A guest blog from Boomerang’s Paul Dewick:
Remember Slinky’s? They were essentially a long, very flexible spring that you placed on the top step of a set of stairs. Then you would slowly tip the top of the spring and, assuming you had positioned it right it would gracefully descend the stairs and settle at the bottom in a neat tube. If the positioning was wrong, then they would start well but gradually begin to slip off their centre of gravity and end up in a tangled disaster. In the worst-case scenario, the loops of metal would become irretrievably entangled, and you had to throw it away.