It’s one of those nagging thoughts many of us have had: is our existence a reality or an illusion? Philosophers and scientists have grappled with the question, though today much of the discussion focuses on a related question: do we live in a computer simulation? In my (first hopefully of multiple) essays for Aeon magazine, I discussed one possible formulation of the question and how it could be answered — but also why the question may be less scientifically meaningful than many popular accounts would have you believe.

The idea isn’t as crazy as it sounds. A pair of philosophers recently argued that if we accept the eventual complexity of computer hardware, it’s quite probable we’re already part of an ‘ancestor simulation’, a virtual recreation of humanity’s past. Meanwhile, a trio of nuclear physicists has proposed a way to test this hypothesis, based on the notion that every scientific programme makes simplifying assumptions. If we live in a simulation, the thinking goes, we might be able to use experiments to detect these assumptions.

However, both of these perspectives, logical and empirical, leave open the possibility that we could be living in a simulation without being able to tell the difference. [read more….]