From a dictionary perspective, “ephemera” are things that can only be enjoyed for a short period of time.
It just depends on the time scale I suppose. In one sense, all of us are ephemera; we exist on this sphere for a brief instant and then we’re gone. In other perspectives, we deal with things that go away or break as we use them.
Other than mass and energy, at their most basic, there is nothing that isn’t temporary. What is here at one instant can be gone in the next.
This follows, in many ways, from the laws of thermodynamics. I was having this discussion after lunch today but on its head. The idea posited was “what if someone’s metabolism was endothermic?” As you lived, you made thing colder. This was the proposal by my co-worker who claimed he was cold-blooded.
It’s an interesting sci-fi thing to think about what would happen with a set of changed cosmic laws. What would happen if you withdrew the laws around entropy? Things could form — out of nothing. Things may not break; alternately, they may simply rematerialize.
But at its core, we’re still stuck with things breaking for now.