I was thinking ‘out loud’ on Twitter about the ‘new’ energy language, discussions prompted in part by science teachers applying the changes in their classrooms. I know I’ve blogged about energy before, but thought it might be time to have another crack at it. I’m not writing here in an official IOP capacity, although I’m also swapping these ideas with colleagues. All thoughts, responses, criticisms and offers of coffee accepted. And if you add the comments here it will be easier for others to join in, as twitter replies get lost after a while. Alternatively, as the responses to a twitter poll led me to post it in chunks, you might want to wait until it’s all done. I’ll crosspost the complete thing to TalkPhysics as well.
- Resistance to change – teachers as much as students!
- Students who have learned one approach in KS3 and are now being told something different for KS4.
- The exam boards can’t seem to agree on which stores to use and which to omit, which has knock-on effects for textbooks.
- Teachers don’t know which answers will get marks in the exams, so don’t know what advice to give students.
- Existing resources are incompatible with the new language – but with enough similarities to make it look like they’ll work (like a false friend in language teaching, which gives you confidence while misleading).
I don’t have answers for these. To be honest, nobody does! What I can say is that many people are trying to figure out the best way to make these changes work well for everyone. It is, in my personal view, unfortunate that they are coming in with both a specification and a grading system that are new. It’s worth noting the stores and pathways model hasn’t been recently invented by the IOP to annoy teachers. For example: Robin Millar, Practical Physics.
There’s lots on the Supporting Physics Teaching resource from the IOP, but one place to start is this suggestion about useful things to keep in mind.
Hopefully Helpful Thoughts
A good thing about the ‘new’ language is that it encourages – pretty much demands – more attention on the actual physics. That’s the point. What is happening? So let’s start there; in any example, what process is involved? Some materials/sources call these pathways, but the idea is the same. Let’s not get hung up on labels for them, but on descriptions of actual events. It may help to emphasize to yourself that they are verbs, not nouns. They can happen fast or slow. But they involve actual physics, forces and EM and heating and so on (obligatory link to the Big Ideas of Science Education, because it’s awesome. When I rule the world every school science lab will have a huge poster of these.)
Now, these processes will change something. It means we can measure something which is different after this process compared to before. We’re not interested, right now, in how quickly this change has occurred – just that it has. This is a change – maybe a temperature increase, a greater separation of two objects, whatever – in a measurable quantity. This is associated with what we call a store. Different kinds of store have different equations, which link the measurable quantities together along with some constants. The result of that equation is a value for the energy associated with that store.
If we pay closer attention, we find that (at least) two stores have changed. What’s really interesting is that if we’re really careful, when we compare the equations, we find that the numbers are the same. An increase in one store is always balanced by a decrease in the other. The equations work as an exchange rate, showing how temperature rise in one part of the system is ‘worth’ faster movement in another part.
This, of course, is the principle of conservation of energy. Energy isn’t lost. But we can lose track of it. Sooner or later, the processes end up heating up the entire universe. Because the universe is pretty big (no, bigger than that) the change in temperature is effectively immeasurable.
So there we are; a very brief introduction to the ‘new’ model. More posts coming up, hopefully one per day. The sooner you comment, the more likely I can address your suggestions in the course of the series!