Jacob's ladder (toy)
As Jakobsleiter a is a toy referred consisting of multiple equal sized blocks (flat cuboids ), which by bands are interconnected. The blocks are usually made of wood or plastic , the tapes are often made of fabric . The construction allows a movement that creates an apparent cascade-like effect .
cascade
If you hold the Jacob's ladder by the narrow sides of the top block so that it hangs vertically and turn your wrist as if you wanted to fold the block you are holding next to the second block, the second block appears to fall down on the other side due to the effect of gravity and to swing alternately through all the blocks downwards. The cascade is created when the folding movement is repeated alternately. It is an optical illusion , the construction and the movement only produce a rotation of the blocks, the illusion is created by impulse transmission.
construction
The bands are attached to the blocks in such a way that two adjacent blocks can rotate around each other. Rubik's Magic uses the same mechanism, but there the threads are diagonally and very tightly stretched, so that you have to fold down even the flat blocks; neither the optical illusion nor the effects of gravity are of interest. What is remarkable there is the adaptation in two dimensions, instead of the linear, one-dimensional arrangement of the classic Jacob's ladder.
Concept formation and history
Since the cascade is only ended by disinterest on the part of the performer, but the cascade can potentially continue indefinitely , one saw here a reference to the Christian legend of Jacob's ladder , in which the difference between transcendence and world is symbolized by an infinitely long ladder .
The toy principle has been known since at least the 18th century , both in Europe and in America . It became better known with the marketing of Rubik's Magic in the 1980s.
