Episode 10: Simulation Argument

From The End Of The World with Josh Clark, a production of HowStuffWorks/iHeartRadio

Josh Clark(2019)

Anyone can say that we are living in a simulation, just like anyone can say that we are living in “real” reality; neither one means anything as they’re both just assertions. But the idea that we are living in a simulated reality actually has a leg up over thanks to probability.

Back at the beginning of the year 2000, the software company Maxus released The Sims, a life simulation game where you, the player, controls individual simulated people. The Sims, as one reviewer put it, is a celebration of the mundane - sim’s go about their lives, they go to work ,they clean their toilets, and they die.

The Sims became an enormously popular game. Between 2000 - 2010, 125 million copies of the game were sold around the world. Each time one of those people brought their CD-Rom home, loaded it into the tray and booted up the software, a new iteration of The Sims universe was created. It was the same universe, it followed the same rules, it followed the same physics and logic, and The Sims all navigated their universe made up of the same set of possibilities. But each iteration was distinct and different; each one was a discrete version of The Sims’s universe and we can expect something along the same lines as anything our ancestors might run - whether it’s a scientific model for an anthropological study of history, or whether its the software of a popular game, whether it’s a class project, each time that simulation is run, a new iteration of our simulated human universe is created.

Say that at some point in the future, across the billions of years, amongst the trillions of people yet to come, there’s a ten year period where an ancestor simulation software that is equally as popular as The Sims is created and sold. As all those future humans load their simulations, a new iteration of our simulated universe is born, each following the same guidelines, the same code, each taking radically different course within the same set of prescribed rules. If we are agreed that our descendants will run ancestor simulations of us, and that we don’t have any frame of reference to distinguish the simulation from “real” reality, and in the future 125 million iterations of that simulated universe are run, then you and I, and everyone alive in our universe, has a 1 in 125 million chance that we are actual humans, 1 in 125 million chance that we are not simulated. Or to put it somewhat less encouragingly, there is a 99.999992% chance that we are simulated humans living in an ancestor simulation being run in the future. Because there was one iteration of humans in real life, there is a chance that we are members of that genuine human race as we like to think of ourselves.

Because so many simulations are run in the future, given that we have no frame of reference to tell us any difference between our reality and basement reality, that utter lack of signs that we live in a dream as Descartes suggested, the chances are vastly greater that we are simulated rather than real - there’s just simply been more simulated humans than real ones. Being members of one group or the other, the chances state quite plainly that it’s likelier we’re members of the simulated group. You can mess with the numbers either way, to make the chances go up or down, but say that ancestor simulation was way more popular than The Sims ever was, and an equal amount of copies are sold each decade for 100 years, that would mean that we had one chance in over a billion of being a human, and so on. Each new iteration of our simulated universe lowers the chances that we are real, but even just one ancestor simulation run in the future activated the simulation argument; even if just once in the whole history of the human race, only one iteration of our simulated universe is run, we still have even odds that we’re simulated. If we make it through the Great Filter[1], and our ancestors run simulations of us, we have at best a 50% chance of being real humans.

[1]See here for further reading by Robin Hanson - http://mason.gmu.edu/~rhanson/greatfilter.html And further reading by Nick Bostrom https://nickbostrom.com/extraterrestrial.pdf


Josh Clark is a senior writer and co-host of the Stuff You Should Know podcast.