
On Wed, 20 Sep 2006 17:00:00 0600, Virgil <[email protected]> wrote:
>In article <[email protected]>,
> Lester Zick <[email protected]> wrote:
>
>> On Wed, 20 Sep 2006 14:18:31 0600, Virgil <[email protected]> wrote:
>>
>> >In article <[email protected]>,
>> > Lester Zick <[email protected]> wrote:
>> >
>> >> On 14 Sep 2006 18:47:35 0700, [email protected] wrote:
>> >>
>> >> >yeah, prove that geometrically using calculus or
>> >> >just algebra . . .
>> >>
>> >> Where m1 is aggregate gravitationally attractive mass
>> >> in a disk of uniform thickness and density in which the
>> >> amount of gravitationally attractive matter ~ area=rrpi
>> >> times unform thickness d:
>> >>
>> >> As a function of radius r the aggregate force of gravitational
>> >> attraction will be:
>> >>
>> >> F=Gm1m2/rr=Gm1(rrpi)m2/rr=Gm1(pi)m2 and
>> >>
>> >> dF/dr=0 and gravitationally attractive force is constant as a function
>> >> of radius r: hence tangential velocity of all m2's will remain
>> >> constant as a function of radius r.
>> >>
>> >> QED.
>> >>
>> >> ~v~~
>> >
>> >Zick's derivation above presumes the the gravitational attraction on a
>> >unit mass due to a uniform thin ring of mass at a point in the plane of
>> >that ring and inside the ring is zero.
>> >
>> >And it presumes that at a point in the plane of the ring but outside the
>> >ring the force is equal to that exerted by an an equal mass
>> >concentrated at the center of the ring.
>> >
>> >Both these assumptions are false.
>> >
>> >Perhaps Zick is being mislead by Newton's result for a thin spherical
>> >bubble of mass, for which similar arguments are true.
>>
>> I think it more likely that Zick is being mislead by charasteristics
>> of inverse square gravitation.
>
>Then Zick should note that the gravitational attraction at a point on
>its circumference due to a mass evenly spread over a circular disc is
>not equal to that of the same mass concentrated at the center of the
>disc.
Remarkable, professor. I reach my conclusion that gravitationally
attractive force over a circular disk of uniform density is not a
function of radius through tedious calculation and you reach your
miscellaneous conclusion apropos of nothing in particular through what
exactly, the trivium of truth and tedium of divine inspiration?
>So that Zick's analysis is faulty.
And which of my equations is faulty pray tell?
~v~~

