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Thread: GR is great, but it has to fail sometime

  1. #31
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    Quote Originally Posted by Jerry View Post
    No, but it should have been. Adding more and more epicycles is a valid mathematical solution, but not a scientific principle.
    This sounds like you are advocating making no models until after we have all of science absolutely right. Am I reading you correctly?
    Forming opinions as we speak

  2. #32
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    The Newtonian model, with some empirically determined fudge terms added for extreme cases such as Mercury's perihelion advance rate, is still a useful tool for practical calculations of planetary orbits.

  3. #33
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    Quote Originally Posted by antoniseb View Post
    This sounds like you are advocating making no models until after we have all of science absolutely right. Am I reading you correctly?
    Abstractions are useful as long as they don't impede scientific progress. We should question the basic assumptions when significant efforts to advance the theory are frustrated.

  4. #34
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    Quote Originally Posted by Jerry View Post
    Abstractions are useful as long as they don't impede scientific progress. We should question the basic assumptions when significant efforts to advance the theory are frustrated.
    Well, see, that's a problem with your complaints of mainstream science Jerry. Those people who actually study and work in these areas don't believe that scientific progress is being impeded. When we ask you to provide some kind of support for your contentions, you don't normally provide such support or worse, you provide papers that generally refute your own contention.

    You flat out said that Newtonian Mechanics (actually gravity) should have been thrown out, which is ridiculous. It only needs to be extended, or generalized, to work in regions where it fails. Which is what GR does. But Newtonian Gravity is just fine for everything else in the solar system.

  5. #35

    Epicycles again? Uggh!

    Quote Originally Posted by Tensor View Post
    {Snip!} You flat out said that Newtonian Mechanics (actually gravity) should have been thrown out, which is ridiculous. It only needs to be extended, or generalized, to work in regions where it fails. Which is what GR does. But Newtonian Gravity is just fine for everything else in the solar system.
    As I have pointed out before, Jerry wants to "efface and replace" whereas I (and most of us here) prefer to "amend and extend".

    I also get tired of Jerry's constant appeal to "epicycles". Any new terms added and treated as perturbations to Newtonian celestial mechanics are not abitrary parameters chosen to fit the data, but actually depend on orbital elements and masses already known and measured. All current ephemerides such as those from JPL take GR into account, and guess what? -- the ephemerides work.

    I'm beginning to think that maybe I should assess penalties for gratuitous use of the word epicycles just as I do for gratuitous use of the phrase "paradigm shift". How many points should it be? Five or ten?

  6. #36
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    Quote Originally Posted by Celestial Mechanic View Post
    I'm beginning to think that maybe I should assess penalties for gratuitous use of the word epicycles just as I do for gratuitous use of the phrase "paradigm shift". How many points should it be? Five or ten?
    I would think five is more appropriate. After all, epicycles is only an "amend and extend". Since a paradigm shift is a "efface and replace", that should be worth ten, more points for a complete replacement.

  7. #37

    Five it is!

    Quote Originally Posted by Tensor View Post
    I would think five is more appropriate. After all, epicycles is only an "amend and extend". Since a paradigm shift is a "efface and replace", that should be worth ten, more points for a complete replacement.
    Good argument! Five it is!

    {Writes in the Armaments book:}
    "Neither shalt thou assess four points, nor shalt thou assess six. Five shall be the count of the penalty. Seven is right out!"
    Last edited by Celestial Mechanic; 2012-Apr-04 at 03:55 AM. Reason: Typo

  8. #38
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    Barbarians at the Horizon

    Many of the earlier theorists including Einstein sought logic in Nature and developed ideas that appealed to an aesthetic. They looked for both simplicity and beauty in their ultimate expressions. GR is no exception. As Friedmann first noted, the equations are naturally dynamic leading to either expansion or contraction and the Lambda was considered and ultimately rejected by Einstein as an aesthetic violation to its dynamic nature or a “great blunder”.

    While the observations attributed to the dark sectors can not be denied, is it correct to incorporate their effects into the “canvass” that GR is “painted” upon?

    Would it be correct to assert that DaVinci did not appreciate saints and proceed to add a “halo” about the head of the Mona Lisa and then add a Lambda shaped moustache to express accelerated aging?

    Would it be correct to assert that Beethoven took his “Fate Knocking at the Door” motif opening his 5th symphony too seriously and proceed to scrape off the three flats of the key signature to create a lighter “halo” suggestive of bellowing laughter of a jolly giant, and then append to the Allegro con brio tempo a “ma poco a poco accelerando quasi Lambda”?

    Einstein is not here to defend the aesthetic integrity of his work any more than DaVinci or Beethoven. While it may seem temporarily expedient to incorporate the LCDM on top of GR, into its “canvass” as it were, it detracts from its original aesthetic quality. As these myopic crutches become more entrenched and mar the original beauty, possible failures of the additions might be errantly also associated with the original theory which did not incorporate them and improperly suggest the original theory might be at fault as well.

    Furthermore, as the LCDM blemish continues over time to be associated with GR leading to a GR + LCDM paradigm on the same canvass, the searching for their own aesthetic “canvass” for each of separately Lambda and separately CDM is less considered.

    Not all unifications are beautiful.

  9. #39
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    Quote Originally Posted by borman View Post
    Barbarians at the Horizon
    Non-supported complaints in the Circus Maximus.

    Quote Originally Posted by borman View Post
    Many of the earlier theorists including Einstein sought logic in Nature and developed ideas that appealed to an aesthetic. They looked for both simplicity and beauty in their ultimate expressions. GR is no exception. As Friedmann first noted, the equations are naturally dynamic leading to either expansion or contraction and the Lambda was considered and ultimately rejected by Einstein as an aesthetic violation to its dynamic nature or a “great blunder”.
    Aesthetics had nothing to do with lambda being a great blunder. The great blunder lies in the fact that he could have predicted the expansion of the universe, but didn't. By that time, many of his ideas concerning unifications are much less aesthetic, but bothered him not at all. It doesn't appear that you know the history behind lambda or Einstein's work.

    Quote Originally Posted by borman View Post
    While the observations attributed to the dark sectors can not be denied, is it correct to incorporate their effects into the “canvass” that GR is “painted” upon?
    I don't know, what quantitative arguments do you have?

    Quote Originally Posted by borman View Post
    Would it be correct to assert that DaVinci did not appreciate saints and proceed to add a “halo” about the head of the Mona Lisa and then add a Lambda shaped moustache to express accelerated aging?
    Can you put that into some mathematics for us? If not, then no, it wouldn't be correct to assert that.

    Quote Originally Posted by borman View Post
    Would it be correct to assert that Beethoven took his “Fate Knocking at the Door” motif opening his 5th symphony too seriously and proceed to scrape off the three flats of the key signature to create a lighter “halo” suggestive of bellowing laughter of a jolly giant, and then append to the Allegro con brio tempo a “ma poco a poco accelerando quasi Lambda”?
    Can you put that into some mathematics for us? If not, then no, it wouldn't be correct to assert that.

    Quote Originally Posted by borman View Post
    Einstein is not here to defend the aesthetic integrity of his work any more than DaVinci or Beethoven.

    snip...

    Lambda and separately CDM is less considered.
    Your last few posts have had no actual evidence or calculations to back up your complaints. It seems you don't like the idea of a lambda, but you don't seem to want to show us why exactly.

    Quote Originally Posted by borman View Post
    Not all unifications are beautiful.
    Yeah, neither are complaints about GR and lambda cosmology, without using math.

  10. #40
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    Quote Originally Posted by Tensor View Post
    Well, see, that's a problem with your complaints of mainstream science Jerry. Those people who actually study and work in these areas don't believe that scientific progress is being impeded. When we ask you to provide some kind of support for your contentions, you don't normally provide such support or worse, you provide papers that generally refute your own contention.

    You flat out said that Newtonian Mechanics (actually gravity) should have been thrown out, which is ridiculous. It only needs to be extended, or generalized, to work in regions where it fails. Which is what GR does. But Newtonian Gravity is just fine for everything else in the solar system.
    I don't think so.

    Notice that I am not sure.

    There is little variability from where we sit: On the surface of the earth, plane geometry dominates, so an inverse square law works very well.

    As for the rest of the solar system, (and indeed the rest of the galaxy), there are puzzles that resist solutions - everything from the mascons of the moon to the core composition of comets. There are some interesting observations here:

    http://arxiv.org/abs/1109.0266 Mercury and frame-dragging in light of the MESSENGER flybys: conflict with general relativity, poor knowledge of the physical properties of the Sun, data reduction artifact, or still insufficient observations?

    From the abstract:
    Quote Originally Posted by Iorio
    The Lense-Thirring precession of the longitude of perihelion of Mercury, as predicted by general relativity by using the value of the Sun's angular momentum S = 190 x 10^39 kg m^2 s^-1 from helioseismology, is -2.0 milliarcseconds per century, computed in a celestial equatorial reference frame. It disagrees at 4-{\sigma} level with the correction 0.4 +/- 0.6 milliarcseconds per century to the standard Newtonian/Einsteinian precession, provided that the latter is to be entirely attributed to frame-dragging...
    In other words, taken at face value, there is no measurable Lense-Thirring effect and the General Relativistic prediction is falsified. Iorio's take on this if found in a subsequent paragraph:

    Quote Originally Posted by Iorio
    By taking the figure of eq. (7) as valid, the prediction of general relativity for the
    Lense-Thirring effect is questioned by eq. (8), even if one takes into account a 19%
    uncertainty in it resulting from the recent outcome of the GP-B mission (Everitt et al.
    2011). Indeed, by reducing the predicted Lense-Thirring perihelion precession of Mercury
    down to −1.6 mas cty−1, a discrepancy of more than 3 − σ with respect to eq. (1) would
    still linger. On the other hand, if one assumes the validity of general relativity, it is the
    magnitude of the Sun’s angular momentum in eq. (7) to be challenged by eq. (8): S⊙
    should be much smaller than it was considered so far
    . It must be stressed again that such
    considerations would be valid if the supplementary advance of the perihelion of Mercury of
    eq. (1) were entirely explained in terms of frame-dragging.
    (my bold)

    So is it the Lense-Thirring effect that is not being realized, or have we really screwed up in our estimates of the solar angular momentum? (Which would really throw off the predicted degree of relativistic gravitational lensing.)
    Or, as Iorio further speculates:

    Quote Originally Posted by Iorio
    Actually, in principle, there is the possibility that the unmodeled gravitomagnetic effect was partially or totally removed from the post-fit signature in the data reduction process, having been somewhat “absorbed” in the values of some of the standard parameters estimated in the fits like, e.g., the planetary initial conditions.
    Actually, in principle; if you have to throw in major unanticipated 'gravitomagnetic' effects that cancel the expected motions, nobody has game. I can just as reasonably speculate that both the unanticipated gravitomagnetic effects and the Lense-Thirring effects are null; and everything we see that does not agree with Newton is simply because Newton never gave us true causality in the first place: He gave us a set of equations that work near the earth. But we must prove, without broad prior assumptions, that they work elsewhere.

    Right now, Messenger scientists are trying to make sense out of the extraordinary gravity fields they are observing. (I don't think they can!) On Earth, gravitational scientists are pouring over data; looking for the slightest glimmer of a gravitational wave, and LHC scientists are trying to draw lines between the latest round of experiments and what they are observing. What they all have in common, is that they are not seeing what they anticipated. Far from being ridiculous, Newton's fundamental assumptions can and should be challenged.
    Last edited by Jerry; 2012-Apr-02 at 04:36 AM.

  11. #41
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    Quote Originally Posted by Celestial Mechanic View Post
    As I have pointed out before, Jerry wants to "efface and replace" whereas I (and most of us here) prefer to "amend and extend".
    There is nothing more frustrating to the theoriest or the experimenter, than trying to extrapolate and have the curve bending in ways that you did not predict. I am reminded of all the hoops the designers of vacuum tubes jumped through to extent the effective range of amplifying valves; and likewise, all the corrections to solid state circuits.

    Most of the time; the corrections applied are experimental errors - interference from neighboring circuits; or electron clouds or cascading breakdowns; but once in a while a new and unpredicted phenomenon pops up - such as the Hall effect.

    It takes time and patience to determine if the another knob is needed or another theory. If adding another knob improves the predictive power, it is sometimes the correct solution. (Sometimes a small planet just drifts into the picture and gets blamed for causing the problem.)

    I also get tired of Jerry's constant appeal to "epicycles". Any new terms added and treated as perturbations to Newtonian celestial mechanics are not abitrary parameters chosen to fit the data, but actually depend on orbital elements and masses already known and measured. All current ephemerides such as those from JPL take GR into account, and guess what? -- the ephemerides work.
    Noted. Knobs it is!

  12. #42
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    Quote Originally Posted by Celestial Mechanic View Post
    I'm beginning to think that maybe I should assess penalties for gratuitous use of the word epicycles just as I do for gratuitous use of the phrase "paradigm shift". How many points should it be? Five or ten?
    Epicycles to be included for penalties? Now that's quite a paradigm shift!

  13. #43
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    Quote Originally Posted by Jerry View Post
    snip...

    Right now, Messenger scientists are trying to make sense out of the extraordinary gravity fields they are observing. (I don't think they can!)
    Can you be more specific?
    On Earth, gravitational scientists are pouring over data; looking for the slightest glimmer of a gravitational wave, and LHC scientists are trying to draw lines between the latest round of experiments and what they are observing. What they all have in common, is that they are not seeing what they anticipated. Far from being ridiculous, Newton's fundamental assumptions can and should be challenged.
    My bold. Shouldn't you be saying Einstein here? We all know that Einstein's GR outperforms Newton's simple theory in extreme cases and thus has superseded it.

  14. #44
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    Quote Originally Posted by Jerry View Post
    We should question the basic assumptions when significant efforts to advance the theory are frustrated.
    I'm sure people do that all the time. One good example is when the missing energy (which later turned put to be neutrinos) was identified, one of the suggestions was that conservation of energy might have to be modified/abandoned. You don't get much more basic than that.

  15. #45
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    Quote Originally Posted by borman View Post
    Some have suggested that some excesses such as the PAMELA excess might be due to Cold Dark Matter decay or self-annihilation. However, extended looks at Cold Dark Matter dominated sources have yet to reveal the required signal from their direction.
    A new paper out looking for gama-ray signals from interacting Dark Matter in a larger collection of Dark Matter Effect dominated sources.

    Still no signal detection and constraints on the energy of potential signals improved.

    Press release from NASA:
    http://www.nasa.gov/mission_pages/GL...-insights.html

    Paper:
    A model-independent analysis of the Fermi Large Area Telescope gamma-ray data from the Milky Way dwarf galaxies and halo to constrain dark matter scenarios
    http://arxiv.org/abs/1203.6731

  16. #46
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    Quote Originally Posted by borman View Post
    ... Still no signal detection and constraints on the energy of potential signals improved. ...
    The various efforts to hunt Dark Matter are interesting, but I really don't think that CDM is an issue for GR. The nature of Dark Energy is probably connected to GR.
    Forming opinions as we speak

  17. #47
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    Quote Originally Posted by Hornblower View Post
    Can you be more specific?
    http://web.mit.edu/newsoffice/2012/m...view-0322.html
    Quote Originally Posted by MIT
    “Prior to MESSENGER’s comprehensive observations, many scientists believed that Mercury was much like the moon — that it cooled off very early in solar system history, and has been a dead planet throughout most of its evolution,” says co-author Maria Zuber, the E.A. Griswold Professor of Geophysics at MIT. “Now we’re finding compelling evidence for unusual dynamics within the planet, indicating that Mercury was apparently active for a long time.”
    ...
    “We had an idea of the internal structure of Mercury, [but] the initial observations did not fit the theory so we doubted the observations,” Smith says. “We did more work and concluded the observations were correct, and then reworked the theory for the interior of Mercury that fit the observations. This is how science is supposed to work, and it’s a nice result.”
    It is nice, but not necessarily correct. It bumps against planet formation theory and is very curious. Basins are showing gravity anomalies of up to 100 mgal. That is unreal. http://www.lpi.usra.edu/meetings/lps...df/sess401.pdf

    http://www.sciencemag.org/content/ea...18809.abstract

    Quote Originally Posted by MIT
    Given Mercury’s extremely thin mantle, as revealed by MESSENGER, Zuber says it’s challenging to understand how convection operated to raise broad expanses of terrain to the elevations observed.
    Then there is this:

    http://meetings.copernicus.org/epsc2...2009-653-1.pdf

    Quote Originally Posted by Europlanet
    During both flybys the orbital perturbations by the Mercury gravity field were larger than anticipated on the basis of the gravity field inferred from observations made during the Mariner 10 flybys of 1974-75. Those perturbations could not be modeled fully by adjustments only to the planet’s mass, gravitational flattening, and equatorial ellipticity. The Doppler residuals to the new gravity model suggest that additional gravity information is contained in the tracking data but is not resolved in HgM001.
    By the way, I didn't know these articles were out there until I went looking for them. I knew the gravity fields would be difficult-to-impossible to model because they have been for every other moon and planet: I expected unreal gravity field solutions because Newtonian rules are not really working anywhere.

    Here are the session papers: http://www.lpi.usra.edu/meetings/lps...df/sess401.pdf

    The current solutions are not well constrained- there is significant uncertainy due to the solar wind and radiation pressure.


    Quote Originally Posted by Hornblower
    My bold. Shouldn't you be saying Einstein here? We all know that Einstein's GR outperforms Newton's simple theory in extreme cases and thus has superseded it.
    Nope. Einstein buffered the errors in the Newtonian solution by redefining space and time. It is a curious solution; because it says the non-Newtonian results are spacial and not caused by any active force. It also means that when the bent-space solution does not work; non-baryonic matter is required. This is an iffy solution - can I use unobtainium?
    Last edited by Jerry; 2012-Apr-08 at 08:08 PM. Reason: Added Session Paper reference.

  18. #48
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    Lunar and planetary science conference.

    Here are the session papers: http://www.lpi.usra.edu/meetings/lps...df/sess401.pdf

    The first year of Messenger orbital data has created many more mysteries than it has resolved. First, the libation and core-to-crust solution requires a eggshell-thin crust over a heavy (liquid)mantle with perhaps a solid core. A thin crust should mean mascons of the denser materials percolating through the bottom of craters, such as we have identified on the moon. But there is a snag on mercury: while some mascons may exist, the composition, so far, is similar to the surface composition; a low-Iron crust that is high in sulfur. The one possible exception is the Calois impact basin; which has a center that has risen above the creater rim, and displays a positive anomaly of greater than 100Mgal.

    There are several problems with this solution: in order to lift a large heavy mass in the center of a crater higher than the rim; there should also be displacement of the rim - the thin crust should have trouble supporting such an upswell without more displacement in the over all crater structure.

    So there are challenges in the composition and topography that make the current solution difficult to model, not to mention the problem with the core not cooling enough in the time frame Mercury has been getting pummelled with rocks to solidify the outer core.

    Mercury is going to be hard nut to crack, and as I said, It is a major challenge to model Mercury using known physics.

  19. #49
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    By the way, I didn't know these articles were out there until I went looking for them. I knew the gravity fields would be difficult-to-impossible to model because they have been for every other moon and planet: I expected unreal gravity field solutions because Newtonian rules are not really working anywhere.
    Then why have you just presented Mercury as an example? Surely something this dramatic you should be able to easily find dozens of papers covering just about every mission out there?

  20. #50
    Jerry DO not post ATM ideas outside the ATM Forum. You know this and we have seen your 'alternative' ideas on gravity before, keep them out of mainstream threads.
    Rules For Posting To This Board
    All Moderation in Purple

  21. #51
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    Quote Originally Posted by Jerry View Post
    Nope. Einstein buffered the errors in the Newtonian solution by redefining space and time. It is a curious solution; because it says the non-Newtonian results are spacial and not caused by any active force. It also means that when the bent-space solution does not work; non-baryonic matter is required. This is an iffy solution - can I use unobtainium?
    Can you identify these errors?

  22. #52
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    Quote Originally Posted by Hetman View Post
    Can you identify these errors?
    We just asked him not to... This is a recurring ATM idea for Jerry. You can ask him to open an ATM thread to discuss it, but this GR thread is not the place.
    Forming opinions as we speak

  23. #53
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    But I'm not interested in another sensational theory of gravity.
    He could only point out what he meant, without going into details.

  24. #54
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    Quote Originally Posted by Hetman View Post
    But I'm not interested in another sensational theory of gravity.
    He could only point out what he meant, without going into details.
    If he does so, it should be in a new thread. It is off topic to *this* thread.
    Forming opinions as we speak

  25. #55
    Jerry, per yours above: The Lense-Thirring effect (some think it should be called, per GR, the Einstein-Thirring-Lense effect) can very easily be described with the Sun's angular momentum and its inverse square law application to Mercury's perihelion period (when its spin coincides with its orbital velocity, so appears to stop), as I had done in this simple calculation, FYI: (Sept. 1, 2006) http://www.humancafe.com/discus/mess....html#POST1733

    It works out rather neat, though crude. Einstein's GR had more elegant finesse.
    Last edited by nutant gene 71; 2012-Apr-15 at 08:56 PM.

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