What is energy?
Nobody knows what energy actually is and by pretending otherwise we actually do the students a disservice. Not only are we ignoring the wonder associated with the idea, we are also denying them the opportunity to engage with the concept at any level beyond the superficial.
Bottom line; nobody gets energy because there’s nothing to get. Energy is not tangible (it is ‘an indirectly observed quantity’); you can’t hold it in your hand, you can’t weigh it on an electronic balance, you can’t see it, touch it, smell it etc. Yet when the universe was first created there was a certain amount of this put in to the mix (actually now that I think about it the mix itself was energy (with perhaps just a little dash of time)), and it’s all still there today. Its form can change, but the energy itself can’t ever disappear – no sirree bob.
It could be argued that it is in fact merely an accountant’s trick which enables him to ensure that all actions balance.
Consider the following analogy which I like to use.
If a child asks you ‘what is money?’ you could take a few coins out of your pocket and show them to the child and say ‘this in money’. Now fast forward a couple of decades; all transactions are now done electronically/online and all coins and paper money are no longer legal tender. Now how do you explain what money is?
Well it’s a means of payment for goods and services, right? Somebody sells you an orange and you agree to transfer into their account a set amount of this ‘money’. And now that the shopkeeper has this money in his account he can use it to buy something else. So in effect money is just a transferrable IOU.
Now energy is a bit like this, but there is only a certain amount of IOU’s in the universe and this was set when the universe first came into being.
To complicate matters further, since the early part of the last century we now know (thank you Albert) that all matter (‘stuff’) is basically energy in another form.
Anyone still with me?