We are getting closer to agreement.
Our world is really a 3D world. But a 3D model is not what I use to describe and predict phenomena in my 3D world. Like you, I also use an imaginary 4D model (which takes time into account) to describe and predict phenomena in my real 3D world. But I don’t jump into the conclusion that I live in a 4D world just because the imaginary 4D model works great in describing phenomena in my 3D world. I am ok with thinking of a “warped spacetime continuum” to describe how bodies interact. But I find it nonsense to say that real space or real time is warped just because the imaginary spacetime model can flex and bend. The 4D spacetime model is really just that – an imaginary model. And it can be replaced by a different model in the future, if a better one is found.
At one time people thought that the behavior of bodies can be described by the gravitational force. Was gravity real, or was it just a conceptual model? I think it was just a model, and it worked great in many cases. However, we now have a better model – spacetime. Now the same question comes up: is it real or is it just a model? At one time the Rutherford model of the atom was very popular. Was the atom really just a miniature solar system or was that just a model? It worked great, and is still being used today. But the real atom is far more complicated than Rutherford envisioned. We have to be careful about the concepts we use in physics. Many of them are mathematical models and concepts, not real entities. Think of work, for example. I don’t deny that there is such a thing as real work. But work in physics is not what real work is. In physics work is the
mathematical product of force and distance. It is a
concept. That means, a man holding a heavy barbel for 1 minute but not moving it, has done zero work. He might perspire, but he has done less work than an ant that walked one inch. And it is correct, because “work” in physics has a different meaning than real work. The same can be said of “mass,” “energy,” the “quarks,” the “anti-particles,” etc. They are all concepts and models of modern physics. It is useful to think of reality in terms of those concepts. But it is an unpardonable mistake in the philosophy of nature to think that they are real entities just because they work well in describing the real world. They are describing something real, of course, but they themselves are just models that can be replaced in the future depending on the progress of our scientific knowledge. Medieval philosophers have a term for concepts like these. They are called
entia rationis cum fundamento in re, or “beings of reason with a foundation in reality.”