Can Zero Gravity exist?

The symphony and sound of zero gravity are quite interesting, particularly when some news would appear on the TV or Radio. The very recent one was when Stephen Hawking from Cambridge University was taken by a specially designed plane to experience the so called zero gravity situation. There is not doubt that whenever a space shuttle goes to space the astronauts are shown floating inside the cabin and some statements about the zero gravity is mentioned. Sometimes zero gravity is also called weightlessness, which means no weight.

The point that I am interested in is the explanation of the way zero gravity takes place. Most of the time even in media when presenters are talking about the zero gravity, their explanation and interpretation do not seem to be compatible with the real scientific meaning of the phenomena. In a recent survey carried out by myself to understand how much people have understanding on the concept of zero gravity, the outcome was: nearly every normal people could not tell a proper understanding and among academics even those who are physics but may not be specialised on the fundamentals of dynamics would give the same misunderstanding. As the result of my finding; almost all of them agree on one statement:

The shuttle goes to a very far distance from the earth so that the effect of gravity would be nearly null!!

Although, sometimes I tell myself that I should not blame those people because for some unknown reason from the start this phenomenon has been named zero gravity and certainly every one would attempt to provide a solution that is related to the gravity. We have learnt from basics of physics in school that gravitational force is inversely proportional to distance, if the object is further away from the earth, the gravitational force would become smaller. But let tell one fact, achieving zero gravity from the earth would be impossible practically unless the distance is infinite! And secondly, something like the altitude of shuttle is just above the earth by approximately 300 Km, which is much more smaller than the gravity force manifests any significant difference. Any how, it might happen that we tend to use complicated answer for simple question.

Let us now come back to the main point; how does this phenomenon take place? I would like to answer and explain as simple as possible so that the reader in background and experience can understand. There are a number of fundamental facts we should know, these are:

There exists a gravitational force between the shuttle and any components of it such as the astronauts and the earth. As I said before, the difference in the force when the shuttle is on the earth and at the height of 300 km is very little, i.e. the force is reduced by 8%, which is very small. So there is no way the gravitational force that reduces by this amount would demonstrate the zero gravity.

When an object is orbiting, some sort of force is created that attempts to throw the object outside the orbit. You know we experience this on daily basis, when the vehicle we are driving or a bus on a bent we experience a force towards outside the orbital path the orbit moves on.

This is what is happening, the shuttle is on its orbit, the astronauts are part of the system. On the orbit, the gravitational force is equal to the force that is generated by the circular path of the shuttle. Therefore the shuttle, the astronauts and any other part within the system behave in the same way they are affected upon by no force. You experience no force acting on you. This is the same as the moon orbiting the earth, the earth orbiting the sun and all other planetary motions in their orbits.