This is not a post proposing an ATM, but a post asking a question to all proponents of ideas which say that the universe is infinitely old (or at least much older than what the BBT says, i. e. about 14 billion years). To the moderators: I don't know if such a post is allowed in this forum; if not, please either move the post to the approriate forum, or simply tell me and don't post it at all.

Assuming that this will be posted, let's go to my main point. About 91% of all main sequence stars are of the class K or M, i. e. most stars are of that type (source). Now we know from our theories about stellar development that such "red dwarfs" have very long lifetimes - tens of billions up to trillions of years (source).

On the other hand, determinations of ages of stars in the Milky Way as well as in other galaxies, nearby or distant, have shown that apparently all stars there (and the Milky Way as a whole) are at most 13-14 billions years old. Some papers on that:

L. Pasquini, P. Bonifacio, S. Randich, D. Galli, and R.G. Gratton, Beryllium in turnoff stars of NGC6397: early Galaxy spallation, cosmochronology and cluster formation, Astr. and Astrophysics 426 (2004) 651 (astro-ph/0407524)

L. M. Krauss and B. Chaboyer, Age estimates of globular clusters in the Milky Way: constraints on cosmology, Science 299 (2003) 65

B. Hansen et al., Hubble Space Telescope observations of the white dwarf cooling sequence of M4, Astrophys. J. Suppl. Ser. 155 (2004) 551 (astro-ph/0401443)

N. Dauphas, The U/Th production ratio and the age of the Milky Way from meteorites and Galactic halo stars, Nature 435 (2005) 1203

L. Nolan, J. S. Dunlop, R. Jimenez, A. F. Heavens, F stars, metallicity, and the ages of red galaxies at z > 1, Mon. Not. Roy. Astron. Soc. 341 (2003) 464 (astro-ph/0103450)


Now my question is obvious: how do you explain the presence of only "young" (at most about 14 billion years) stars in an "old" (infinitely old or at least much older than 14 billion years) universe - although most of the stars should be able to live much longer than 14 billion years? Do you think that we, by chance, have so far only seen the younger stars? Do you claim that our ideas of stellar development are hugely wrong? Or what?

Please only respond if you actually plan to answer these questions. And please give arguments why you think your alternative ideas for explaining this are true; do not simply say something like "well, your ideas of stellar development are obviously wrong!" Also, do not simply say something like "But the BBT also can not explain this and that...!".

You could also address why the ages obtained for stars are so nicely consistent with the age of the universe obtained in the BBT by other methods (13.7 billion years). But that's not the main point here. And please consider that claims like "they fudged/tweaked the observational data until they reached agreement between the numbers!" are also not acceptable - as long as you don't provide evidence that such fraud indeed occured.

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QSSC has expanding space and continuous matter creation, so the expanding space slowly carries old galaxies out of our sight, and we see only new ones.

Static universe models have to have some kind of matter/energy recycling process ongoing (for other reasons, such as preventing all matter to end up as iron, and entropy issues), which renews all matter during certain time period.

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(1) Does QSSC explain why apparently all old galaxies have been carried out of our sight already? Or are there still some in sight, and by chance we haven't looked at them so far?

(2) How does QSSC explain that the age of the Milky Way is so nicely consistent with the age of the universe?

(3) How does this explain that all galaxies at high z which have been looked at up to now look even younger as the Milky Way - and the determined ages are again nicely consistent with the age of the universe?


I knew this already, thanks. But that's not very relevant to my questions, I would say.

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The Alfvén plasma cosmology (PC) has, I understand, an infinite universe, composed equally of matter and antimatter.

As I understand it, in at least one version of PC, the matter and antimatter somehow separate, into regions of only (or predominently) matter and only (or predominently) antimatter. I do not know if PC specifies a mechanism, nor do I know if, having specified a mechanism, the size distribution (etc) of the regions can be estimated.

However, by virtue of the fact that matter appears to dominate, out to at least many billion ly, I would guess (and it would be only a guess) that in PC we happen to live in a matter region, of approx that size.

More guessing: in PC, age and size are approximately the same: a matter region of size ~1 billion ly will be ~1 billion years' old.

PC apparently accepts that gravity plays a role in the evolution of the universe, and PC does not offer an alternative theory of gravity (to GR).

Whether any PC proponent - e.g. Alfvén - has put all this together, to make a consistent, complete cosmology, I have no idea.

In the paper cited by Bancor in the thread "Current theory is ...", Alfvén says that we can't even be sure if Alpha Centauri consists of matter or anti-matter.

And I don't see how these PC ideas could explain the fact that the star populations in galaxies at high z are younger than the star populations of the Milky Way, and that the measured ages agree nicely with the age of the universe obtained from the BBT, if one takes the light travel times into account.

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Given the luminosity of stars 20 billion years old, and today's telescopes, how far out in space could we see such objects?

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AFAIK, the methods for examining the ages of distant galaxies do not depend on examining single stars, but on studying the combined spectra of the whole galaxies and thereby determining which stars have already wandered off the main sequence. See e. g. this paper for details:
R. Jimenez, J. MacDonald, J. S. Dunlop, P. Padoan, and J. A. Peacock, Synthetic stellar populations: single stellar populations, stellar interior models and primordial protogalaxies, Mon. Not. Roy. Astron. Soc. 349 (2004) 240 (astro-ph/0402271)

And even if one couldn't detect the presence of such stars at all at greater distances, you'd still have to explain why the age of our own galaxy agrees so nicely with the age of the universe.

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Assume a supernova has an absolute magnitude of -20.

Assume the apparent magnitude is related to the absolute magnitude via standard Euclidean geometry.

Assume the threshhold for detection is 25 mag.

The furthest we could detect a supernova is ...?

Assume a billion (or a trillion) stars of (main sequence) age 20 billion years.

(same assumptions as in the first case).

The furthest we could detect a 'galaxy' of such a collection of MS stars would be ...?

Assume the 20 billion year old stars have reached maximum luminosity (they've become red giants, or whatever; but not supernovae).

... and so on.

One technique astronomers today use is synthetic spectra - a mixture of stars, of various types, possibly of various ages ...

IN my EU derived model age is related to current density.

From wiki
"One mystery which has not been solved as of 2007 is the lack of red dwarf stars with no metals (in astronomy a metal is any element other than hydrogen and helium)."

From wiki
"As of 2006, no Population III stars have been found; rather, their existence is inferred in current models of the origin of the universe."

In my model nucleosynthesis takes place continuously on the surface in coronal loops. So you never will find pop III stars. Since nucleosysthesis is dependent on local(galactic) current density there should be a correlation of some sort.


from wiki
"Across the Milky Way, metallicity is higher in the galactic centre and decreases moving outwards. "

Current density is higher near the central generator, more nucleosynthesis, more metals.

The most common current density is shown by the fact the red dwarfs are so common. That's interesting. There may be a way to perform some tests on the mechanism powering the sun.
See if velocity is tied to brightness and color. As compared to a sample of other types of stars.
See if local plasma density is tied to brightness and color.

It may also be that high current densities will cause the photosphere to expand there by masking the true metallicity of the star. As is the case with our sun....

Now is the current density of the universe, or galaxy some how related to an intrinsic property that causes redshift? That would explain the redshift- metallicity relationship.

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I am well aware of the empirical issues with trying to claim the observable universe is older than ~15 billion years. It is silly to expect it on prejudice alone. My own ATM posting in this category was born out of attempts to answer questions on this board and the standard model of physics. It is in no way a claim about age in general or even a claim about the legitamacy of the Big Bang. It is merely an attempt to articulate what the Hubble flow can say about it.

M geometry leads to the multiverse conclusion so it is not that the universe existed longer than supposed by BB thaory, it is that prior to the BB it was a diffferent universe. Or, more accurately, the shape of the universe as we know it is shaped due to the shape of parts of the multiverse. The universe and big bang as we know it is one of many things that happen in the geometric relationships of the multiverse.

Sorry, I realized that I must have been talking about old steady state theory, where there was trace amounts of matter continuously created in empty space, it seems that its current version, the QSSC, has different matter creation scenario. In QSSC, new matter is created in regions of strong gravitational fields, and I'm not really sure how that works in the point of view of your questions. But I'll address your question 1 anyway (don't know the answers to 2 and 3), but in the context of the old steady state theory, not QSSC.

Due to space expansion there is a limit how much older galaxies, than the one you're in, you can see (because our galaxy has also been created in relatively new space). But I don't know what that limit exactly is.

It is very relevant. Time period for recycling all matter could be so small that all the stars get recycled before reaching ages relevant to your problem. Another possibility is that the recycling process might work on very large scales, so that matter creation is roughly synchronous over large regions of space (for example regions comparable to the size of our visible universe), and in that case all the matter in those large regions would have roughly the same age.

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I don't know much about these "recycling" ideas, but I thought these processes took place outside stars. I never heard that the matter inside stars can also be "recycled" during their lifetims.


That's also a proposal I've never heard of so far. But it doesn't explain why both the ages of these galaxies (together with light travel time) and of the Milky Way are consistent with the 13.7 billion years from the BBT.

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Nothing what you wrote actually adressed my questions. Read my post again, and then try again, please.

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As you said, your own ATM posting doesn't deal with the age of stars or the age of the universe. So why did you bring this up in this thread? Are you simply advertising for your ideas, or what? Try again, please - or if you have nothing to say WRT the specific questions raised in this thread, please don't post here anymore.

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If I understand you correctly, you are not proposing a universe with infinite age, but say that the BB happened in a pre-existing "multiverse". Such ideas are obviously compatible with the measured ages of stars. If they are compatible with other data is not the topic of this thread.

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In the souce above it is written:
This just means there are no very young red dwarfs, RD. Where do you read that there are no very old dwarfs? What would be a determining factoR in the age estimate of a RD, spectra, heavy elements? My point, how do we know there are no RD that are 20 or 30 Gyr old.

What kind of metallicity would be expected of a 50 Gyr old red dwarf (or a trillion Gyr old red dwarf)?

In another way, the "fact that red dwarfs and other low mass stars remain on the main sequence while more massive stars have moved off the main sequence" allowing one to date star clusters by finding the mass at which the stars turn off the main sequence, providing a "lower, stellar, age,"(source) how are the upper limits, a higher stellar age, determined?


If you look here, you will read:
Looks to be like an 18 Gyrs star precludes the existance of a 13.7 +/- 2 Gyr old universe.

The possibility that some stars may be 18 billion years old seems to counter what you assume: that the low stellar ages contradict a world model with a universe older than the suspected age of the universe according to the big bang theory.

Simply put, how does an 18 Gry old star fit into the new post-1998 standard hot big bang-CDM, kooky energy model?


cc

I suggest looking up all the papers I cited........

(For short: the crucial point is that one can look which stars have already wandered off the main sequence and become red giants. And there simply are no red giants corresponding to late K and M stars. Look up the Hertzsprung-Russell diagram.)

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While true in principle, the A. Cent does not exist in a vacuum (literally and figuratively). The dust and gas expelled by both A. Cent. and Sol would mutually annihilate, producing a whole bunch of easily detectable gamma radiation. Does he address that?

Yes, he does (although one could argue if his argument is satisfactory...). See section V in the paper, on pages 3 and 4. (the link I originally provided in my post was broken; I fixed it now)

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I asked a specific question, in a variety of ways, so there could be no other interpretation possible, and you have simply asked me to look at your links. I have gone through every cm of your links to no avail. Please answer my question in your own words or (preferably) provide a link specifying what part of the work (which paragraph, section or page) responds specifically to my question.

Stars wandering off the main sequence and become red giants does not answer my questrion about the age of red dwarfs?

I will ask it again very simply, and in another way: What is your proof (or evidence, if you prefer) that there are no stars older than 18 billion years (or 14 billion years as you wrote, seemingly in disagreement with the 18 Gyr old age found on the WMAP website).

I noticed you conveniently avoided my question on how you reconcile the 13.7 +/- 2 Gyr old universe with the upperlimit of observed stars estimated 18 Gyr.

Coldcreation

But I did answer your question already in my own words. See the stuff I wrote in the last post!!!


It does. If you think it doesn't, I suggest you become familiar with our theories of stellar development and how the Hertzsprung-Russell diagram is used for determining the ages of stellar clusters.


The fact that the HRD for stellar clusters shows that no late K and M stars have yet wandered off the main sequence. If you don't understand that: see my suggestion above.

And, BTW, I don't know of any "18 Gyr old age" found on the WMAP website. IIRC, you already made that claim once, and had to correct it to 15 Gyr shortly afterwards. So why do you make that claim now yet again?


No, I did not avoid that, I answered that already weeks ago in another thread, and back then, you didn't say anything against my answer: there simply are no stars observed which are that old. There may be stars which an age of 15 Gyr (I don't know where the WMAP site got that number from), but the error margins for stellar ages are usually so big that this still is consistent with 13.7 Gyr.

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WMAP - NASA

http://map.gsfc.nasa.gov/m_uni/uni_101age.html



You will reply (again) that 13.7 billion (+/- 2 Gyr) year old universe fits inside this 11-18 Gyr estimate, but it does not. It leads to the possibility that some objects (stars) may be older than the big bang universe, by several billion years.

The old age problem really has never gone away. It is still here, alive and kicking.

Coldcreation

I don't see where Bjoern has clearly answered why he thinks there are no old red dwarfs. To me it seems that hidden assumptions are involved which are not apparent in the links (eg, the paper by Jimenez et al). Perhaps there is a review article out there which states the matter more clearly than Jinenez et al do.

As for the white dwarfs, I have read a number of papers on these, including by Hansen. It should be noted that the ages of white dwarfs are 'determined' exclusively with the use of very hypothetical cooling curves. When you read these papers, it is amazing the degree of speculation which goes into them. When the calculated ages of white dwarfs don't mesh with the age of the universe that the Big Bang model currently accepts, they just rejuggle the assumptions. There is no way of actually determining the age of a white dwarf star (excluding ones which very recently came into being).

No - Alfvén seems to assume that the ISM comprises a fully ionised plasma (no dust, no neutral gas).

In fact, I'm grateful to Bancor for introducing that Alfvén paper ... while some of the ideas in it may be interesting, I think some pretty simple OOM calculations would quickly highlight several deep (and potentially fatal) inconsistencies, of which the local anti-matter claims would be just one.

Unless anyone wants to try to make a PC/PU case, I think it's safe to say PC/PU can't even get to first base in terms of addressing Bjoern's OP questions.

In static models, energy and matter are going through cycles that are governed by a cycle time parameter, which is 1/H. It all stems from the tired light redshift, whereby photons lose energy at the rate:

dE/dt = -EH.

For an individual photon, the decay has an exponential character. But if you look at all the photons in the universe, with total energy E(tot), you see that there is an average amount of energy E(tot)H being lost per second. The time it would take for an amount of energy equal to all the current em radiation in the universe to decay would be 1/H = 13 billion years or so, depending on H.

Now the same relation holds for the atoms in stars. At any instant, the amount of H going to He, relative to the amount of H present, is also proportional to H (Hubble). Also the same for the stars themselves. In a static universe, the number of stars being formed per unit time, relative to the number of stars present, is equal to H. That ratio holds more or less for the Milky Way, the galaxy we know most about. So in SU, galaxies can also look to be about 13 billion years old, since there will be at least some stars in them that are that old.

That's one part of the answer. The second part is that galaxies themselves may be being recycled too. Phenomena such as quasars (as in Arp's model) suggest that new galaxies are coming into existence. The new ejected galaxies presumably arise from all the matter being drawn into the central black holes of galaxies. If the structural components of galaxies are being recycled over time periods comparable to 1/H, then this also would explain why we don't see stars older than this.

Pardon??? 13.7 does not lie between 11 and 18??? Maybe you should look up some quite basic math...


First, even the numbers you quoted lead, as you said, only to that possibility - not to a certainty. The possibility that these stars are younger than the universe is equally valid.

Second, again, I don't know where the WMAP team got that number from - all papers I've looked at in the last years gave much smaller numbers (for examples, see the paper list I provided in the OP).

Third, may I remind you what I said in the OP? These thread is not intended for people simply replying "but the BBT also can't explain this and that!!!". So please go back on topic. If you want to discuss this number of 18 billion years, go to another thread.

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Oh, come on, do I have to explain all the basics about age determinations of stellar clusters using the HRD?


I'd say that the Jimenez paper is quite clear on the assumptions and problems which are involved. What don't you understand there?


Please support you claim, i. e. point to an actual example of such a "rejuggling".

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This is about the first real attempt to actually answer my questions, thanks!


Is that right for all static models? (judging from what I read about e. g. the QSSC, that idea is not used here - they need more time to make the observed He!) And how does that recycling work, specifically?


With the actual values of H (around 70 km/s/Mpc, arrived at by using several independent methods), you'd get about 1/H = 14 billion years, right.


There are studies for the star formation rate in the universe, e. g. this:

A. Heavens, B. Panter, R. Jimenez, and J. Dunlop, The star-formation history of the Universe from the stellar populations of nearby galaxies, Nature 428 (2004) 625 (astro-ph/0403293)

They talk about a "peak" in star formation rate around 5 billion years ago (and provide a lot of more detail). That doesn't sound as if "the number of stars formed per unit time, relative to the number of stars present, is equal to H".


Also, I don't see how this explains the "primordial" helium (i. e. the helium abundance obtained by extrapolating the data back to "no metals presented - about 23%, IIRC).


Does this also address the age of the Milky Way measured by the U/Th ratio? (see one of my links)


But that wouldn't explain why the ages of galaxies at high z plus the light travel times matches the 13.7 Gyr of the BBT. The first part of your answer was better.

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This includes the sentence you cut off above:

Again: It leads to the possibility that some objects (stars) may be older than the big bang universe, by several billion years.

Please do not cut the most important section of what I write. Your cuuting half off and posting the remark that followed will get no one anywhere.

Yes, 13.7 in between 11 and 18 Gyrs.

The point that followed is as simple as it is obvious. There is a grave discrepancy between the estimated age of the universe and its constituents.


Even with in a near 20% margin of error (+/- 2 billion years, that is a huge margin of error) on the high end of the estimate we arrive at 15.7 Gyr. Yet the possibility exists that some stellar components are 18 billion years old. That means some stars may be 2.3 Gyr older than your universe. If 13.7 is taken at face value, the universe could be 4.3 Gyr older than the hot big bang cold dark matter dark energy model suggests.

Does this not strike a mortal blow to the premise with which you began this thread? Or, at the least, does it not point to an error in your supposition that there are no stars older than 14 Gyrs (your text quoted below)(which is already older than 13.7 Grs, the new revised age of the universe according to your favorite, current, pet theory: "Lambda-CDM")