[andrewon]

But a digital computer at present in this world may not be a good reference to the capability of the computer that supposedly simulate this world. We know nothing about the "real" world that computer resided, and nothing about that computer.

[stromgo]

We do know that the real world is richer than the simulated world, since it holds a computer that runs the simulated world. Therefore if you exist, then it's more likely that you're the result of evolution in the real world than the result of evolution in the simulated world.

Imagine the warehouse-size computer that is needed to simulate a bacterium here on Earth. Computers are dusty, and dust contains bacteria, so if you're a bacterium, then it's more likely that you're one of the billions of bacteria in the dust on the computer, than the bacterium being simulated by the computer. The same reasoning should hold for other worlds.

[BoiledCabbage]

This is faulty reasoning. The game "The Sims" has sold over 200 million copies. If the average number of characters created per game is over 40 then there have been more sims characters than people in the world. Add in a few more games and there have been more game characters than people that have ever lived. And that's with computing being in its infancy not even 80 years old yet. Give 1000 years and its not even close.

Additionally your fidelity is backwards. Thre fact that the simulation is simpler than the real world means we can fit many more people/entities in it - because the computer doesn't have to simulate at full fidelity.

[shrimpx]

This is true if you assume that the simulating world is what’s being simulated in the simulated world. That is, if bacteria exist only in the simulated world, then if you’re a bacterium there’s 100% probability that you’re simulated.

[pegasus]

That's a powerful argument against the usual anthropic argument for the world being a simulation. I haven't encountered it before but it makes total sense.

[_0w8t]

The assumption that real world is richer than simulated world is just that, an assumption. For one it assumes that both are finite.

[pegasus]

It's logically necessary, not just an assumption. The simulated world with all its richness is by definition a strict subset of the simulating world. So the latter must be richer than the former.

[vidarh]

Only if you talk about the simulated features of the simulated world, rather than compare the "simulated world as seen by its inhabitants" with the simulating world.

We don't have dragons on earth, but I can simulate dragons.

In the sense that this simulation exist in our world, you are right that the simulating world will then always be "richer" because it contains the simulation.

But if I could enter the simulated world, I could ride dragons. I can't ride dragons in "our" world, so in that sense it is clear that we can simulate things that do not have a concrete existence in our own world, and I to me at least that would make the simulated world "richer" in that respect by making things possible in the simulation that requires you to be in the simulation for it to be possible.

Similarly, we can clearly simulate something with more detail - e.g. we could simulate a world where our elementary particles can be subdivided endlessly, if we choose to. In the simulating world this would "just" be a simulation, but in the simulated world it would be that worlds reality.

There is even no reason why, with sufficient resources and time dilation, it would not be possible for the simulating world to simulate a world equivalent to the simulating world, so it could well be turtles all the way down.

[andrewon]

I believe it is not correct. You can put new features that do not exist in the physical world in a simulation. For example, you can double the number of quarks in a proton as long as you define a mathematically consistent interaction to allow so.

Then you created a richer simulated world.

[_0w8t]

This is not true for infinite sets where a subset can be equivalent to the whole.

[mistermann]

Could you possibly explain/reason why this must be, without using "by definition"? Many people in this thread agree with you on this, but I don't understand it (see my other comment using a video game analogy).

Is the richness you describe in your comment implicitly constrained to that which exists physically perhaps?

[mistermann]

Unless I misunderstand what your conception of a simulation is, I don't see why a virtual world is limited by the constraints of the parent world, any more than video games are limited by the constraints of our world?

I would think this would apply to the individual molecule tracking requirement above as well.

[yyyk]

If we don't know anything about the "real" (or at least, "realer") world, I don't see how we can argue for a simulation either.

If we don't know the "real" rules, how can we make any proposition? At best we might argue that our world is inconsistent, but we cannot say that's any more or less likely than a simulation (who says the world has to make any sense?).

The only semi-useful simulation arguments have to assume the "real" world is sorta like our world or at least functioning according to math. But that returns us to the simulation cost problem.

[joe_the_user]

If we have posited a thing with unknown properties and say maybe that is generating our universe, we've pretty much taken the opposite position to Occam's Razor, which is often stated as "Entities should not be multiplied without necessity."

https://en.wikipedia.org/wiki/Occam%27s_razor

[andrewon]

Occam's Razor is a good principle for choosing scientific hypotheses. But I think when it comes to studying big questions like fundamental fabric of this physical world, we are at a lost here. Essentially we elect to believe, without justification, that the world got to follow a reductionist paradigm - if the world can be made simpler, it must not be more complex.

[roywiggins]

Right, but that is then a totally unfalsifiable idea. You can't prove the non-existence of something you can't begin to define.

[andrewon]

I guess that's the gist of all these arguments -- they are ideas not something we can prove or disprove.