ABSTRACT
Geometry is the descriptive science of space. An object takes up a portion of space in which it resides. This certainly is a different kind of containment from that of, say, an object's being contained in a box. In the seventeenth century, the philosophy of space and time became a central issue of metaphysics and epistemology. The light should take different amounts of time to traverse the different paths, depending on the length of the paths and on the state of motion of the apparatus in the aether. In some spacetimes, it is possible for observers to have spacetime split into spaces-at-a-time. That means that in these worlds, for an observer in a particular state of motion, the spacetime can be sliced into three-dimensional spaces of events that all can be assigned a specific time in a time order that can hold globally.
