  The determination of the velocities, accelerations and the gravitational
field intensity at a given location in a galaxy could potentially be achieved
in an unexpected manner with the environment of the observer, for instance, the
local mean mass density in the galaxy. This idea, mathematically supported by
the asymmetric distance concept, is illustrated here by a study regarding the
rotation of spiral galaxies. This suggestion is new in the astrophysics field
(in the following, it is called the \k{appa}-model) and could help to mimic the
main effects seen in modified Newtonian dynamics (MOND) theory, modified
gravity (MOG) models, or other related models built with the aim of eliminating
dark matter that are already well-established theories. Thus, starting from two
selected examples of galaxies, in section 5, we show that there is an
equivalence between MOND and the \k{appa}-model. In particular, on the opposite
side, we have the speculative nature of the dominant paradigm, the elusive dark
matter, a matter whose properties always remain undefined despite intense
theoretical, experimental and observational efforts for over 50 years.
