In response to 'pzkpfw', Post 11. I fully understand this explanation of how pressure increases the closer you get to the 'Y' of the model.It is very probable that I will have to accept that the enormous pressures present in the interiors of any planet or star will be enough to negate the effects of gravity and therefore the possibility of the presence of any central void. It is relevant to mention at this juncture that the initial proposal of there perhaps being a void at the centre of any massive celestial sphere,( as so proposed at the start of this thread), was intended to be more an excercise in mental gymnastics,( specifically in relation to the effect of gravity within the interior of said sphere), as opposed to being a definitive proposal which challenged mainstream theories.Continuing in that vein therefore,your '123456789Yabcdefghi' model,is correct when applied to a sphere which is has a solid core.The model however, does not apply to a sphere which has a supposed void at centre.( Given also that supposed theoretical said void could have a diameter of at least many 100's,if not 1,000's of kilometers).The question arises of when, in the formation of a planet, does a central void begin to develop? The only answer which seems legitimate is when the increasing internal friction created from the accumulating pressure exerted by the matter which is being added to the fledgling mass of the planet, starts to turn the interior into molten magma.This, in combination with the centrifugal force of the rotation of the planet, could initiate the formation of the central void. Early massive volcanoes would further purge this central magma and would create the subsequent layers which would later dictate the subsequent composition of the adult planet,( crust, mantle, outer core etc.). Also,with regard to post 10.
'It seems to me that the answer to this question relies on an equation which takes into consideration 1. The force of gravity of the mass of the Earth 'pulling' at the centre. Versus 2. The amount of 'squeeze' pressure exerted on the core by that same mass. ...
1. Will become zero.
2. Will become very large.
With great respect, this does not strike me as being much of a definitive equation.