The fortune fish is a small, thin, fish-shaped piece of plastic, typically red, known for its peculiar ability to curl and move when placed in the palm of your hand. This novelty toy has entertained generations with its contortions, sparking curiosity about the forces that make it twist and bend.
The Scientific Explanation
The fortune fish is crafted from a hygroscopic polymer, often cellophane, a form of cellulose. This material readily absorbs moisture from its surroundings, including perspiration on human skin. When placed on a warm, moist hand, the side in contact with the skin absorbs moisture.
As one side of the plastic fish absorbs moisture, it causes that side of the polymer to expand. The other side, exposed to drier air, does not absorb moisture or expand to the same degree. This differential expansion between the two surfaces of the material creates a bending or curling motion. The material is engineered to respond to environmental shifts, translating changes in humidity into visible movement.
Decoding the Movements
Beyond its scientific basis, the fortune fish is known as a novelty item that supposedly reveals one’s personality or fortune. The packaging often includes a guide interpreting the various ways the fish might curl.
For instance, a moving head signifies jealousy, while a moving tail might suggest indifference. If both the head and tail curl, it is interpreted to mean the person is in love. When the sides curl inward, it might imply a fickle nature. Should the fish turn completely over, some interpretations suggest the person is false.
These interpretations are purely for entertainment, offering a playful way to engage with the toy rather than providing any actual predictive insights.
A Clever Novelty
The fortune fish remains a fun, inexpensive novelty that cleverly utilizes basic scientific principles to create an illusion of magic. Its appeal lies in its simplicity and the curiosity it sparks among those who encounter it. Its enduring popularity stems from its ability to prompt questions about how everyday objects can exhibit unexpected behaviors. The fortune fish is a testament to how fundamental scientific concepts can be harnessed to create an engaging and entertaining item. It continues to be a simple, yet fascinating, example of science at play.