Read more: “Existence special: Cosmic mysteries, human questions“
IN A nutshell, you don’t know.
Philosopher René Descartes hit the nail on the head when he wrote “cogito ergo sum”. The only evidence you have that you exist as a self-aware being is your conscious experience of thinking about your existence. Beyond that you’re on your own. You cannot access anyone else’s conscious thoughts, so you will never know if they are self-aware.
That was in 1644 and little progress has been made since. If anything, we are even less sure about the reality of our own existence.
It is not so long ago that computers became powerful enough to let us create alternative worlds. We have countless games and simulations that are, effectively, worlds within our world. As technology improves, these simulated worlds will become ever more sophisticated. The “original” universe will eventually be populated by a near-infinite number of advanced, virtual civilisations. It is hard to imagine that they will not contain autonomous, conscious beings. Beings like you and me.
According to Nick Bostrom, a philosopher at the University of Oxford who first made this argument, this simple fact makes it entirely plausible that our reality is in fact a simulation run by entities from a more advanced civilisation.
How would we know? Bostrom points out that the only way we could be sure is if a message popped up in front of our eyes saying: “You are living in a computer simulation.” Or, he says, if the operators transported you to their reality (which, of course, may itself be a simulation).
Although we are …