Is there any level of physics that is "solved"? At each level of physics, between rotating galaxies, orbiting planets, wind and motion of matter, to motion of molecules, atoms, particles, and maybe strings, there's always some degree of uncertainty in predicting the physics from theory. Relativity and quantum mechanics are the usual culprits in this uncertainty, but sometimes it's just the huge number of complicated interactions that make the physics impossible to calculate (e.g. even the 3-body problem has no known closed-form solutions)
So my question is, is there a level of physics that is "solved" per se?
I can think of quantum electrodynamics which is experimentally verified to ten parts in a billion, but I was hoping to understand more examples. Thank you.
 A: How can you guarantee that there will be no physics discovered in the future that will resolve to our theoretical physics of today, while at the same time providing a greater depth of knowledge?
You can't, no one can. Only mathematical proofs can be considered to be solved, or closed.
A: From a purely practical standpoint, there are a number of fields of study which by now contain very few unanswered questions and can be considered (again, for practical purposes) "solved". These include AC and DC circuit analysis (both lumped and distributed), continuum mechanics (elastic behavior of beams, columns, etc.), subsonic airflow around wings, fluid mechanics (even though the navier-stokes equations still cannot be solved explicitly in most cases), dynamic systems analysis both in the time and frequency domains (i.e., newton's laws for complex machinery), and heat transfer and thermodynamics.
In short: if you can take engineering classes in a technical field, physicists will have moved on to something else.
