Explanation of the 'chain fountain': some doubts

[Gruxg]

In an alternative setup we again placed the chain bunched together on the table, but now in such a way that every single link touched the table surface (all of the chain was in a horizontal plane). When letting the chain fall over the edge of the table in this case, no vertical arc formed but all wavelike behaviour was confined to the horizontal plane.

There are some youtube videos showing the formation of a vertical arc in those conditions:

How can it be explained with Biggin's theory? Or am I missunderstanding something?

 

[A.T.]

How can it be explained with Biggin's theory? Or am I missunderstanding something?

Don't know about Biggin's theory, but it seems obvious that a fast chain cannot make sharp turns, because the internal tension providing the centripetal force will redistribute along the chain. It also cannot fall off in a smooth inverted parabola like independent beads would, because its horizontal speed at the edge is increasing, and thus higher than that of the previously dropped chain below. The fall path would have a sharp turn down, which is redistributed to a rounder curve around the edge in all directions, including lifting upwards.