  Newtonian gravity can be regarded as a hypothetic-deductive system where the
inverse square law is the starting point from which gravitational phenomena are
deduced. This operational form of presenting gravity endorses problem solving
and seems to be predominant in the teaching practice. In contrast, regarding
phenomena as a source for the development of the theory is also possible, of
course, and can be advantageous to scientific education since it deals with
model conception and construction. This article intends to introduce
undergraduates to Newtonian gravity using its empirical basis, i.e. the free
fall and the planetary motion, to deduce the universal law of gravitation.
Additionally, an elemental analysis of the theory's structure is presented. It
also steps into the modern interpretation of gravitational phenomena i.e.
Einstein's general relativity, including a discussion on the instantaneous
action at a distance in this context. This didactic presentation of the theory
of gravity differs from the standard approach usually found in common
textbooks. It is designed to reach a threefold equality, similar to those
applied in the method of separation of variables in partial differential
equations, where G is treated as a separation constant. By doing so, the
universality of the gravitation constant emerges as a conclusion rather than a
statement. It is also meant to create a perception on how imagination can be
helpful in discovering Physical laws.
