Zuse’s thesis is the idea that the Universe could be running within a digital computer. It was formulated by Konrad Zuse in Rechnender Raum (Calculating Space) in 1969. The computer could be a very large Cellular automaton according to Zuse.
A computer program to simulate our Universe (and all the others)
Systematically create and execute all programs for a universal computer, such as a Turing machine or a CA; the first program is run for one instruction every second step on average, the next for one instruction every second of the remaining steps on average, and so on.
Juergen Schmidhuber in (Schmidhuber 1999)
The need for interlacing computations like this is to avoid the halting problem if we were to wait for any of these programs to finish.