On Oct 11, 2008, at 3:17 PM, Robin van Spaandonk wrote:
In reply to Michel Jullian's message of Sun, 12 Oct 2008 00:34:39
+0200:
Hi,
I haven't actually worked it out, but I don't even think that the
gravitational
field of a massive disc would be perpendicular to the disk, but
probably
directed more toward the center, and I suspect exactly at the center.
In close proximity to a mass plane having planar mass density rho the
gravitational field is given by gravimagnetic theory to be:
g = a rho/(2 * epsilon_0_g)
where a is a unit vector normal to and directed toward the plane for
positive rho, away for negative rho, where rho is mass density (say
in i kg/m^2), and epsilon_0_g is given by:
epsilon_0_g = 1/(4 Pi G) = 1.192299(31)x109 kg s^2/m^3
as specified on Table 2, on Page 11 of:
http://mtaonline.net/~hheffner/FullGravimag.pdf.
This is because the electric field about an infinite plane of uniform
charge is given by:
E = a rho/(2 * epsilon_0)
so it is just a matter of applying the gravimagnetic isomorphism to
obtain the result. In both formulations rho includes the sign of
charge, and in the case of mass also includes the imaginary number i
= (-1)^(1/2).
So, I think Michel is correct in his assertion with regards to the
field in the space near the plane resulting from the mass in the
plane. GR considerations, like frame dragging from a high mass
rotating plane, are beyond me. However, some close enough
approximations may be had by looking at the gravimagnetics of the
fields for spinning bodies. Of course the field of the black hole
itself has to be superpositioned to get a complete picture.
Beyond this, my theory predicts a massive magnetic field from the
quark soup of a black hole, even a black hole singularity, if such
can exist, which is proportional to the mass of the black hole, and
this field overwhelms gravimagnetic forces for interacting black
holes or even black holes acting on ionized accretion disks.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
