You will have observed that each event-particle is as much an instant of time as it is a point of space.

I have called it an instantaneous point-flash.

Thus in the structure of this space-time manifold space is not finally discriminated from time, and the possibility remains open for diverse modes of discrimination according to the diverse circumstances of observers.

It is this possibility which makes the fundamental distinction between the new way of conceiving the universe and the old way.

The secret of understanding relativity is to understand this.