Learning by Degrees: Demonstrating Thermal Expansion

Jonathan Smithby: Jonathan Smith

I’m a big fan of applied science.  Whenever possible, I like my labs and demos in my Physical Science classes to be as “real-life” as I can make them.  One rich area for science application is the topic of thermal expansion of solids.  Once students understand the underlying principles of why solids expand as they warm, I can choose from a plethora of great examples to teach the concept.

Over the years I have put together a walk-around laboratory experience where students can see the concept of thermal expansion of solids in action.  Of course I have the standard bi-metallic strip and ball and ring demos, but I also include thermostats, a taken apart toaster, and my absolute favorite, the Large Scale Thermal Expansion Apparatus from Educational Innovations.

This demonstration dramatically shows the effect of temperature change on standard household plumbing. The apparatus comes as a set of 4 segments of plastic pipe with easy twist-connectors.  One end of the apparatus fits a standard plastic funnel; the other has a downward turned drain spout.  One of the segments has a “foot” attached to it, which allows the funnel end to be firmly clamped to a table or counter top.  demonstrating Thermal Expansion

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