Anti-gravity is an idea of creating a place or object that is free from the force of
gravity. It does not refer to the lack of weight under gravity experienced in
free fall or
orbit, or to balancing the force of gravity with some other force, such as electromagnetism or aerodynamic lift. Anti-gravity is a recurring concept in science fiction, particularly in the context of
spacecraft propulsion. An early example is the gravity blocking substance "Cavorite" in
H. G. Wells'
The First Men in the Moon.
