[z2trillion]

The bobbles retain their mass. There is a scene in the book where a bobble floats aways because it was created during the day, and at night the surrounding air cools enough for the bobble to effectively become a hot air balloon.

As far as I know, the book doesn't cover if the bobble retain their angular momentum or charge.

[pontifier]

There's a vivid scene where they create a tiny bobble above a candle to catch the hot air.

I always wondered if creating a bobble around an off-center weight would allow you to kind of spin it by wobbling it.

There were some places where large pieces of land unbobbled without any relative movement, so maybe they were locked in their rotation somehow?

I really liked that book a lot.