Convection: A Current Event
Written by Alan Gould
Convection is a powerful and exciting force in many natural physical
eventsmovement of the Earth's crust and volcanic eruptions,
weather, wind, ocean currents. Its influence is enormous.
In the course of this dynamic unit, students explore the many
roles of convection by observing and diagramming convection currents
in fluids. Where traditional textbooks use two-dimensional images
to convey the notion of convection, this GEMS guide brings
the concept to life with physical experiments on the movement
of heat, the diffusion of scent, the trajectory of carbon dioxide,
and other seeming intangibles. From these activities students
learn to predict and track wind patterns and other intangible
phenomena. A background section for the teacher is provided.
Fundamental knowledge of the concept of density provides a full
understanding of why convection occurs, but is not necessary
to this unit (which introduces the idea, characteristics, and
application of convection in stand-alone fashion). If your students
are ready to learn about density, however, we encourage you to
precede this unit with the GEMS guide Discovering
Time: Three 30- to 60-minute sessions, plus follow-up sessions.
Comment on this GEMS unit.