News: The International Astronomical Union has no Definition for Big Bang

[DavidD]

The International Astronomical Union has no Definition for Big Bang

 

After putting in a bit of effort in getting answers and permissions and writing it up, I thought you might appreciate learning of two significant, related cosmology news events that occurred last week.

 

1. The International Astronomical Union confirmed that they have no definition for Big Bang, and their Cosmology Commission VP explained why they probably will not do so.

 

2. ". . . the [standard model] definition is a mess." according to perhaps the most cited cosmologist - P. James E. Peebles of Princeton (author of "Principles of Physical Cosmology")

 

You can read about these on my Cosmology Science website at --

http://cosmologyscie...m/cosblog/?p=66

 

If IAU is not interested, who should take responsibility for maintaining the scientific claim we call "Big Bang?"

 

I believe this is important because without a clear scientific hypothesis, how can one claim to be discussing science?

 

-David Dilworth

[Cap'n Refsmmat]

I like how you cite a paper you wrote yourself as external evidence of your claims, along with an 18-year-old book. Cosmology evolves rapidly.

 

I'm not sure what your problem is; the response you got from the IAU is perfectly right. The "Big Bang" is not one theory, but a broad descriptor. There are many agreed-upon details in cosmology, and many details needing further explanation. Hence there are multiple proposed models to account for these details.

 

When a scientist writes a paper about new evidence for the Big Bang, he specifies which cosmological models he's using and what specific implications the evidence has. He does not handwave and say "and this proves the Big Bang."

 

Your premise is flawed.

[rktpro]

Big Bang is only a conception. It has been proved by some experiments and disapproved due to others. But, all agreed to have this theory and take it as a base until they find something new(and they won't because the capturing of antimatter at CERN has verified everything).

[DavidD]

The quote from Princeton's widely respected cosmologist P. James E. Peebles is from last week, not 18 years ago.

 

He wrote last week ". . . the [standard model] definition is a mess."

 

Each of last week's thoughts from Peebles and IAU's Schmidt should cause one to pause, but taken together they are worthy of discourse.

http://cosmologyscie...m/cosblog/?p=66

 

I completely agree with you that "The "Big Bang" is not one theory, but a broad descriptor. There are many agreed-upon details in cosmology, and many details needing further explanation. Hence there are multiple proposed models to account for these details."

 

Perhaps you can help cite one paper that provides a complete scientific hypothesis for any agreed upon model. I've looked hard and haven't found a complete one yet.

Edited February 11, 2011 by DavidD

[Cap'n Refsmmat]

Perhaps you can help cite one paper that provides a complete scientific hypothesis for any agreed upon model. I've looked hard and haven't found a complete one yet.

Presumably if it were an agreed-upon model, we wouldn't have the problem of multiple theories floating around.

 

What is a "complete scientific hypothesis," in your mind?

[lemur]

Why can't Big Bang theory be generally defined as theories that attempt to describe possible origins of the universe, where the dimensions of space and time are given special attention as emergent rather than essential aspects of physical existence that transcend observable phenomena as they are known (or something similar)? Can't anything be relatively defined by generating a general description that is sufficiently vague to encompass common aspects of all competing expressions?

[DavidD]

Presumably if it were an agreed-upon model, we wouldn't have the problem of multiple theories floating around.

 

What is a "complete scientific hypothesis," in your mind?

Thank you for asking.

 

A complete scientific hypothesis is an un-ambiguous testable claim.

 

For a more thorough definition see -- 

 

http://www.cosmology....htm#Hypothesis

 

and for details and examples see the paper "Ground Rules for Cosmological Physics" (pgs 2-3) --

http://cosmologyscie...og/?page_id=165

[ajb]

1. The International Astronomical Union confirmed that they have no definition for Big Bang, and their Cosmology Commission VP explained why they probably will not do so.

 

I am not surprised by this at all. Until we have a great understanding of the very early universe, and in particular the presumably quantum nature of the singularity it would be premature to put in place a definition. And what would we mean by a definition? To me this would mean singling out some theory.

 

 

2. ". . . the [standard model] definition is a mess." according to perhaps the most cited cosmologist - P. James E. Peebles of Princeton (author of "Principles of Physical Cosmology")

 

See above.

 

If IAU is not interested, who should take responsibility for maintaining the scientific claim we call "Big Bang?"

 

The multitude of cosmologists and astronomers. It is not up to one organisation to define any scientific theory.

 

I believe this is important because without a clear scientific hypothesis, how can one claim to be discussing science?

 

There is a clear hypothesis, well there are many. If we ignore the initial singularity the best model of cosmology is the lambda CDM model.

 

I expect this will get suitably modified in the future to take care of dark energy, what ever that is!

[Cap'n Refsmmat]

Thank you for asking.

 

A complete scientific hypothesis is an un-ambiguous testable claim.

 

For a more thorough definition see --

 

http://www.cosmology....htm#Hypothesis

 

and for details and examples see the paper "Ground Rules for Cosmological Physics" (pgs 2-3) --

http://cosmologyscie...og/?page_id=165

Ah. As ajb points out, there is no single hypothesis of the early universe. There are many hypotheses about specific conditions that are tested and re-tested by different astronomical observations. Once various difficult questions are answered, a complete theory of the Big Bang can be put together.

[swansont]

Perhaps you can help cite one paper that provides a complete scientific hypothesis for any agreed upon model. I've looked hard and haven't found a complete one yet.  

 

The same holds true for evolution, relativity and quantum mechanics. That's not the function of academic papers.

[DavidD]

 

Until we have . . . it would be premature to  put in place a definition.

Thank you for your thoughts and time. 

 

Do I understand that this response suggests that there is not yet a fully complete Big Bang or Standard model hypothesis ? 

 

If so, then could you please help point me to the most complete Big Bang or Standard model hypothesis ? 

 

 

Until we have a great understanding of the very early universe, and in particular the presumably quantum nature of the singularity it would be premature to  put in place a definition.

 

And please pardon me for asking, but isn’t that circular reasoning ? 

(http://en.wikipedia....rcular_argument)

 

Doesn’t the response above assume an idea is a valid hypothesis

 

(“the presumably quantum nature of the singularity” assumes Big Bang 

is a complete and valid hypothesis because "the singularity" is unique 

to Big Bang / expansion models) and

then claim it is impossible ("premature") to define the same idea ? 

 

Maybe I don't understand, but I can't make those two fit. 

How can we assume something is true and valid (and use it), but we can't define it ?

 

 

If IAU is not interested, who should take responsibility for maintaining the scientific claim we call "Big Bang?"

The multitude of cosmologists and astronomers. . . . There is a clear hypothesis, well there are many. If we ignore the initial singularity the best model of cosmology is the lambda CDM model.

From that multitude of cosmologists and astronomers and many clear hypotheses, could you please consider providing a citation to the best valid hypothesis in a published paper. I only need one. 

 

Perhaps you could provide a citation to your favorite (most complete) definition of the lambda CDM model.

 

 

 

 

Thank you

Edited February 12, 2011 by DavidD

[steevey]

Dang, all those people got into all those arguments about what the big bang could possibly be all over nothing...

[ajb]

DavidD, the most complete model that is in general agreement with observation is the lambda CDM model, but this does not address the initial singularity. Have a look at the Wikipedia article and references therein.

 

It won't be the final word on the "big bang", details of the singularity, the nature of dark energy and dark matter will likely result in some revision.

[IM Egdall]

Big Bang is only a conception. It has been proved by some experiments and disapproved due to others. But, all agreed to have this theory and take it as a base until they find something new(and they won't because the capturing of antimatter at CERN has verified everything).

 

PLease give links or references to experiments which disprove the Big Bang. As far as I know, all experiments, observations, tests to date support the concept of a Big Bang and expanding universe.

[ajb]

PLease give links or references to experiments which disprove the Big Bang. As far as I know, all experiments, observations, tests to date support the concept of a Big Bang and expanding universe.

 

This is a good point. The only other serious contender to the Big Bang was the steady state theory of Hoyle,Gold, and Bondi. The model requires the spontaneous creation of matter, which would violate local energy conservation and so destroy general relativity as the mathematical theory of gravity on the cosmological scale. This by itself is not enough to throw out the model. The big thing the steady state cannot explain is the CMBR. Any cosmological model that cannot do this as well as the Big Bang should not be considered a good model.

 

The big observational successes of the Big Bang model (lambda CDM in particular) is in the details of the CMBR.

Edited February 12, 2011 by ajb

[DavidD]

DavidD, the most complete model that is in general agreement with observation is the lambda CDM model, but this does not address the initial singularity.  Have a look at the Wikipedia article and references therein.

 

It won't be the final word on the "big bang", details of the singularity, the nature of dark energy and dark matter will likely result in some revision.

 

Thank you ajb, for your courteous response directing me to the Wikipedia entry for Lambda-CDM model. While Wikipedia articles are indeed useful, as you know they are not primary references.

 

I was hoping to get a citation to a peer-reviewed paper describing or defining an Expansion model; you chose Lambda-CDM model which is fine.

 

While I am familiar with the Wikipedia entry, and am following up on two references I had not previously reviewed, it appears there is a conflict in description.

 

Your kind response mentioned “the lambda CDM model, but this does not address the initial singularity.“

 

However, the Wikipedia article states “The model includes a single originating event, the "Big Bang" or initial singularity . . . “

 

While I am sure you can help clear that up, perhaps you or someone could please direct me to a primary reference, a citation to a peer-reviewed published paper for the best available valid hypothesis for standard cosmological model.

 

While waiting, I cannot avoid reflecting on Professor Peebles Feb. remarkable statement  in 2011 -- ". . . the [standard model] definition is a mess."

 

Thank you again,

-David

[ajb]

Your kind response mentioned “the lambda CDM model, but this does not address the initial singularity.“

 

However, the Wikipedia article states “The model includes a single originating event, the "Big Bang" or initial singularity . . . “

 

No-one really believes that the singularity is physics. It is expected that quantum effects will regulate this singularity. So, until we have a good theory of quantum gravity the proper thing to do is "cut the singularity out".

 

 

While I am sure you can help clear that up, perhaps you or someone could please direct me to a primary reference, a citation to a peer-reviewed published paper for the best available valid hypothesis for standard cosmological model.

 

D. N. Spergel, L. Verde, H. V. Peiris, E. Komatsu, M. R. Nolta, C. L. Bennett, M. Halpern, G. Hinshaw, N. Jarosik, A. Kogut, M. Limon, S. S. Meyer, L. Page, G. S. Tucker, J. L. Weiland, E. Wollack, E. L. Wright. First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters, Astrophys.J.Suppl.148:175-194,2003. arXiv:astro-ph/0302209v3

 

The above is I think the first paper to fit observation with lambda CDM.

 

Other works from the WMAP team can be found here. In short the details are to be found in the CMB.