# How to redistribute weight on an O'Neill Cylinder? [duplicate]

Problem With a rotating cylinder, applying weight to one side and not the other will cause it to rotate off axis and give it a 'wobble' likely causing undesired gravitational effects. Now clearly there's a certain scale at which the miniature changes in weight as someone walking around aren't going to affect the rotational axis of the cylinder but over the long term of building buildings or growing trees you might have to start taking that extra weight into account.

Question I was wondering what ways are there of counteracting this weight distribution.

One possible solution Couple of ways I can think of include having a 'ballast' in the hull of large tanks of liquid or movement of solids that apply the same extra weight to the opposite side of the OC to stop the wobble.

Edit This is not referring to the wobble you would get which flips the cylinder back and forth but rather the wobble around the central axis due to a difference in weight around that axis. Think of a washing machine with too much weight on one side, they tend to oscillate.

• Liquid ballast in the form of stored water was what I immediately thought of. A computer would probably continuously adjust to take into account every tiny change in the weight distribution. You answered your own question (there's a badge for that, if you care to actually submit it as an answer). Commented Aug 3, 2020 at 18:44
• Your solution sounds good to me. Probably not solids though...solids can't be pumped through pipes unless you feel like making a dense slurry. Commented Aug 3, 2020 at 22:30
• Well you could do solids with like a rail system but thats way more elaborate than liquid, wasnt sure if liquid ballast would be enough and sourcing that much liquid for each OC might be a lil wasteful. Commented Aug 4, 2020 at 11:37
• @PhillipRoberts Or mercury. That's a buttload of mercury though. Then again, an O'Neil cylinder us a buttload of everything. Commented Aug 6, 2020 at 19:08