Fortune Telling Fish

How Does It Work

Of course the Fortune Telling Fish isn’t alive, so, what makes it move the instant it touches your hand? These toys are made of a super-thin, plastic material and they’re two-sided.

The plastic is hygroscopic which means it’s a water-finding material; it’s moisture sensitive. This property means the fish grabs onto the moisture on the surface of your palm and since the palms of human hands have a lot of sweat glands, the plastic is immediately bonded to moisture. The key is, however, that the plastic grabs water molecules only on the side in direct contact with skin. The plastic doesn’t absorb water molecules, it merely grabs them. As a result the moist side expands but the dry remains as it was. The plastic curls because the dry side pulls the expanding moist side around it. The curling movements come from the orientation of the polymer strands in the plastic. This is called the grain of the polymer. If the grain is oriented from head to tail, the strands curl the fish from head to tail. If the grain is oriented from side to side, the fish curls from side to side as well.

Take It Further

Now that you understand the science behind the Fortune Telling Fish, you can conduct some tests with them when get home from the party.

• Place a fish on different locations of your body. Test the tops of your hands, your arms, or even the tops and bottoms of your feet. The different number of sweat glands and the moisture they produce will have a direct effect on how the fish react.
• How might the fish react if your palms are a different temperature? Test the reaction of a Fortune Telling Fish in your hand after placing your hand on a cool surface and then on a warm surface.
• Test different, non-human surfaces around your home to see how a fish reacts on them. Who knows? Maybe a fish will find residual moisture from countertops, desks, walls, or keyboards.

The wrapper has a list of emotions or feelings that “cause” the fish to curl and move in certain ways.

• If you see just a moving head, it means jealousy.
• A moving tail is a sure sign of indifference.
• If you see a moving head and a moving tail, then… wait for it… you’re in love.
• If the sides of the fish curl, then you’re fickle.
• If the fish turns completely over, you are a false personality.
• You don’t want to see a motionless fish because then you’d be dead.
• If the fish curls up completely, it’s in response to the passionate side of your personality.

You could go along with these traditional findings of the Fortune Telling Fish, but what fun is that? Make up your own list of explanations for the movements you see. Since this is an audience participation experience, think about your list. Write the explanations you create and share them with your crowd. You’ll have some fun revealing others but watch out: you’ll be revealed as well!