All you are doing with your snarky comments is making a fool of yourself." a rocket" is why an acceleration in free space means a resultant force. OK well, I guess someone should have told Einstein, before he went to all that trouble.
A cartoon description of the equivalence principle:
http://www.pbs.org/wgbh/nova/einstein/rela-ele-q-300.html
The normal force is a manifestation of the Coulomb force. Suppose you are standing on the floor. The Coulomb force between the electrons at the surface of the floor exert an upward force on the electrons at the bottom of your feet. Now suppose you grab a pull-up bar and slowly start lifting yourself off the floor. The ground will continue to exert an upward force (but reduced in magnitude) up to the moment that the upward force from the pull-up equals the downward gravitational force. At this point you will be lifting your feet off the ground.Why is there a normal force at the surface?
While the Coulomb force is an inverse force law, the total Coulomb force between you and the ground falls off much, much faster than 1/r[sup]2[/sup].
This is because you and the ground are more or less electrically neutral. From a quasi-classical point of view, the normal force is essentially a high order multipole interaction.
The normal force is a constraint force, as is static friction. Re static friction: A box is sitting on the floor. Exert a small horizontal force on the box and it will not move, seemingly in violation of Newton's second law. Newton's second law pertains to the net force acting on an object rather than the individual components of the net force. Via static friction, the floor exerts a horizontal force on the box that exactly opposes your tiny horizontal force on the box. (Note well: Even though this is an equal-but-opposite force, it is not a third law interaction.) Up to a point, the opposing force by the ground increases as you increase your horizontal force on the box. This point where the ground can no longer match the force you are exerting is described in terms of the static coefficient of friction.Why do you "no longer accelerate" when at rest on this surface.
Back to the normal force: It too has a breaking point. The normal force decreases in magnitude when start doing the pull-up. It reaches zero when you reach the point where your weight is fully suspended from the pull-up bar. Add a tiny bit of force to the pull-up bar and you will lift yourself off the ground. The normal force does not suck you back to the ground. The breaking point for the normal force is the point at which the normal force would have to be directed inward rather than outward.
Good question! Weight is a tricky concept. Legally and colloquially, weight is a synonym for mass. A one pound can of peas "weighs" one pound at the North Pole, at the top of Mt. Everest, and on the surface of the Moon. Ignoring that distraction, weight in physics has units of force. Even then, there are two distinct meanings for weight in physics. One meaning is gravitational force, aka "weight", aka "actual weight". This is simply the mass of the object times the gravitational component of acceleration: W=mg. The other meaning is the net force acting on an object less the gravitational force. This is the "apparent weight" or "scale weight" of the object. To illustrate the difference, consider some astronauts floating around inside the International Space Station. Their actual weight is about 90% of their actual weight on the surface of the Earth. Their apparent weight is essentially zero.Where does the weight I can feel come from? (I can definitely feel weight).
Suppose you are standing still on a scale on the surface of the Earth. That scale does not measure your actual weight. It instead measures your apparent weight. This is why another name for apparent weight is scale weight. Your actual weight is directed down while your scale weight is directed upward. If the Earth wasn't rotating your actual and scale weight would be equal but opposite to one another. However, the Earth is rotating. There is a net force acting on you, just enough to keep you in uniform circular motion about the Earth's rotation axis. Your actual and scale weight are not quite equal but opposite to one another.
So what is it that you feel? You feel scale weight, not actual weight. When you are standing on the scale, the scale is exerting an upward force on your feet. It is this upward force that you feel in your feet. This force propagates throughout your body. You feel it in your guts and in your head. The vestibular system is a part of inner ear. The otolithic organs and semicircular canals in your inner ear are very much akin to the accelerometers and gyroscopes in an airplane's or spacecraft's inertial guidance system.
Place an accelerometer at rest on the surface of the Earth and the accelerometer will register a one g acceleration directed upward. The accelerometer, like your otolith organs, is insensitive to the gravitational force. They are instead sensitive to the net sum of every force but gravity: scale weight. What you feel as weight is scale weight.