The Big Bang Theory: Was There No Space?

[Parbat]

Big bang suggests that there was only a concentrated mass.was there no space?If there was no space where did it come from?[i mean what makes space?].time also started after big bang.how did it start?
Don't u guys think there's somethin missing in this theory?

 

[zhermes]

Space and mass are intertwined, both were highly concentrated at the big bang. From the big bang, space-time itself expanded.
See:
http://en.wikipedia.org/wiki/Big_bang

 

[Waveparticle]

Asking a physicist what happened before the big bang is like asking what's north of the North Pole.

 

[Jack21222]

Asking a physicist what happened before the big bang is like asking what's north of the North Pole.

I often hear this, and I think it's a miscommunication about what is meant by "before." Perhaps a better way to phrase it for the pedantic physicists is "What, if anything, caused the big bang to occur."

A good follow-up question would be "Is that something we can even find an answer for?"

 

[Chronos]

The short answer is 'No'. BBT is only relevant after the first tick of Planck time. It does not attempt to explain initial conditions. There are any number of speculations about what caused the big event. I'm not aware of any that are testable.

 

[skydivephil]

When physicists says there is no before the big bang I think they are speaking prematurely. I think a better answer is, our current model of cosmology, General Relativity implies a begning of time at the big bang. It also implies a whole host of infinite values for the universe at this singular point. One might take this as an accurate description of the universe or more likely a sign that our models simply break dwon at the this point and we need a new theory of (quantum) gravity.
Many attempts to formulate quantrum theories of gravity imply a pre big bang universe, but at the moment we don't know if any of them are correct, maybe none of them are . There are also some other possibilities of a "before the big bang scenario" such as Roger Pensrose Conformal Cyclic Cosmology and eternal inflation. I have made a short video discussing these , you can see it here:

http://www.youtube.com/user/skydivephil

 

[Chronos]

Did you forget to edit out the crap part?

 

[Gaius Baltar]

The short answer is 'No'. BBT is only relevant after the first tick of Planck time. It does not attempt to explain initial conditions. There are any number of speculations about what caused the big event. I'm not aware of any that are testable.

What about CMB? There is on-going studies.

 

[skydivephil]

The latest survey on the CMB is ESA Planck mission. They do discuss the possibility of getting a hint of brane colision models, not sure tis a direct test or not though:

http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI(2005)1_V2.pdf

 

[Chronos]

What about CMB? That was 380,000 years after the big event.
Sky, your previous link was irrelevant, and your latest link also appears to be off topic. Thus far I perceive you have nothing to contribute.

 

[Gaius Baltar]

The model suggests that new universes could be created spontaneously from apparently empty space. The WMAP is collecting data, and so far last I heard, detailed measurements made by the satellite have shown that the fluctuations in the microwave background are about 10% stronger on one side of the sky than those on the other.

http://map.gsfc.nasa.gov/universe/bb_tests_cmb.html

 

[Gaius Baltar]

Apologies,

I should have explained what the meaning was in regards to it being 10% stronger on one side, or the universe is "lop-sided" - The significance of this would be if these fluctuations represented a structure left over from the Universe that created our Universe.

 

[skydivephil]

The topic is before the big bang. My link directs people to peer reviewed papers that discuss the possibility of pre big bang scenarios. No one here has mentioned Loop Quanutm Graivty or Penrose's Conformal Cyclic. The link does does do that. whilst at the same time not endorsing any of these ideas.
My point is that its often said there's no time before the big bang, yet that is a premature statement. We need to get a quanutm theory of gravity to be able to answer these questions. At the moment we don't have one, we have a couple of candidates which some pople think are promising and if true imply a pre big bang era, but that moment we don't have anyhting that's verified by any data. Now which bit of this do you think is irrelevant or incorrect?

 

[Gaius Baltar]

My point is that its often said there's no time before the big bang, yet that is a premature statement

That statement is now widely accepted by many scientists as "We don't know"...

 

[skydivephil]

That statement is now widely accepted by many scientists as "We don't know"...

i think that's very reasonable, yet many people will still say there is no possibility of anything before the big bang and those two statements are not the same.

 

[Gaius Baltar]

i think that's very reasonable, yet many people will still say there is no possibility of anything before the big bang and those two statements are not the same.

Correct. It sometimes boils down to ignorance, but as you can see from my posts above, there is an on-going "theory" if you like into what was before the big bang.

 

[Phyisab****]

The short answer is 'No'. BBT is only relevant after the first tick of Planck time. It does not attempt to explain initial conditions. There are any number of speculations about what caused the big event. I'm not aware of any that are testable.

/thread

 

[Gaius Baltar]

/thread

And this means?

 

[skydivephil]

BBC's horizon broadcast a documentary last night , "What Happened before the big bang"
links is here:
http://www.bbc.co.uk/programmes/b00vdkmj

 

[alt]

BBC's horizon broadcast a documentary last night , "What Happened before the big bang"
links is here:
http://www.bbc.co.uk/programmes/b00vdkmj

Unfortunately, the videos are .. "Not available in your area"

But the following front page comments are interesting;

Neil Turok who runs the Perimeter Institute for Fundamental Physics research in Canada, is so disillusioned with cosmology’s Big Bang, that he’s developed m-theory which holds that there was no bang at all - ‘simply’ the collision of three dimensional universes like ours arranged on parallel membranes. The collision takes place in a fourth dimension that we’re not aware of, but spells the end of the current universes and the beginning of a new one. But no bang.

Sir Roger Penrose has changed his mind about the Big Bang. He now imagines an eternal cycle of expanding universes where matter becomes energy and back again in the birth of new universes and so on and so on.

 

[skydivephil]

The show was pretty good, it basically implied the question isn't was there a before the big bang ? but what was it.
They did a very brief description of matter bounce in Loop Quantum graivty, Ekpryotic Universe , eternal inflation, Penrose's conformal cyclic model, Smolin's Fecund Universe. They also mentioned a theory Id never heard of by Laura Maersini Houghton which i don't think they explained at all except she claims its already made 3 experimental predicitons that have been verified. Anyone shed some light on this one?
There were interviews with Lee Smolin, Andre Linde, Roger Penrose, Param Singh (who they credited matter boiucne to, wasnt the big boucne Martin Bojowald's idea?) , Neil Turok and Laura Maersini Houghton; quite a cast really.

 

[physics_931]

There were interviews with Lee Smolin, Andre Linde, Roger Penrose, Param Singh (who they credited matter boiucne to, wasnt the big boucne Martin Bojowald's idea?) , Neil Turok and Laura Maersini Houghton; quite a cast really.

No. Bojowald did not gave bounce idea. It was work of Ashtekar, Pawlowski and Singh in the paper in Physical Review Letters in 2006. After that paper came out, Bojowald tried to get bounce but his model failed as it could not reproduce Einstein's theory at right scales.

 

[Jack21222]

And this means?

That means "thread over," or in other words, he believes the quoted comment was so good that no further comments are necessary.

The notation is taken from HTML, where a closing tag has a slash before the command. For example, to put something in bold, you'd use <b>text</b>. The first set of angle brackets says "start bold here" and the second set, the one with the slash, says "end bold here."

Hence /thread is indicating the end of a thread, or in the poster's opinion, what should be the end of the thread.

Hope this helps.

 

[WmCElliott]

Something occurred to me yesterday. Matter and Anti-matter (according to Feynman) are the same, except that anti-matter is "time-reversed". If that's true, and there is a t=0 moment at the "origin" of the universe, perhaps the matter created went forward in time and the anti-matter went backward in time (like a mirror image of this universe).

 

[WmCElliott]

Another theory of mine is that our universe is the interior of a black hole in a 10D space (as in the 10D universe of String Theory). Our "Inflationary Period" is precisely what one would expect to see inside a collapsing black hole - caused by the in-falling matter going faster than the speed of light as it would after passing through the Event Horizon. Leonard Susskind states that the surface of an event horizon displays what's essentially a stop-motion hologram of the matter as it passes through the Event Horizon.

Einstein's factor of 1/sqrt(C^2 - V^2), which applies to mass, time, and the dimension along the velocity vector of matter as it approaches the speed of light, all end up generating a weird factor, the sqrt(-1) as V>C. That number is used routinely in complex numbers and mathematical transformations - it implies orthogonality (a rotation of 90degrees for rotating "real" into "imaginary" values. All it means is that when matter passes through the speed of light, it leaves the prior universe for the next, two spaces which can't be accessed directly by each other.

Another point worth considering - String Theory is based on a coincidental match of the form of the four fundamental physical forces with the form of Poincare's (IIRC) equation solving the vibrational modes of a multiple-dimensional "string's" vibrational modes. With all due respect to superior intellects to my own, I suspect that one would get the same form of equations for the vibrational modes of rips between spaces of differing dimensions, and it makes more physical sense if matter from a 10D space falling through an Event Horizon would leave a "rip" in the Event Horizon as it passes through the speed of light.
One further point - Gravity would be our 3D space falling back out through the rips in space back into the greater 10D universe. In a sense, it may be what Hawking Radiation looks like from inside the black hole.

 

[marcus]

... wasnt the big bounce Martin Bojowald's idea?

His paper on it is dated 2001.

At the time he was a postdoc in Ashtekar's group at Penn State. There were no comparable papers by Ashtekar or anybody else for several years.

Bojowald essentially started the field of Loop Quantum Cosmology.
LQC involved radically simplifying at least at first (uniformity assumptions, homogeneous-isotropic) and using an approach that was LQG-like, but not the full LQG theory.

His PhD thesis advisor was Hans Kastrup at University of Aachen. Kastrup's thesis advisor was Werner Heisenberg. It is possible that Kastrup had some input to the beginnings of LQC around 2000.

By 2001 Bojowald was on his own and at Penn State. He had written some LQC papers but not yet the big bounce. The first LQC big bounce paper was:

http://arxiv.org/abs/gr-qc/0102069
Absence of Singularity in Loop Quantum Cosmology
Martin Bojowald
4 pages, 1 figure
(Submitted on 14 Feb 2001)
"It is shown that the cosmological singularity in isotropic minisuperspaces is naturally removed by quantum geometry. Already at the kinematical level, this is indicated by the fact that the inverse scale factor is represented by a bounded operator even though the classical quantity diverges at the initial singularity. The full demonstation comes from an analysis of quantum dynamics. Because of quantum geometry, the quantum evolution occurs in discrete time steps and does not break down when the volume becomes zero. Instead, space-time can be extended to a branch preceding the classical singularity independently of the matter coupled to the model. For large volume the correct semiclassical behavior is obtained."

====================

Working together with Bojowald, two senior peoople Ashtekar and Lewandowski made a highly significant contribution to LQC in 2003----the mathematics was improved.
http://arxiv.org/abs/gr-qc/0304074
Mathematical structure of loop quantum cosmology
Abhay Ashtekar, Martin Bojowald, Jerzy Lewandowski
(Submitted on 21 Apr 2003 (v1), last revised 24 Dec 2003 (this version, v4))
Applications of Riemannian quantum geometry to cosmology have had notable successes. In particular, the fundamental discreteness underlying quantum geometry has led to a natural resolution of the big bang singularity. However, the precise mathematical structure underlying loop quantum cosmology...

Then in 2006-2007 the mathematics was again refurbished---the socalled "improved LQC dynamics"---by Ashtekar, Corichi, Singh and others. Much numerical work (computer simulations of various universes collapsing and bouncing) and solvable equation models were developed, to which the simulation results could be compared.

Now as of 2009-2010 the restrictive uniformity assumptions are being discarded, a wider variety of universes is being handled, and the full LQG (spinfoam) theory is being applied.

The first textbook for the field of Loop cosmology will appear in a few months, by Bojowald. It is called Canonical Gravity and Applications.

 

[skydivephil]

Thanks Marcus, you are an amzing source of info. I have a further question for you , if there is no singualrity in LQC what does it mean for the theorom that eternal inflation has to havea singularity in the past? e.g. here:
http://arxiv.org/abs/gr-qc/9312022
Is there a contradiction here?

 

[skydivephil]

I have to say I don't have the technical knowledge to read a book like, " Canonical Gravity and Applications". For those like me who are fasincated by the field by not trained in it. Bojowald is bringing out a book , which I think is for the layman, in a few weeks, here is the link:
https://www.amazon.com/dp/0307272850/?tag=pfamazon01-20

 

[George Jones]

BBC's horizon broadcast a documentary last night , "What Happened before the big bang"
links is here:
http://www.bbc.co.uk/programmes/b00vdkmj

Unfortunately, the videos are .. "Not available in your area"[/I]

IFor those not in the UK:

YouTube - BBC Horizon 2010: 1/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 2/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 3/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 4/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 5/6 What Happened Before the Big Bang
YouTube - BBC Horizon 2010: 6/6 What Happened Before the Big Bang

 

[marcus]

Thanks G.J. for the links! I'll try them. The program sounded interesting. Any ones you especially thought were provocative, worth watching (whether right or wrong doesn't matter so much, as long as they have edge.)

Thanks Marcus, you are an amzing source of info. I have a further question for you , if there is no singualrity in LQC what does it mean for the theorom that eternal inflation has to havea singularity in the past? e.g. here:
http://arxiv.org/abs/gr-qc/9312022
Is there a contradiction here?

That is a *classical* paper---it assumes that everything is governed by the vintage-1915 Einstein equation. And as you go back in time it finds that the model must break down.

We are familiar with that kind of thing (even without "eternal inflation") classical cosmology models break down, and encounter a singularity (a place where the math blows up and the model does not apply to nature any longer).

In LQC we not in classical cosmology any more. We are in quantum cosmology. Papers like that Vilenkin 1993 are not so relevant. Quantizing tends to remove singularities and let's the model go farther back in time without a mathematical breakdown.
=========================

I can skip Youtubes #1 and #2. I get into it with #3, especially in minute 5 of #3 where a five minute segment with Smolin starts.

 

[Kevin_Axion]

Thanks for the awesome links! I just find it fascinating that research of that magnitude is occurring fourty minutes away from my house - Perimeter Institute.

 

[physics_931]

His paper on it is dated 2001.

...

By 2001 Bojowald was on his own and at Penn State. He had written some LQC papers but not yet the big bounce. The first LQC big bounce paper was:

http://arxiv.org/abs/gr-qc/0102069
Absence of Singularity in Loop Quantum Cosmology
Martin Bojowald
4 pages, 1 figure
(Submitted on 14 Feb 2001)
"It is shown that the cosmological singularity in isotropic minisuperspaces is naturally removed by quantum geometry. Already at the kinematical level, this is indicated by the fact that the inverse scale factor is represented by a bounded operator even though the classical quantity diverges at the initial singularity. The full demonstation comes from an analysis of quantum dynamics. Because of quantum geometry, the quantum evolution occurs in discrete time steps and does not break down when the volume becomes zero. Instead, space-time can be extended to a branch preceding the classical singularity independently of the matter coupled to the model. For large volume the correct semiclassical behavior is obtained."

====================

Marcus, where in the above paper big bounce is described? The above paper does not talk about bounce at all. The above paper only found that for kinematical states singularity is avoided. It does not imply that there is a physical resolution of singularity.

I see that a lot of credit is given to this paper of Bojowald which is in fact incorrect. It was later shown by various authors that this paper actually makes little sense because when one find physics then it does not agree with GR in the limit of small spacetime curvature and gives Planck scale corrections at density of water! This is not physics, this is plainly wrong. The mathematics which you say was "refurbished" after Ashtekar, Bojowald, Lewandowski paper was a major step in LQC which led to the bounce idea. It gave correct limit at low curvatures and a well defined scale at high curvatures. The papers before Ashtkar, Pawlowski, Singh's can be simply described in LQC as very incomplete. It is not without reason that the bounce idea in scientific community is given to Ashtekar, Pawlowski and Singh. Singh describes it in youtube video 3 in first 5 minutes which you skipped.

I don't see a reason why you say Bojowald gave bounce idea where as the first paper to show quantum bounce was not his. It was by Ashtekar, Pawlowski and Singh's PRL. I am well aware of these papers and the their details as I did my under-grad project in this. Have you read these papers? I request you to do not misinform people.

 

[physics_931]

This is the paper which showed bounce for first time. Read the abstract, the paper and compare with previous papers to know the truth. The long standing issues refer to very severe problems with works prior to this paper (that includes Bojowald's papers).


Quantum Nature of the Big Bang (arXiv:gr-qc/0602086)

Abhay Ashtekar, Tomasz Pawlowski, Parampreet Singh
(Submitted on 22 Feb 2006 (v1), last revised 6 Apr 2006 (this version, v2))

Some long standing issues concerning the quantum nature of the big bang are resolved in the context of homogeneous isotropic models with a scalar field. Specifically, the known results on the resolution of the big bang singularity in loop quantum cosmology are significantly extended as follows: i) the scalar field is shown to serve as an internal clock, thereby providing a detailed realization of the `emergent time' idea; ii) the physical Hilbert space, Dirac observables and semi-classical states are constructed rigorously; iii) the Hamiltonian constraint is solved numerically to show that the big bang is replaced by a big bounce. Thanks to the non-perturbative, background independent methods, unlike in other approaches the quantum evolution is deterministic across the deep Planck regime.

 

[2rashmi1993]

looks like am talking to future comologists.....thanx all 4 such great sources...
definitely will try them......

 

[thumbsup1]

I believe the universe is the result of a collision that occurred between two other universes, I say this as if the universe is the result of a big bounce within a much older universe then surely our universe would be in it's lowest energy state (of which it isn't).