There were the two inhabited worlds in their own time lines, or probability orbits, or whatever.
The probability orbits were separate but both involved.
There is only a single world.
A child is bored with Christmas.
Shahjahan built the Coliseum in Rome.
There is a viewing platform built around the camera.
There is a group of people playing a sport.
the girl is stretching her legs
The Chinese were happy to share their insight on the bombs