Why assume that our universe is running on a substrate exactly as constrained as it is? Just because our universe doesn't permit, say, hypercomputers, doesn't mean the universe simulating our universe doesn't permit them.

The assertion that we are living in a simulation has the same epistemological status as the assertion that God is a pygmy turtle who created the physical laws of the universe while smoking hashish.

You don't even have to think about Roko's Basilisk to get paranoid. You can just suppose that the turtle has rigged the universe so that if you urinate more than 4 times a day, your future children will slowly torture then murder you.

If you suppose that we are living in a simlulation, you can come up with any number of ghastly thoughts. You don't even need to suppose the conditions of Roko's Basilisk. That's just extra BS on top.

BTW, the reason I brought up "with the computers of today" is because the I think the only reason anybody believes simulation is possible is because computers exist. I'm pretty sure that nobody in the 19th century was writing about simulation, because they couldn't imagine a mechanism by which it is possible.

I still can't imagine a mechanism by which it's possible... but some people can, simply because computers can do kind of impressive things that are not really related to simulating the universe.

We're going to have a thread about LessWrong and people bring up Karl "hypothetico-conjectural I DON'T REALLY BELIEVE THERE'S A SCIENTIFIC METHOD YOU MAKE THINGS UP WITH YOUR MAGICAL HUMAN MINDS" Popper?

For God's sake, it's not as is unfalsifiability doesn't have a meaning in Bayesian philosophy of science as well.

Not that I believe in such a thing - at this point the argument would devolve into something unfalsifiable, since the way that logic works outside of our simulated universe would not be same way that logic works inside, and you'd just have to take my word for it that the simulation is being run by an infinitely stacked series of hyperintelligent turtles, since you cannot use "inside logic" to prove anything about anything that is "outside."

More importantly, our perception of time is unimportant from within the simulation. For example, if we assume the shortest possible unit of time is planck's time and call it a "frame", and it takes the computer running the simulation 10 million years of "external time" to simulate 1 frame. It won't matter to us, because we'll have only experienced 1 frame of simulation. Trillions of years could be passing in the real world while we're only ever aware of seconds passing.

So long as the hypothetical real computer can fit the simulation in some kind of memory, the simulation doesn't have to occur in 1:1 real time. It's like emulating a powerful computer on another more powerful computer. You might only get a few percent of the speed of the original, but from the point of view of the program running in the emulator, it doesn't know the difference.

If you have enough memory, you can even emulate a machine from the future on a less "capable" machine from the past. It'll be slow and horrible for you, as the person running the simulator. But suppose you're immortal? You pop in every few hundred years to see if Windows has finished booting.

It is being run by whatever creatures inhabit that other universe. Our actual descendants will live in this, the simulated universe.

And if they decide to run a simulation, they will simulate a less or different universe, meaning they will also not be simulating their ancestors (us).

The simulation argument relies on a loop of logic that is broken by entropy.

I see what you are saying, within the bounds of the article, the Basilisk, requires that our descendants are simulating our present. But by necessity, our genetic descendants would also be members of the simulated universe. Of course, they don't have to simulate the entire universe, they only have to simulate the local part that immediately affects what we do. So long as the model we're in produces equal results to "reality" it's good enough.

All simulation hypotheses discount two other kinds of descendants, intellectual "descendants" for one. Observers of the simulation who learn or are influenced by the simulants. Just like I might run a program on an emulated Commodore 64 and be exposed to some idea I hadn't considered before.

"Escapees" - e.g. Tron: Legacy, Agent Smith from the Matrix movies, The Doctor from Star Trek Voyager. Simulated mentalities which find an external host to "upload to". In the case of Tron movie, the particle laser thing constructed a body for Quora, in the Matrix movies, Smith uploaded his consciousness into a real human and in Voyager the doctor was given a portable hologram generator to let him leave the holodeck/sick bay. Any of these could potentially produce a long of descendants.

Why would anyone ever consider a theoretical concept purely under the terms of an environment bound by obviously inferior technology?

It's not so impossible to conceive of a perfectly accurate atomic-scale simluation, capable of mirroring significant parts of our own reality. The problem arises only when you attempt to run the model in real-time. Only at that point do the physical limits of the parent reality come into play.

It's possible to short-circuit this fact by pre-computing certain results in advance. But, then what you'd be doing is presenting the simulation with assumptions.

Since physical constraints prevent us from operating in real time, and force us to inject pre-fabricated assumptions, this would mean we can't make perfectly accruate predictions, or perhaps start a simulated universe with a "big bang" event, and then fast forward to observe the exact future, or operate with the same concept in reverse and witness mysteries of the past, simply because it doesn't seem possible to force a simulation to accurately operate at speeds faster than the parent universe. At least not without distortions, substitutions and abstractions.

Nor does it seem possible to simulate an accurate universe that isn't smaller than the container universe. The simulation must occupy an amount of space within the parent universe, somehow, and yet still leave at least some space for the simulation's operable framework and infrastructure. Thus, the simulation must be arbitrarily smaller than it's outer reality. Since we are hypothesizing, it's not necessary to specify how much smaller, so long as we acknowlege that obvious truth.

But could we simulate a small part of the parent universe with perfect accuracy, inside itself? Yes, I think so. Although assumptions would have to be pre-defined for inputs to bootstrap the simulation.

Could we simulate one living sentient entity, trapped in a tightly-bound, controlled, claustrophobic prison, an environment devoid of the richness of a raw, unpredictable natural environment? Sure, why not?

Well obviously. Nobody who believes we're in a simulation thinks that the real world looks like our world. It's still a fairly absurd theory, but this is not a hole at all, it's basically irrelevant.

Edit: Perhaps it's adaptive and only simulates what will be observed. And if some cost saving optimization artifacts are discovered within the sim, it can be fixed and reverted to a earlier state.

Edit2: Perhaps it only has to simulate from your perspective, but the more you critically observe and interact, the more expensive the simulation is.

New life goal: be as difficult to simulate as possible ;-)