Railway Track Illusion
This marvellous effect is based on an optical illusion first described by Joseph Jastrow in 1891.
A) Two quality wooden train tracks
B) Detailed sheet of instructions.
C) Sheet with 2 Pair (4) Printed Railway Track Sections.
Once the principle is understood, many other similar objects can be used to replicate/demonstrate this effect.
e.g. In my shows, I often use coloured pieces of cardboard and invite a spectator to rub the cardboard and demonstrate how it can stretch and shrink with ease!!