In reply to Sean Logan's message of Mon, 24 Aug 2020 12:20:28 -0700: Hi, You might consider adding a mirror image of it along the axis. Wide ends together. Maybe then it will generate a "hole in the vacuum" in the middle?
[snip] >Thank you JonesBeene. The thought that the mass of the device may change >under certain conditions had not crossed my mind. Can you refer me to some >good papers on the Shawyer truncated cone?
