I attended yesterday some presentations on diverse topics of current research. This sessions were intended for the students of an introductory course in modern physics and I presented a little talk about baryogenesis, you can get it here (in spanish), as the course didn't cover cosmology in its (large) list of topics I actually spent a large fraction of the talk in some elementary concepts like the Friedmann equation and the critical density.
One of the talks was actually very intersting for many reasons, it was a 6d extension of the old Kaluza-Klein theory that was worked by a local faculty member some years ago when he was at Moscow State University. The intersting stuff is that he claimed that the model could reproduce the Glashow-Salam-Weinberg theory of electroweak interactions, unfortunately the talk was pressented by a student that was unable to give absolutely any detail of how they arrived at that conclusion (I have requested the original author a copy of the article, I'll post it when I have it), but the most interesting result was that they derived that some constants were changing in time (this is not a really new idea) and among the changing constants was e, the unit of electric charge.
Although it would be an amazing discovery this simply looks wrong, changing the value of e over time would change the fine structure constant (α ≡ e^2/h bar c ≈ 1/137). However there have been many attempts to check if α is constant and any of them have found nothing, you can look at a recent one here (the published article is here). Look at Sean Carroll's entry on changing constants (in his case it is the ratio between the mases of the proton and electron) here.
At the end of my talk I was bombarded by questions that sounded to me like the stationary universe: the idea that the universe looks the same in time, this needs some matter creation mechanism (otherwise the density would change in time). I actually went to explain that practically anyone in the astrophysical community believes in this kind of theories, that CBR really looks like blackbody radiation and it lacks the polarization one would expect if CBR is light from ancient stars which has been scattered by galactic dust (the usual explantion of CBR in steady state theories), and that we have a really big body of evidence that suggests that indeed the density is changing some members of the audience still seemed to prefer to just ignore the bulk of experimental evidence.
I don't want to state a debate here (there are so many intersting debates at Peter Woit's blog "Not even wrong"), but it really concerns me that a (rather small, to be honest) fraction of the theoretical community is so distanced from the experiments.
11 comments:
There is at least one valid quasi-steady state model that includes matter generation, except the process works via asymmetric transitions, which enable the universe to evolve through an infinite series of big bangs, so you don't have the problems with the CBR and you don't need inflation when the universe has volume when a big bang occurs, so it's necessarily preferred.
Actually this quasi-steady-state models have been around since 1993 and had been publicized by Hoyle and Narlikar since then. To be honest, I have never studied this theories in detail, and the reason is simple: they have a bad reputation. Probably the clearest exposition of the current position of the QSSC is in in Ned Wright's page: http://www.astro.ucla.edu/~wright/stdystat.htm.
Anyway, I will take a look at the latest QSSC papers later and maybe make a post about them.
Well, Hoyle and Narlikar's was one of the models that I was referring to, but matter generation in Einstein's static model *causes* expansion via vacuum rarefaction, which holds the universe flat and stable as it expands. Einstein didn't know about the particle potential in the quantum vacuum or Ned Wright might be telling a whole nother story today:
http://www.lns.cornell.edu/spr/2006-02/msg0073320.html
Do you see what I'm getting at, Luis? In Einstein's static model, G=0 when there is no matter.
He initially added the cosmological constant to balance things out, because we do have matter, but you have to condense the matter density from the zero pressure metric in order to get rho>0 from of Einstein's matter-less spacetime structure, and in doing so the pressure of the vacuum necessarily becomes less than zero, P<0.
It is plainly evident from this that most natural way to create new matter in Einstein's model, ("the most compatible with the spirit of general relativity"), also holds it flat and stable while driving expansion, so any other conclusions that have been made since Einstein abandoned his finite universe without this knowledge, are, therefore, subject to suspect review.
You can ascertain all of this by studying Ned Wrights other page:
Vacuum Energy Density, or How Can Nothing Weigh Something?
Yes, I see the point of the argument. This is essentially the argument for matter creation in inflationary models.
QSSC models actually make definite predictions and the creation of matter isn't a very perturbing one (after all you have something similar in the widely accepted inflation), the real problem with QSSC is the CBR, there have been many proposals for thermalizing the low energy radiation you get from stars (usually using iron whiskers), but none of them seems convincing (just look here and here, where Narlikar claims to explain the acceleration of the universe in terms of QSSC but arrives to completely different conclusions in each one).
But the interesting question is if new matter has been created after the first moments of the universe (of course this don't applies to QSSC), I don't have a completely satisfactory answer to this.
thermalizing the low energy radiation you get from stars (usually using iron whiskers
Yes, I too have read about this, which is the reason for my earlier point that you don't need this explanation because you don't have these problems with the CBR, and you don't need inflation when the universe has volume when a big bang occurs.
In the scenario that I've described, particle creation from vacuum energy requires that you isolate enough energy to condense the vacuum energy down over a finite enough region of space to attain the matter density before you can create real massive particles from this energy, which explains why the only known and expected sources for this are Black Holes, SuperNovae, and us... that I know of.
In this case the offset increase between the matter density and negative pressure causes tension between the vacuum and ordinary matter to increase as the universe expands at a naturally accelerating rate.
Eventually the integrity of the forces will be compromised by this growing tension and, boom... you have causality.
There is a valid quantum gravity theory in there... in case you didn't notice?... but it doesn't look much like the current one and it doesn't conflict with relativity, so...
Anyway... here's a link to a short article that I wrote for the physics research group about that!
Real Objects of Negative Orthodoxy... not mass
So Luis, I've put all of this stuff before more PhD theorists than I'd care to remember and have yet to ever be shot down by them. Instead, I get a consensus of dumbfoundedness, like nobody really wants to look into this that hard, or nobody seriously believes that the universe might be finite, or what the ever reason???... doen't make any sense to me. With all of the problems with quantum gravity, you'd think that they would want to jump all over anything that might possibly shed some light on the subject, but that seems to be qualified by their own personal limits on what accepted assumptions they consider are up for review, and not one of them believes that it could go all the way back to 1917, even given proof!
It doesn't make any sense, and I am so frustrated with this that I'm ready to throw 20 years worth of learning to the wind and take up gardening.
Honestly, if you believe you have the seed of a coherent theory of quantum gravity what you should do is to write a paper and publish it, maybe in the arxiv. But if you don't have any calculation backing up your models I'm afraid you won't get very far.
Thanks very much for your good advice, luis.
Yes, you're right, and no, not completely, are my replies though, because part of this has to do with the fact that Einstein was not proven wrong. He simply didn't know something that quite obviously does justify his argument that the universe is finite, even though it is expanding, and it will not run-away, so there was no logical reason for him to abandon this model, given what is now obvious and factually verified information about the particle potential of the quantum vacuum.
It's not up to me to prove what is already proven in order for me to say that he was not wrong until somebody proves it, since this has never really been done!
This represents plenty good enough of a reason for someone besides me to write down the basis of wave functions in this background, including an expansion of the field in corresponding creation and annihilation operators - compute the stress-energy tensor in that background - quantitatively describe the vacua - and then work out the matrix elements of the stress-energy tensor between the vacuum and the one-particle states.
Once some better person than I does that, then it can be quantitatively shown how Dirac's Hole Theory works without need for a reinterpretation of the negative energy states to hold this model stable and "flat" as the universe expands, because particle creation becomes the mechanism for expansion when the normal distribution of negative energy does not contribute to particle pair creation, which can only occur in this vacuum by way of the condensation of negative pressure energy into isolated depatures from the normal background energy density. This new physics repairs Dirac's Cosmological model and his Large Numbers Hypothesis, as well, which, in-turn, completes and clarifies the Anthropic Principle, which is where Robert Dicke originally got his anthropic coincidence from.
That's the ice that nobody wants to feel.
Luis, I'm very sorry to bother you again, but the point to all of this is that I can't do this by myself, and I'm only a student. I have no endorsers, nor any previous history of papers, and I can't do the math for the most important part to this.
I can do enough math that reasonably proves that Einstein's simple model has never been disproven, so it is still preferred until somebody proves otherwise. I can write a paper to that effect, and I can write relevant astrophysical papers about other related aspects to all of this.
But I can't do it by myself, so I'd like to know if you might tell me how to go about finding somebody that will co-author a paper or more. Or some other avenue of pursuit, maybe? Any suggestion is welcome.
The math that proves it is simple and can be easily understood for its obvious merrit, so there is no question about validity. This is so simple and so obvious that the must be some way to reach people.
Again, I'm sorry to bother you with this, but I honestly have no idea how to go about it.
Hi, island, sorry for the delay (I surely need a better mechanism for tracking comments). I think that the faculty of your local university is the best place to start, let me know which are the closer universities to you and maybe I can make some further suggestions, it might be a good idea to speak with the grad students first, they can give you valuable information not only in physics but also on which members of the faculty are more accesible.
I also suggest you to read some nice books, just tell me which is are the books at the current level and I can make some further suggestions, in the maths regard "The geometry of physics" by Theodore Frankel and the mathematical methods book by Arfken (or the one by Hobson) have most of the mathematics you need to start reading the advanced treatments.
Post a Comment