My frustration is with the term Mould Effect. In my view it specifically refers to the dramatic rising “fountain” not the generic “basic fountain”. I’m increasingly annoyed at the fixation with the “basic fountain physics”. And, would like to hear more about the physical properties of the ball-chain specifically. In an earlier post (since deleted) I suggested a standing wave being propagated. Though probably wrong it was my naive attempt at explaining the movement specific to the ball chain. Perhaps, it’s forced oscillation resonance. Mould’s kicking ball action could be generating the “external” force necessary to drive the oscillation. I think the oscillation allows the chain to be both bendy and taught. The Beeblebrox Effect (spiral chain movement) is also significant. Is it possible that resonance cause each bead rotate on its axis? I think it’s worth discussion.