A full diagram in that style would be 1 dimension of graph for each dimension of space for each particle that happens to exist, and you have a separate diagram for each different combination of different numbers of particles.
Obviously, he’s simplified it, so the answer to your question is just, “That’s how he chose to reduce it”.
A full diagram in that style would be 1 dimension of graph for each dimension of space for each particle that happens to exist, and you have a separate diagram for each different combination of different numbers of particles.
Obviously, he’s simplified it, so the answer to your question is just, “That’s how he chose to reduce it”.