# Expansion acceleration an anomaly?

1. Jul 19, 2008

### ThomasT

Is it possible that the observed acceleration in the expansion rate of observable large scale cosmic structures is just a temporary blip -- an anomaly in an otherwise fairly steady decrease in the universal expansion rate?

Is it possible that the observed acceleration isn't characteristic of the universe at large?

2. Jul 19, 2008

### Garth

The inferred cosmic acceleration is derived from the fainter than otherwise expected SNe Ia supernovae. They are spread all over the sky and seen at various red shifts around z = 1, so the effect would seem to be a feature characteristic of the universe at large.

However they may be other explanations as to why the SNe Ia are fainter than expected at those ranges and therefore ages past, but cosmic acceleration is seen as the best explanation that fits in with other data to form the standard $\Lambda$CDM model.

Garth

3. Jul 20, 2008

### yuiop

It had been known for a long time that SNe Ia supernovea at less than z=1 are fainter than they should be. That information was not conclusive by itself.

They only really came to the conclusion that the universe is accelerating when they observed SNe 1a supernovae at greater than z=1.7 are brighter than they should be. That suggested that galaxies receded much slower in the early epochs of the universe and more recently they have receding much faster indicating the recession velocities are not constant over time.

4. Jul 31, 2008

### JimJast

It's funny that the "recesion velocities" are not constant over time happens also in a stationary (Einsteins' universe) model. The time profile of Hubble constant (in this case the Hubble constant of apparent expansion) comes out also as if the universe were a subject to accelerating expansion and with almost the same acceleration as observed ($$dH/dt=-0.50H_0^2$$ theoretically and $$(dH/dt=-0.45H_0^2$$ observed). Of course it has to be a pure accident, the same as with the Pioneer 'anomaly' that is accidentally equal to the theoretical value of the Hubble redshift in Einsteins' universe (theoretically $$c^2/R_E$$, where $$R_E$$ is Einstein's radius of the universe, acceleration observed as $$8\times10^{-10}m/s^2$$) .

I have to explain that I'm doing my PhD work on the history of Einstein's universe model that's why I know such data which normally are of no interest to physicists and astronomers. It turns out that this model happens to be quite interesting even if not quite right. It turns out that Einstein's gravitation explain much more things that is known by looking at its surface. It also happens to be a quantum theory, which apparently Einstein was not too fond of since he didn't believe in gravitational attraction mediated by gravitons but rather in it being an illusion caused by the curvatures of spacetime.

Last edited: Jul 31, 2008
5. Jul 31, 2008

### Garth

What explanation of Hubble red shift do you then have in such a stationary model?

These coincidences may not just be a pure accident.......

Very interesting subject, I wish you well.

What do you mean by "Einstein's gravitation"? That (GR) is normally accepted as the standard theory!

Garth

6. Jul 31, 2008

### JimJast

The explanation of Hubble redshift in Einstein's universe is illegal from the point of view of the standard model cosmology since this explanaton assumes global conservation of energy while the standard cosmology allows the global conservation of energy only in the Newtonian physics and doesn't allow it in expanding universe (because of Noether's theorem).

Therefore it doesn't allow it in the general relativity in which the expansion of the universe is included as a separate axiom of the theory that is presently called standard model or standard general relativity. This way Einstein's universe has only a historical significance and not being valid in standard GR is still valid in "Einstein's gravitation", and that's why I call so Einstein's theory of 1916, and 1917 when Einstein proposed Einstein's universe together with its cosmological constant ("Einstein's biggest blunder") when Einstein didn't know yet that the universe is expanding and energy is not conserved.

As for your first question ("What explanation of Hubble red shift do you then have in such a stationary model?") it is fun to calculate how much redshift one could have in stationary space since it is very simple. You do it by taking sheet of photons in a homogeneous space of certain density, move it perpendicuralry to its plane and calaculate the amount of gravitational energy that you created this way in this space (in something like a "gravitational capacitor"). After subtracting this energy from energy of photons (relying on the principle of conservation of energy) you get Hubble constant. The fun is in the fact that it comes out $$70km/s/Mpc$$ (which is about Hubble constant in our universe) for the density of space of $$6\times10^{-27}kg/m^3$$. So if the density of Einstein's universe were such we wouldn't need the expansion to explain the Hubble redshift. Since we need the expansion it means that astronomers had to give up an option of stationary space for good reasons. E.g. that they know for a fact that the density of space is different or that the conservation of energy that we used in this calculation was is not allowed in standard general realativity.

Furthermore you derive the relation between the Hubble constant and distance or time and take Taylor series of it. That's why you get mentioned relation between acceleration of expansion and time. The only bad thing about it is that it is all done with assumption of global conservation of energy and for non expanding universe and we know that our universe is expanding and therefore energy is not conserved in it... too bad. Luckily there is enough material in it that it might make a decent PhD thesis about the history of Einstein's attempts (even if failed) to discover the truth about gravitation and the universe.

7. Jul 31, 2008

### Garth

We observe Hubble red shift - Einstein did not know that when he proposed his static Einstein model, once known he acknowledged his belief in a static system, and the cosmological constant it required, to be a blunder. If he had only believed in his own equations without the CC he would have predicted the expanding (or contracting) universe years before Hubble discovered it.

If the universe is static, as in the model you say you are researching the history of, then you need an actual physical mechanism to produce such a red shift, such as the discredited 'tired light' theory. I do not find your explanation at all convincing as an alternative cosmological theory - if you are saying cosmological red shift is simply a gravitational red shift then that could be considered an interpretation of the standard theory.

There are however other observations that provide evidence of a universe that has expanded from a very small dense and hot volume viz:
1. The 3/4:1/4 ratio of primordial hydrogen and helium. (BBN)
2. The CMB.
3. The power spectrum of the CMB that leads to the standard $\Lambda$CDM model.

If you really are doing research on the static model you must constrain yourself to history and not explanations such as above, that is unless you can also adequately explain all these other observations in your model!

Garth

8. Jul 31, 2008

### yuiop

Could you put this into context? The value of $$6\times10^{-27}kg/m^3$$ does not seem that far removed from the current estimated mass density of the universe. What would it be in terms of Omega(mass)? (which is estimated to be about 0.27 in the current model)

As I understand it, Einstein introduced the cosmological constant to create a static universe in which the attraction of gravity is exactly balanced by the repulsive gravity of the cosmological constant. In such a model would there be no observered redshift of distant galaxies? (ignoring local peculiar motions). What I am trying to understand is why Einstein dropped the csmoloigcal parameter so readily and called it a blunder as soon as he found out that distant galaxies had redshift proportional to distance. If the cosmological parameter is a free parameter and not rigidly determined, predicted or dependent on anything else why didn't Einstein just simply change the value of the free parameter and say his cosmological parameter still stands which is what modern cosmologists have effectively done?

In another thread I think you mentioned the current observations can be accounted for by time speeding up. I think that is an interesting approach. If we had a hypothetical static and infinite universe, an increase in the tick rate of clocks and a corresponding decrease in the length of physical objects would make the speed of light to appear to be constant, but at the same time the distance between galaxies would appear to increasing and they would also appear to be redshifted proportional to distance. Now imagine that over a period of time, the clock rate has doubled and lengths have halved. The orbital radius of gravitationally bound objects would halve over the same period. If we work out the Keplerain orbital period for a halved orbital radius it would look like orbiting objects are orbiting faster over time and this does not seem to agree with what we observe. The way round this annomaly is to propose that the gravitational constant G increases over time. By varying the value of G over time in the Planck units, the Planck length would decrease over time, the Planck time interval would get shorter (same as clocks speeding up) , the local speed of light would be constant, and the Planck Inertial mass would be increasing. The overall effect is that locally the speed of light is constant, the orbital period of gravitationaly bound objects appears to be constant and the distance to far galaxies would appear to be increasing over time and light coming from them would appear to be redshifted.

Of course the real crux of the matter is how luminosity of distant galaxies and angular distance is correlated with models.

I think it is obvious that some fundemental assumption being made by cosmologists is wrong. I make this statement based on this diagram http://www.astro.ucla.edu/~wright/Wm-Wv-wMAP5yr-wSNe.gif . If the assumptions of current cosmology were correct, then the green dot at the centre of the Supernova ellipses, showing the cosmological parameters calculated from Supernova data would be right on the line for cosmological parameters calculated from WMAP CMB data. The diagram is from Ned Wrights cosmology tutorial here http://www.astro.ucla.edu/~wright/sne_cosmology.html

Last edited by a moderator: Apr 23, 2017
9. Jul 31, 2008

### Garth

Hi kev,

Einstein dropped the CC because it was no longer needed, if you like an application of Occam's Razor, and an approach taken by most cosmologists right up until the 1990's when the distant SNe 1a indicated that the universe might be accelerating.
You are describing a conformal gravity model, (such as the Jordan conformal frame of http://en.wikipedia.org/wiki/Self_creation_cosmology [Broken]).

Garth

Last edited by a moderator: May 3, 2017
10. Aug 1, 2008

### JimJast

Or his acknowledging it might have been an urban legend, since it hangs on a testimony of one guy only who wanted to promote his own idea of the behavior of universe for which the cosmological constant's value happened to be zero:
In my opinion based on my talks with Roy Glauber, my one time physics professor at Harvard, who was Einstein's coworker, the phrase "the biggest blunder of my life" was meant by Einstein as a joke since it started an endless procession of cosmologists bothering Einstein with their pet ideas about the value of cosmological constant to the point that Einstein forbade his secretary to let in anybody who would like to talk with Einstein about the universe. Since if you think about it seriously, how come discovering anything can be a blunder (not to mention even "the biggest") of somebody's life? Gamow might have used Einstein's joke as if it were a confession by Einstein since it was advancing the cause of Gamow's Big Bang and was formally not a lie. Einstein really said this but do you believe it was as serious as Gamow interpreted it? Without Roy Glauber's testimony we might have even no hint that it might have been a joke.

But it's probably too much about Einstein, and it might look like "highjacking the thread" to moderators, which I'd like to avoid or at least avoid being banned for gossiping about Einstein's ideas instead of talking about acceleration anomaly about which Einstein couldn't know. It just might be predicted by his theory (as I pointed out) which is not the same thing. So I guess I have to shut up not to get banned for life from this forum which happened already to me in astronomy forum for (allegedly) highjacking some's thread by responding to some question in too much detail. So let limit out exchange to acceleration anomaly only.

He couldn't since he believed also in the principle of conservation of energy and with sticking to this principle one can't demonstrate that the universe is undergoing an accelerating expansion (just an illusion of it, as I explained in one of the previous posts). The big progress in understanding the nature is in admitting that the energy is not conserved globally if the universe is expanding (Noether's theorem, that I mentioned earlier).

Of course I agree with you that if I had a cosmological theory I had to explain all those things. Luckily, I don't have any theory about it and I explain only what Einstein might have though extrapolating the results of his theory of gravitation and noting a few things that it predicts with quite simple (almost Newtonian) math. Between other things also the acceleration anomaly. I'm resaerching the internal mechanisms of Einstein's universe, whether they make sense and to what degree, and not only some long dead historical facts and urban legends.

.
I'm researching only Einstein's universe and its consequences and I can only comment on them. I'm not a cosmologist nor even an astronomer and so I don't know a thing about Omega(mass) (which is also a good thing since I'm not biased neither way). All my life (atually since age of 14) I belived that the universe is expanding and only after researching Einstein's universe I see other possibilities. I'm not expert enough to know how important they are. Context to the above value is that in Einstein's universe there is a very simple relation between the Hubble constant at observer and the radius of curvature of space that comes directly from the (almost) Newtonian mechanics and the principle of conservation of energy and is necessarily interpreted as time slowing down in deep space because of the presence of matter in this space: $$H_0=c/R_E$$, and in Einstein's universe $$R_E=c/\sqrt{4\pi G \rho}$$, where $$\rho$$ is density of space, other constants are standard. This slowing of the time and the curvature of space is of course not Newtonian stuff but it is calculated with formally Newtonian mechanics with observing all necessary rules of being exact.

Would you believe me if I told you that he was too shy and too unsure of his mathematical skills to argue with mathematicians? Didn't he say "I stopped understanding my theory when mathematicians started to explain it to me?" (quoted from memory so exact words might differ). Hasn't he told his secretary not to let anybody in if he wants to talk about the universe? He simply gave up on general relativity assuming that it is in better hands than his (he just mentioned that he thinks there is a lot of non discovered potential in it). And besides he didn't believe in "attraction of gravity" which you mentioned above since there is no such a thing in his theory of gravitation. The gravitational forces in his theory of gravitation are purely inertial forces resulting from deviations of worldlines of particles from geodesics in spacetime so they can't even act at the distance, only when the particles are pushed out of their geodesic worldlines by some force. As the reaction to this other force (most of the time to the electromagnetic force).

It is the only approach for Einstein's universe that is consisten with Einstein's theory. It requires a presence of a 3D delated time tensor that be the same with opposite sign as the 3D tensor of curvature of space. So far this tensor was not discovered unless you assume that the spacetime is static and we observe this tensor as the inability of nature to create enrgy form nothing. So far the expanding universe model assumes the energy is not conserved in the expanding universe so this new tensor is not needed for anything. It is just a way of handling the Hubble redshift in case of lack of expansion. But who needs two theories explaining the same thiing? So today we assume non conservation of enrgy which is OK in expanding universe and have a lot of other things explained with it as well. While Einstein's uiverse requires necessarily conservation of energy and so it has a historical meaning only. Which I don't mind since it allows me to study the mind of Einstein's and his approach to gravitational forces noticing in the process that his theory is really a quantum theory (a thing not widely known neither).

Hold your horses: it would be in special realtivity, but in general you have also a matter in this space that curves the space a tiny bit. So your scenario is right for an empty space and in Einstein's uiverse, this tiny amount of curved space is responsible for the $$H_0=c/R_E$$ I mentioned earlier. So the rest of your scenarion don't need to apply. Besides this clocks ticking slower in the past is only a local relativistic effect (Einstein's GR is only a local theory:) something like time rinning slower "simultaneously" in two passing by rockets. It is tougher to understand in two stationary points in space but luckily it does not cause any logical contradiction cince it may be considered globally also as time running faster and faster. So we don't need to worry about the interpretation and consider it one more relativistic paradox (eg. "general" twin paradox: each stationary twin observing the other getting older but when he meets her she is the same age as him).

Of course. And I'm only second year within my PhD work. I hope after next few years I might know more things and tell you, providing I'm not banned from this forum for discussing Einstein instead of acceleration anomaly :)

Last edited: Aug 1, 2008
11. Aug 2, 2008

### yuiop

In that case it is probably better to start a new thread concerning your research into the history of Einstein's thoughts and motivations for the Cosmological Constant. I am sure it would be an interesting and perfectly legitimate subject to discuss in this forum and I would be glad to continue our conversation on the topic in its own thread. (As time allows).

12. Aug 2, 2008

### JimJast

Unfortunately, whenever I try to discuss Einstein's universe it is treated as if I were trying to promote my own theory of our universe insisting that it is static. Even if I surely couldn't be there to talk Einstein into inventing his universe to promote mine. If not for other things than just for the fact that I was not yet born then. I thouht it should be a legitimate enough reason but moderators didn't believe me (how they could be sure that I'm not just pretending?) and I was banned for life from BAUT forum not to be able show that lack of expansion of Einstein's univers might be a legitimate science.

It turns out that it is dangerous to even mention that Einstein universe might be legitimate physics (which is my opinion, possibly since I know only gravitation, not enough astronomy, and nothing about the cosmology). For some reason it tuns out not to be legitimate cosmology however cosmologists get angry whenever they are asked why? and rather ban the guy from their forums than answer.

But if you think it is safe to open a thread on Einstein's universe in Physics Forum I'll do it just out of curiosity and to prove that physicists are different than cosmologists. If not then I'll be banned from another forum, which might have its advantage of leaving me more time for doing my PhD stuff :). So see you in Einstein's universe thread.

13. Aug 2, 2008

### Garth

We do not discuss crackpot theories here, but I am sure that if you can show the ideas you want to discuss are actually Einstein's then that would be perfectly acceptable.

I don't think anybody here has the arrogance to judge Einstein a crackpot!

Garth

14. Aug 2, 2008

### George Jones

Staff Emeritus
As you have already been told,

personal theories are allowed only in the Independent Research Forum.

You responded,
Long posts that have lots of LaTex in them generate this type of problem in all forums here. See

and

If you make a submission to the Independent Research Forum, I will encourage (no promises, though) Mentors and Science Advisors who have cosmology backgrounds to have a look at your submission.

15. Aug 2, 2008

### MeJennifer

Note that in FWR spacetimes the "expansion of space" is equivalent with "clocks speeding up".

16. Aug 2, 2008

### JimJast

Not quite since "clocks" don't have particle horizon while "space" has.

17. Aug 2, 2008

### MeJennifer

That is clearly not an argument against the equivalence of changing distances with changing clock rates.

18. Aug 2, 2008

### Garth

" why Einstein's universe is neglected"??

Because there is no cosmological red shift due to expansion in a static universe!

If you have a hypothesis that yields some other mechanism for producing red shift, as you see to have, then that would be a personal theory for discussion here only on the Independent Research Forum.

It was the observation of Hubble Red Shift that meant everybody gave up the Einstein universe, even Einstein!

Garth