Origin of the Universe,,,,Bang or no Bang

[Pluto]

G'day from the land of ozzzzzzzz

That was a mouth full.

No time to stay

Its sleep time.

Thought I'd read myself to sleep.

[freeztar]

Originally Posted by coldcreation

True, and this is exactly what happened after 1998, in light of the SNe Ia data, which showed that neither of the three Friedmann models (the pre-1998 standard model) could be validated, i.e., the predictions made by the three possible scenarios became obsolete. Thus the standard big bang theory was replaced by the concordance model, lambda CDM (LCDM).

Science changes constantly. I see your point and raise you one...

[coldcreation]

Originally Posted by freeztar

The Big Bang Theory is a direct result of observations that confirm it.
It has predicted new observations to a very high level of accuracy. This is what makes it such a strong theory!

Correction: The big bang was an idea first. Observations appeared to support it afterwards (not the other way around). I. Kant, E. A. Poe, I. Newton, A. Friedmann had all imagined an initial inferno.


In fact, the BBT was stricken with many problems. Inflation, which predicted a flat universe, solved some of these problems, but inflation itself remains on the fringes of science. Furthermore, recent supernova data indicates the expansion of the universe is accelerating (again, unlike the original Friedmann models), these problems cannot be reconciled without a large contribution to the energy density of the universe, aside from baryonic matter, namely a negative pressure (dark energy). This can be viewed as a weakness inherent in the theory.

Current theory predicts that the 'dark ages' began about 400,000 years after the big bang, as matter in an expanding universe cooled and formed cold hydrogen clouds. Stars and galaxies began to form. Their collective light reheated the hydrogen, ending the dark ages approximately one billion years after the big bang.

To confirm or refute this prediction (which is fundament to the standard model) telescopes such as The James Webb Space Telescope (JWST) are required. We'll have to wait until 2013, or shortly thereafter, for the results.

JWST has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

See too: JWST Science Questions

EDIT: And, Frequently Asked Questions (FAQ) about JWST

Originally Posted by freeztar

Science changes constantly.

I totally agree. Science changes constantly. So too the standard model (even when it should be discarded). As stated above, the price for saving the big bang model was the infusion of DE and CDM.

Originally Posted by freeztar

I see your point and raise you one...

I'll call you on that and raise the stakes. There's no maximum raise; you can raise as much as you'd like. If you wish to call a bet but don't have the chips to cover it, that's fine .

Future observations (as those by JWST mentioned above) will make strong demands on theoretical predictions, and will certainly tightly constrain differing models.

All of my chips will be placed on this bet (see 2 below). And indeed all of the big bang chips too. Results should show either: (1. the BBT prediction) all stars and galaxies directly post-dark ages are young metal-poor, in the process of formation. Or, (2) there are stars at these distances (during this same epoch) that are old, metal-rich, and galaxies are mature, well-formed (e.g, large spiral galaxies) with high metallicity.

Originally Posted by enorbet2

...2) All of the arguments regarding oldness/flatness, horizon, 1a supernovae, abundance of primordial elements, etc have all been well explained by BBT and until and unless some new compelling evidence to the contrary is observed BBT, and the Standard Model, is safe.

Even the laws of physics themselves are subject to modification, to confirmation (to some extent) or refutation. So nothing really makes the current standard model "safe."

Recall, Enorbet2, that it was inflation (Steinhardt and Guth, circa 1979), with its whimsical false vacuum, that appeased the flatness problem (along with most of the other problems) previously inherent in the BBT. This problem, and others, could not without inflation could be resolved by the BBT itself. The SNe Ia data was a fine natural demonstration that highlighted the vulnerability of the pre-1998 standard model. The pre-1998 standard model was not "safe" before the SN survey, nor is it safe now.

The primary weakness of Lambda-CDM (the current standard model), as touched upon above, is its use of the dark energy parameter to 'fill in the blanks.' The concordance model would have been on firmer ground (i.e., it would have been more secure, safer) had this ethereal parameter not become such an essential feature, or ingredient, of the cosmos (2/3 of the mass-enery density).

The secondary weakness of L-CDM is of course the nonbaryonic dark matter component (1/3 of the mass-enery density: SOURCE: Dark Energy and the New Cosmology, Michael S. Turner).


In order to secure a standard model in cosmology (to be "safe"), many (if not all) of the following often-related quandaries should be satisfactorily addressed:

1. A unified theory must be devised that either bridge the gap between QM and GR, or elucidates why the unification of these two theories are irreconcilable.

2. Unification should be achieved between gravity with the other forces of nature (or it should be illuminated why this is unachievable).

3. Lambda (the cosmological constant): an all-inclusive, logically consistent and self-sufficient definition and interpretation of this hitherto unrecognized state (or property, or entity, or force). It's value should follow.

4. The interpretation of cosmological redshift z should be unambiguous.

5. A justification for the observed abundance of elements should be unambiguous.

6. The origin of the cosmic microwave background should be unambiguously determined.

7. The age of objects [located both locally and] at the limits of observational capabilities should be unambiguous.

8. When predictions are made empirical evidence should support the claims (cosmology needs to be held to the same standards as other fields of science).

There's a long way to go baby...


Conclusions:

(1) Standard models are never "safe" (at least not any more than Euclidean geometry was safe against the onslaught of non-Euclidean geometry, or Newtonian gravitation against the general postulate of relativity).

(2) The big bang theory is not a direct result of observations that confirm it. It is a model that continually changes according to observations.

(3) Experimental and observational tests need to be continually devised whereby the empirical evidence will either support or refute the model’s predictions. When those prediction fail (i.e., when predictions are in disagreement with observations) the standard model should either be modified or discarded. In other words, substantiation or contradiction should in principle be determinable through successful (or unsuccessful) quantitative predictions compared with observations. The question then arises, when should a model be modified rather be discarded? I would tend to answer that if the modification involved the massive adjunction of entirely speculative entities (vis dark energy and CDM) then we may be better off discarding the model. Indeed, the SNe Ia data signaled a need for a wholesale revision and a major restructuring of a substantial portion of the standard model.

Yes, it is my contention that DE and CDM are but an example of modern cosmological gobbledygook introduced in the face of contradictory evidence, an example of how the standard model is changed rather than discarded when detrimental observations emerge.

The greatest blunder became the greatest revelation.





CC

[modest]

Originally Posted by coldcreation

True, and this is exactly what happened after 1998, in light of the SNe Ia data, which showed that neither of the three Friedmann models (the pre-1998 standard model) could be validated, i.e., the predictions made by the three possible scenarios became obsolete. Thus the standard big bang theory was replaced by the concordance model, lambda CDM (LCDM).

The LCDM model is both a big bang model and a Friedmann universe. It uses the Friedmann metric.

Originally Posted by coldcreation

Correction: The big bang was an idea first. Observations appeared to support it afterwards (not the other way around). I. Kant, E. A. Poe, I. Newton, A. Friedmann had all imagined an initial inferno.

Yup. Big bang was a theory first. It made predictions. Then there were observations which appeared to support it. Yup, yup, yup.

Originally Posted by coldcreation

Furthermore, recent supernova data indicates the expansion of the universe is accelerating (again, unlike the original Friedmann models), these problems cannot be reconciled without a large contribution to the energy density of the universe, aside from baryonic matter, namely a negative pressure (dark energy). This can be viewed as a weakness inherent in the theory.

The concordance model *is* an original Friedmann model. The only difference between the model then and the model now is the value of the parameters chosen for the model—in particular, a non-zero cosmological constant.

The value of the cosmological constant should not be declared by conviction. It should be determined (as for example SNe 1a data). Einstein agrees:

Originally Posted by Einstein

The postulate of general relativity requires the introduction of the [cosmological constant] into the field equations. It will be our factual knowledge of the composition of the starry heavens, of the apparent motions of the stars, and of the state of spectral lines as a function of conditions far from us that will allow us empirically to answer the question whether the [cosmological constant] equals zero or not. Conviction is a good mainspring, but a bad judge!

-source

Sounds reasonable, yeah?

~modest

[enorbet2]

When one wishes to disprove a mechanical assumption the course is very clear. Although there is some doubt now that Galileo actually dropped two different size (and weigh) balls over the side of the Leaning Tower of Pisa, instead he used inclined planes, but still the methodology is the same - set up repeateable experiments that attack the weakest point of the assumption, in this case and since there was not yet an understanding of why things fall at all,.the weakest point is simply whether or not heavier things fall faster than less heavy things.

It would have been foolhardy to attack it by trying to prove that things small enough fall up or worse, that things don't fall at all and that it is just an illusion created by the phenomona that we fall up when we release heavy objects. Things get more complex when we must attack ideas, particularly if they are, or seem, abstract, but the methodology is still the same, attack it where it is weakest. Furthermore, with ideas and their proponents, it is best to attack it where the proponents agree the idea is weakest. As the old saw says "A mind convinced against it's will, remains unconvinced still" . So again given the nature of people as well as problems, attack it where the proponents agree it is weakest, that is as long as your goal is to actually be successful in changing minds and not some other agenda.

The proponents of BBT strongly assert, based on evidence and resolved predicitions, that oldness/flatness, horizon, 1a supernovas, are essentially dead horses that further beating cannot alter the fact that they are dead, in this case dead issues. Dark matter as a concept while not as solid as the above issues, has now been around long enough to have been indirectly observed in several different and independently observed phenomena of which lensing is now the least of the evidence, so large is the catalogue of consistant observation. Dark Energy, although silghtly newer and this having less time to amass such a catalogue of support, but let is not forget that Einstein's general relativity led him to a "negative pressure" that so disturbed him he created the fudge factor that he later determined was the worst mistake of his life, that he hadn't trusted his own mathematics. So in that respect Dark Energy has been around longer than we usually give credit. It dosn't hurt that the existing "hole" happened to nearly exactly match the "size" of the calculations required by observed data. Quantum Gravity and Quantum Loop Gravity while initially interesting have apparently stalled, and Dark Energy still prevails.

Both Dark Energy and Dark Matter are consistant with WMAP and COBE data and in April of this year may get a boost from the Planck Surveyor. The implications of Dark Matter and Energy are disturbing not satisfying and I think it is fair to say that the vast majority of scientists wish it were not so and in the face of that denial *still* were forced to recognize how much they explain and how coherent a picture they complete.

I therefore repeat, if you wish to change minds and have any success at chipping away at as powerful an edifice as is the Standard Model, you must focus on what is widely agreed to be the weakest points - baryogenesis and inflation (recall that several models of inflation have already been ruled out) These are the areas that are most speculartive and likely will take longer to devise any useful experiments that have any hope of being definitive.

One of the ways such experiments are devised is by creating doubt in the minds of well-funded science groups. This cannot be done if you persist on attacking issues they contend are "all over but the shouting" like the so-called horizon problem and others mentioned above. They are however considerably more open to alternate takes on the remaining two and probably especially inflation, since it is less likely that an individual with limited resources can gather important data on baryogenesis, wheras Einstein type "thought experiments" still work on inflation, given sufficient skill in mathematics.

Fortunately for us all, assuming the global economic problems are not allowed to be exascerbated by bad politics, support for cutting edge science is better than it has been in some time (espcially now that the fundamentalist driven drought in the US is finally at end) and many longterm experiments are within a fairly short rime to completion and real results. Let us all hope Large Hadron recovers well and is free from gremlins for a good five years at the least and that the nextgen telescopes proceed on shedule. Then we will have new and exciting data suitable for lively discussion. After all, WMAP is fast approaching the relatively old age (in science these days) of 10 years old.

I'll close with a quote from the WMAP wiki, I think important as a community distillation, that says:

"The WMAP's measurements are more accurate than previous measurements; per the Lambda-CDM model of the universe, the data indicate the age of the universe is 13.73 ± 0.12 billion years old, with a Hubble constant of 70.1 ± 1.3 km·s-1·Mpc-1, and is composed of 4.6% ordinary baryonic matter; 23% unknown dark matter that neither emits nor absorbs light; 72% dark energy that accelerates expansion; and less than 1% neutrinos — all consistent with a flat geometry, and the ratio of energy density to the critical density Ω = 1.02 ± 0.02. These results support the Lambda-CDM model and the cosmologic scenarios of cosmic inflation, and evidence of cosmic neutrino background radiation."

Maguejo says he sees structure in it. Smolin says he sees problems in it's interpretation. Here's hoping Planck Surveyor refines and/or eliminates such issues this year.

[Pluto]

G'day from the land of ozzzzzzz

enorbet said

I'll close with a quote from the WMAP wiki, I think important as a community distillation, that says:

How does it show that the universe is 13.73 Gyrs?

[freeztar]

Originally Posted by coldcreation

Correction: The big bang was an idea first. Observations appeared to support it afterwards (not the other way around). I. Kant, E. A. Poe, I. Newton, A. Friedmann had all imagined an initial inferno.

You are correct. I should have said (which is what I meant) that *modern* BBT (Lambda-CDM) is a direct result of observations that have honed the original BBT.

inflation itself remains on the fringes of science.

How so?

Furthermore, recent supernova data indicates the expansion of the universe is accelerating (again, unlike the original Friedmann models), these problems cannot be reconciled without a large contribution to the energy density of the universe, aside from baryonic matter, namely a negative pressure (dark energy). This can be viewed as a weakness inherent in the theory.

enorbet2 did a great job of explaining why this is not a "weakness" in his post above.

To confirm or refute this prediction (which is fundament to the standard model) telescopes such as The James Webb Space Telescope (JWST) are required. We'll have to wait until 2013, or shortly thereafter, for the results.

If you recall, we've discussed this before on a news release thread of the JWST.
I predict that the results from the JWST will strengthen the BBT, either by providing direct support or recommendations for revision, rather than abolish it.

[Pluto]

G'day From the land of ozzz

Freeztar said

I predict that the results from the JWST will strengthen the BBT, either by providing direct support or recommendations for revision, rather than abolish it.

We should take a poll of how JWST will or will not strengthen the BBT.

I vote that the evidence will be the last nail for the BBT.

If I'm wrong I will have to eat my hat.

[coldcreation]

Originally Posted by modest

The LCDM model is both a big bang model and a Friedmann universe. It uses the Friedmann metric.

The concordance model *is* an original Friedmann model. The only difference between the model then and the model now is the value of the parameters chosen for the model—in particular, a non-zero cosmological constant.

Remember the pre-1998 standard canonical hot big bang Friedmann models predictions:

(1) The favored possibility Ω = 1 describes the universe in which omega is precisely equal to one, the critical density. There is a one-to-one relation between the density of the cosmos and its spatial curvature, i.e., this model has a flat, Euclidean geometry (with zero curvature). The velocity of expansion tends to zero as its radius approaches infinity.

(2) Ω > 1: this model has a closed spherical geometry; it expands and collapses to infinite density in a finite time. There is enough gravitating mass to halt the expansion and reverse it, leading to a big crunch.

(3) The model with Ω < 1 has a hyperbolic geometry and expands for ever, tending to infinity with a finite velocity. The galaxies are undecelerated as there is not enough gravitating mass to stop expansion or to slow it down.

Non of the above predicted an accelerated expansion.

Compare SNe Ia data with the pre-1998 predictions:

Hubble Space Telescope Observations of Nine High-Redshift ESSENCE Supernovae See Figure 13 of the pdf file.

Notice the deviation from linearity. This deviation is the reason why the supposed "age" of the universe had to be revised down from 15 Gyr to 13.7 Gyr post-1998, why universal expansion had to be "accelerating" as opposed to pre-1998 standard model prediction of decceleration or coasting (recall, the latter was the favored Friedmann model, the so-called flat or critical model).

This deviation shown in Fig 13 is also the reason why 96% of the mass-energy of the universe is thought to consist of both nonbaryonic dark matter and an unknown form of energy (dark energy).

This curvature shown in Fig 13 of the above link is why the standard big bang model had to be replaced with the post-1998 Lambda-CDM model.

Originally Posted by enorbet2

...set up repeateable experiments that attack the weakest point of the assumption...

Any assumption pertaining to cosmology can and should be attacked, especially those that remain speculative.

The problem, of course, is that NO direct experiments at all (let alone repeatable) can be devised, concocted, or set up in a laboratory that will validate or falsify inflation, cold dark matter or dark energy, even in principe.

Originally Posted by enorbet2

...it is best to attack it where the proponents agree the idea is weakest...

The above phrase is equivalent to saying 'it is best not to attack it when proponents agree the idea is strongest.' Or simply, 'don't attack the strongest points,' which sound (unintentionally most likely) like an argumentum verbosium.

I am not persuaded by the volume of material that make the inflation, CDM and DE argument sound plausible. Though inflation, CDM and DE superficially appear to be well-researched, pinning down the actual physical properties of these (states, forces or whatever) is too laborious (in that there is no direct supporting empirical evidence) to let slide by unchallenged.

Originally Posted by enorbet2

The proponents of BBT strongly assert, based on evidence and resolved predicitions, that oldness/flatness, horizon, 1a supernovas, are essentially dead

Interestingly enough, the opponents of BBT strongly assert, based on evidence and resolved predicitions, that oldness/flatness, horizon, 1a supernovas, are far from dead.

Inflation, from its inception, was generally accepted proof that the standard model was faltering, lurching from crisis to crisis.

Too, the oldness/flatness, horizon problem are thought to be resolved by the one-and-only inflation theory (you choose the version). Yet you write that inflation is one of the weakest points of the BBT.

Originally Posted by enorbet2

Dark matter as a concept while not as solid as the above issues, has now been around long enough to have been indirectly observed in several different and independently observed phenomena ...

Euclid's Fifth Postulate was around for a couple thousand years, and Newton's theory of gravity for a couple hundred; that doesn't make them right.

Originally Posted by enorbet2

Dark Energy, although silghtly newer and this having less time to amass such a catalogue of support,...Dark Energy has been around longer than we usually give credit. It dosn't hurt that the existing "hole" happened to nearly exactly match the "size" of the calculations required by observed data.

Same counter-argument as above.

The "hole" (96% of the mass energy density) was filled in with "stuff" that may not exist.

Originally Posted by enorbet2

The implications of Dark Matter and Energy are disturbing not satisfying and I think it is fair to say that the vast majority of scientists wish it were not so and in the face of that denial *still* were forced to recognize how much they explain and how coherent a picture they complete.

The deductive argument is invalid because the conclusion doesn't follow from the premise in the manner described. No one should be "forced to recognize" something that may not exist at all. Accepting inflation, CDM and DE diverts attention away from the artifice in dispute rather than address them directly.

Recall when people were 'forced to recognize' the pre-Michelson–Morley-experiment aether.

Originally Posted by enorbet2

I therefore repeat, if you wish to change minds and have any success at chipping away at as powerful an edifice as is the Standard Model, you must focus on what is widely agreed to be the weakest points - baryogenesis and inflation [...] These are the areas that are most speculative and likely will take longer to devise any useful experiments that have any hope of being definitive.

Baryogenesis, I agree, is a weak point. It seems to me nonbaryogenesis (the origin of CDM) would be even weaker.

Inflation is weak for sure (see below).

Originally Posted by freeztar

How so?

There is no way to experimentally distinguish between competing inflation models in the near or distant future. That is because there is no way to test inflation is a vacuum experiment. The false vacuum state, slow-rollover phase transition, are not producible or reproducible. For this reason, and others, inflation remains strictly hypothetical, speculative.

Originally Posted by freeztar

If you recall, we've discussed this before on a news release thread of the JWST.

I predict that the results from the JWST will strengthen the BBT, either by providing direct support or recommendations for revision, rather than abolish it.

I remember. And I hope we can discuss this topic again soon.



CC

[modest]

Originally Posted by coldcreation

Remember the pre-1998 standard canonical hot big bang Friedmann models predictions:

(1) The favored possibility Ω = 1 describes the universe in which omega is precisely equal to one, the critical density. There is a one-to-one relation between the density of the cosmos and its spatial curvature, i.e., this model has a flat, Euclidean geometry (with zero curvature). The velocity of expansion tends to zero as its radius approaches infinity.

(2) Ω > 1: this model has a closed spherical geometry; it expands and collapses to infinite density in a finite time. There is enough gravitating mass to halt the expansion and reverse it, leading to a big crunch.

(3) The model with Ω < 1 has a hyperbolic geometry and expands for ever, tending to infinity with a finite velocity. The galaxies are undecelerated as there is not enough gravitating mass to stop expansion or to slow it down.

Non of the above predicted an accelerated expansion.

Sure they do, and I'm pretty sure we've already discussed this. Here is Carroll 1992. It would be a good read:

http://preposterousuniverse.com/writings/cpt92.pdf

It solves 5 friedmann "models" with different valued parameters,

which can have accelerated expansion,

This paper is from 1992, before the SN 1a findings. The concordance model is a Friedmann universe. It is an exact solution to General Relativity and it is a model of Big Bang theory.

The Freidmann equation can take this form:

Making non-zero doesn't make it NOT a Friedmann universe (and NOT big bang theory)... that wouldn't make sense.

~modest