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From: Simple Simon on 16 Mar 2010 16:46 Is it possible that some of the dark matter is simply matter that is outside of our past light cone but gravitationally bound to objects within it?
From: dlzc on 16 Mar 2010 17:13 Dear Simple Simon: On Mar 16, 1:46 pm, "Simple Simon" <pi.r.cubed-nos...(a)gmail.com> wrote: > Is it possible that some of the dark matter > is simply matter that is outside of our past > light cone but gravitationally bound to > objects within it? No. Dark Matter is essentially equidistant to the "bound normal matter", to first approximation. Examples are spiral galaxies, whose Dark Matter has the same gravitational center, but more of a torus or crushed sphere than a flat lens. Direct counter example to your posit, is that eventually you'd expect to encounter light from that normal matter, which must occur unless it is FTL. We have new objects being discovered for sure, but not "adjacent" to known matter. Just "improved imaging techniques". David A. Smith
From: BURT on 16 Mar 2010 17:16 On Mar 16, 2:13 pm, dlzc <dl...(a)cox.net> wrote: > Dear Simple Simon: > > On Mar 16, 1:46 pm, "Simple Simon" <pi.r.cubed-nos...(a)gmail.com> > wrote: > > > Is it possible that some of the dark matter > > is simply matter that is outside of our past > > light cone but gravitationally bound to > > objects within it? > > No. Dark Matter is essentially equidistant to the "bound normal > matter", to first approximation. Examples are spiral galaxies, whose > Dark Matter has the same gravitational center, but more of a torus or > crushed sphere than a flat lens. > > Direct counter example to your posit, is that eventually you'd expect > to encounter light from that normal matter, which must occur unless it > is FTL. We have new objects being discovered for sure, but not > "adjacent" to known matter. Just "improved imaging techniques". > > David A. Smith Dark matter at the Big Bang would forever commingle with normal matter. But we don't find it on Earth where it would be. There is another explanation to fast orbits. Mitch Raemsch
From: Simple Simon on 16 Mar 2010 19:17 dlzc wrote: > Dear Simple Simon: > > On Mar 16, 1:46 pm, "Simple Simon" <pi.r.cubed-nos...(a)gmail.com> > wrote: >> Is it possible that some of the dark matter >> is simply matter that is outside of our past >> light cone but gravitationally bound to >> objects within it? > > No. Dark Matter is essentially equidistant to the "bound normal > matter", to first approximation. Examples are spiral galaxies, whose > Dark Matter has the same gravitational center, but more of a torus or > crushed sphere than a flat lens. > > Direct counter example to your posit, is that eventually you'd expect > to encounter light from that normal matter, which must occur unless it > is FTL. We have new objects being discovered for sure, but not > "adjacent" to known matter. Just "improved imaging techniques". > > David A. Smith I gather from your response that it is "possible" that there is such matter (that is, nothing about space-time precludes such a condition from existing) but that the dark matter necessary to account for observation must be distributed otherwise. If that is correct, then I would expect that it is "necessary" for there to be such "ordinary" dark matter since there is nothing to preclude it and it is frame dependent. Additionally, one would expect the preponderance of such "ordinary" dark matter to be a predictable extension to the existing distribution and to inversely increase with the square root of the temporal distance (as does the inverse of the area of the spatial (simultaneity) cross section of of the past light cone) assuming a circular light cone. Is that accurate?
From: xxein on 16 Mar 2010 18:21
On Mar 16, 5:13 pm, dlzc <dl...(a)cox.net> wrote: > Dear Simple Simon: > > On Mar 16, 1:46 pm, "Simple Simon" <pi.r.cubed-nos...(a)gmail.com> > wrote: > > > Is it possible that some of the dark matter > > is simply matter that is outside of our past > > light cone but gravitationally bound to > > objects within it? > > No. Dark Matter is essentially equidistant to the "bound normal > matter", to first approximation. Examples are spiral galaxies, whose > Dark Matter has the same gravitational center, but more of a torus or > crushed sphere than a flat lens. > > Direct counter example to your posit, is that eventually you'd expect > to encounter light from that normal matter, which must occur unless it > is FTL. We have new objects being discovered for sure, but not > "adjacent" to known matter. Just "improved imaging techniques". > > David A. Smith xxein: Excuse me Dave. Could you elaborate more on that? And I mean logic, not math. Can you be more complete in your thinking with just words? |