|About matter and fields of forces|
"We no longer contrast matter with forces and field of force as different entities, we know now that these concepts have to be merged. It is true, we call a spatial region free of matter, call it empty if there is nothing but a gravitational field. But space is never really empty because even far away in the universe there is starlight, and that is matter [...]"
Erwin Schrödinger, 1952