Re: How can I prove experimentally that fire is energy?

Hi Brittany,

OK. We want to prove that fire is energy, by proving it can do work. By work, for early-education purposes, we mean mechanical work, so if you can effectively demonstrate conversion of chemical energy to heat energy to mechanical energy, you will have demonstrated that fire is energy.

A good demonstration for this purpose would involve removing the engine from your car, and setting it up on a lab bench so that your students can examine-- just kidding.

But building a simple engine is quite easy, really. This site describes a fairly involved (~2-3 hours) project to build a simple engine that looks quite cute and has a neat ancient-greek-history angle as well, but just for illustrating the principle, you could do something extremely simple, like so:

1. Boil water in a tea kettle;
2. Place a pinwheel over the vent where the steam is escaping;
3. QED.
4. To drive the point, thread a needle, and drive the pointy end of the needle into the center of the pinwheel axis. The thread will curl around the needle eye, and you can lift something attached to the end of the thread.

I approve of your student's skepticism! :)

Hope this helps,

Dr. Edward J. Hyer
Post-Doctoral Researcher
Naval Research Laboratory
Marine Meteorology Division
Monterey, California 93940