Is the universe a computer?

Yes. The universe is a perfectly normal computer program, the observer consensus protocol, running on a holographic screen. The screen is the hardware, built by observers inside the history it computes, by us, in our subjective future. The program is simple. Each piece of the world repairs disagreements with its neighbors by local arithmetic, and networks of such pieces compute every finite logical function. Wire a circuit as one piece per gate, set every other register to anything, and let the pieces repair in any order, with no synchronized clock and no leader. The answer lands in a designated register every time. The trick fits on five playing cards. Undo one shuffle, undo a second, then do the first and the second. A commuting pair would leave the deck untouched, and the right pair moves every card one place along. That leftover cycle builds an AND gate.