In 2003, the philosopher Nick Bostrom made an ingenious argument that we might be living in a computer simulation created by a more advanced civilization. He argued that if you believe that our civilization will one day run many sophisticated simulations concerning its ancestors, then you should believe that we’re probably in an ancestor simulation right now. His reasoning? If people eventually develop simulation technology — no matter how long that takes — and if they’re interested in creating simulations of their ancestors, then simulated people with experiences just like ours will vastly outnumber unsimulated people.
Nick Bostrom is the author of Superintelligence. (Check out Tim Urban’s take on it for Wait but Why.)
He makes a compelling argument with, again, grave consequences.