Tumbling does not support a world ship but that it accelerated certainly does. It is also likely quite robust as well.
Has anyone asked were it is going yet? Or is it truly a random piece of oddly shaped rock and comet. Now explain that acceleration with reference to distance from the sun.
The argument for the existence of world ships is plausible and it is technology we could rig out today as we jump into space. They also need to be cylindrical. A one mile diameter with say one hundred shells and a length of ten miles represents 10 X 3 X 100 square miles or 3000 square miles of working one G max surface area. This is ample to handle and feed 3,000,000 people at least and possibly several times even that.
The outer surface can also be shielded with a thick layer of water and other materials as well all frozen and acting as a resource reservoir and protection..
Jason Arias for Quanta Magazine
Ramin Skibba Contributing Writer
October 10, 2018