Energy in physics feels analogous to money in economics. Is a manmade medium of exchange used for convenience. It is the exchange medium between measureable physical states/things.
Is energy is real in the same way money is? An incredibly useful accounting trick that is used so frequently it feels fundamental, but really it’s just a mathmatical convenience?
Small aside: From this perspective ‘conservatipn of energy’ is a redundant statement. Of course energy must be conserved or else the equations are wrong. The definition of energy is it’s conservation.
If a one-ton boulder rolls down an Earthly hill in my direction and I don’t move, what happens is not a manmade concept. Call it what you will.
Time on the other hand exists only as a useful mental tool to describe change. When I repeat the experiment of going to sleep, when I wake up it’s still always now. That experiment -always- produces the same result.
Well, technically the ‘now’ experiment only works one time. Of you exclude time as an assumption there isn’t another location to place previous or subsequent results.
Isn’t another location
“previous” and “subsequent” locations in space are memory phenomena, High-energy location changes are closer together in memory. Our “time” is a bookshelf of physical events in space, one following another. Of course they’re sequential, so it was convenient to ‘measure’ the ‘distance’ between the books for purposes of prediction. But we’ve invented that ruler, then forgot we made it up. Many indigenous people have no ‘time’, and they manage.