  Since laws of physics exist in nature, their possible relationship to
terrestial growth is introduced. By considering the human body as a dynamic
system of variable mass (and volume), growing under a gravity field, it is
shown how natural laws may influence the vertical growth of humans. This
approach makes sense because the non-linear percentile curves of different
aspects of human physical growth from childhood to adolescence can be described
in relation to physics laws independently of gender and nationality. Analytical
relations for the dependence of stature, measured mass (weight), growth
velocity (and their mix as the body mass index) on age are deduced with a set
of common statistical parameters which could relate environmental, genetics and
metabolism and different aspects of physical growth on earth. A relationship to
the monotone smoothing using functional data analysis to estimate growth curves
and its derivatives is established. A preliminary discussion is also presented
on horizontal growth in an essentially weightless environment (i.e., aquatic)
with a connection to the Laird-Gompertz formula for growth.
