Question about gravity
in [Physics]
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From: PD on 15 Mar 2010 14:27 On Mar 15, 1:25 pm, "kens...(a)erinet.com" <kens...(a)erinet.com> wrote: > On Mar 15, 10:08 am, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > On Mar 15, 9:04 am, kenseto <kens...(a)erinet.com> wrote: > > > > On Mar 15, 6:43 am, "Peter Webb" > > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > > Not a whole lot to add to what Inertial in particular said. > > > > > In GR, gravity is a virtual force in a similar way to centrifugal force in > > > > Newton. In both cases its really an acceleration, and the force is just the > > > > product (literally) of this acceleration and the mass of the object.. > > > > > Einstein in GR gave a geometric interpretation of what gravity is. This is > > > > very appealing, because it provides a mechanism for force at a distance. > > > > Wrong it provides no such physical mechanism. It merely assumes the > > > existence of a physical entity caLLED the fabric of spacetime for the > > > interacting object to follow. The problem with such assumption is: > > > What is the fabric of spacetime physically? This question is relevant > > > because SR/GR deny the existence of physical space. > > > > Ken Seto > > > What ? ".... SR/GR deny the existence of physical space......" > > > What the devil are you saying man ????? > > > The theory of relativity says that gravity IS deformation of space. > > How can this same theory deny the existence of space ??? Better visit > > your optometrist really, really soon. > > Sigh...How can you deform space when space is defined by Einstein as > "empty space".???? Being empty means it has no matter in it. Having no matter in it does not mean that space cannot have physical properties. Physical properties are not limited to matter. PD
From: kenseto on 15 Mar 2010 14:35 On Mar 15, 10:09 am, "Inertial" <relativ...(a)rest.com> wrote: > "kenseto" <kens...(a)erinet.com> wrote in message > > news:09cf23d5-351a-4602-adce-f4cfbf00034c(a)a18g2000yqc.googlegroups.com... > > > > > > > On Mar 15, 6:43 am, "Peter Webb" > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > >> Not a whole lot to add to what Inertial in particular said. > > >> In GR, gravity is a virtual force in a similar way to centrifugal force > >> in > >> Newton. In both cases its really an acceleration, and the force is just > >> the > >> product (literally) of this acceleration and the mass of the object. > > >> Einstein in GR gave a geometric interpretation of what gravity is. This > >> is > >> very appealing, because it provides a mechanism for force at a distance. > > > Wrong it provides no such physical mechanism. It merely assumes the > > existence of a physical entity caLLED the fabric of spacetime for the > > interacting object to follow. > > Its just how things move. There no more need for there to be a 'physical > entity' (and certainly not a material one) for that to happen, than there > needs to be one in 3D Newtonian/Euclidean/Gaillean space to make objects > follow a straight line (ie follow Newton's first law) Then why did you guys say that object follows the curvATURE in the fabric of spacetime? What is that fabric of spacetime? Ken Seto > > > The problem with such assumption is: > > What is the fabric of spacetime physically? This question is relevant > > because SR/GR deny the existence of physical space. > > What do you mean by 'physical space'- Hide quoted text - > > - Show quoted text -
From: PD on 15 Mar 2010 14:41 On Mar 15, 9:16 am, kenseto <kens...(a)erinet.com> wrote: > On Mar 15, 9:16 am, Huang <huangxienc...(a)yahoo.com> wrote: > > > > > > > Can someone in this forum please help me sort out a confusing issue? > > > > > Many scientists (including Einstein) claim that gravity is not a > > > > force, but the effect of mass on the "fabric of spacetime". Many other > > > > scientists refer to gravity as one of the four fundamental > > > > interactions (three, if one considers the unification of the weak and > > > > electromagnetic interactions, the "electroweak" force). > > > Einstein is correct, that gravity can be regarded as curvature or > > deformation of space. Other views are equivalent to this model, such > > as the view that gravity is a force. These two approaches are > > equivalent in my opinion. > > > The pieces which are missing in this puzzle: > > [a] Explaining strong force in terms of spacetime curvature, > > [b] Explaining weak force in terms of spacetime curvature, > > [c] Explaining electromagnetism in terms of spacetime curvature. > > > When a,b,c have been explained in terms of spacetime deformation, and > > are shown to be equivalent to the particle explanations of a,b,c, then > > you will be very close to grand unification. > > a, b, c can be explained with a special aether called the E-Matrix in > place of the none physical existence of spacetime in the following > link:http://www.modelmechanics.org/2008irt.dtg.pdf Uh, no. In [a], if you think you have an explanation, you'll need an account of Bjorken scaling, three-jet cross-sections, transverse momentum spectra, and asymptotic freedom. In [b], if you think you have an explanation, you'll need an account of neutral currents, parity violation, the resonances labeled W and Z, and neutrino oscillations. In [c], if you think you have an explanation, you'll need an account of Lorentz covariance, absence of longitudinal polarization, the Aharonov-Bohm effect, and the anomalous magnetic moment of the muon. Start digging.
From: kenseto on 15 Mar 2010 14:43 On Mar 15, 2:27 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Mar 15, 1:25 pm, "kens...(a)erinet.com" <kens...(a)erinet.com> wrote: > > > > > > > On Mar 15, 10:08 am, Huang <huangxienc...(a)yahoo.com> wrote: > > > > On Mar 15, 9:04 am, kenseto <kens...(a)erinet.com> wrote: > > > > > On Mar 15, 6:43 am, "Peter Webb" > > > > > <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > > > > > Not a whole lot to add to what Inertial in particular said. > > > > > > In GR, gravity is a virtual force in a similar way to centrifugal force in > > > > > Newton. In both cases its really an acceleration, and the force is just the > > > > > product (literally) of this acceleration and the mass of the object. > > > > > > Einstein in GR gave a geometric interpretation of what gravity is.. This is > > > > > very appealing, because it provides a mechanism for force at a distance. > > > > > Wrong it provides no such physical mechanism. It merely assumes the > > > > existence of a physical entity caLLED the fabric of spacetime for the > > > > interacting object to follow. The problem with such assumption is: > > > > What is the fabric of spacetime physically? This question is relevant > > > > because SR/GR deny the existence of physical space. > > > > > Ken Seto > > > > What ? ".... SR/GR deny the existence of physical space......" > > > > What the devil are you saying man ????? > > > > The theory of relativity says that gravity IS deformation of space. > > > How can this same theory deny the existence of space ??? Better visit > > > your optometrist really, really soon. > > > Sigh...How can you deform space when space is defined by Einstein as > > "empty space".???? > > Being empty means it has no matter in it. Having no matter in it does > not mean that space cannot have physical properties. Physical > properties are not limited to matter. Bullshit. fields are stresses in a solid medium occupying space according to steven weinberg
From: "Juan R." González-Álvarez on 15 Mar 2010 14:45
PD wrote on Mon, 15 Mar 2010 10:22:55 -0700: > On Mar 15, 1:42 am, MicroTech <henry.ko.nor...(a)gmail.com> wrote: >> Can someone in this forum please help me sort out a confusing issue? >> >> Many scientists (including Einstein) claim that gravity is not a force, >> but the effect of mass on the "fabric of spacetime". Many other >> scientists refer to gravity as one of the four fundamental interactions >> (three, if one considers the unification of the weak and >> electromagnetic interactions, the "electroweak" force). >> >> Adding to the confusion, some scientists use both concepts with no >> apparent difficulty: >> Stephen Hawking (in his "A Brief History Of Time") first says that >> gravity is not a force, but "simply" the effect of mass on the >> "spacetime fabric" (making it "curve"). However, later in the book, he >> refers to gravity as a fundamental force, carried by the graviton. >> >> So what is gravity, "really"? Does anybody really know? Or do we just >> know its effects? >> >> Is it an attractive force "mutually pulling" the Earth towards the Sun >> (and vice versa), "causing" the Earth to "fall" towards the Sun? And >> due to the "forward motion" of the Earth, exactly matching the >> "gravitational pull", it stays in orbit (just like any other satellite, >> man-made or not); OR >> >> Is it the mass of the Sun that "curves spacetime", so no force is >> interacting with the Earth, it is just moving in a "straight line" >> along a "curved spacetime" geodesic? >> >> At my current level of understanding, gravity should be one or the >> other, and not both... >> >> If Einstein's concept of "curved spacetime" is "correct," where does >> the (hypothetical?) "graviton" (and/or "gravitino") enter the picture? >> >> References to published papers (accessible online) would be much >> appreciated! >> >> Henry Norman > > It's definitely a different kind of animal. Part of the issue is > understanding better what it is the particle represents. > For example, in electromagnetism, the classical picture is a field in > the background of space and time. The particle is a quantization of > disturbances in that field in the background of space and time. A moment, please, you are talking about the field picture of electrodynamics, not about the general formulation of classical electrodynamics. In the more general action-at-a-distance picture, particles are not quanta of fields, but fundamental buildings of matter. The concept of field is derived and valid only under certain restrictions. To learn more: # Classical Electrodynamics in Terms of Direct Interparticle Action 1949: Rev. Mod. Phys. 21(3), 425—433. Wheeler, John Archibald; Feynman, Richard Phillips. # Cosmology and action-at-a-distance electrodynamics 1995: Rev. Mod. Phys. 67(1), 113—155. Hoyle, F.; Narlikar, J. V. # Action-at-a-distance as a full-value solution of Maxwell equations: The basis and application of the separated- potentials method 1996: Phys. Rev. E 53(5), 5373—5381. Chubykalo, Andrew E.; Smirnov-Rueda, Roman. Erratum: Action-at-a-distance as a full-value solution of Maxwell equations: The basis and application of the separated-potentials method [Phys. Rev. E 53, 5373 (1996)] 1997: Phys. Rev. E 55(3), 3793—3793. Chubykalo, Andrew E.; Smirnov-Rueda, Roman. # Classical Electrodynamics without Fields and the Aharonov-Bohm effect 2008: arXiv:0803.1326v2. Stefanovich, Eugene V. # Classical Relativistic Many-Body Dynamics 1999: Springer. Trump, Matthew A.; Schieve, William C. http://www.canonicalscience.org/publications/canonicalsciencereports/20093.html The rest of your misconceptions about GR and field theory were already answered in this thread. -- http://www.canonicalscience.org/ BLOG: http://www.canonicalscience.org/publications/canonicalsciencetoday/canonicalsciencetoday.html |