It sounds like your friend is using 50-50 to mean "we have no evidence either way". In itself, that's problematic; but probably the bigger issue is violation of Conservation of Expected Evidence. In other words, there are things he could see which would make him think it more likely that this is the Matrix (e.g. unmistakable glitches in ordinary physics), so the fact that he hasn't seen any of them should make him think it less likely that he's in the Matrix.
If I'm parsing what she's saying correctly, her friend is claiming that there's absolutely no evidence either way, since we ought to expect to see every piece of evidence with equal probability whether or not we're in a simulation; so expected evidence is conserved.
And yet, going through the plot of The Matrix would seem to be an example of receiving evidence that we're in The Matrix.
In which case TheaterAddict can say something like, "if all our time in this universe has given us zero evidence for or against being in the Matrix, that suggests it makes no difference to our lives whether we're in the Matrix or not, and your Matrix hypothesis is of no real importance."
The more common name is the simulation hypothesis.
I don't know if it's been discussed in the sequences, but this paper argues, "Unless we are now living in a simulation, our descendants will almost certainly never run an ancestor-simulation."
As far as I'm concerned, the simulation hypothesis is firmly in the class of propositions which probably do not matter on the time scale of my expected lifespan.
Yes ... I've never been quite clear what practical difference it makes whether I'm in a simulation or not. (The Wikipedia article doesn't really give me much, though it's possible I'm just underthinking it.)
It doesn't help that humans do in fact appear to be brains in vats, sustained on a nutrient solution and fed external sensory input - the vat being our skulls. I posit that this is why "brain in a vat" arguments are of philosophical interest to humans.
Yes ... I've never been quite clear what practical difference it makes whether I'm in a simulation or not.
Right. So, some papers exist on that topic. Perhaps start with: How To Live In A Simulation by Robin Hanson.
As much as I like Hanson, generalizing from fictional evidence seems the wrong way to go. In that essay, he also only considers being simulated by our descendants, and tacitly assumes that our descendants will be human.
Ancestor simulations are not that implausible.
They represent the case where we can say the most (if it is true that we are in an ancestor simulation).
However, certainly there are other possibilities.
Ancestor simulations are not that implausible.
I didn't say they were implausible. I said there was a vastly larger class of possible simulators.
They represent the case where we can say the most (if it is true that we are in an ancestor simulation).
First, we can say the same things about them whether or not we're actually being simulated. Secondly, everything we can say about them is predicated on our descendants being similar to ourselves, which (I claim) is an unreasonable assumption.
Ancestor simulations are not that implausible.
I didn't say they were implausible.
Sure - I just meant that they were worthy of consideration.
I said there was a vastly larger class of possible simulators.
Well, yes, but we have to weight according to the chances of them actually being run. Take movies, for instance. A non-trivial fraction of them are simulations of the past - since we are interested in the past.
Well, yes, but we have to weight according to the chances of them actually being run. Take movies, for instance. A non-trivial fraction of them are simulations of the past - since we are interested in the past.
As far as I can tell, your argument is that the proportion of simulations of us that are run by our descendents is significant with respect to the total number of simulations of us, because the number of simulations we currently run of our past is significant with respect to the total number of simulations of our past.
My argument is that we all have no data about either proportion, so it is ineffective to specialize our simulation arguments to the subclass of those simulations made by our descendants.
Well, yes, but we have to weight according to the chances of them actually being run. Take movies, for instance. A non-trivial fraction of them are simulations of the past - since we are interested in the past.
As far as I can tell, your argument is that the proportion of simulations of us that are run by our descendents is significant with respect to the total number of simulations of us, because the number of simulations we currently run of our past is significant with respect to the total number of simulations of our past.
I don't think I ever said that. Rather, I was criticising the idea of comparing the number of past simulations with the number of "possible simulations" - by pointing out that considering the number of possible simulations ignored the important issue of motive - and I gave an example illustrating how motive might matter.
Obvious alternatives to ancestor simulations include optimisationverse and the adapted universe. We do have a whole universe worth's of data about which idea is more likely.
Oh, okay. Relevant in comparison to some other ad hoc simulator theory. I can understand that.
Occam's razor is in your favor here, although there are more compelling arguments than the one your friend is making (see paper-machine's comment).
Yeah, he's trying to make the argument that Occam's Razor doesn't work. He insists he understand probability theory and how Occam's Razor works, but he still thinks it's an invalid argument.
I don't understand why. He's religious, and he says that Occam's Razor should prove God exists, then. Because it's easier to just say, "God did it." But I argued that God is a complex being.. ehh.
There are a variety of problems with why "God did it' is actually discounted by Occam's razor. The issue here is somewhat subtle, but the basic idea is that "God did it" only seems like a simple hypothesis because of artifacts of human language. Any notion of "God" as usually used as an explanatory entity is actually an extremely complicated idea. Natural language doesn't reflect how complicated or simple something actually is. For example we have single words for "love" and "anger" and other emotional states that seem intuitively simple but actually are extremely complicated with a variety of predictions associated with them. It is only because of human intuition that such things seem simple. More careful formulations of Occam's razor such as using a Solomonoff prior will result in that hypothesis being registered as extremely complicated. (And in fact similar remarks apply to many versions of the "Matrix hypothesis".)
Does he not accept Occam's Razor at all, or just in this context?
If at all, there's the nice example of: "The sun rose every day of my life"---> "The sun rises every day" vs "The sun rose every day before now, and won't in the future"
If he doesn't like Occam in this particular case, do you have any idea why?
Occam's Razor is required reading for anyone who thinks Occam's Razor proves the existence of God.
Matrix is a nice metaphor, but what exactly does it mean?
If it only means that there is some lower level below us, something like ones and zeroes in a computer memory, I agree -- we are constructed from quarks and similar particles, which we don't see in normal life. By scientific theories and experiments, we can discover these elementary particles, just like people living in a computer simulations could experimentally discoves some basic properties of their universe. Are we just using "computer" as a metaphor for "physics"?
There is more in the movie Matrix metaphor. It says that there are intelligent beings outside of this universe, and that this universe was designed and is manipulated to fulfill their goals. It also says that there are bugs in this program, which allow people to do magic, win against these intelligent creators and escape outside.
Note that the manipulation is necessary for the metaphor, because if this universe is just a fair simulation of physical laws, there is no difference from being a real universe. We can discuss whether a simulated universe has the same "qualia" as the original one, but the point is that if the simulation is exact, then the same things will happen in both universes, therefore your suspicion of being in a simulation is useless, and you cannot break out of the simulation any more than "2+2=4" could break out of your calculator. And psychologically speaking, the manipulation and possiblity of escape is what makes all this Matrix discussion interesting, isn't it? If you say "let's assume that some aliens outside of our universe made a detailed movie of it, and are watching it now, so in some sense we both exist in the reality and as a movie stars" that's boring. It would not motivate you to do anything differently.
The motivation in the Matrix movie did not make sense -- even if the basic idea wouldn't contradict thermodynamics, the machines would have made a smarter choice by using pigs instead of humans. Let's say that instead of energy they would harvest human thoughts. (We could assume machines that don't understand their own design, can't build a machine-friendly AI, so making a simulation for humans and letting them solve problems is useful for them.) Even so, it would be completely stupid to make a simulation where people can break the rules simply by the power of their imagination or will or whatever. How exactly is the gravity simulation routine programmed that when Neo simply thinks "I believe I can fly" strongly enough, the simulator will change the gravity vector of Neo's body? And by the way, if the Agents can posess anyone in the Matrix, why can't they simply possess Neo (instead of running after him) or why can't they simply kill him? Why can't agents do the same kind of magic and make Neo levitate helplessly in the air? Why shoot at Neo when levitating any object could kill him just as well? Simply, why the simulation constrains the machines to some rules, but not Neo? It does not make sense, except as the classical paranoid setting -- an enemy that is both omnipotent and omniscient, but at the same time kind of stupid and helpless against an adversary who knows.
The difference between "Matrix hypothesis" and "simulation hypothesis" is that the former is a pseudo-scientific justification for whatever, while the latter adds up to normality. This world may be real or simulated, but the rules remain the same, so you should not care; what difference does it make whether the quarks are simulated by computer, if the simulation if flawless? If the simulation has flaws, they may appear as new physical laws and maybe we can use them to extract some energy -- so in this sense it is useful to look for them, but it falls under the umbrella of particle physics. (A simulation hypothesis is not helpful here, unless it contains details about how exactly are we simulated and what kind of bugs can we expect in the simulation.)
In other words: If you believe that we live in Matrix, what testable predictions do you make that you wouldn't have made otherwise?
Okay...how is this an instance of privileging the hypothesis? Also, if it is so easy to assign a low probability to the hypothesis, what is wrong with the simulation argument? Is it invalid (or inductively weak) or does it contain a false premise?
"We are in the Matrix" privileged when we could be in any simulation. The original poster can use this to knock down the friend's Matrix argument.
I am not capable of arguing against the simulation argument ever since I realised that "do things that would make you an interesting simulation target (to increase the count and fidelity of simulations of you) and be near events that are likely simulation targets (to increase the number of simulations involving you, which feeds into the previous)" looks a lot like "be important, leave an interesting history, and be involved in pivotal events" which is just good advice, so I accept the simulation argument to lend weight to that advice.
I interpreted his friend's claim that "we are in the matrix" to mean, merely, that we are in a simulation. I did not interpret it to mean that we are in a simulation, our actual bodies are being used as batteries, small human communities live underground outside of the simulation and battle robots, etc... The latter strikes me as somewhat non-charitable.
Well if I broaden it to "in a simulation" I don't think there is a response. The friend is underconfident in saying 50%.
The concept of 'living in the matrix' is only meaningful if there is some difference with not living in the matrix. Thus, there should be something, at least in principle, that we can observe. And based on this observation (or lack thereof) we can determine probabilities.
Regarding the 50%, suppose (for the sake of argument) that there really is some property of the universe that is either true or false, but we have no evidence whatsoever in either direction. Then the probability is simply unknown, not 50/50. Of course, as a Bayesian prior starting point, you can use 50%, but that is only a rule-of-thumb, and shouldn't import all the connotations of a "50%" in cases where we do have facts.
You can't assign all hypotheses 50% prior probability, "Occam's razor" or otherwise.
If you assign H1 and H2 50% probability, then you shouldn't assign H1 & H2 50% probability. If you assign "The world is a simulation" 50% probability, you shouldn't assign "we live in the matrix" 50% probability. If you assign "There is an objective state of affairs, which my senses don't reflect in the expected way" 50% probability, you shouldn't assign "The world is a simulation" 50% probability.
To get around this, you either need to privilege the matrix/simulation hypothesis aggressively, or give up on your beliefs being consistent under even the simplest applications of modus ponens. Neither seems defensible.
First of all, that we are "in the Matrix" is one of a zillion zillion functionally equivalent and indistinguishable theories of "simulated reality". While we're at it, maybe we're in the Matrix_1 in the Matrix_2. Maybe in the Matrix_3. Maybe in the Matrix_4. Etc.
So your friend is just incorrect. Once you admit "The Matrix" as a possibility, you're committed to admitting an infinite number of theories into your universe of discussion, so the odds of The Matrix being true are 1 out of infinity.
Bur as long as we're not contesting the statistical regularities we observe where ever we are, I don't care which of the zillion we're in. Until your friend comes up with observable and falsifiable consequences to his Meta Reality, I will treat it as a superfluous complication to my model.
Until "we're in the Matrix" can pay rent, it's not living in my head.
As mentioned by others, it's important to draw a distinction between having no information about the relative probability of two events, and saying they're equally probable.
If you aren't going to apply occam's razor here to eliminate the matrix possibility, then don't you also have to give equal weight to all other alternate possibilities which are mutually exclusive with these two, no matter how complex? Each time you think of a new idea, it will have to share probability with the other ideas and the probability of each isolated scenario will approach zero.
For example, what if our brains are controlling artificial bodies that exist outside of any matrix, but our sensory input is being edited to alter specific details we observe (such as making us unable to notice clues that this is happening)?
Check out Occam's Razor. The Simulation Hypothesis requires that a real, physical universe exists, and that someone is simulating another universe within that "real" universe. P(our universe is a simulation within a "top level" universe) < P(ours is the "top level" universe), given no further evidence of simulation. The God hypothesis (typically) assumes the existence of a complex, sentient being -- not really a simple explanation when known physical laws can describe our observations.
P(our universe is a simulation within a "top level" universe) < P(ours is the "top level" universe), given no further evidence of simulation.
I thought the argument was that since there will almost certainly be more simulated universes than the one real one, we are more likely to be in a simulation? Note that I don't have a strong opinion either way, I don't see, despite Robin's essay, that it makes any real difference.
Robin ultimately calculates that he is probably not a sim in this post. Much like the variables in the Drake equation, Robin's probability estimates are built on a number of unknowns, so we really can't do the calculation. But I have to admit that my own logic failed to take any of these variables into consideration, so please ignore that part of the grandfather.
By Solomonoff induction, we should suspect we are in the matrix if we can find a mathematical description of a simpler universe that simulates ours even when taking into account the loss of simplicity that results from having to precisely identify our own universe simulation in that other universe (having to identify the simulation prevents all universes from being reduced to the simplest universe which simulates all possible universes).
Although, in the terms of Solomonoff induction it only even makes sense to ask the question if being in the simulation makes a testable difference (i.e. interference from outside entities or we are fated to break out).
First, an obligatory SMBC reference. Second, the probabilities might be guessed as 50/50, but the confidence intervals on those numbers are so large, they make the numbers themselves meaningless. And third, would you do anything differently if someone convinced you that you are simulated? If not, what does it matter? If yes, why aren't you doing it already?
It would depend on the simulation. If I was convinced that I was in an ancestor simulation, I would do things differently (an ancestor simulation implies a lower chance of human extinction).
His argument is based on two things:
Being in the matrix and not being in it each have a prior probability of 50%.
Our world is equally likely both in the matrix and out.
I vehemently disagree with this one. For one, we have never been told that we're in the matrix. This would most likely happen if we are in the matrix, and almost definitely not happen if we are not. Also, some people live lives much worse than to be expected in a world with a remotely benevolent behavior. There is no reason for so many people to suffer. It's possible that I'm wrong about that, in which case the problem is that there is no reason for so many other people not to suffer.
There's no reason to expect the Machines to care about human suffering.
Also I don't see why creating a simulation requires that you start flashing messages at its inhabitants.
Alright, so this is going to sound a bit silly. I'm fairly sure I've read this on the Sequences somewhere, but for the life of me I can't find it. A friend of mine insists that there is a fifty-fifty chance that we live in the Matrix. His argument is that every bit of evidence we have to say that we exist outside of the Matrix is already based off of the idea that we live outside of the Matrix, and that we really have no evidence either way. He says there isn't a way of falsifying that we're not in the Matrix.
Yet I feel like he's wrong, and just can't explain why. I keep repeating that we don't have any evidence to suggest that we live in the Matrix, so why would we bother believing it?
I feel like this could possibly be an analogy for the belief in God or something. >_> I'm tired, and I need help figuring this out.