What about the absence of a unified field?

[marcus]

here's a quote from the abstract of the Padmanabhan paper:
http://www.arxiv.org/abs/gr-qc/0409089

From Gravitons to Gravity: Myths and Reality
T. Padmanabhan

"There is a general belief, reinforced by statements in standard textbooks, that:

(i) one can obtain the full non-linear Einstein’s theory of gravity by coupling a massless, spin-2 field h_ab self-consistently to the total energy momentum tensor, including its own;

(ii) this procedure is unique and leads to Einstein-Hilbert action and

(iii) it only uses standard concepts in Lorentz invariant field theory and does not involve any geometrical assumptions.

After providing several reasons why such beliefs are suspect--and critically re-examining several previous attempts--we provide a detailed analysis aimed at clarifying the situation. First, we prove that it is impossible to obtain the Einstein-Hilbert (EH) action, starting from the standard action for gravitons in linear theory and iterating repeatedly.

This result follows from the fact that EH action has a part (viz. the surface term arising from second derivatives of the metric tensor) which is non-analytic in the coupling constant, when expanded in terms of the graviton field. Thus, at best, one can only hope to obtain the remaining, quadratic, part of the EH Lagrangian (viz. the Gamma² Lagrangian) if no additional assumptions are made. Second, we use the Taylor series expansion of the action for Einstein’s theory, to identify the tensor S^ab, to which the graviton field h_ab couples to the lowest order (through a term of the form S^ab h_ab in the lagrangian). We show that the second rank tensor S^ab is not the conventional energy momentum tensor T^ab of the graviton and provide an explanation for this feature.

Third, we construct the full nonlinear Einstein’s theory with the source being spin-0 field, spin-1 field or relativistic particles by explicitly coupling the spin-2 field to this second rank tensor S^ab order by order and summing up the infinite series. Finally, we construct the theory obtained by self consistently coupling h_ab to the conventional energy momentum tensor T^ab order by order and show that this does not lead to Einstein’s theory. The implications are discussed."

 

[Haelfix]

For technical reasons I don't like that paper, he keeps total derivatives here and there and there seems to be some issues with some of his math. I haven't looked at it since then but I was and still am a little skeptical.

It takes quite a bit to challenge 30 years of tried and true field theoretic results (note this has nothing to do with string theory necessarily).

 

[marcus]

For technical reasons I don't like that paper, he keeps total derivatives here and there and there seems to be some issues with some of his math...

Haelfix, thanks for the reply. You hear coffee-room stuff which I am always glad when you pass along.

What has struck me as odd is that no one seems to have written a paper replying to Padmanabhan. He is prominent in his field, so if there is something wrong with the math in that paper I would expect more than unpublished gossip to that effect. I am surprised no one has published their misgivings. Or if they have I haven't heard. I will do a citation check and see what "cited by" there are.

Nope. No one critical of the Padmanabhan paper has published anything citing it.

I guess you know: Ashtekar is editing a book to be published this year called "A Hundred Years of Relativity" and Padmanabhan is one of the authors.
The "Myth or Reality" paper will be apparently cited in Ashtekar's book because Padmanabhan cites it in his draft chapter.

 

[Fredrick]

Black hole

Oh, you mentioned that part of the picture is missing, so there is an empty part of the picture in the middle.
I suppose that part is the tube where the particles collide (so there cannot be any detector there) the image would only be generated from what happened in the ringshaped space around the tube where they could position detectors.

correct me if I'm wrong but it seems that if they could situate detectors closer into where the collision occurred, then they would see a whole lot more activity not included here, but this is a great picture already (even with the missing detail in the middle)

does anybody know more about the RHIC (relativistic heavy ion collider) "fireball"

Dr. Nastase states that a (mini) black hole may have been recreated.

 

[Fredrick]

Momentary nothing

I read it again in the New York Times science section this last week, that during the collision at BNL of two gold nuclei a momentary nothing - a fraction of a second in which nothing occurred - was detected before materialization of the new plasma became visible. I find this highly telling.

 

[mosassam]

Apologies for just butting in randomly (I wasn't sure where else to go). Just a quick question - can anyone tell me if strange attractors have their own, independent existence or are they always dependent on something? (or is this a stupid question?)

 

[Anonym]

In the eye of the ant beholder

Fredrick :” I never thought I would talk here about Adam and Eve, but when it comes down to order, then ordering is in question and it must be addressed. There are two versions of ordering and I mention it here because it brings us back to the reason of this thread, which is basically the question: Unification or not.

With establishing the story that god created Adam first and from Adam god created Eve, an ordering has been used in time. Not to dispell any person's belief that this is true, a different way of ordering exists as well. God could have easily created both Adam and Eve at the same time.

What is the difference between these two versions? The difference is the ordering in time, and the link that exists (or not exists) between Adam and Eve.

When god created Adam and from Adam Eve, god established a top and bottom, a first and last, an important and an unimportant aspect, or however you want to frame it. This way a version of ordering has been created that appears applicable to everything; and everything is linked to each other. I think that the truth is not that simple. What is most important for you, is not most important for me. What is the top for you, I regard as not that high of a standard, what is first for me, may be second for you. You may give importance to leadership, I want everyone to follow their own voice while being respectful to others' voices.

When god created Adam and Eve at the same time, god delivered two segments that may have a lot in common, but in at least one aspect both have nothing in common: on one level of separation there is no link. Ordering can still be applied but each has their own version of ordering, in which various segments have their own positions. The parts may, but whole picture is not based on ordering because it is based on two equals that are not identical. One can armwrestle and decide who will be the winner, but that does not deliver an order that is natural; it is an order of results only. In this version it is preposterous to mention one of the two as top and the other as bottom, because each is not organized according to the other's principle, but to their own. Same goes for culture. Cultures can never top other cultures as a whole, only in segments. What is great in Western society, may be dummm in other societies, and vice versa.

Sorry to bring a religious story (Adam & Eve) into a scientific/metaphysical thread, but I am using it because it is familiar to everyone (Christian/Jewish/Muslim or not). It delivers an order, which may have much appeal, but which is not the only way in which everything can be ordered. It lacks information; it lacks options that clearly exist. That's why we have different religions. Some have only one god, others have multiple gods, while there are also a lot of people who believe there's no god(s) at all. I know that nobody can answer that question for everyone, only for ourselves.”

Creating Adam and Eve was His last step. He worked hard five “days” before that.Moreover, before He started to work, it was T&V simultaneously. They may be considered as different and separated entities, but mathematically it is also possible to treat them as the same object, only conjugated to each other, and defined at the same point also in space, provided that the notion of the space-time continuum is well-defined.

Fredrick :“Can I ask you to reply to this message with regards to our thread: do you believe unification exists?”

Yes.

Fredrick :”or do you believe a separation of at least one level is the norm?”

No.The norm is defined as a single positive real number (measurable quantity).

In addition, I prefer to do math-ph exercises and let Him to decide.

Fredrick :” Again, the math is terribly simple, but it may give you a nice look at the prime number sequences that exist within the natural numbers, and how they are all connected.”

Sorry, I did not read your book, but if you call the natural numbers or any subsequence within the natural numbers the mathematics, you are deadly wrong. You apparently missed the last 3000 years of the physically relevant development in the mathematics. The physical picture behind the unification is beautifuly simple, but the mathematics involved is terribly complicated. Otherwise, how one may explain the beautiful complexity of the real world?

And now let us look again at the origin.

Fredrick :” I am going to give one example of a singular platform (our earth) with four active members (North, South, East, and West). Though the platform is (or appears to be) singular, these four active ingredients do not have a common thread; the platform is known, but does not contain unification.

East and West can go on forever in their direction, but some unification can be found in that they can cover exactly the same spots. Depending on your point of view, a single place can be East or West.

For such single spot, North and South appear to deliver the same set-up as East and West, but North and South cannot go on forever in their direction. When on the North pole, one cannot go further North. One cannot even go East or West on the North pole. There is only one direction on the North pole, and that is South. To unify North and South in absolute terms is not possible, while it appears possible for East and West.

These four directions contain a pair of opposition without the possibility of unification (North and South), and a pair of opposition in which unification appears very well possible (East meets West).”

You use the Euler’s parametrization to describe the 3-dim rotations. Why you do not consider the Cayley-Klein parametrization which is analytical? Since it looks to you too complicated to comprehend? The physical picture behind it is very simple: 3 continuous parameters define the direction of the axis of rotation and the pseudoscalar continuous parameter define the angle of rotation around that axis. I leave to you as exercise to find who is The Physicist behind that parametrization.

For everybody who with me: don’t be fantasioners. Three other fundamental interactions are still not unified since the proton is stable (it is the QM ground state of three bounded quarks). And the electroweak U(2;c)~U(1;q) is still only nearly adequate phenomenological model. And the “theory of everything” or the “final theory of everything” is obviously nonsense.

Marcus:” It would just be some theory. surviving by continuing to accurately predict the next accelerator experiment and the next astronomical observation,each day betting its life on predictions of microscopic physics and of cosmology-----and destined to eventually be shot down”

“The next accelerator experiment” is obsolete. The pulse compression will allow to perform the necessary verification/prediction experiments in microphysics as well as in cosmology on the laboratory tables of average universities.

Fredrick :”Before the Renaissance theologians and scientists were often one and the same people”

Long ago I had an interesting student. He had Ph.D. in theology and came from Vatican. He decided to know what physics is. He was 2-year undergrad. I asked him the basic questions in optics. He did not know the answers, but said that he was not able to imagine how difficult the study of physics is.

Marcus:” But everybody knows that Gen Rel is wrong!”

Who are these everybody, please? GR is the Chapter and the most beautiful chapter so far.

Fredrick :” The unity that existed no longer exists after divorce or death.”

I am divorced twice. Now my last X seems want the unification again (the same had happens also in the previous case). With respect to death I have no experience yet. And this is the reason why I am not “able to deliver evidence that unifies the forces in one field I will be the first one to cheer you on.” Simply I don’t want waste my time.

Daniel Gleekstein.

P.S. Thank you for your presentation. I should change my attitude to the philosophers. Please, send my best regards to your friend Karl.