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Mathematically
speaking, we can call these fabulous formations spheres because they
are both round and three-dimensional. Also, when we compare one bubble to
another, we can call them congruent, if they have the same size and
shape or similar if they are different sizes. Of course, it isn’t
essential to use this vocabulary with your young child, but school age
children will be introduced to these terms and concepts in their classrooms,
so reinforcing them in play activities is a terrific.
Individually, bubbles are always spherical because spheres have the smallest
surface area of any three-dimensional shape. When bubbles form
around a gas (such as the air we blow through a bubble wand), the molecules
of liquid (soap, water, etc.) want to take up as little space around the gas
as possible. Also, the air inside the bubble pushes out on the walls of the
bubble equally in all direction making a perfect sphere.
To compare the surface area of various three-dimensional shapes, and to
explore more about bubble science, check out The Exploratorium (San
Francisco’s “museum of science art and human perception”) at its website
http://www.exploratorium.edu/ronh/bubbles/shape_of_bubbles.html
Before telling your child that all bubbles are round, ask
them what shape(s) they think bubbles can be. They might simply say, “All
bubbles are round,” because that is what they have already observed. In
that case, you might ask, “Are you sure? How can we prove it?” If they tell
you bubbles can be all shapes or different shapes, ask the same questions
and proceed to make bubble wands of different shapes to test this idea.
Bubble wands
can be made from many household objects, from yarn to wire hangers.
Essentially, anything that can be safely bent or looped into a closed shape
can be made into a bubble wand. (Even your hands can make a bubble wand if
you make a shape between your thumbs and forefingers.)
Here are some inexpensive, easy and earth friendly ways to make bubble wands
at home.
1.
Make a loop out of yarn or string. Use different lengths of string
(by measuring with a ruler or just estimating) to create different sizes of
loops. Experiment to see if different sizes of loops make different sizes
of bubbles.
2.
Bend the end of a pipe cleaner to make a loop or other closed shape.
Dip the looped end into the bubble soap and blow through the loop to make
bubbles. Use this kind of bubble wand as a way to test if all flat shapes
will make a round bubble.
3.
Use a wire coat hanger to make the same kind of bubble wand as in #2,
but larger. Since hangers are already bent into a “loop”, just bend the loop
into the shape you want. Younger hands may need help bending the stiff wire
of a hanger.
4.
Look around your kitchen to see if there are objects you can use to
blow bubbles such as cookie cutters, spatulas, and cooling racks.
5.
Check your recycling bin for containers and lids that can be used for
bubble blowing. A yogurt tub can be cut into rings that can be dipped into
bubble soap. Likewise, the rings from a six-pack of soda can be cut apart
and dipped. Try dipping the end of a toilet paper or paper towel tube.
Compare different materials: Which makes a better bubble blower, a wand made
of plastic or cardboard? |
