Chain fountain

This process establishes a self-sustaining flow of the chain which rises over the edge and goes down to the floor or ground beneath it, as if being sucked out of the jar by an invisible siphon.

[non-primary source needed][5] The phenomenon with the rising chain was already described in 2011 as an open problem[note 1] for the 2012 International Young Physicists' Tournament (IYPT)[6][4] and subsequently brought to widespread public attention in a video made by science presenter Steve Mould (namesake of the effect) in 2013.

[7] Mould's YouTube video[8] in which he demonstrated the phenomenon of self-siphoning rising beads, and his subsequent proposed explanation on a BBC show,[9] brought the problem to the attention of academics John Biggins and Mark Warner of Cambridge University,[10][11] who published their findings in Proceedings of the Royal Society about what they called "chain fountain" or "Mould effect".

[12][13][14][7] A variety of explanations have been proposed as to how the phenomenon can best be explained in terms of kinematic physics concepts such as energy and momentum.

The self-syphoning phenomena can be also observed in viscoelastic fluids[19] that are mainly composed of long polymers, like polyethylene glycol.