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Gravity Question

  1. Apr 24, 2004 #1
    My question is simply why do people believe in the Einstien theory over the Push theory/Radiation Theory? Now I am no expert, but I have done alot of reading and can see no reason for it. The curved space theory is a dinosaur. I get the sense that people are hanging on to this for the same reasons that people hang onto religion. Thats what they are taught so they can not change even though the evidence seems to favor radiation presure to a large degree. What an I missing?
     
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  3. Apr 24, 2004 #2

    Integral

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    I was not aware that a USEFUL Push gravitation theory existed. Are there any predictions made by this theory that are not made by the current theory of gravitation? If does does not offer a significant improvement over existing theories in either predictions or fundamental understanding of the concepts there is no reason to switch.
    Is there a single mainstream Physicist which is working on this theory?
     
  4. Apr 24, 2004 #3
    Sure lots of good people working on this. The problem in my mind is that they are percieved as not mainstream for no good reason. I am an outsider looking in and it seems like people just except the curved space theory and ignore the other theory just because they have been taught that GR is the holy grail of sorts. Now again I am not an expert and am just makeing an observation.
     
  5. Apr 24, 2004 #4

    LURCH

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    I can think of one right off; one that has been mentioned in these Forums on several occassions. If gravitation is the result of positive push being blocked by some object, then that push is being supplied by moving particles. If these particles exist, and are providing enough pressure to account for gravitational effects observed, then they would create drag. For example, as the earth orbits the sun one side would be pushing through this medium. As a result, things on the "leeward" side of the planet (those things in the planet's wake) would experience slightly less "push" than things along the leading edge. Also, the earth's orbits would be decelerated by the drag from passing through this medium.

    Neither of these predictions agrees with observation, however. AFAIK, no predictions made by the "push" model of gravity agree with observation. In all cases where the push model makes a prediction different from GR, the GR prediction has proven to be the correct one. This, IMHO, is the reason most mainstream physicists prefer GR.
     
  6. Apr 24, 2004 #5

    Integral

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    As you said you are an outsider. This just shows how little you do know about General Relativity, and Physics in general.
     
  7. Apr 25, 2004 #6
    From Nature’s Physical Sciences Editor Karl Ziemelis’ 26 November 1996 letter to Nigel Cook: ‘… a review article on the unification of electricity and gravity… would be unsuitable for publication in Nature.’

    From Galileo’s letter to Kepler: ‘Here, at Padua, is the principal professor of philosophy, who I have repeatedly and urgently requested to look at the moon and planets through my glass, which he pertinaciously refuses to do. Why are you not here? What shouts of laughter we should have at this glorious folly!’ (Translation: Oliver Lodge, Pioneers of Science, 1893, p. 106.)

    While editors like Philip Campbell of Nature magazine (see http://members.lycos.co.uk/nigelbryancook/) act like like paranoid zombies and refuse to use their organs to discuss new ideas on old scientific topics, scientists have to fight with their hands tied behind their backs. This is why there is no proper debate in mainstream journals, and why this forum is essential for discussions despite the difficulties with having to explain everything for a wider range of readership than would occur in a specialist magazine.
     
  8. Apr 25, 2004 #7
    Agreed.
    If you don't study what a theory says (like GR) in terms of observational predictions and work out for yourself what other theories say in comparison, opinions about the validity of theories like general relativity are empty. If you're going to have an alternative theory replace an accepted one, you must provide reasons where the accepted one makes predictions that do not agree with experiment (within the regime in which the theory claims to live in), and state what predictions the alternative theory makes that can be tested and compared to observation. (If you simply want to state an alternative possibility, you can leave out showing that the current theory is false.)
    It is possible that you can construct an alternative to some theory, but these have historically introduced superfluous things as compared to the accepted theory (as well being convoluted in some cases), and therefore there is no good reason not to accept the original theory.
    Using these criteria, there has been no good reason to give up general relativity as the theory of gravitation in the regime it claims to describe. Furthermore, there has been no alternative attempt that describes things we have seen *and* that does not predict things that clearly aren't true.
    An uncomfortability with ideas that differ from the experiences we had growing up (aka "common sense") do not count as reasons why a theory should be rejected. For example, since its advent, people have searched for a classical foundation underlying quantum mechanics because they do not like what quantum mechanics says as a fundamental description. But this has not yielded any good reason why we should give up the modern interpretation of quantum mechanics (for a discussion of this, see Omnes' "Interpretation of QM").
     
  9. Apr 25, 2004 #8
    link to UCSD General Relativity and Black Holes -
    scroll down to heading Predictions of General Relativity
    read items 1. through 5. --->
    http://cassfos02.ucsd.edu/public/tutorial/GR.html

    Can a push-gravitation theory produce explanations of these phenomena just as well?

    EXTRA:
    more stuff on general relativity and gravitational redshift of spectral lines:

    link to yourencyclopedia entry for gravitational redshift
    read 1,2,4:
    1 first experimental verification
    2 gravitational redshift in stars
    4 gravitational redshift, the applied side of general relativity --->
    http://www.yourencyclopedia.net/Gravitational_redshift.html

    I ask the same question about explaining these redshift phenomena.

    (I admit that GR explanations of black hole phenomena seem to be still largely speculative, rather than confirmational, so they are unfinished business.
    Gravitational wave detectors, such as LIGOs, are just starting up, so they represent unfinished business also)
     
    Last edited: Apr 25, 2004
  10. Apr 25, 2004 #9
    You are very naive. First, you are vague on "people". Who do you mean? Most people simply don't have time for physics, and most physicists prefer experiments and simple laws to General Relativity. I give an analysis of what General Relativity says in the Frequently asked questions section on http://members.lycos.co.uk/nigelbryancook/.

    All general relativity does is to set up a tensor equation system for equations of motion in space-time to replace the simple algebra of Minkowski, and then it cleverly normalises the slow speed solution to force it to give the Newtonian gravity law in that case for energy fields equivalent to mass, and it also (more impressively) introduces a contraction of the distance surrounding a mass to make it consistent with the principle of conservation of energy. It is the contraction term, literally a reduction of distance around a mass (well explained by Feynman in saying that the earth's circumference is 4 mm different from that you would expect from Euclidean geometry) which gives the non-intuitive predictions of general relativity for high speeds (light deflection by gravity, etc).

    My proof of a gravity source term from the fabric of space which is shown to be compatible with general relativity (http://members.lycos.co.uk/nigelbryancook/) has been treated appallingly by bigoted idiots who are so clever that they can sneer and ridicule without checking the maths or the experimental basis. However, if they go too far they can experience a taste of their own medicine when more experimental evidence mounts up.

    The moderator's comments are all well and good, but just remember that physics moderators were defending the reigning earth-centred universe against the solar system for two thousand years between Aristarchus of Samos and Copernicus. The politician is the man who shoots the messenger; the scientist needs to be more careful with his gun.
     
  11. Apr 25, 2004 #10
    General relativity is compatible with push gravity:

    "In many interesting situations… the source of the gravitational field can be taken to be a perfect fluid…. A fluid is a continuum that ‘flows’... A perfect fluid is defined as one in which all antislipping forces are zero, and the only force between neighboring fluid elements is pressure." – Bernard Schutz, General Relativity, Cambridge University Press, 1986, pp. 89-90.

    Einstein himself said: ‘To deny the ether is ultimately to assume that empty space has no physical qualities whatever... Recapitulating, we may say that according to the general theory of relativity, space is endowed with physical qualities... therefore there exists an ether. According to the general theory of relativity space without ether is unthinkable.’ – Albert Einstein, Leyden University, 1920. (Einstein, A., Sidelights on Relativity, Dover, New York, 1952, pp. 15, 16, and 23.) http://members.lycos.co.uk/nigelbryancook/
     
  12. Apr 25, 2004 #11
     
  13. Apr 25, 2004 #12

    Integral

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    This quote must be read very carefully. Einstein is NOT talking about the "classical "aether" He is saying that space has properties, these properties can be called the 'ether". He does not specify what the properties are or how they behave. You cannot assume that this is Einsteins affirmation of the classical ether. It is his statement that space time has measurable properties.
     
  14. Apr 25, 2004 #13

    Integral

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