Allen D Where used below, the terms "rotation" and "revolution" have the following meanings - rotation -- radial motion of a body about a line -- the axis -- which passes through the body's centre of mass. revolution (first approximation) -- translation of a small mass body about a large mass body in an elliptical orbit. Concerning the "Parent 1" proposition. (Parent 1 is assumed to be a disk of negligible thickness and of uniform density). The LHS Parent 1 body as shown is not rotating. If we assume it is radially accelerated for a finite period of time in a CW direction and in the plane of its mass, then it will be rotating CW at a constant rate (neglecting friction) determined by its mass and the accelerating energy applied. It will rotate about the "Common point of progressive radial orientation" -- its centre of mass. A line through the centre of mass orthogonal to the plane of the disk defines its axis of rotation. This rotation will be fully concentric. The RHS Parent 1 body will be considered to be rotating as described for the LHS Parent 1. The argument that all parts of the disk are independently and synchronously rotating at a fixed rate is specious and will be ignored in favour of the prevailing view that what is rotating is Parent 1 -- not all the bits of Parent 1, ie it is a rigid body(*). However, every part of the disk, including the cutouts, have mass, and if moving, store energy. If we extract a portion of Parent 1 -- say Cutout A (it doesn't matter which one) -- while Parent 1 is rotating, Cutout A will carry radial motion with it. It will rotate concentrically about its individual centre of mass as was described for Parent 1, and Parent 1 will -- due to the lost mass (and the location from which this mass was removed) rotate eccentrically about its new centre of mass ie its axis has moved. If I were sufficiently skilled in applied maths, I'd calculate what the rates of rotation were both before and after the removal of Cutout A but I'm not and so I can't at this time. If I were sufficiently motivated and felt the investment in time were worth the effort, I'd study the matter so as to be able to do so. But I don't think it is, so I won't. The reason I don't think it is so, is that this model -- Parent 1/Cutout A -- is not an accurate analogy for the Moon in its orbit or Uranus in its orbit. An orbital plane has no mass. Though I can't do these calculations, of one thing I'm sure -- the total energy of the system would remain constant. Did I miss anything? OK -- I've addressed your model -- time for you to reciprocate. In the HC model -- how many 360 deg rotations does the Earth make in one 360 deg revolution about the Sun? Paul D (*) This "... how many motions ..." argument reminds me of the acquittal of the police in the case of the assault of Rodney King. The film evidence was broken down to tiny increments of time and used to demonstrate that Rodney King was responsible for his own injuries. Come on! Stay connected to the people that matter most with a smarter inbox. Take a look http://au.docs.yahoo.com/mail/smarterinbox