  Physical theories must stem from observation. The possibility that perceived
events are simulated, not real, raises a crucial dilemma about the credibility
of known physics, known as the simulation hypothesis. To analyze this
hypothesis in deterministic and mechanistic terms, an observer is conceptually
developed, whose internal state depends on external events. It is demonstrated
that the observer cannot distinguish between simulated and real events. It is
argued that if the observer could observe its entire dynamics, it could
formulate the necessary principles of relativity to distinguish real from
non-real physical motions. Finally, an attempt is made to apply the same
considerations developed for the mechanistic observer to the human being.
