..the more the demonstrations sound like the sort of silly multi-tasking you end up doing as a parent of young children. Like I’ve just been reading about balance carts which demonstrate an inverted pendulum (also easily demonstrated by balancing a broomstick on the end of your finger), and an extension or variation on the initial ‘simple’ set up (balancing the cart-pendulum system on a see-saw) then starts to sound like the layering of feeding, watching, helping, answering, that all takes place a few seconds here, a few there…