Primary Unit Science Float your boat : The Philadelphia School

Primary Unit Science
The Philadelphia School
Float your boat :
At many schools, primary science instruction is based
on learning and repeating poorly understood facts. We
prefer to show children some intrinsically bizarre
phenomenon, let them play with it, saying as little
theory as possible, and ask for their ideas. Then we try
to connect to other phenomena.
We studied various examples of buoyancy, for example
making Cartesian divers. The goal was to stay with
phenomena close to everyday experience.
Above: we show that soap bubbles will bounce off an
invisible layer of carbon dioxide at the bottom of a bucket.
Right: A can of regular soda sinks in water, but a can of
diet soda floats. We make the can of regular soda float by
dissolving a whole lot of salt in the surrounding water.