Zooming Fish

The high temperature tomorrow is supposed to be four degrees below zero.  Although I’ve grown to love Minnesota, it makes me wonder if I’m insane to live here!  So, I’m dreaming of summer science:  planting seeds, catching bugs, measuring the rainfall and hatching butterflies!  Soon I’ll buy some forced bulbs for my kitchen to help get me through these long winter months.

Here’s an easy, fun science project to do inside on a cold winter’s day.  I found this project a few years ago on pbskids.org/dragonflytv.  My children will do it again and again.  Even my three year-old joined in, cutting up construction paper into “fish food” and throwing it into the water. 

You will need some sort of pan for water (a cake pan will work), construction paper, scissors, and dish soap.  Have your child cut out some fish shapes from the paper (around two inches long works well.)  See the photo below.  Then, have them cut a small slit in the back of the tail.  Put a few inches of water in the pan and add the fish.  Before the paper soaks up too much water, have  your child add a drop of dish soap behind the fish.  The fish should zoom across the water.  You will have to add fresh water to make it work well again. 

The soap breaks the surface tension of the water.  Imagine that the surface of the water is a sheet of fabric and the soap is a pair of scissors.  The soap cuts through the water, pushing the fish ahead of it.  For a more coherent explanation, have your child look up surface tension or visit the dragonfly tv website!

Don’t forget those science notebooks!  Have your children record their results.  They could even try using different liquids to break the surface tension.  My kids made some fish out of that foam that is used for craft projects so that they wouldn’t soak up the water!  Hopefully, the zooming fish will keep your child interested and busy for a while!

Tags: kids science, surface tension