Let me explain what I mean. Some people say that Ben Franklin messed up when he named positive and negative charge -- that the charge which is on the electron should have been called "+" instead of "-". Imagine legions of physicists arguing back and forth over this issue, some vigorously defending "=" and others advocating for "-". It would all be wasted breath: they are just NAMES, and it doesn't MATTER which name you use. What matters is building a transistor, which depends on understanding that it's electrons that carry the charge, not on what the charge is called.
Similarly, any time that two MATHEMATICALLY equivalent theories both explain the facts, I personally don't care which one is true... I don't want to spend time debating it, and honestly I don't believe that one is more "true" than the other. Is classical mechanics driven by Newton's laws or by the Lagrangian "action is zero"? Both! Either one implies the other.
And this is how I view the question of whether the universe is a simulation. Finding out the laws of our universe seems interesting. Finding out whether those laws are implemented by a universe or a computer simulation of a universe... there is no meaningful difference so I don't care.
i've thought for a while now that the "speed of light" limit is a result of a distributed consesnus algorithm taking a bit of time to convergd.
also, quantum mechanical noiss is leakage current flipping bits in memory.
Interesting, software engineers know there are no programs without bugs. Some weirdest things in physics like quantum entanglement may just be bugs in the simulation :)
If I create a fantasy world in my head, the people and places exist in my head; if I create a fantasy world in my computer, the people and places exist on my computer. Thus, at least in some sense, they exist. In a way, everything within the simulation makes up a universe; in another way, it's more like a sub-universe that has internal interactions as well as external interactions with the simulation hardware. From the perspective of a simulated character who doesn't know about the computer or my brain, they live in their own universe.
(P.S. are you the Suncho from the Descent world? If so, it's good to see you again.)
(P.S. Yes. Hi Lothar. Small world.)
The fundamental difference between knowing that electrons do the moving and knowing whether the universe is a simulation or a universe is that there haven't been testable predictions (yet) using the simulation hypothesis. That is why it is a moot question (so far).
To continue your VM and hypervisor analogy, there is a class of hacks in which virtualized software breaks out of the VM and is able to observe and/or mannipulate host. For example, http://www.theregister.co.uk/2008/02/25/vmware_critical_vuln...
Moreover, even without breaking out, it is -- in some cases, at least -- possible to detect presence of hypervisor by carefully timing computations. Albeit those methods seem to depend on access to a timing source that is reliable (i.e., outside of hypervisor's control). For example, http://www.cs.cmu.edu/~jfrankli/book_chapters/virtual_machin...
For the general case of virtualization, breaking out of the simulation would be as impossible for us as it would be for a video game character.
See my other comment about Kant: http://news.ycombinator.com/item?id=3932514
If we could find a cosmic equivalent to plug into the universe we might just be able to determine whether we're in a real or virtual one after all.
Fun to think about, though. Have you read Greg Egan's Permutation City or Diaspora?
Or perhaps I've just spouted some technobabble. The point is that we are at such an early stage of thinking about such things that they may yet be put on a scientific footing. And if we do find answers to age-old philosophical conundra (the universe-simulation one not being much different to older questions about what we can determine about reality) then any answers that come will come from science, not philosophy.
I believe a fractal is not a viable experiment.
You hinge the experiment on assumption any simulation would be bound by memory size or time taken to compute. Practical constraints aside (matter and space is quantized at very small scale, so the depth of computation is finite), I don't believe we can just assume such limitations.
I believe memory shouldn't be a problem for a fractal, because properties of the fragment you are trying to observe can be computed directly from equations describing the fractal, never mind the scale.
As for time taken to compute, it is not observable. We don't know of any reliable timing source outside of the hypervisor to compare time taken for computation to; the supposed VM is free to take as long as it needs to to advance to compute state, before advancing one http://en.wikipedia.org/wiki/Planck_time
* * *
It could be argued the http://en.wikipedia.org/wiki/N-body_problem of all the celestial bodies already puts our supposed VM to a good test ;-)
 if we knew one, it would make the experiment moot, as we would have a direct proof we're inside of a simulation ;-)
I'm not really a philosopher, at all, but the Oxford Companion to Philosophy says:
"Do you know that you are looking at a... book right now rather than, say, having your brain intricately stimulated by a mad scientist? The sceptic carefully describes this alternative so that no experiment can refute it. The conclusion that you really are looking at a book, however, explains the aggregate of your experiences better than the mad scientist hypothesis or any other competing views."
which I think makes sense to me. I've met one or two people who say they believe that they live in a Matrix/Alien computer simulation, but observing, they live as if they don't.
He said that the "world of objects in themselves" - i.e. numinal reality, or a reality independent of our perception - must exist in order for us to have experience at all.
The reason? We know that there is a reality because something must persist between each one of our "computations" - our perceptions - in order for us to be able to order our perceptions in time.
We just don't know anything about that reality besides that it exists.
To sum up: We do live in reality at some level. How many layers we are removed from the bottom-most substrate,how many simulations-within-simulations we are in, is something we might not ever know. Kant actually said we can't ever know.
You can suspect. (That's honest.) Then, not being intellectually lazy like "believers," you have to apply the scientific method to test your suspicions. (Note: Using philosophy and semantics is no proof at all. It's physics or nothing. You could start with the double slit photons experiment.)
I really wouldn't put too much time into this. Votes don't matter. Even if we all agreed, it wouldn't matter.
I'd put more time into things that do matter.
If it was true, and you wanted to exist some more, then it might be thinking about what would be make you in-demand in the higher level up. Perhaps some generalized broadbased creative knowledge combined, combined with an interesting well-thought perspective, and good communication skills?
The article is based on an interview with Nick Bostrom, a philosophy professor at Oxford. His thoughts on the computer simulation scenario are very interesting. I've reproduced them below, but I recommend reading the whole interview; it's very fascinating. From the interview:
"Can you explain the simulation argument, and how it presents a very particular existential risk?
Bostrom: The simulation argument addresses whether we are in fact living in a simulation as opposed to some basement level physical reality. It tries to show that at least one of three propositions is true, but it doesn't tell us which one. Those three are:
1) Almost all civilizations like ours go extinct before reaching technological maturity.
2) Almost all technologically mature civilizations lose interest in creating ancestor simulations: computer simulations detailed enough that the simulated minds within them would be conscious.
3) We're almost certainly living in a computer simulation.
The full argument requires sophisticated probabilistic reasoning, but the basic argument is fairly easy to grasp without resorting to mathematics. Suppose that the first proposition is false, which would mean that some significant portion of civilizations at our stage eventually reach technological maturity. Suppose that the second proposition is also false, which would mean that some significant fraction of those (technologically mature) civilizations retain an interest in using some non-negligible fraction of their resources for the purpose of creating these ancestor simulations. You can then show that it would be possible for a technologically mature civilization to create astronomical numbers of these simulations. So if this significant fraction of civilizations made it through to this stage where they decided to use their capabilities to create these ancestor simulations, then there would be many more simulations created than there are original histories, meaning that almost all observers with our types of experiences would be living in simulations. Going back to the observation selection effect, if almost all kinds of observers with our kinds of experiences are living in simulations, then we should think that we are living in a simulation, that we are one of the typical observers, rather than one of the rare, exceptional basic level reality observers.
The connection to existential risk is twofold. First, the first of those three possibilities, that almost all civilizations like ours go extinct before reaching technological maturity obviously bears directly on how much existential risk we face. If proposition 1 is true then the obvious implication is that we will succumb to an existential catastrophe before reaching technological maturity. The other relationship with existential risk has to do with proposition 3: if we are living in a computer simulation then there are certain exotic ways in which we might experience an existential catastrophe which we wouldn't fear if we are living in basement level physical reality. The simulation could be shut off, for instance. Or there might be other kinds of interventions in our simulated reality."
How about this: the universe is an artificial life machine aimed at generating some interesting diversity. The intention is that the slime on planets begin performing galactic-scale engineering. Yes, we're a brilliant ant farm in God's den.
I've toyed with the idea, with the notion that the laws of physics are written such that it's easier and cheaper to simulate the universe.
But then one would have to ask, If the universe is a simulation, what is the seed number?
I would rather someone 'kill -9'ed us instead of using Control-C.
Still, there's one way to test the simulation hypothesis: build our own planet-sized universe-simulating computer and see if our own universe has a segfault.