Yeah, that sort of depends on the level of physics you’re talking about. regardless, it’s still a property of stuff even if that stuff is not always matter. if you want to go off on the weeds on that, go for it.
even so, energy is not something that exists, but a quantified attribute of things that do exist.
To clarify, energy isn’t a “thing” that exists. It’s a property of matter, and so is mass.
So spacetime are only related in that matter exists in spacetime, and can influence it in ways we don’t (or at least I don’t,) really understand.
Anything that occupies space and has weight is matter. And yes, every matter exists in time.
Energy is not only a property of matter. Photons have energy, no mass, and are not matter but in fact force carrier particles.
Yeah, that sort of depends on the level of physics you’re talking about. regardless, it’s still a property of stuff even if that stuff is not always matter. if you want to go off on the weeds on that, go for it.
even so, energy is not something that exists, but a quantified attribute of things that do exist.
Thanks for that link.