere, went around the Earth back then, and all that we could see (with the eye) was all that their was.

I'm suspicious therefore, that somehow, she is continuing to be that way, that we still don't have all of it right just yet. We have dark matter, dark energy, the nature of black holes, the expansion and acceleration of the Universe, and of course origins that may in some ways be in the same category as the flat earth, the geo-centric universe, and the wandering planets.

 

[baywax]

Plenty of work is in progress to remove the big bang 'singularity'. It is highly theoretical and speculative - largely because we have little or no clue haw to obtain the necessary observational evidence. We are fairly certain singularities are illogical, but, lack the math/evidence to dismiss them with any confidence. The nature of the universe remains quite mysterious.

Here's a stab at the mystery...

A new theory revealing another universe, whose collapse appears to have given birth to the one we live in today, has just been announced in the online edition of the journal Nature Physics. The research, conducted by Martin Bojowald and colleagues at Penn State University, reveals a contracting universe that existed before the expanding one we live in today, and replaces the Big Bang with a Big Bounce. Bojowald's work also suggests that there will always be some uncertainty concerning the exact properties of the earlier universe. His calculations reveal a "cosmic forgetfulness" resulting from the extreme quantum forces that were at work during the Big Bounce.

http://plus.maths.org/content/big-bang

 

[Chalnoth]

I strongly suspect that Loop Quantum Cosmology will turn out not to work. The fundamental issue is that it attempts to take a generic state and make a low-entropy state out of it. And I just don't think that's possible.

From what I understand, the specific model currently depends upon the universe going into the bounce being uniform from the start, a situation which is entirely unphysical (even a small amount of clumpiness would tend to just get more and more clumpy as the universe collapses towards the bounce).

 

[marcus]

...
From what I understand, the specific model currently depends upon the universe going into the bounce being uniform from the start,..

Who says that?

 

[Chalnoth]

Who says that?

Well, it is in the abstract of http://hermes.aei.mpg.de/lrr/2005/11/article.xhtml :

One particular realization is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities.

(emphasis mine)

Perhaps it's since been generalized, but unless it's been generalized to systems where subsets of the collapsing universe can obtain angular momenta, I don't think it's terribly enlightening.

 

[alt]

Here's a stab at the mystery...



http://plus.maths.org/content/big-bang

A new theory revealing another universe, whose collapse appears to have given birth to the one we live in today, has just been announced ..

Which merely 'kicks the can down the road' giving rise to the same questions.

I think Chronos said all we can say ...

The nature of the universe remains quite mysterious.

 

[Chalnoth]

The nature of the universe remains quite mysterious.

In some ways, this is very true. On the other hand, there are many aspects of our universe which we know quite a lot about. It's quite stunning, for instance, that quantum electrodynamics has been tested to an accuracy of one part in 10^{14}. It's amazing that we can talk about black holes, objects that can't even be seen, or detect a small deviation from the expected rate of expansion that leads to dark energy. And yet, it does remain true that a tremendous amount remains to be learned. And that's just what we know that remains to be learned. When we learn more about our universe, we're likely to discover that there are even more things we don't know.

To take a simple example, before the 20th century, nobody suspected that there was any such thing as a "galaxy": people thought that our own local group of stars was all there was. It wasn't until Hubble showed just how far away some of these "nebulae" were that the astronomy community was really convinced that our own group of stars was just one island, one galaxy among many. More knowledge led to an entirely new class of object to understand!

 

[baywax]

A new theory revealing another universe, whose collapse appears to have given birth to the one we live in today, has just been announced ..

Which merely 'kicks the can down the road' giving rise to the same questions.

I think Chronos said all we can say ...

The nature of the universe remains quite mysterious.

True...

Did the universe, at one time before the big bang expand to such a degree that the space between particles and even waves was so great it became something other than space... like the infamous "void"? Then, in this sort of medium, a lone wave is pressured (somehow) to expand in the manner seen in atomic reactions... big bang?!

 

[Chalnoth]

True...

Did the universe, at one time before the big bang expand to such a degree that the space between particles and even waves was so great it became something other than space... like the infamous "void"? Then, in this sort of medium, a lone wave is pressured (somehow) to expand in the manner seen in atomic reactions... big bang?!

There is no known mechanism by which such a thing could occur, nor even how to describe it.

 

[baywax]

There is no known mechanism by which such a thing could occur, nor even how to describe it.

Cosmic Osmosis?... nah... but thanks anyway!