Speed of gravity
in [Relativity]
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From: Art on 28 Feb 2010 13:37 On Sun, 28 Feb 2010 09:32:39 -0800 (PST), dlzc <dlzc1(a)cox.net> wrote: >Dear Art: > >On Feb 28, 6:05�am, Art <n...(a)zilch.com> wrote: >> Has this question been settled yet? > >Yes. Changes in gravitation must propagate at c, in GR. But changes >in gravitation are not orbiting bodies. Closest I can figure would be >what happens to mass as it crosses the event horizon of a black hole, >and how fast is it seen to be "at center". > >> I've read that Einstein assumed gravity >> travels at c. > >*Not* assumed, it falls out of the equations. > >> But I've also read that certain orbits are >> iunstable unless gravity travels >> c. > >No. Imagine that the curvature of spacetime the corresponds with the >body, orbits with the body and has since the body coalesced. No need >for FTL gravitation to stabilize orbits... Ah, I hadn't considered that. >David A. Smith Thanks for the info. Art
From: BURT on 28 Feb 2010 14:57 On Feb 28, 10:37 am, Art <n...(a)zilch.com> wrote: > On Sun, 28 Feb 2010 09:32:39 -0800 (PST), dlzc <dl...(a)cox.net> wrote: > >Dear Art: > > >On Feb 28, 6:05 am, Art <n...(a)zilch.com> wrote: > >> Has this question been settled yet? > > >Yes. Changes in gravitation must propagate at c, in GR. But changes > >in gravitation are not orbiting bodies. Closest I can figure would be > >what happens to mass as it crosses the event horizon of a black hole, > >and how fast is it seen to be "at center". > > >> I've read that Einstein assumed gravity > >> travels at c. > > >*Not* assumed, it falls out of the equations. > > >> But I've also read that certain orbits are > >> iunstable unless gravity travels >> c. > > >No. Imagine that the curvature of spacetime the corresponds with the > >body, orbits with the body and has since the body coalesced. No need > >for FTL gravitation to stabilize orbits... > > Ah, I hadn't considered that. > > >David A. Smith > > Thanks for the info. > > Art- Hide quoted text - > > - Show quoted text - The gravity field around a mass will move all at once in the distance. If the Earth is surrounded by a field that field moves with its movement through space. This is a nonlocal effect of field propagation. Mitch Raemsch
From: G. L. Bradford on 28 Feb 2010 15:08 "Art" <null(a)zilch.com> wrote in message news:2jdlo59ubhojtpi7d7e3tv3j22s526ct9h(a)4ax.com... > On Sun, 28 Feb 2010 09:32:39 -0800 (PST), dlzc <dlzc1(a)cox.net> wrote: > >>Dear Art: >> >>On Feb 28, 6:05 am, Art <n...(a)zilch.com> wrote: >>> Has this question been settled yet? >> >>Yes. Changes in gravitation must propagate at c, in GR. But changes >>in gravitation are not orbiting bodies. Closest I can figure would be >>what happens to mass as it crosses the event horizon of a black hole, >>and how fast is it seen to be "at center". >> >>> I've read that Einstein assumed gravity >>> travels at c. >> >>*Not* assumed, it falls out of the equations. >> >>> But I've also read that certain orbits are >>> iunstable unless gravity travels >> c. >> >>No. Imagine that the curvature of spacetime the corresponds with the >>body, orbits with the body and has since the body coalesced. No need >>for FTL gravitation to stabilize orbits... > > Ah, I hadn't considered that. > >>David A. Smith > > Thanks for the info. > > Art > ======================== Both bodies are in perpetual motion, traveling, in the universe. Only thing is, one of the bodies does not realize that the other is in motion too, traveling. To it, the other is the still center of the universe. Though! Things will become much more complex with a multiple body system (overlapping fields system) such as the solar system is or, on a different plane, the galaxy. No, gravity in maintaining the existance and extent of field, including a [center] of gravity and any kind of continuing integral cohesion, in the midst of the existence and influencing extents of all other similar fields, cannot afford to recognize such a miserably slow speed as 'c' ruling its reaches. In all the extents of all its fields -- which is to say too, in all the inclination and declination of all its wells or holes -- it remains a matter of singularity (thus far more broadly and deeply and fundamentally connected, a matter of the infinite of BC/BB Singularity). GLB =======================
From: BURT on 28 Feb 2010 16:53 The gravity curve flows with mass center movement. The gravity field moves altogether in a nonlocal way around mass. Mitch Raemsch
From: eric gisse on 28 Feb 2010 17:24
Art wrote: > Has this question been settled yet? I've read that Einstein assumed > gravity travels at c. But I've also read that certain orbits are > iunstable unless gravity travels >> c. > > Art gravity =/= gravitation Changes in gravitation travel at c - exactly - within general relativity. In Newton, changes in gravitation propagate infinitely fast. Newton's orbits are unstable unless the speed of gravitation is infinite. |