The big idea: are we living in a simulation?

Elon Musk thinks you don't exist. But it's nothing personal: he thinks he doesn't exist either. Instead we are just immaterial software constructs running on a gigantic alien computer simulation. Musk has stated that the odds are billions to one that we are actually living in "base reality", ie the physical universe. At the end of last year, he responded to a tweet about the anniversary of the crude tennis video game Pong (1972) by writing: "49 years later, games are photo-realistic 3D worlds. What does that trend continuing imply about our reality?"