Yes. An object is weightless if gravity is the only force acting on it. (for example, a ball falling in a vacuum)
There is no true "weightlessness", because, even if two masses are separated by billions of light years, there is still a gravitational attraction force. There is a distance at which this cannot be felt anymore, but there is still a force.
Objects in freefall are not weightless; they still have mass and therefore experience the force of gravity. However, in freefall, they are accelerating towards the Earth due to gravity, which gives the sensation of weightlessness as the force of gravity is canceled out by the acceleration.
Objects weigh less in water than they do in air because of the buoyant force exerted by the water. This force counteracts the weight of the object, making it feel lighter or even weightless when submerged in water.
It's not possible to make stone weightless in the physical sense because all objects have mass and weight. However, in a virtual or augmented reality environment, you can manipulate the perception of weight using visual effects or simulations to create the illusion of a weightless stone.
Something can only be weightless in zero gravity.
Antaganism
Objects in freefall are not weightless; they still have mass and therefore experience the force of gravity. However, in freefall, they are accelerating towards the Earth due to gravity, which gives the sensation of weightlessness as the force of gravity is canceled out by the acceleration.
Objects weigh less in water than they do in air because of the buoyant force exerted by the water. This force counteracts the weight of the object, making it feel lighter or even weightless when submerged in water.
It's not possible to make stone weightless in the physical sense because all objects have mass and weight. However, in a virtual or augmented reality environment, you can manipulate the perception of weight using visual effects or simulations to create the illusion of a weightless stone.
By learning enough basic physics to know that objects on the Moon are not, in fact, weightless.
Something can only be weightless in zero gravity.
Antaganism
Yes. Air will provide some upwards force, according to the volume of air displaced.
Objects in communication satellites still have weight, as weight is a measure of the force of gravity acting on an object. However, in the microgravity environment of space, objects appear weightless because they are in free fall around the Earth.
You can be weightless when experiencing free fall, such as in an elevator dropping or skydiving, because you are in a state of apparent weightlessness due to the force of gravity acting equally on you and the objects around you, causing you to float. This sensation occurs when the acceleration from gravity counteracts the force of gravity pulling you downwards, creating a feeling of weightlessness.
A shadow is something that is weightless but can be seen.
No. It is light -- not heavy, but it is not weightless.
I don't quite understand why you mix "gravitation" and "weightless" in the question. The gravitational acceleration of Earth is 9.8 m/sec2 near the surface; further away, it will gradually decrease. The presence of air - if that is what you referring to - is quite irrelevant to the fact that there is gravitation.