ABSTRACT
The pre-Socratic Greek philosophers (600^400 BC) already discovered how difficult it is to say what space is. Is space the void between thingswhich really exist? But if the void is non-existent, isn’t the spatial separation only an illusion? This was the point reached by Parmenides of Elea (500 BC), who only recognized fullness, the plenum, as reality, and consideredultimate reality tobe found in the formofa sphere (a sort of neutron star, as we should say now).
