The finding that distant Type Ia supernovae are dimmer than expected has led to the notion that the rate of expansion of the universe is accelerating. I suggest an alternative model in which the extra dimness is caused by a postulated intrinsic small blueshift in these supernovae. (I should perhaps add at the outset that I do not support the Big Bang model, but rather a static, equilibrium-type model; that's probably why I automatically question this idae of universal acceleration.)

Here is the basic idea. When multiple redshifts are involved in observations it is incorrect to simply add them up, as is the usual practice, but rather they must be multiplied together. (In Stuart Clark’s book "Redshift", for instance, conventional astronomers use the correct multiplication formula to try to counter Arp’s interpretation of the large redshift of Markarian 205). A 'typical' composite redshift might be given by

(1 + zc) = (1 + zH)(1 + zG)(1 + zD),

where the 'subscripts' c, H, G and D stand for composite, Hubble, gravitational and Doppler respectively. Thus, if we have zH = 1 and zG = 1, then zc = 3, whereas merely adding them gives zc = 2. The composite redshift law could explain the dearth of quasars beyond z = 2, often hailed by Big Bang proponents as proof of ‘cosmic evolution’. The high intrinsic redshifts of quasars quickly inflate zc for these objects far beyond the value which would be obtained through simply adding the redshifts.

I suggest a similar type of effect might be true for the Type Ia supernovae, but in reverse. If they have a small intrinsic blueshift zS, then the correct formula for their composite shift would be of the form

(1 + zc) = (1 + zH)(1 + zS),

where zS is now negative.

At higher values for zc, we would see the effect of the small intrinsic blueshift progressively kick in. The distances to the more distant supernovae would be further than expected from the composite redshift alone. As to what could be causing the blueshift I don't have any suggestions, but merely note that some galaxies appear to have intrinsic blueshifts.

In Euclid's Elements a postulate is something not proved, mainly because it is self-evident. E.g., "Through two points there is one straight line." In Euclidean geometry this is, like, obvious.

But you admit that you have no idea why your "postulate" should be accepted (shades of van Flandern?). So perhaps this should be called an unproven, unsupported hypothesis.

How do you figure?

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

There are proximal causes and then there are ultimate causes. Discussions about proximal causes should pose no big problems for Big Bang supporters. After all, they accept universal expansion without having to know why this expansion is occurring. I am just talking about a possible proximal cause (of dim supernovae) here.

My information on the blueshifted galaxies comes from Arp's book Seeing Red. According to Arp, the galaxies in our system see the dominant galaxy of the system, M31, to be blueshifted. A similar pattern is seen within the members of the nearby M81 system.

E.E.M.

Whether dopler, gravitational and Hubble redshifts are added or multiplied does not change the conclusion; galaxies that are further away have a larger redshift.

M31 is a very big, very nearby galaxie. It and the Milk Way are headed toward each other. So it is blue shifted.

Galaxies in nearby clusters are also swirling around each other. Some of them happen to be heading towards us at this particular moment in cosmic time. So they are blueshifted. But as galaxies get fainter and smaller in the obsever's telescope, their redshift gets bigger.

I agree the SNe's should be blueshifted. After all, we see what is beeing blasted towards us. More so with gamma ray bursts. If GRB's are relatavistic jets beamed straight at us, you'd expect a hefty blue shift in the emmission lines from the initial gamma rays. But all the emmission lines we get to measure are from the afterglow, which moves much more slowly.

I think the real problem here is lack of a high resolution spectrometer in the 100 kev - 10 Mev range.

~Bub

We do of course see a blueshift of material heading outward from the core of a supernova (SN), toward us. The velocity is typically a few thousand kilometers per second, for a blueshift of, say, 1/30 or 3% (for a 10,000 km/s velocity, compared to 300,000 km/sec velocity of light). That's small compared to the redshift of a very distant supernova, with a z=1 for example. So as you get farther away, that blueshift becomes less important. Also, it's pretty much constant for every supernova and can be accounted for.

Now, an intrinsic blueshift that's enough to account for the acceleration would have definite observational effects. For example, a z=1 SN would suffer a time dilation, because of relativity. This effect is seen, clearly, in distant SNe. They can match the rise and decay time of the SN to the redshift, and see that they fit; that is, if you assume a redshift, that gives you a time dilation factor, and you can then slow down a "standard" SN light curve by that amount and see if it fits.

If there were a significant intrinsic blueshift, that would alter that fit. This would at the very least put an upper limit to the intrinsic blueshift of a SN. I don't know if this has been done, but it is an interesting question. I'll ask around when I can.

Bear in mind, though, that we see SNe at essentially zero redshift as well. That is, they are very close. An intrinsic blueshift would be seen to make a supernova appear to be headed toward us, even if it's in, say, the Virgo cluster, which has a definite redshift. I have never heard of this happening, and if it did, it would be huge news to the supernova community. Also, it would be easily observable to anyone with a spectrometer, so if this idea were right, I really think we'd have seen evidence of it by now. Just from that counterexample I strongly suspect this idea won't fly.

__________________
Phil Plait
The Bad Astronomer
http://www.badastronomy.com
badastro@badastronomy.com

Thanks BA. That helps.

Let me put my question very bluntly:

If a jet of matter is accelerated in our direction from a distance of z=3.2769, and the ultimate velocity of the jet reaches 0.99835 c in our direction, what will the blue/redshift be?

And second, how much spectroscopic resolution do we have available in the >1 Mev range?

~Bub

Forget the first question. I got the equations to figure it out myself.

~Bub

Arp is talking about a different effect than this Doppler shift. He says all the companion galaxies of M31 are positively redshifted relative to M31. He says too that this effect was later seen in other systems, i.e., that the companion galaxies are always redshifted relative to the central, dominant galaxy. The discussion appears on p. 62-64 of Seeing Red, and the issue seems to be just one of the many controversies Arp got caught up in. I think Arp associates the blueshift with younger matter, according to his aging matter hypothesis. The blueshift could also be size-dependent however. I don't want to get too sidetracked on this point though. The galaxy blueshifts were just given as an example.

I had supposed that the Doppler shifts of material heading towards us from the explosion would be blended in with those of material moving in other directions, with no overall shift apparent. But if the light comes mostly from the material heading our way, then this effect alone would cause a blueshift, as you say.

I think this is correct, and the overall effect is simply to broaden any spectral lines, since the material will be more or less evenly distributed in different directions.

On this point of time dilation in distant supernovae, I have to say I'm also a little skeptical. The light curves of supernovae have to be adjusted for a factor related to their intrinsic brightness. The bigger supernovae have broader light curves. If we were to look at this from the standpoint of a static model, might it not be possible that what we are really seing is a selection effect? At we go to higher z's, we may progressively be seeing only the more powerful supernovae.

Thanks!

Maybe, but if the intrinsic blueshift were quite small it might only reveal itself at larger redshifts due to the multiplication effect.

The supernovas considered are all SN Ia specifically because they all have the same intrinsic brightness, or close to it.

They accept universal expansion because there is a large body of evidence supporting such a conclusion. The question of why the expansion is occurring is another matter, which BTW I think is answered by the big bang theory, which has its own large body of evidence supporting it.

By the way, a review I read of Arp's book stated that there is not one mention of supernovas throughout the text. How can anyone deal with red shift without discussing supernovae evidence?

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

That's not quite true, cougar. They were initially thought to be good "standard candles", but subsequently it was found that a correction factor was necessary to incorporate small variations in the power of the supernovae. (e.g., Perlmutter et al, ApJ 483, 565, 1997)

Seeing Red was published in 1998, which means it was probably written in 1997 or earlier. Much of the supernova stuff touching on cosmology only started to come out in 1995-96, so it is conceivable it just didn't come to his attention. It would certainly be good to have his perspectives on it now.

Right. Actually it was Mark Phillips who first published a paper that demonstrated that Type Ia supernovas have a correlation between their peak luminosities and the rates at which their brightnesses decline: More luminous Type Ia's fade more slowly than less luminous ones. Later Adam Riess refined this with his "light curve shape analysis" that allowed astronomers to deduce a SN Ia's peak luminosity, and thus its distance, from the details of its changing brightness. Of course, as previously mentioned, further adjustment must be made for the slowing of time due to relativistic effects.

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

Another relevant article is this article by Rowan-Robinson.

Bingo!

If real those motions should be random relative to the morphology of the galaxy and Arp has pointed out that they're not. It turns out Sb galaxies such as M-31, M-81 and the large Sb galaxies in the Virgo cluster are systematically blueshifted relative to the cluster mean redshift.

Arp says that the galaxies that have excess redshift are younger and the galaxies such as Sb galaxies that have redshift deficits (relative blueshifts to cluster means) are older.

Its interesting that Arp's anomalies are often dismissed because people don't like the proposed intrinsic redshift mechanism but it is ok to conclude Type Ia supernova indicate an accelerating universe even though the mechanism that causes Type Ia supernova is unknown (though thought to involve white dwarfs).

The huge gravity of the Virgo cluster (with over 2,000 large and small members) has accelerated some of its members to extremely high peculiar velocities - up to 1600 km/sec. Since the cluster's center of mass is moving away from us at only 1100 km/sec, some members are indeed heavily blueshifted. Here are some examples of Virgo members with high peculiar velocities:
My reading of the data shows that not all of the Sb galaxies in the Virgo cluster are blueshifted. Sb galaxy NGC 4388 in Virgo has a very high peculiar velocity adding to its redshift, not blueshift. Doesn't it take just one observation to falsify a theory?

Well, they appear to be more random than Arp suggests. And remember that "random" does not mean perfectly distributed. I've seen a roulette number come up 3 times in a row. (Luckily I had it covered each time. :P ) So if a majority of the Sb's are blueshifted, I don't see that as necessarily "systematic".

______________________________
Ref: http://www.seds.org/messier/more/virgo_gal.html

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

Thanks for the ref. Rowan-Robinson obviously has a lot of misgivings about the supernova data, relating to factors such as the possible extinction of light in distant host galaxies and whether the correction factor Cougar and I discussed has been applied. He concludes that the high-z supernova teams have not been cautious enough in interpreting their data.

What a killjoy!

Seriously though, I'm surprised the interstellar extinction factor was not determined directly for each of the SN Ia's (rather than adjusting the magnitude via formula... or not adjusting it at all). Extinction is detectable (and measurable) by the change in the ratios of light of different colors, indicating dust and gas have preferentially absorbed the blues or violets.

After adjusting for Hubble flow redshift, astronomers can compare the spectra of nearby and distant supernovas. In the case of the two high-z supernova teams, it is quite possible that this was indeed done, with a finding that the spectra of near and distant supernovas were nearly identical - with the same relative amounts of light at each wavelength. If light from the distant supernovas was getting blocked by more gas and dust, the spectra would not be identical.

Rowan-Robinson is right to question this remarkable finding that the expansion is accelerating, especially since there is no known mechanism that could make it accelerate. But more and better data is being collected, so we'll see if R-R's criticisms hold up.

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

First we should be clear about the theory. Arp has noted that the largest Sab/Sb type galaxies are systematically blueshifted relative to the cluster means while the large SbcI/ScI and Seyferts are systematically redshifted relative to the cluster mean. NGC 4388 is a Type 2 Seyfert. Its a perfect example of what Arp is talking about. To really start to see the pattern, working with distances helps. The core of the Virgo cluster comprises galaxies between 13-20 Mpc. Here are the peculiar motions (H0=72)of the large spirals in the Virgo with TF or cepheid distances:

NGC 4254 ScI +1281
NGC 4303 SBbcI +465
NGC 4321 SBbcI +588
NGC 4535 SBcI-II +891
NGC 4501 SbI-II (Seyfert) +947
NGC 4536 SBbcI-II +773

NGC 4192 SBbII -1133
NGC 4216 SBbII - 821
NGC 4548 SBbI-II -579
NGC 4569 SBabI-II -1059

Sab/Sb galaxies would have to have systematically approaching peculiar motions while ScI and Seyferts have systematically receding peculiar motions. And these are the largest galaxies - the ones that are supposed to be tossing around the smaller ones.

And the large ellipticals (> 20kpc) in the core which have surface brightness fluctuation method distances:

NGC 4365 -134
NGC 4374 -285
NGC 4406 -1400
NGC 4472 -204
NGC 4486 +240
NGC 4526 - 663
NGC 4552 -693
NGC 4621 -762

If we look at mean redshifts we find that the ellipticals with SBF distances break down the following way:

> 20 kpc (9 galaxies) mean redshift = 784 km s-1
<20 kpc (18 galaxies) mean redshift = 1201 km s-1

For Sa/Sb spirals:

rotational velocity (10) > 160 km s-1 mean redshift = 865 km s-1
rotational velocity (11) <160 km s-1 mean redshift = 1142 km s-1

for ScI/Seyferts:

11 galaxies mean redshift = 1854 km s-1

for ScII-III to ScIV galaxies:

18 galaxies mean redshift = 1310 km s-1

This is traditionally dismissed as a fluke, but there can be little doubt that there is a morphological/diameter pattern to the redshift distribution of Virgo Cluster galaxies which is certainly not expected in the traditional view. The morphological-density relation (Dressler 1980) does not explain this away because it cannot account for the systematic part of the pattern.

When I started this topic, I did not have any speculation on what could cause an intrinsic blueshift in Type Ia supernovae. But I've come up with one just now.

In Arp's aging of matter hypothesis, and also in some other theories (notably certain Le Sage-type theories), there is an increase in the mass of baryons over time. To simplify the discussion let's focus on the Arp/Narlikar model. In that model quasars for instance are very young objects which thus have low mass. This accounts for their high redshifts, since the subatomic particles in these objects all have lower masses as well.

The Type Ia SNe, however, are older objects, much older than our sun. They are explosions occurring at the end of the stars' normal lifetimes, so I assume they're 10 billion years old or thereabouts. Consequently, if these objects started off with the same mass as the Sun, then they should have had a higher mass than the Sun's prior to their explosion. If we looked at their spectra at this time we would expect to see a slight blueshift, according to Arp's theory. The lines we see in a supernova are different lines than we normally see in a star, but they effectively should be blueshifted too.

Elliptical galaxies in general should also have a slight blueshift relative to non-ellipticals, since ellipticals are mostly older stars. They may look redder, since they are cooler, but their lines should be slightly blueshifted. We might not see this effect at low z, because it's small. (In Arp's model, the increase in mass is exponential, and so the difference between the spectra of a star like our sun and an older star could be much smaller than in the earlier 'quasar' phases). So perhaps there is a way of testing the idea by looking at ellipticals.

Incidentally, if Arp's mechanism were true, a star that was less than 1.4 times the solar mass (the limiting mass for Type Ia SNe) might attain the necessary mass to explode simply through aging! It would not be necessary to hypothesize mass being drained off companion stars, etc.

But aren't the stars that end as supernova supposed to burn very rapidly, and ending their lives quite young?

No, the Type Ia SNe arise from stars not much bigger than our Sun. The fast-burning stars are the much bigger ones such as the blue giants.

Even if your "what-ifs" are true (which is highly speculative), how does this have any effect on redshift?

But we don't, therefore Arp's theory fails. QED.


It's been done, EEMan. The farther away an elliptical is, the more redshifted is its spectrum. Same with nonellipticals. Unlike "recession" or expansion effects, there's no room for alternative "interpretations" here. I really don't understand the attraction of this dead end.

And monkeys might fly out of my butt!

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

If the mass of an electron in a quasar atom is less, then the photon emitted when the electron jumps from an excited state to a lower state is less too, therefore a redshift.
However, they don't usually see the spectrum of the star prior to the explosion. They pick up the SN only after the fact.
You didn't address my point here. The intrinsic blueshifts of ellipticals could be very small, and so would only become apparent at high z, due to the multiplying effect of red/blue shifts. The attraction is to a better cosmology than what passes at present.

As ExpErdMann explains below, the explanation does derive naturally from the Narlikar&Arp model.

In Arp's model older objects at large distance are still redshifted - but they have smaller redshifts than younger objects at the same distance.


It is ironic that you ask that in the same sentence that you demonstrate your own attraction for declaring alternatives dead. I strongly recommend you read this preprint from the Los Alamos website. It is an exhaustive, heavily referenced (258 articles cited) discussion of the various unresolved and potential problems with the standard views as well as the issues surrounding various alternatives. He takes the same position that I have advocated here - that the Big Bang could be wrong and that the alternatives may have something to offer.

And monkeys might fly out of my butt![/quote]

TMI

That's the Lopez-Corredoira paper. I've not memorized all 26 pages of it, but I've done some browsing. Has this been accepted for publication anywhere? Has this received a peer review by someone with a lot better grasp of the issues than I've got? I'd be interested to hear what they've got to say about this paper.

It seems to be an exhaustive rehash of every non-mainstream paper Lopez-Corredoira could find. I don't know that Lopez-Corredoira has anything new to add to all these controversial constructs. He does give his vague opinion on some of the positions, which I don't find particularly worthy of scientific publication, but on most of the "potential problems with the standard views", including Narlikar&Arp's "variable mass" speculation, Lopez-Corredoira simply says it's out there and adds another notch to his outlandish reference list. Lopez-Corredoira's paper is more a literature review as opposed to any cutting-edge research. Plus, he clearly needs my services as a Technical Editor.

It is possible but unlikely that "the Big Bang" is wrong. It is possible but very unlikely that the fundamentals of "the Big Bang" are wrong. It is possible that "the alternatives" have something to offer. It is very unlikely that some of those alternatives have much to offer. It is likely that some of those alternatives are WAY off. I hope that's not TMI.

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

I would too. I think you need to confer with JS about this. He's insisted that alternatives must first get themselves published, but then the last thing he said was that publication wasn't the be all and end all of science. Now you're telling me that publication is important. I feel as if I'm getting a case of mental whiplash! (Incidentally, I do agree that publication is important.)

Nope. Sounds good Cougar!

Sure, publication is important, especially if it is peer-reviewed. But I agree with JS - publication does not automatically confer biblical inerrancy. Not all journals and not all peer reviewers are equal. After something has been published, then the real peer review, repeated testing, and verification begins, conducted by some fraction of the entire community.

I believe numerous times there were publications about neutrinos having mass, and numerous times such claims were soon shot down. Apparently this claim has finally been made for the right reasons, with accurate data, and the claim is standing... so far.

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