postpischil@castor.DEC (Eric Postpischil) (12/26/85)
> weight: The gravitational force exerted by a planet (Earth) on > an object. By this definition an orbiting spacecraft and a person > falling from a rooftop both have weight. > > weightless: The absence of the subjective feeling of 'weight' due > to supporting forces. I do not think it is appropriate to give "weightless" a special definition; its definition should follow from the definition of "weight" and the normal patterns of the English language. Something should be weightless when its weight is zero. weight the apparent gravitational force on an object in a particular frame of reference Choosing the surface of the Earth as a frame of reference gives objects on the surface of the Earth weight. An object in an elevator accelerating in space has weight, because the force it feels, with the elevator as a frame of reference, is indistinguishable from gravity. An object in an orbiting spaceship, using the spaceship as a frame of reference, is weightless, as is any object when considered in an inertial frame of reference. -- edp Eric Postpischil "Always mount a scratch monkey."