The Simulation hypothesis, part 1

Are we living in the Matrix?

Are we living in the Matrix? This question seems futuristic, a theme from a science fiction movie. (Which of course it is.)  But the best science fiction is philosophy in fancy dress, and philosophers have been asking the question since at least the ancient Greeks.

The question generated considerable interest in June this year when Elon Musk said the chance that we live in a “base reality” was “one in billions”. But as long ago as 380 BC, when the Greek philosopher Plato wrote “The Republic”, he included the Allegory of the Cave, which argued that men are like prisoners chained to a wall in a dark cave. Their only impression of reality is the shadows cast on a wall in front of them by a fire behind them which they cannot see. If they could see reality in all its true glory it would blind them.

In 2003, the question was given the formal structure of a trilemma (a difficult choice between three options) by the Oxford University philosopher Nick Bostrom. He observed that we use our technology to simulate worlds inhabited by creatures which are as realistic as we can make them, and that some of the most compelling of these worlds contain people who could be our ancestors. There are many reasons to create these “ancestor simulations”, and a civilisation which could create them at all would create many of them. He concluded that one of these three statements must be true:

  1. All civilisations are destroyed (or self-destruct) before their technology reaches the stage where it would allow them to create ancestor simulations.
  2. Numerous civilisations have reached that stage of technology but they all refrain from doing so, perhaps for moral or aesthetic reasons.
  3. We live in a simulation. (1)

People often that assume that Bostrom argues that we are living in a simulation, but in fact he thinks the self-destruction scenario is also a contender.

Answering Enrico
The simulation scenario and the inevitable demise scenario also both offer plausible answers to Enrico Fermi’s Paradox, the apparent contradiction between the absence of evidence of other intelligent life in the universe, and the high probability of there being lots of it. Maybe civilisations inevitably collapse before they acquire the power to build Dyson Spheres or blurt out Pi in a durable pan-galactic email. Or maybe, like Douglas Adams’ mice (2), the creators of the simulation we live in only needed the one world to achieve whatever goal they had in creating the earth. Populating the universe with teeming swarms of aliens was simply unnecessary, as well as being hideously expensive in computational resources.

Reasons to simulate us
If we do live in a simulation, why was it made? If the sole purpose was entertainment then the prevalence in our world of torture, child leukemia and much else makes it hard to avoid concluding that our creator was either incompetent or callous. (Conscientious theists have to wrestle with a fiercer version of this problem known as the Problem of Evil. I say fiercer because in their case the incompetent or callous entity is also omniscient, omnipresent and omnipotent, which makes their world a very scary place. Especially since most theists believe in a deity which actively intervenes in their world from time to time.)

Perhaps we are part of a massive modelling exercise (a Monte Carlo simulation, perhaps) to determine the optimal way of achieving a specific goal. One candidate for that goal is the creation of superintelligence. From the perspective of a superintelligent alien species, individual humans might be about as interesting as dogs if we are lucky, or as microbes if not. Whereas a superintelligence might be seriously interesting. Maybe our simulators are in the business of creating new friends. Or maybe they need a lot of clever new colleagues to solve a really big problem, like the heat death of the universe.

Next week: the economical twist

(1) Bostrom’s trilemma makes a few assumptions, notably:

  1. It is not impossible to create simulations inhabited by entities which consider themselves to be alive.
  2. It is implausible that we are the most (or one of the most) technologically advanced civilisations that have ever existed in this universe.
  3. It is implausible that we are one of the tiny, tiny minority of civilisations in this universe which arose naturally.

(2) The Hitchhikers Guide to the Galaxy

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