the north Koreans definitely already know...

Energy conservation is related to a continuous symmetry (invariance under translation in time). I do not think baryon number is on the same footing. Energy non conservation would be a big, fundamental problem. Baryon number violation is actually part of the Standard Model.

If we prefer definition 3, do we not then require an interpretatoin of the "action" which is minimised in order to then understand energy?

Does Leibniz's conservation objection to Descartes's philosophy of mind get discussed in the new edition of your book? I have been trying to assemble that history.

You mentioned T and V, but what about L and H? E.g.in the principle of least action energy enters as a Lagrangian

I liked your point about trying to resolve paradoxes by `doing the thing'. This is also true for quantum non-locality, where the best way to understand is to try to devise a strategy yourself to win a non-local game.

The assumption that energy should be positive is one reason why massive graviton theories were rejected in the early 1970s. There is a bit of controversy whether that was necessary. It seems somewhat plausible to me that there is no problem classically.

Thankyou Ian :) Liked your talk - just want to point out the difficulty of "orange fluid" - too reminiscent ot CALORIC!

As far as I am aware, this model is only adopted in England. Wales, Scotland and NI are still using Forms of Energy as their teaching model.

Can I make a comment

Yes David please do

There is of course the question of how one would know that the idea, I’m avoiding the word concept, is understood by students. I don’t know of a good assessment of conceptual understanding.

Thanks everyone! I need to “go” to give a talk in Warsaw now…

Fascinating!

Thanks Karim - thanks again for talking and good luck with next talk

If F: Don't you get the same issue with listing the types of store, as you had with number of forms of energy

Thanks Tony

Q: Just to clarify my understanding, if an object would normally have two forms of energy (e.g. kinetic and gravitational) would you give it two different 'beakers' for the orange fluid?

can I make a comment?

OF course. I'll bring you in in a sec

If it would be useful - I am very happy to run a "This is how we try and do it in school" presentation at a later date. From the school of education.

Thanks!

I do :)