A discussion by Jon Ogborn, emeritus professor of science education at the Institute of Education, London.
An intrinsic problem of teaching about energy at secondary level is that school science is obliged to try to run before it can walk. School biology and chemistry need to use the idea of energy before its physical meaning or its measurement in terms of force multiplied by displacement can be taught.
Teachers want and need to talk about the role energy plays in changes, but the idea that energy is conserved (first law of thermodynamics) is simply not enough to do the job. What they need are some ideas from the second law of thermodynamics.
It is no real surprise that the world is richer and more complicated than science textbooks make it appear. And it is no surprise that it takes a lot of skill, knowledge and creativity to find good ways to explain things simply to young people.
In the document downloadable here, I offer a rough guide to the fundamental physics, using these subtitles:
- What is energy?
- Energy is conserved
- Energy amongst the molecules
- Free energy
- Is energy needed for a change to happen?
and concluding with
- Is there a better way to teach energy?