So O.K: The difference between inertial motion of the first law of
physics, and the concept of inertia itself, is too much for most
scientists to swallow:
Here is an easier one: Weight is the force exerted between an object;
body, or mass of matter and the surface of a planet - like Earth or
the moon - that it is bearing upon.
Without something to bear upon: Object's; bodies and mass's of matter
are weightless; all forces require something to bear against!
The magnitude of an object's; body's, or mass's weight-force [w] is
proportional to the deceleration [g] at which the planet's surface is
restraining them from further gravitation:
That is, for any given object; body, or mass of matter, at anytime,
the ratio of its weight to the acceleration at which it will free
fall, is a constant [w/g].