A metaphysicist is someone creates or develops theories based on metaphysics. Metaphysics is a bransh of philosophy that explains the world, i.e., existence, space, time, cause and effect, objects and their properties, etc. Metaphysicists concentrate more on philosophy, and less on scientific method.
One scientist who can expound on forces, center of gravity, and acceleration is Sir Isaac Newton. His laws of motion describe how forces affect the motion of objects and how acceleration is related to the net force acting on an object. Newton also developed the concept of center of gravity, which is the point at which the entire weight of an object can be considered to act.
Metaphysics is the philosophical study of the nature of our existence. Modern scientists consider this area as opposite to the scientific method.Metaphysics is the collective processes that are beyond basic physics principles. For example, the study of Oncology, which peaks questions at perception and the state of being.It is also used as a word to describe using unseen forces to effect a seemingly unrelated event, person, area, etc. The higher echelon of magick, where one understands why this leads to that (some answers found through studying the worlds state of being) as opposed to many systems of magick which send practitioners blind to delve into forces unseen.