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Old 24th January 2023, 03:51 PM   #721
jonesdave116
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Originally Posted by Mike Helland View Post
And.......?
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Old 24th January 2023, 03:54 PM   #722
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Originally Posted by jonesdave116 View Post
So, this non-expanding, eternal universe makes no checkable predictions? Not really a hypothesis then, is it?
...
A much older universe would predict a higher ratio of them to main sequence stars than what we actually see.
Which is it?

Yes, it wouldn't make much sense for an old universe to be filled with young things.
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Old 24th January 2023, 04:04 PM   #723
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Originally Posted by Mike Helland View Post
Which is it?

Yes, it wouldn't make much sense for an old universe to be filled with young things.
Wut? Long-lived stars such as white dwarves should be at a higher ratio in a much older universe. Because the main sequence stars, with the exception of red dwarves possibly, should have disappeared. Into supernovae, or by turning into white dwarves.
Unless you think the rate of star formation in galaxies is the same now as it was in the past? Which somehow just keeps replacing the dying stars? There is no indication of that. Yes, there are 'starburst' galaxies and, iirc, they are likely due to recent/ ongoing mergers. Eventually you run out of gas. In particular, generation after generation of stars will burn all the H and He, and you will be making stars out of........well, whatever is left. Which seems unlikely, given the conditions necessary to fuse the heavier elements.

Or.....something is continually reseeding the universe with H and He. Let's call it 'God', for want of a better word.
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Old 24th January 2023, 05:18 PM   #724
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Originally Posted by Mike Helland View Post
According to that link and to no one's surprise, those early galaxies have lower metalicity than later galaxies, thereby disproving the claim that things look the same then as they do now.

Is this your way of conceding that you were wrong?
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Old 24th January 2023, 05:23 PM   #725
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Originally Posted by Ziggurat View Post
According to that link and to no one's surprise, those early galaxies have lower metalicity than later galaxies, thereby disproving the claim that things look the same then as they do now.

Is this your way of conceding that you were wrong?
Originally Posted by Fujimoto, et al
We find that galaxies at z ∼ 8−9 have higher SFRs and lower metallicities than galaxies at similar stellar masses at z ∼ 2−6, which is generally consistent with the current galaxy formation and evolution models.
Bolding mine.

Which is what I was going to comment on before I got sidetracked!
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Old 24th January 2023, 05:37 PM   #726
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Originally Posted by jonesdave116 View Post
Wut?
You said it makes no predictions, then you said it predicted something.
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Old 24th January 2023, 05:39 PM   #727
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Originally Posted by Ziggurat View Post
According to that link and to no one's surprise, those early galaxies have lower metalicity than later galaxies, thereby disproving the claim that things look the same then as they do now.

Is this your way of conceding that you were wrong?
I also posted this:

https://www.quantamagazine.org/stand...inds-20230120/

I'm just following the news. I don't have any particular side.
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Old 24th January 2023, 06:09 PM   #728
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Originally Posted by Mike Helland View Post
You said it makes no predictions, then you said it predicted something.
Well, it is an implicit prediction, which falsifies it! What I was looking for was - 'this model says x,y and z happened, and the evidence for that should be seen if we look at.........'
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Old 24th January 2023, 06:54 PM   #729
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Originally Posted by jonesdave116 View Post
Well, it is an implicit prediction, which falsifies it! What I was looking for was - 'this model says x,y and z happened, and the evidence for that should be seen if we look at.........'
So what should be the specific white dwarf to main sequence ratio (WD/MS) for a universe 10 billion years old? How about 100 billion?

If the dimmest of the white dwarfs out there were any dimmer, would we even see them?

"The usefulness of white dwarf stars as cosmochronometers
was recognized more than 40 years ago by Schmidt (1959),
but it is only in the last decade or so that the potential of white
dwarf cosmochronology reached a practical level of applica-
tion. This is because the intrinsic faintness of the coolest, oldest
white dwarfs in a given population has made them difficult to
observe. In addition, realistic models of such cool, evolved
white dwarfs have also been difficult to compute because of
uncertainties in the input constitutive physics in this extreme
regime of very low effective temperatures."

https://iopscience.iop.org/article/10.1086/319535

It would be interesting to know the WD/MS given by HST, and what JWST eventually reports.
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Old 24th January 2023, 07:02 PM   #730
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Originally Posted by Mike Helland View Post
So what should be the specific white dwarf to main sequence ratio (WD/MS) for a universe 10 billion years old? How about 100 billion?

If the dimmest of the white dwarfs out there were any dimmer, would we even see them?

"The usefulness of white dwarf stars as cosmochronometers
was recognized more than 40 years ago by Schmidt (1959),
but it is only in the last decade or so that the potential of white
dwarf cosmochronology reached a practical level of applica-
tion. This is because the intrinsic faintness of the coolest, oldest
white dwarfs in a given population has made them difficult to
observe. In addition, realistic models of such cool, evolved
white dwarfs have also been difficult to compute because of
uncertainties in the input constitutive physics in this extreme
regime of very low effective temperatures."

https://iopscience.iop.org/article/10.1086/319535

It would be interesting to know the WD/MS given by HST, and what JWST eventually reports.
So, your 'model' makes no predictions, and the evidence that might show it, is going to be invisible even if it were there, so we can't check it? Think you would get that past peer-review?
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Old 24th January 2023, 07:15 PM   #731
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Originally Posted by jonesdave116 View Post
So, your 'model' makes no predictions, and the evidence that might show it, is going to be invisible even if it were there, so we can't check it? Think you would get that past peer-review?
Huh? I don't have a model. You're arguing with something that doesn't exist.

The question is, how many stars are in the Milky Way, how many are white dwarfs, and how many are main sequence?

It seems like the white dwarfs we do observe are usually pretty close, and toward the limit as far as dimness goes for them to be observable.

We know that there are no black dwarfs in our galaxy, because the universe isn't old enough for them to show up.

That could be right. Could be wrong too.

*edit: ChatGPT says*

How many stars are in the Milky Way galaxy?

It is estimated that the Milky Way galaxy contains between 100 billion and 400 billion stars. The exact number is still uncertain and scientists continue to study the galaxy to better understand its structure and composition.

How many white dwarf stars have been observed?

As of 2021, it is estimated that there are around 100 billion white dwarf stars in the Milky Way galaxy. However, this number is based on models and estimates, and it is possible that the actual number could be different. Additionally, this number is likely to be a lower limit, as there may be many white dwarfs that have not yet been observed.

Last edited by Mike Helland; 24th January 2023 at 07:28 PM.
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Old 28th January 2023, 04:44 PM   #732
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Point-like sources among z>11 galaxy candidates: contaminants due to supernovae at high redshifts?

https://arxiv.org/abs/2301.09614
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Old 29th January 2023, 05:50 AM   #733
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Originally Posted by Mike Helland View Post
Point-like sources among z>11 galaxy candidates: contaminants due to supernovae at high redshifts?

https://arxiv.org/abs/2301.09614
This is a draft letter, with title as quoted by Mike Helland, written by Haojing Yan et al. and submitted on 23 Jan 2023.

Here is the last sentence of its introduction, which I am quoting primarily because Mike Helland has quibbled with estimates of H0 other than 74 km s-1 Mpc-1, even though several of the calculations he presented within this thread assume H0 is 70 km s-1 Mpc-1.
Originally Posted by Yan et al.
We adopt the following cosmological parameters: ΩM = 0.27, ΩΛ = 0.73 and H0 = 70 km s-1 Mpc-1.

In the following quotation, "SNe" abbreviates "supernovae" and "Y22" refers to a previous paper by Yan and four co-authors (one of whom is also a co-author of this letter).

Originally Posted by Yan et al.

4. DISCUSSIONS

4.1. Implications of the supernova interpretation

While our result suggests that the point-source dropouts are consistent with being SNe, by no means it proves that they are. One argument against this interpretation is the lack of obvious host galaxies associated with these sources....


4.2 Supernovae as possible contaminants in z > 11 candidate galaxy sample

Y22 cautioned that there could be some new types of contaminators in the z > 11 candidate search that were not encountered before. This current work shows that SNe could be one such type that should be considered if the candidate is point-like....To effectively remove such contaminants, multiple-epoch imaging is probably the most efficient. Due to the time dilation at high redshifts (z ≳ 3 in this context), SNe will not necessarily manifest themselves as transients in the multiple-epoch observations. However, they can be singled out as variable objects.
By the way, that association of time dilation with redshift is not compatible with tired-light theories in which the universe is not expanding.

Originally Posted by Yan et al.
If these point sources are indeed SNe, the contamination rate due to SNe is only ∼10%. Therefore, the tension between the current NIRCam z > 11 candidates and the previously favored model predictions cannot be removed by resorting to this new type of contaminator; the non-point-source candidates cannot be explained in this way....


SUMMARY

In this work, we investigate the problem of the point-like sources in the z > 11 candidate galaxy sample of Y22, which are unlikely Galactic brown dwarf stars. We find that such sources might indeed be a new kind of contaminators to high-z candidate samples: these could be SNe at various redshifts. This somewhat alleviates the tension but does not eliminate it, as there are plenty of non-point-source objects in the z > 11 candidate samples published to date....
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Old 29th January 2023, 09:57 AM   #734
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Originally Posted by W.D.Clinger View Post
By the way, that association of time dilation with redshift is not compatible with tired-light theories in which the universe is not expanding.
That's true.

So an SN in a z=3 galaxy should last 4 times longer than usual (cuz 1+z), right?
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Old 29th January 2023, 10:46 AM   #735
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Originally Posted by Mike Helland View Post
Originally Posted by W.D.Clinger View Post
By the way, that association of time dilation with redshift is not compatible with tired-light theories in which the universe is not expanding.
That's true.

So an SN in a z=3 galaxy should last 4 times longer than usual (cuz 1+z), right?
Pretty much.

See
S Blondin et al. Time Dilation in Type Ia Supernova Spectra at High Redshift. The Astrophysical Journal, Volume 682, Number 2, 2008.
and that paper's preprint.
Originally Posted by Blondin et al.
We present multiepoch spectra of 13 high-redshift Type Ia supernovae (SNe Ia) drawn from the literature, the ESSENCE and SNLS projects, and our own separate dedicated program on the ESO Very Large Telescope. We use the Supernova Identification (SNID) code of Blondin & Tonry to determine the spectral ages in the supernova rest frame. Comparison with the observed elapsed time yields an apparent aging rate consistent with the 1/(1+z) factor (where z is the redshift) expected in a homogeneous, isotropic, expanding universe. These measurements thus confirm the expansion hypothesis, while unambiguously excluding models that predict no time dilation, such as Zwicky's "tired light" hypothesis. We also test for power-law dependencies of the aging rate on redshift. The best-fit exponent for these models is consistent with the expected 1/(1+z) factor.
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Old 29th January 2023, 02:12 PM   #736
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Originally Posted by W.D.Clinger View Post
Pretty much.

See
S Blondin et al. Time Dilation in Type Ia Supernova Spectra at High Redshift. The Astrophysical Journal, Volume 682, Number 2, 2008.
and that paper's preprint.
Looks like they require a free parameter, b. That's pretty standard for cosmology though. Just throw another free parameter at it.

If we see supernovae at z=3, it should be about 4 times longer than usual. It'll be interesting to see if the evidence eventually confirms that.

The only "out" for a non-expanding universe would be that these supernovae that last a little longer at huge distances are selection bias.

Imagine I'm standing in front of you with an orange golf ball in one hand, and a basketball in another hand. As I walk away from you, the golf ball will become invisible to you before the basketball.

It could be that the most distant supernovae we see are actually bigger. That was Jerry Jensen's take:

https://arxiv.org/abs/astro-ph/0404207

"Supernovae Ia (SNe Ia) light curves have been used to prove the universe is expanding. As standard candles, SNe Ia appear to indicate the rate of expansion has increased in the past and is now decreasing. This independent evaluation of SNe Ia light curves demonstrates a Malmquist Type II bias exists in the body of supernova data. If this bias is properly addressed, there is very little budget for time dilation in the light curves of supernova. A non-relativistic distance modulus is proposed, which is based on the predictable attenuation of light by an intergalactic CREIL (Coherent Raman Effects on Incoherent Light) radiation transfer functions. "
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Old 29th January 2023, 04:59 PM   #737
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Originally Posted by Mike Helland View Post
Looks like they require a free parameter, b. That's pretty standard for cosmology though. Just throw another free parameter at it.
Your remark reveals profound misunderstanding of the paper's section 4.

The authors introduced that exponent b as a free parameter that sets up an elegantly simple and easy-to-understand empirical contest between general relativity (which predicts b=1) and tired light theories such as Zwicky's and yours (which predict b=0).

Originally Posted by Blondin et al.
Again, we performed a least-squares fit to the entire sample, and also to the individual high- and low-redshift samples (see Table 4). The data constrain the b exponent to 10% (1σ), and yield b = 0.97 ± 0.10 for the entire sample (Fig. 8; dotted line and gray region) and b = 0.95 ± 0.10 for the high-redshift sample.
In other words, general relativity's prediction that b=1 is compatible with the data, while tired light's prediction that b=0 is clearly incompatible with the data.

Section 4 goes on to assess the statistical significance of that finding, but there's no point talking about that analysis when you don't even understand the purpose of the free parameter b.

Originally Posted by Mike Helland View Post
It could be that the most distant supernovae we see are actually bigger. That was Jerry Jensen's take:

https://arxiv.org/abs/astro-ph/0404207
According to ResearchGate, that is the one and only scientific paper Jensen has ever claimed to have written. Jensen wrote it in 2004, five years before the paper by Blondin et al. I enjoyed the third paragraph of Jensen's abstract:
Originally Posted by Jerry Jensen
Without relativistic expansion, new explanations are required to explain background radiation and light element synthesis. An electro-gravimetric energy transfer function activated at extremely low temperatures in molecular hydrogen by a Bose-Einstein condensation is proposed as a candidate mechanism. This proposed solution to Obler’s paradox hints of a tantalizing link between the large numbers theories of Mach and Dirac and a non-Friedman field limited gravimetric tensor. This is a highly speculative reintroduction of Hoyle’s steady-state cosmology.
"Highly speculative" was an apt description of the paper.

Here's a bit of more recent crackpottery along the same lines. As discussed at PhysicsForums:
kurros: I'm not a cosmologist, but my gut reaction from that abstract is that it is a load of garbage....

kurros: It seems like this guy has been on a bit of crusade to prove that the universe is static....

kimbyd: ...my initial guess is that they used measurements of light curves which already corrected for the time dilation. Naturally you wouldn't expect to see any time dilation after they had already corrected for it.

kimbyd: Indeed this is his problem....the time is rest-frame time. Time dilation is already factored out. So Crawford's result is the result of a supremely basic misunderstanding of the data.
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Old 29th January 2023, 05:33 PM   #738
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Originally Posted by W.D.Clinger View Post
kimbyd: ...my initial guess is that they used measurements of light curves which already corrected for the time dilation. Naturally you wouldn't expect to see any time dilation after they had already corrected for it.

kimbyd: Indeed this is his problem....the time is rest-frame time. Time dilation is already factored out. So Crawford's result is the result of a supremely basic misunderstanding of the data.
Uh, that's in reference to a completely different paper.

Jensen's paper on page 4 says:

Quote:
By correcting for time dilation before selecting a ‘template’ for curve matching, Goldhaber may underestimate the true magnitude. If the Malmquist bias is proportional to the redshift, and it should be, this method of analysis rolls this magnitude bias right into the time dilation factor.
So, I guess its a matter of identifying all the biases and factors and also correcting for them in the right order.

He goes on to say:

Quote:
This same argument can be made with the most basic piece of statistical data: Supernovae rise times: In the local universe, the average rise time is 20 days, but in the redshifted universe; it is 17.5 days, which again, would tend to indicate more distant supernova are smaller (Li). If this time dilation factor is removed, the high redshift sample has an average rise time of about 25 days. (Email from Filippenko). This is too long for normal Ia, but not if the distance modulus and the corresponding attenuation factor are underestimated. In this case, the higher redshifted SNe Ia would indeed be over-represented by very high magnitude ‘peculiar’ Ia, or hypernova. Credence is given to this conjecture by the fact the number of supernova actually found in high redshift surveys represent only a small fraction (~4%) of the expected yield (Tonry)

In 1998 a very peculiar supernova was observed. SN 1998bw is the brightest supernova ever seen in the 'local' universe (redshift z = 0.0085). It also has the longest blue light curve, dimming less than one magnitude in more than 28 days (Galama). This is especially unusual because SN 1998sw has a spectrum similar to the core collapse class SN Ic , which normally burn faster and dimmer than supernova Ia. Recently SN 1998bw has been reclassified as a hypernova (Iwamoto). The magnitude, light-curve, and associated gamma ray burst may indicate asymmetric burning of a binary pair (Hoeflich). Until SN 1998 was observed, there were no known local supernova events with light curves as long as the small sample of events at high redshift (Leibendgut).

The implications for using supernova Ia as cosmic indicators could not be clearer: If SN Ic can burn in a hypernova state, is it possible for SN Ia to burn as a binary pair as well? Could SN Ic at cosmic distances be mistaken for a binary pair which includes a SN Ia? What separates a SN Ia from SN Ic? In theory, a Type Ia is a critical mass explosion of a white dwarf, while types Ib, Ic and II are core collapse supernovae. Since SN 1998bw, at least four additional Ic have been identified as hypernova (Nomato, see also Bennetti on the difficultly of classifying SN 2002bo). Three of these four are the most energetic supernova events in the local universe (Matheson). If local hypernovae occur, they should also be observed at higher redshift, and since a local SN Ic is the brightest local event ever, very bright Ic hypernovae should also be manifest at higher redshifts, with extremely long time-dilated light-curves. Where are they? Are the supernovae observed at high redshifts truly small, time-dilated Ia supernova, or hypernova events like local Ic, with little or no time dilation?

In other words, it's not that the distant universe has smaller supernovae that are time dilated, it has larger hypernovae that are easier to detect than supernovae, which is why we detect them.

I'm not saying he's right. And I'm definitely not agreeing with him about bringing back a steady state universe (which is still an expanding one, I'm not sure why that's chronically incorrectly understood).

But if a non-expanding universe had any chance, it would have to show that time dilation in supernovae light curves is not actually time dilation, but much larger explosions in the universe than we think.
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Old 29th January 2023, 06:21 PM   #739
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Originally Posted by Mike Helland View Post
In other words, it's not that the distant universe has smaller supernovae that are time dilated, it has larger hypernovae that are easier to detect than supernovae, which is why we detect them.
Type 1a supernovae are standard candles. They all have identical light curves in their rest frame because of their mode of action (gradual accretion in a white dwarf up to the Chandresekhar mass).
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Old 29th January 2023, 06:35 PM   #740
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Originally Posted by hecd2 View Post
Type 1a supernovae are standard candles. They all have identical light curves in their rest frame because of their mode of action (gradual accretion in a white dwarf up to the Chandresekhar mass).
Of course. Everyone knows that.

But is it 100% true?

Page 3:

Quote:
Of celestial events, the explosions of supernovae are among the rarest and most spectacular. A supernova Ia (SN Ia) is thought to be the death throws of a white dwarf star depleted of light, fusionable elements. A supernova has accreted enough mass to exceed the Chandrasekhar limit,meaning all baryonic matter is compacted into a critical state. The remaining fusionable matter, consisting primarily of 12carbon and 16oxygen, complete a thermonuclear sequence into 28silica, 56nickle, 56cobalt, and finally 56iron, while the nova explodes in a final, brilliant nuclear spasm.(Arny). The unique spectral fingerprint, and narrow range of magnitude of this brilliant explosion makes SN Ia excellent ‘standard candles’ for measuring distances.

Characteristic of supernovae Ia are the shapes of the light-curves over many days, both approaching and receding from maximum luminescence (Fig 1). In 1939, Wilson hypothesized that if these supernovae could be identified at high Doppler shifts (redshifts), the time dilation characteristics of an expanding universe could be verified by plotting the light-curves of supernovae that exploded eons ago, and comparing them with ‘local’ supernovae (Leibundgut).

For example, assume a local supernova Ia (SN Ia) dims by one magnitude from its peak magnitude in fifteen days. Now assume an exactly identical supernova is moving away from our galaxy at about half the speed of light (redshift ≅ 0.5). In an expanding universe, this twin supernova would appear to explode more slowly, losing one magnitude in 22.5 days {(1+0.5) x 15 days}.

Current interpretations of supernovae Ia light curves at high redshift distances support this thesis. However, as the database of supernovae light-curves expands, it has become evident that even the most carefully defined SN Ia exhibit light-curves that vary in absolute magnitude (Figure 1). Even though the variance in magnitudes is relatively small, the light-curves (in days) vary significantly. Longer light-curves correlate with higher magnitude SNe Ia. (Goldhaber 1996, Hamuy 1996.)
Then on page 7:

Quote:
The implications for using supernova Ia as cosmic indicators could not be clearer: If SN Ic can burn in a hypernova state, is it possible for SN Ia to burn as a binary pair as well? Could SN Ic at cosmic distances be mistaken for a binary pair which includes a SN Ia? What separates a SN Ia from SN Ic? In theory, a Type Ia is a critical mass explosion of a white dwarf, while types Ib, Ic and II are core collapse supernovae. Since SN 1998bw, at least four additional Ic have been identified as hypernova (Nomato, see also Bennetti on the difficultly of classifying SN 2002bo). Three of these four are the most energetic supernova events in the local universe (Matheson). If local hypernovae occur, they should also be observed at higher redshift, and since a local SN Ic is the brightest local event ever, very bright Ic hypernovae should also be manifest at higher redshifts, with extremely long time-dilated light-curves. Where are they? Are the supernovae observed at high redshifts truly small, time-dilated Ia supernova, or hypernova events like local Ic, with little or no time dilation?
If there are hypernovae nearby, but only smaller supernovae at higher z's, isn't that a bit suspicious?
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Old 29th January 2023, 06:44 PM   #741
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Originally Posted by Mike Helland View Post
Uh, that's in reference to a completely different paper.
As was clear from my phrasing and also from the link I supplied.

Originally Posted by Mike Helland View Post
Jensen's paper on page 4 says:

...snip...

He goes on to say:
Originally Posted by Mike Helland View Post
Page 3:

Then on page 7:
Let the archives record that Mike Helland is quoting an old and unpublished manuscript, which is the only scientific paper ever written by its author. Its abstract accurately describes the paper as "highly speculative".
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Old 29th January 2023, 06:51 PM   #742
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Originally Posted by W.D.Clinger View Post
As was clear from my phrasing and also from the link I supplied.

Let the archives record that Mike Helland is quoting an old and unpublished manuscript, which is the only scientific paper ever written by its author. Its abstract accurately describes the paper as "highly speculative".
The paper makes some claims toward the end that is describes as highly speculative. There's no need for that type of dishonesty.

Here's a different source:

https://www.researchgate.net/figure/..._fig4_50893590
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Old 29th January 2023, 07:14 PM   #743
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Originally Posted by Mike Helland View Post
The paper makes some claims toward the end that is describes as highly speculative. There's no need for that type of dishonesty.
Everything I wrote in that post is unquestionably true. It was dishonest of you to pretend my true statements were dishonest.
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Old 29th January 2023, 07:20 PM   #744
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Originally Posted by W.D.Clinger View Post
Everything I wrote in that post is unquestionably true. It was dishonest of you to pretend my true statements as dishonest.
"Its abstract accurately describes the paper as 'highly speculative'."

No, it doesn't.

It's not a journal paper, it was a conference paper. The 3rd paragraph of the abstract is abstract:

"Without relativistic expansion, new explanations are required to explain background radiation and light element synthesis. An electro-gravimetric energy transfer function activated at extremely low temperatures in molecular hydrogen by a Bose-Einstein condensation is proposed as a candidate mechanism. This proposed solution to Obler’s paradox hints of a tantalizing link between the large numbers theories of Mach and Dirac and a non-Friedman field limited gravimetric tensor. This is a highly speculative reintroduction of Hoyle’s steady-state cosmology."

And from the paper:

"Part VII: Is a highly speculative attempt to frame a steady state cosmology without invoking a cosmological constant, substituting instead field-limited gravity. A CREIL mechanism is also proposed for the celestial radiation transfer functions necessary in the balance of this paper."

The other six parts of the paper are not what you are construing it to be.
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Old 29th January 2023, 07:46 PM   #745
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Originally Posted by Mike Helland View Post
It's not a journal paper, it was a conference paper.
Mea culpa. The preprint page says the paper was "To be presented at the APS April Conference, May 4, 2004 Alternative Redshift Session, Denver CO". The online program for that session, which was chaired by Jensen, does indeed list Jensen's paper as "Session V13.002".

The title of the following paper, for paper V13.010, may give some idea of how hard it was to have a paper accepted for presentation in that section of that physics conference:
Schools Of Up to A Dozen Animal Skeletons, Each In Form of the Ellipitcal Letter "O", Ranging in Height From 4 Inches to Over 1 Ft. and Body Thickness of 1/2-3/4 Inches, Have Been Found Embedded in Top 1 of Only 2 Extruded Limestone Streambeds That Run Across West Face of Grandeur Pk., Wasatch Range and Then Turn East, Going Upstream, to Church Fork (or Park), Millcreek Canyon, Remaining Separated. Lower Streambed Was Not Examined Beyond West Face. Various Other Skeletal Structures Exist and Strata of Seashells Have Previously Been Shown(1), Esp. in Antitributary Streams.
The word "Ellipitcal" is spelled as in the program. The next-to-last sentence of that paper's abstract, with grammar as in the program, says
If one we a bioevolutionist he might surmise that the "0" skeletons are a forerunner of our present-day turtle, even though no leg bones accompany the "0".
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Old 29th January 2023, 09:00 PM   #746
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Originally Posted by W.D.Clinger View Post
Mea culpa. The preprint page says the paper was "To be presented at the APS April Conference, May 4, 2004 Alternative Redshift Session, Denver CO". The online program for that session, which was chaired by Jensen, does indeed list Jensen's paper as "Session V13.002".

The title of the following paper, for paper V13.010, may give some idea of how hard it was to have a paper accepted for presentation in that section of that physics conference:
Schools Of Up to A Dozen Animal Skeletons, Each In Form of the Ellipitcal Letter "O", Ranging in Height From 4 Inches to Over 1 Ft. and Body Thickness of 1/2-3/4 Inches, Have Been Found Embedded in Top 1 of Only 2 Extruded Limestone Streambeds That Run Across West Face of Grandeur Pk., Wasatch Range and Then Turn East, Going Upstream, to Church Fork (or Park), Millcreek Canyon, Remaining Separated. Lower Streambed Was Not Examined Beyond West Face. Various Other Skeletal Structures Exist and Strata of Seashells Have Previously Been Shown(1), Esp. in Antitributary Streams.
The word "Ellipitcal" is spelled as in the program. The next-to-last sentence of that paper's abstract, with grammar as in the program, says
If one we a bioevolutionist he might surmise that the "0" skeletons are a forerunner of our present-day turtle, even though no leg bones accompany the "0".
Ha.

In any case.

Are supernovae smaller at z=0.5?
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Old 30th January 2023, 02:58 AM   #747
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Originally Posted by Mike Helland View Post
Ha.

In any case.

Are supernovae smaller at z=0.5?
Type 1a? No.
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Old 30th January 2023, 03:31 AM   #748
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Originally Posted by hecd2 View Post
Type 1a? No.
Do they all have the same magnitudes and number of days between epochs? 18 for the first one:

Quote:
We have obtained high-quality Keck optical spectra at three epochs of the Type Ia supernova 1997ex, whose redshift z is 0.361. The elapsed calendar time between the first two spectra was 24.88 d, and that between the first and third spectra was 30.95 d. In an expanding universe where 1 + z represents the factor by which space has expanded between the emission and detection of light, the amount of aging in the supernova rest frame should be a factor of 1 / (1 + z) smaller than the observed-frame aging; thus, we expect SN 1997ex to have aged 18.28 d and 22.74 d between the first epoch and the second and third epochs, respectively.
https://arxiv.org/abs/astro-ph/0504481

Is the first epoch from its peak to down a magnitude?
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Old 30th January 2023, 05:03 AM   #749
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Originally Posted by Mike Helland View Post
That preprint, by Foley et al., was submitted in 2004, four years before the Blondin et al. paper was submitted in 2008. Foley and two more of that preprint's six authors were co-authors of the Blondin et al. paper. Blondin et al. discuss the Foley et al. results here:
Originally Posted by Blondin et al.
As of today there are two published examples of aging rate measurements using spectra of a single SN Ia (SN 1996bj at z = 0.574, Riess et al. 1997; SN 1997ex at z = 0.362, Foley et al. 2005). In both cases, the null hypothesis of no time dilation is excluded with high significance (> 95%).

And also here:
Originally Posted by Blondin et al.
We note that comparing the inverse of the slope in Fig. 6 (denoted “age factor” by Foley et al. 2005) and (1 + z) leads to asymmetric errors. The errors on the “age factor” [≡ (1 + z)] become highly non-Gaussian when the uncertainties of the individual age measurements are large (≳ 1 d, as is the case in this paper, and in Foley et al. 2005 for SN 1997ex), whereas the errors on the aging rate [≡ 1/(1 + z)] are always Gaussian. This is illustrated in Fig. 7 using a Monte Carlo simulation of the age measurements for SN 1997ex presented by Foley et al. (2005). Using the same errors on the individual age measurements, the distribution of the slope measurements is highly non-Gaussian in (1 + z) space, while it is normally distributed in 1/(1 + z) space.

And the Foley et al. paper is cited in a couple of other places, including here:
Originally Posted by Blondin et al.
Given the rapid and predictable evolution of SN Ia spectral features with age, as well as the relative homogeneity of SN Ia spectra at a given age, one is able to determine the (rest-frame) age of a single spectrum with a typical accuracy of 1–3 d (Riess et al. 1997; Foley et al. 2005; Hook et al. 2005; Howell et al. 2005; Blondin & Tonry 2007).

Last edited by W.D.Clinger; 30th January 2023 at 05:05 AM. Reason: added link to preprint by Blondin et al.
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Old 30th January 2023, 08:47 AM   #750
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Originally Posted by Mike Helland View Post
Do they all have the same magnitudes and number of days between epochs? 18 for the first one:
No


Quote:
https://arxiv.org/abs/astro-ph/0504481

Is the first epoch from its peak to down a magnitude?
No. See here.
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Old 30th January 2023, 02:09 PM   #751
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Originally Posted by hecd2 View Post
No

No. See here.
Thanks.

Regarding this figure:

https://www.researchgate.net/figure/..._fig4_50893590

It's from this paper:

https://arxiv.org/abs/1103.5870

Which is rather large. I can't tell if the SNe in the figure are around the same z or not.

And if the same stretch factor is applied to all of them? Jensen seems to be saying that it isn't.
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Old 30th January 2023, 04:18 PM   #752
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https://arxiv.org/abs/2301.11413

A massive quiescent galaxy at redshift 4.658
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Old 30th January 2023, 04:52 PM   #753
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Originally Posted by Mike Helland View Post
Thanks.

Regarding this figure:

https://www.researchgate.net/figure/..._fig4_50893590

It's from this paper:

https://arxiv.org/abs/1103.5870

Which is rather large. I can't tell if the SNe in the figure are around the same z or not.

And if the same stretch factor is applied to all of them? Jensen seems to be saying that it isn't.
They are from the Calan/Tololo survey. They are at various distances. The curves shown are after the distance correction and scaling for time dilation are applied. The upper panel shows that most fall on the same curve but there are a small number of outliers. The lower panel shows that they all fall on the same curve if the Phillips correction for absolute luminosity is applied to the small number of outliers. SN1a curves exclude no time dilation according to the 1/(1+z) relationship to high confidence.
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