Remember your Accelerando - the computers spent a lot of effort creating historical constructs so that they could create a "brain" exactly like an historical or fictional figure. For example, creating a 16th century Europe to come up with a William Shakespeare AI. The test - does the AI write the same works?

Kind of cool, and scary, and very, very interesting. I was disappointed by the quality of the comments on the NYT site, though.

Well, arguing about whether we are living in a simulated universe or not seems purely academic, because if the simulation is any good, then from our perspective, we cannot actually detect the fact.

Having written a cycle-accurate instruction-level simulator, I know that the programs that run inside the simulator have no means to detect that they are running in a simulation as opposed to an actual hardware device.

If the "designers" of the simulation we are supposedly running in have done a good enough job, then the hypothesis becomes unfalsifiable--which makes it unscientific.

This might be a fairly interesting philosophical question, but it isn't one of science--unless we can conceivably come up with experiments that exploit the possibility that maybe the designers of the simulation didn't do a good job. If they did, we can prove nothing, of course.

But then the question is, even if we are able to devise experiments that would have different outcome in a simulated universe than the "real" universe, how can we determine what the "real" outcome should be, since we don't have the ground truth of the what "real" universe "should" do?

This is just me, but if I designed an entire simulated world, I would want the inhabitants to be able to figure out that it's a simulation. I wouldn't want it to be easy -- no reason to ruin the suspense. Still, sooner or later I would want them to know the truth.

Alternatively, I might feel the need to get in there and reveal myself as the designer to some of the inhabitants. Especially if one of them was a simulation of me!

Sure, this is a philosophical discussion for now. That doesn't mean these questions will always be beyond the reach of science. Optimist that I am, I hold out hope that science will eventually get us to the truth about our place in the universe, or rather, the place of our universe in whatever it is that lies outside the universe.

D. Vision:

I agree with everything you said, but this is still "cool, and scary, and very, very interesting."

Yeah, this falls into the realm of philosophy.

Phil:

You know, maybe I spoke too soon about there being no way to test this.

Maybe there's no way to test for this now, but later - who can say?

Maybe somewhere - in quantum weirdness perhaps - the seams of this universe/simulation lies waiting to be discovered.

The answer to these questions, to all of this is...

42

I wouldn't be to eager to toss the 2nd point in the rubbish (any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history).

David Brin wrote a very interesting piece of online fiction called "Stones of Significance" which ponders this very issue. In it, the central debate is the rights of sentient beings. If your simulation is sentient, certain simulations might be considered a violation of their rights, cruel and inhuman punishment, etc.

What responsibilities would an advanced civilization decide a simulation creator would owe to his creations - continuity of existence ?, rule of law ?, freedom ?

I would think that the (probable) resultant burden of responsibility would greatly limit the widespread use of sentient sims.

There might also be an option of running models that would yield some or all of the data that we would look for from a simulation, but which would still not be "live." That is, there wouldn't be anybody "in there" convinced that he or she was living in a real world, but the model world could still yield interesting data. Between running models on one end and somehow being able to access or mathematically approximate what's going on in parallel universes (if any) on the other, simulations might not be that important to posthuman civilizations.

BTW, I couldn't help myself. He just popped in there.

What a coincidence, I just spent a heap of time writing about the same thing:
http://www.geocities.com/MotorCity/Factory/9051/blog/archive24.html#16/08/2007

Conclusion: They are simulating the effect of not having slorths.