This article states that a large data set of Supernva 1a's rules out "all" cosmologies (of the CDM type I think).

It seems SN 1a's are not very good standard candles (or CDM models fail), and we're back to square 1, namely understanding how a supernova explosion really works.

Cheers.

Yes and no, applying orthodox statistics and data reduction methodology, supernova Ia ruled out all expansion-based cosmologies at least four years ago. This is not big news to cosmologists and supernova researchers, who have had to come up with new techniques for data reduction every time the field of vision has enlarged and the supernova range extended.

There has not been deception in the treatment of the data, just a Herculian attempt to reduce the data in a way that mates in some plausible manner with existing theoretical constraints.

The problem is not so much with the understanding of how a supernova explodes, as with the root theories supernova are burning against.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

Four years ago.... let's see, that would be 2001. Perhaps you can explain, then, this 2001 Physics Today article, Farthest Supernova Strengthens Case for Accelerating Cosmic Expansion, that does rather the opposite of "ruling out expansion-based cosmologies."

Regarding the article cited by VanderL, it is my understanding that these "xxx.lanl.gov" papers are not peer reviewed. Are you, VanderL or JerryJ, qualified to verify that the author's methods, mathematics, assertions, and conclusions do not contain fatal errors? Are you qualified to verify that this paper is not a spoof, designed to look very professional and convincing, yet the author is cleverly deceiving his audience to see how many "fall for it"? If you are so qualified, have you carried out the verification?

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Everyone is entitled to his own opinion, but not his own facts.

Are you? Have You? Does it matter? Are you implying that the article is a lie?

The site is a mirror site of the on-line arXive/astro-ph database, mostly manuscripts being prepared for publications. Many researchers use it to have their papers out complete and PDF format. As an example:
Vishwakarma has published other papers on SNe and cosmology, see this list.
I think you are better advised to think about the implications of the article than worry about my, or others' "qualifications".

Cheers.

Aren't the implications of the article moot if it doesn't hold together under scrutiny?

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

We've discussed this before on post#'s 20-24 of this thread . The review status of papers on ArXiv can be found in the comments section of the abstract. Some papers are posted after they have been reviewed and accepted by a journal. Some are posted after submitted for review. And some are just posted. You can also check ADS for older ArXiv papers to see if the paper was eventually accepted.

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"The scientist who asks the right question reconnoiters a new patch of the unknown, and may, with luck, bring it within the constricted but expanding boundaries of the known."

~Timothy Ferris (The Red Limit) 1982

Absolutely.

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Everyone is entitled to his own opinion, but not his own facts.

There is no need for these papers to be "per reviewed", as that system doesn't make much sence anymore. The amount of research material every day greatly exceeds physical possibility to find so many reviewers and there is no time either. The autor gave us his methodology and it should be enough to judge the papers quality.
Of course, arXiv library has itself censorship, so I don't believe every crackpot would be allowed to put it's woo-woo in it.
(Yeah, I know, someone will point the finger on O.M.-M.M. axis :-))
Thank you VanderL for bringing this paper to attention (I read it on the first day). It might be an idea to preserve this thread just for "alternative" arXive papers, as we have so many threads dealing with "against Bing Bang".
I'm lost in so many threads without structure ("mass exodus..." i.e.).
If we could hold us to one item per thread it will be great and I appreciate Nereids attempts to bring the order into the chaos.
As I see it, this paper states that Supernovae Ia data (up to z~1,5) are not compatible with WMAP data.
It's not the only paper that raises question about SN Ia data (and it's interpretations = "accelerated" rate of expansion, cosmological constant...).
We have some with questions like: "Where are hypernovae?", "Where is Quasars time dilation?", "Why do light curves of distant SN Ia, despite all, differ from those of nearby?"
If it turns out that Universe is not accelerating, 50% of papers published in arXiv will be worthless.
Inclusive those per-reviewed.

This observations may suggests many questions:
1. Are the supernovae always identical in all environment ?
2. Is the expansion of our Observable Universe because of a hidden space energy or because an energy supplying from outside ?

Mike T comment
I do not give much credibility to the SN 1a's data.
White dwarf masses and temperatures vary from 1/4 to 3/4 solar masses (guess) and from 3000K to 100,000K. With these large variations, can you expect their data to be accurate?

And more importantly, I consider all explosions in space to be the result of bodies impacting the stars. All these bodies like meteroids, asteroids and even planets contain 'oxides' that break down to release the oxygen. This, of course creates the explosions that blast out free electrons. some positive ions and a lot of water and star dust.

To me, the best distance indocator would be the cosmological redshift with corrections for the Arp redshift anomaly by using the observed emitting temperature of the emitter.

Sure, but it did hold under my "scrutiny" (but alas, I'm no expert), I could wait until the rest of the world discovers this article and subjected it to their scrutiny and wait for a verdict, or I could post it in this forum and discuss the findings. I included a list of publications that cover the same ground mostly, so I think this author really has a point and presented the point well. Do you think there is anything wrong with the work in this paper?

Cheers.

Supernovae 1a's are the result of abrupt triggered fusion, not bodies impacting. Type 2's are from core collapse with both gravitational, and nuclear binding energy involved, not bodies impacting. Both types are asymmetrical, and produce remnants that are prolate spheroids...kind of football shaped. The luminosity of the expanding fireball for the optical display will depend on your viewing angle. Different ejecta velocities have different cooling rates and the luminosity is both surface area, and temperature dependent. The type 1a standard needs polarimetry data using Faraday rotation curves of the remnants as they age to properly determine viewing angles and then retrofit luminosities.

You could be correct - but it would be difficult to get a spoof posted in archives, and it would be deleted just about as quickly. The papers are not peer reviewed, but authors must have established credibility, in terms of qualifications, recommendations, and publications. The author in this case, is extracting from a very large body of supernova data, and while I agree peer review is important, so are good data reduction techniques. This authors conclusions are close to this assessment:

http://lanl.arxiv.org/PS_cache/astro...10/0510155.pdf

By a formidable array of Supernova Ia researchers:

4-sigma is a long ways from a comfortable agreement, so the for the author of the paper Vander cited's, to conclude that supernova Ia may not be great cosmic distance indicators is reasonable...(not that I agree.)

'PRES' is at least the sixth supernova data reduction technique I have seen introduced in the last six years. (M(b50), MCLC, MCLC, CMAGIC, "Stretch"). So the researchers are still trying to come up with a methodology that does not have to change every time a new crop of supernovae are examined.

edit: gramatical clarification

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jwj

It's a big universe out there...is it really unwinding, really burning out?

TravisM,

Is this all you have to say about the paper in question? Does it hold under your scrutiny?

Cheers.

Cougar, while of course I disagree, what about the rest of my post, does this paper contain any obvious mistakes?
Given the fact that the author is knowlegdeable and has published many papers on this subject before, is he right in his assertion that the SNe 1a data indicate that they are inconsistent with the currently accepted cosmological model(s)?

You haven't addressed anything important, just the usual attempt to discredit the person asking the question (plus accusing the author of the paper of producing a "spoof").

Cheers.

I tend to distrust conclusions based on the behaviour of cosmologically distant supernovae.

How do we know the distance of the supernova? Presumably by its redshift.

How do we know the brightness of the supernova? Presumably by its decay curve.

But the same factor that causes the redshift would also change the decay curve. During the time where the supernova loses, say, half of its luminosity, it has produced a certain number of wavecrests. This same number will arrive here during the time where we see the supernova lose half its brightness. As these wavecrests arrive at greater intervals in time (redshift), the decay must seem slower too.

This phenomenon must occur, whatever the real cause of the redshift, i.e. whether the supernova is distant or not, whether its motion is peculiar or cosmological, and whether the universe expands or not.

Did "they" try to correct for this phenomenon? I have never seen it mentioned anywhere.

If "they" did not, what would the result be? The result would be that the supernova seems dimmer than it should be. Just what "they" found, and from which "they" concluded that the expansion is accelerating, or that all cosmologies must be wrong.

If I had to guess, I would guess that the universe is in fact expanding, but not with an accelerating expansion. I would rather expect the expansion to decelerate.

This paper an inhomogeneous alternative to Dark Energydeals with SNIa data, too.

I wrote since one year - the Dark Energy is an energy supplied from outside and our Observable Universe is surrounded by this energy. A visible matter and this energy together allow for flat geometry. The Universe around as is underdense but with the energy supplied from outside and surrounded our Observable Universe is it just enough.
This energy drives the galaxies too - Dark Matter is it Dark Baryon Matter + Dark Energy of Birkeland and other intergalactic streams.

Search a Black Hole objects - they will show us a truth.

This was a simple statement that was self contained.
I haven't read the paper yet.

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

As I said, I just got done reading this thread and haven't event tackled reading the paper yet.
I rarely browse this site, as I've recently been married Any free time I have I typically wase on, you know, video games, playin guitar in the band, college classes.

I am reading the paper now, and will report back to you.

I appologize for the time it took for me to respond.

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

Comments, as I'm reading through the article:

First, I've never seen an exclimation mark in the title of a paper before. I found that strange. If this is normal, I wouldn't know as I haven't read a whole lot of papers before.

There seems to be a lot of math that I don't readily understand in this document. I've not really had enough exposure/training in math as I could hope to. Hopefully going back to college will fix this.

Outside of that, I can't even say if the mainstream idea of SNIa's is correct, from my own observation/reduction of the data. I just don't understand the maths.

Closing, I think most cosmologists know what they're doing and await the group to lead me to the layman's version of the next big thing.

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

Thanks for taking the time to look at the paper and answer my questions, I was getting a bit frustrated by a perceived lack of interest in discussing the paper and seeing some replies that only questioned either my or the author's credibility (sorry for lumping your reply on the same heap). I guess this paper is quite technical and concentrates mainly on statistical arguments but the author's conclusion is that, based on an extensive SN 1a data set, either the concordance cosmology is incorrect, or SN 1a's are not standard candles.

I agree that the title is provocative, but the message is clear; even the concordance model could be on shaky grounds, there's no reason to think we already have the answer, or even the right direction (expansion). So, I'm not so sure cosmologists know what they're doing, they seem to be overly sure about many unproven assumptions.

Cheers.

P.S. Does getting married take the fun out of participating in this forum?

In all that math that I don't understand, is there room for error? I would hope that that the "people in charge" of modern cosomology know what they're about.
I'm just a guy that likes physics, mostly of the quantum sort, the kind we observe here on earth. When we model real events that follow our preceived notions of space and time and they tend to match observation, I'd like to think that we've hit the mark. The idea that all spaces and times should be treated as 'equal' has an appeal that's hard to budge.
However, with symmetry breaking taking a foothold in the evolution of the universe, not only my own favor, but the community at large, it's not such a leap of the imagination the universe behaving 'differently' at periodic intervals. Which is not too mainstream a statement...

__________________

Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

I think it might be more fundamental than the analysis in the paper, there are a number of things that need to be true for SNe 1a before they can be used as cosmological probes. It is assumed that the mechanism for a SN explosion is well understood and they can be used as "standard candles", it is also assumed that there are no intrinsic redshifting mechanisms influencing the data, SN lightcurves need to be "processed" first before any conclusions are drawn (see Jerry's post on the different data reduction techniques).

All of these factors could produce errors in the SN 1a data, both in showing accelerated expansion and the analysis in this paper. But this paper uses the same techniques as Perlmutter, Riess and all the others claiming the Universe is in an accellerated expansion phase and reaches a totally different conclusion. How is this possible? If the same data can be used to show something mutually exclusive (as I interpret this) there must be something "fishy". My conclusion would be that there is something wrong with the assumptions.

Cheers.

This paper as above is another alternative how to explain a redshift of the supernovae. Our Universe till 6 billions years ago seems homogeneous but how is it exactly in the farthest space ?
We know the Supergalactic Walls. There is may be a higher hierarchy.
According a flat geometry in our Universe is anywhere an invisible mass. If we do not see it around us , it is far away , may be.

Homogeneous universe is still an open question IMO. There is ongoing debate, where the group of people findes our universe inhomogeneous with fractal distribution of matter up to 100 Mpc, directly questioning fundamental assumptions of Bing Bang Theory : the homogenity and the isotropicness of our universe. (The Cosmological Principe)
Just to provide a link (outside arXiv) Large scale distribution of galaxies
This treatise is somehow different, the underdense bobble required for SN data to show no accelerated expansion has the same weakness as current BB model, it places us at the special place in the universe.
But, it's not impossible.

Thermal balance or thermal expansion of the Universe ?
A Galaxy Cluster with 10^15 solar masses (10^45 kg) is attracted from distance 10^8 ly (10^24 m) by next Galaxy Cluster with a gravitationally force of 10^32 N.

There are everywhere photons pushing from a Cosmic Voids onto this Galaxy Clusters.
There are about 4x10^-14 J/m^3 energy of CMBR and other photons – This photons press 4x10^-14 N/m^2 the Galaxy Clusters cross-section about 10^46 m^2 with force about 10^32 N.

If the photons are coming from outside the Cosmic Voids bubbles may expands faster and faster without any additional mysterious Dark Energy (Gravity diminishes with distance^2, flat geometry requires energy supply with distance^1).

This is really a striking paper if it has any validity. Is Vishwakarma indicting other SN1a researchers for fitting data to match their predictions?

"However, the introduction of Sint in equation (12) is justified only when we use independent measurement uncertainties Sint,j on the parameter, instead of using it as a free parameter. The latter case is just equivalent to increasing the error bars suitably in order to have a desired fit. In this way one can fit any model to the data ... This shows that the approach does not have any predictive power."

"the present approach (which is equivalent to assuming that the data have a good fit to the model) prohibits an independent assessment of the goodness-of-fit-probability P, in the absence of which the estimated parameters do not have any significance"

"The situation has worsened to the extent that the most recent SNe Ia observations made by the Supernova Legacy Survey (Astier et al. 2005) are analyzed in a way which does not address the goodness-of-fit of the data to the models, rather it assumes that the data have a good fit, and just estimates the parameters of the models. However, it may be noted that unless we have a credible goodness-of-fit, the whole parameter estimation becomes suspect." (emphasis from source)

It appears that Vishwakarma either greatly overemphasizes the value of goodness-of-fit-probability, greatly misunderstood the Astier et al. paper, or has noticed a faulty trend in SN1a research. It'd be interesting to see if any authors of the studies he examines take contention with his analysis.

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there is no governor anywhere

It sure would, however I think there is still a lot of uncertainty about the SN 1a data, even among astronomers supporting an accelerated Universe model. But if nobody shows exactly where the errors are, the model stands. Maybe this paper is a "reality check".

Cheers.

I recall watching (I believe it was) a Nova program, with supernova hunters collecting spectra from automated search telescopes. They were pretty routinely discarding spectra that had mixes of elements in the ejecta that looked "too messy" was the expression, from their expectations.Here I was thinking that the models should fit all the data. Pete