The weight created in an elevator (or in an accelerating rocket, etc.) is just as real as weight created on the surface of the Earth. It is created in both cases because a Secondary Force (an ordinary contact force) is being exerted on a body altering the body's primary acceleration. It doesn't make any difference whether it is a person in an accelerating rocket or a person standing on earth, the effect of weight will be created. Weight is simply the measure of the amount of an ordinary "contact" force being exerted on a body. It could be on the surface of Earth or the moon or in an accelerating rocket, etc. It does not matter - weight is simply an indication of the amount of ordinary "contact" force that is being exerted against the body. If there is no contact force being exerted, the body is weightless. The weight of the body varies under different conditions - for example a body 'resting' on the surface of the earth or moon is always in a constant restrained state of acceleration - the surface of the earth or moon is constantly obstructing (stopping) the body's gravitational acceleration toward the center of the earth (changing the velocity of the body) creating the 'effect' of weight. The weight created is proportional to the amount of ordinary "contact" force that is being exerted on the body. The surface of the Earth ( an ordinary contact force) must exert much more force to obstruct the body's acceleration then the surface of the Moon must exert, due to its weaker gravity - therefore the body's weight will be greater on Earth then on the Moon.     Inertia is the law of nature that requires a primary force be exerted on a body to change its motion in any way (accelerate).     Secondary Forces, (an ordinary "contact" force) creates the unique effect of weight by exerting its force, by direct contact, in succession on a body. (the floor pushes on your feet, which pushes on your leg bones, which pushes on your hip bones, et., etc.., from one end of the body to the other end.) The Secondary Force has no energy of its own, it derives all its energy from the Primary Force. Primary Forces, there are four primary forces. The primary force of gravity, exerts its energy on all the atoms of a body simultaneously, not in succession. That is the big difference! A body under Gravity's influence alone is weightless. (This is what fooled Einstein into thinking is a force.) Only when a Secondary Force (contact force) alters the body's acceleration, in some manner, is the effect of weight created. The effect of weight is created only when a secondary (contact) force is being exerted on the body.   Weight created on the Earth's surface:   Due to the force of gravity, all bodies are trying to accelerate (fall) toward the center of the earth. The only reason it cannot do this is because the surface of the earth is constantly obstructing our downward acceleration. The amount of force the surface of the earth must exert is the "weight" of the body. "Weight" is the measurement of the amount of contact force that is being exerted on the body to stop its downward acceleration. Bodies do not rest on the surface of the earth - they are constantly in a state of restrained acceleration. It is similar to a boat with its motor running being restrained by the dock its up against rather the the boat with its motor off simply resting against the dock.  Weight created in an accelerating rocket:   Inertia requires that a force be exerted to accelerate a body.    The floor of the rocket (an ordinary "contact" force) is constantly pushing (accelerating) the astronaut as the rocket accelerates through space - again causing the 'effect' of weight to be created. The astronaut's weight will depend on how fast the rocket is accelerating. Again - weight is the measurement of the amount of "contact" force that is being exerted on the body. If the rocket is accelerating 32.2 feet /sec/sec the astronaut will weigh the same as he does on earth. If the rocket is accelerating twice as fast, it will weigh twice as much. No gravity is created in the rocket - only "weight" is created. Weight created in an accelerating rocket has nothing to do with gravity. If the rocket's engines are turned off the astronaut will immediately become weightless because there is no longer a secondary force being exerted against him(or her). Donald Hamilton Reference: - Chapter 18, "The MIND of MANKIND: Human Imagination, the source of Mankind's tremendous power!" ISBN 09649265-1-2, Published 1996, Suna Press. More about - Weight, Inertia, Mass and Gravity - Chapter 18. ( Click on cover) Imagination - The Power that makes us Human! Plus - New concepts in science: Geophysics, Cosmology, Physics, and Astronomy, Plus much more! "Seeking reality with Imagination." The Earth's Slowing Rotation Comments Home