According to him (q_1, q_2, q_3, q_4) determines an event-particle, and (q_1, q_2, q_3) determines a point and q_4 a time.

But the collection of event-particles which he thinks of as a point is entirely different from any such collection which the man on earth thinks of as a point.

Thus the q-space for the man on Mars is quite different from the p-space for the land-surveyor on earth.
So far in speaking of space we have been talking of the timeless space of physical science, namely, of our concept of eternal space in which the world adventures.

But the space which we see as we look about is instantaneous space.

Thus if our natural perceptions are adjustable to the p-system of measurements we see instantaneously all the event-particles at some definite time p_4, and observe a succession of such spaces as time moves on.