[Procyon]

I was about to respond before you did, Felix, when an interesting thought occurred to me. gravitational attraction is often modeled as a point source at the center of gravity of the bodies, when in reality, the attraction is conic with the radius of the attracting bodies being the radius of the 2 ends of the conic section and gravitational attraction being strongest along the axis of the cone and falling off as you reach the edges. In the case of the earth becoming a black hole, one end of the cone will collapse from having the radius of the earth to having a radius of approximately 1/2 centimeter. The black hole scenario will more closely resemble the simple mathematical model, but will there be any effect on the orbit given the new configuration of the attraction? Is the point source gravitational model accurate, or just close enough for us laymen?