Garth said:
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.
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:
Much later, when I was discussing cosmological problems with Einstein, he remarked that the introduction of the cosmological term was the biggest blunder of his life.
-- George Gamow, My World Line, 1970
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.
Garth said:
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.
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).
Garth said:
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 \LambdaCDM 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!
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.
kev said:
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)
.
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.
kev said:
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?
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).
kev said:
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.
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).
kev said:
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, ...
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).
kev said:
Of course the real crux of the matter is how luminosity of distant galaxies and angular distance is correlated with models.
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 :)