imatfaal Posted January 6, 2014 Posted January 6, 2014 A triple system with millisecond pulsar has been found and studied which has the potential to provide new observation data that will strongly test the so far unblemished predictive power of General Relativity in the Cosmological Realm and may even cast into doubt some of the core assumptions. The Strong Equivalence Principle can be read about here in wikipedia or here in Living Reviews In Relativity My layman's reading is that conditions are such that the tiniest flaws in GR ( ie GR's equivalent of the precession of mercury) which we are certain will be manifest in the very very small (ie at the borders of quantum mechanics) will actually be observable here in the macro cosmological world. Any hints of where GR fails in extreme conditions, or when measured very precisely will be invaluable for those theorists attempting to construct the more general theory uniting the large and the small. 140.04 – A Millisecond Pulsar in a Stellar Triple System Scott M. Ransom et al. In late 2011, as part of the Green Bank Telescope 350MHz Driftscan survey, we uncovered a fast, bright, and so-far unique millisecond pulsar in a hierarchical triple system with two white dwarf companions. Since that time, using a variety of telescopes and a huge number of observations, we have fully "solved" the system, PSR J0337+1715. Gravitational interactions between the 1.6-day and 327-day orbits and the relativistic transverse Doppler effect of the pulsar are detected with extremely high precision, providing all masses and inclinations to four significant figures. Fitting the data with a 3-body integrator, pulse arrival times are predicted with microsecond-level or better precision. The compact natures of the three stars and their very different gravitational binding energies (3GM/5Rc2; ~0.1 for the pulsar and ~1x10-4 for the white dwarfs) will likely provide the best tests so far of the Strong Equivalence Principle and therefore strong constraints on alternative metric and scalar-tensor theories of gravity. High-quality optical observations of the hot inner white dwarf combined with an upcoming precise distance measurement from the VLBA will allow the system to be used as a calibrator for low-mass Helium white dwarfs. Finally, the exquisitely measured properties of the system will allow detailed investigations into its likely very strange evolutionary history. From the AAS abstract http://files.aas.org/aas223/aas_223_abstracts.pdf Gravitationally bound three-body systems have been studied for hundreds of years1, 2 and are common in our Galaxy3, 4. They show complex orbital interactions, which can constrain the compositions, masses and interior structures of the bodies5 and test theories of gravity6, if sufficiently precise measurements are available. A triple system containing a radio pulsar could provide such measurements, but the only previously known such system, PSR B1620-26 (refs 7, 8; with a millisecond pulsar, a white dwarf, and a planetary-mass object in an orbit of several decades), shows only weak interactions. Here we report precision timing and multiwavelength observations of PSR J0337+1715, a millisecond pulsar in a hierarchical triple system with two other stars. Strong gravitational interactions are apparent and provide the masses of the pulsar (1.4378(13) , where is the solar mass and the parentheses contain the uncertainty in the final decimal places) and the two white dwarf companions (0.19751(15) and 0.4101(3) ), as well as the inclinations of the orbits (both about 39.2°). The unexpectedly coplanar and nearly circular orbits indicate a complex and exotic evolutionary past that differs from those of known stellar systems. The gravitational field of the outer white dwarf strongly accelerates the inner binary containing the neutron star, and the system will thus provide an ideal laboratory in which to test the strong equivalence principle of general relativity. From the Nature abstract http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12917.html
michel123456 Posted January 6, 2014 Posted January 6, 2014 Is this a new chance for SCC Theory? A Theory that so far seems consistant with data and "is concordant without requiring the unverified process of Inflation, unknown dark energy, or exotic non-baryonic dark matter." A Theory that incorporates the CMB without the Big Bang. see http://en.wikipedia.org/wiki/Self-creation_cosmology
imatfaal Posted January 6, 2014 Author Posted January 6, 2014 I think the first step for all theories that intend to probe the earliest stages of the universe is to be able to work in the sort of energies in which you have to take account of quantum effects and gravity at the same time - the near-beginning of the universe being a prime example of this. Once you can claim to have a theory that can simultaneously cope with the four forces on a unified basis then the idea of having to explain gravity as either continuous or created ex nihilo changes - not necessarily for the better. The idea of unification of forces at high energy and the symmetry-breaking during cooling is well understood through the electro-weak theory and we can postulate that gravity will symmetry break through an analogous situation; however you are left with explaining how and why you have the unified force in the first place. On SCC theory - i am not qualified to comment properly. Although I do wonder about the veracity of some of the claims made on the wiki-page linked - with a solution to both dark matter and dark energy why is it not being worked on in every physics dept around the world. As dark matter is incredibly lumpy and can be mapped and dark energy is completely universal then I cannot begin to imagine a change to GR that could do away with both I found this review article by Barber who seems to be a fundamental key to the development so I will try and read it http://arxiv.org/abs/1009.5862 That same Reverend G A Barber (who does not seem to be academically tenured - more ecclesiastically) also wrote the majority of the wiki-page - he could be a second Lemaitre
michel123456 Posted January 7, 2014 Posted January 7, 2014 I think the first step for all theories that intend to probe the earliest stages of the universe is to be able to work in the sort of energies in which you have to take account of quantum effects and gravity at the same time - the near-beginning of the universe being a prime example of this. Once you can claim to have a theory that can simultaneously cope with the four forces on a unified basis then the idea of having to explain gravity as either continuous or created ex nihilo changes - not necessarily for the better. The idea of unification of forces at high energy and the symmetry-breaking during cooling is well understood through the electro-weak theory and we can postulate that gravity will symmetry break through an analogous situation; however you are left with explaining how and why you have the unified force in the first place. On SCC theory - i am not qualified to comment properly. Although I do wonder about the veracity of some of the claims made on the wiki-page linked - with a solution to both dark matter and dark energy why is it not being worked on in every physics dept around the world. As dark matter is incredibly lumpy and can be mapped and dark energy is completely universal then I cannot begin to imagine a change to GR that could do away with both I found this review article by Barber who seems to be a fundamental key to the development so I will try and read it http://arxiv.org/abs/1009.5862 That same Reverend G A Barber (who does not seem to be academically tenured - more ecclesiastically) also wrote the majority of the wiki-page - he could be a second Lemaitre Right.
Unity+ Posted January 8, 2014 Posted January 8, 2014 A triple system with millisecond pulsar has been found and studied which has the potential to provide new observation data that will strongly test the so far unblemished predictive power of General Relativity in the Cosmological Realm and may even cast into doubt some of the core assumptions. The Strong Equivalence Principle can be read about here in wikipedia or here in Living Reviews In Relativity My layman's reading is that conditions are such that the tiniest flaws in GR ( ie GR's equivalent of the precession of mercury) which we are certain will be manifest in the very very small (ie at the borders of quantum mechanics) will actually be observable here in the macro cosmological world. Any hints of where GR fails in extreme conditions, or when measured very precisely will be invaluable for those theorists attempting to construct the more general theory uniting the large and the small. From the AAS abstract http://files.aas.org/aas223/aas_223_abstracts.pdf From the Nature abstract http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12917.html In some ways, it is expected that General Relativity would fail in some areas like Newtonian Mechanics had with the way it described time. This is due to the fact that it only applies at a certain level as Classical mechanics had. It will be interesting to see what the new theory will be and will provide.
pantheory Posted January 11, 2014 Posted January 11, 2014 (edited) Unity+, In some ways, it is expected that General Relativity would fail in some areas like Newtonian Mechanics had with the way it described time. This is due to the fact that it only applies at a certain level as Classical mechanics had. Yes, it will be interesting seeing what kind of conclusions they will come to I believe GR has already failed in that dark matter is just a temporary place holder for a much better answer. It will be interesting to see what the new theory will be and will provide. Yes, it will be extremely interesting. Although I think reality is quite simple, I also think a great many u-turns will be needed as well as many years, before they start barking up the right trees. This I expect will result in a great many or most theories in modern physics to be seriously re-evaluated concerning their merits compared to simpler explanations. In the broadest sence of the words, self-creation cosmology could also include the BB model and the steady state models. In the classical version the BB entity, according to theory, had the potential to create everything thereafter. In Hoyles Steady State theories matter is continuously being created either selectively where matter is condensed, or universally everywhere. And Dicke's ideas that gavity is involved in the processs seems like a type of selective creation. No one seems to realize that if matter were continuously being created then when going backward in time, eventually you could come to a beginning field, or even simpler, a single entity. Maybe not 13+ billion years ago, maybe countless past time but still not an infinite beginnning. I think there are a great many simpler answers than today's models and theories, that are waiting for our further investigation rather than our settling for some of the most complicated answers that by their complications, I think, will eventually be their undoing. Edited January 11, 2014 by pantheory 1
Sensei Posted January 19, 2014 Posted January 19, 2014 Will we soon find the first glitches in General Relativity We really don't have to search far for extremities... http://en.wikipedia.org/wiki/Galaxy_rotation_curve Without introducing dark matter it would fail immediately in prediction of Milky Way stars velocity/distance from the center of galaxy: A - predicted by GR B - the real measurement
imatfaal Posted January 21, 2014 Author Posted January 21, 2014 We really don't have to search far for extremities... http://en.wikipedia.org/wiki/Galaxy_rotation_curve Without introducing dark matter it would fail immediately in prediction of Milky Way stars velocity/distance from the center of galaxy: A - predicted by GR B - the real measurement I think the excitement over this new experimental testbed is that fundamental assumptions can be tested - and due to the nature of the triple system very few extraneous items (like estimating the mass of a galaxy) need to be taken into consideration. And the fact that the strong equivalence can be tested (high rest mass slow star and low rest mass very fast stars - do the sums show that masses behave as the SEqP predicts) And the fact that we can (indirectly) detect dark matter in at least two other methods shows that there is something out there that is not shown via our observations in the EM spectrum. If GR had predicted the exact velocity of rotation of the galaxies we would be at a loss to explain the gravitational lensing or the behaviour of the bullet cluster etc. I am fairly certain that dark matter is not merely a glitch with GR
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